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HP C++
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This appendix describes the qualifiers available to the CXX command.
Qualifiers indicate special actions to be performed by the compiler or special input file properties. Compiler qualifiers can apply to either the CXX command or to the specification of the file being compiled. When a qualifier follows the CXX command, it applies to all the files listed. When a qualifier follows the file specification, it applies only to the file immediately preceding it.
Table A-1 summarizes CXX qualifiers. Detailed descriptions follow the table.
/ALTERNATIVE_TOKENS
Enables use of the following operator keywords and digraphs to generate tokens:
/NOALTERNATIVE_TOKENS
Operator Keyword Token and && and_eq &= bitand & bitor | compl ~ not ! not_eq != or || or_eq |= xor ^ xor_eq ^=
Digraph Token :> ] %: # %> } <% { <: [ The default is /NOALTERNATIVE_TOKENS when compiling with the /STANDARD=ARM, /STANDARD=MS, or /STANDARD=RELAXED option. The default is /ALTERNATIVE_TOKENS when compiling with the /STANDARD=STRICT_ANSI or /STANDARD=GNU option. Specifying /ALTERNATIVE_TOKENS also defines the __ALTERNATIVE_TOKENS macro.
/ANSI_ALIAS
Directs the compiler to assume the ANSI/ISO C aliasing rules, which gives it the freedom to generate better optimized code.
/ANSI_ALIAS (D)
/NOANSI_ALIAS/NOANSI_ALIAS specifies that any pointer can point to any object, regardless of type. /ANSI_ALIAS specifies that pointers to a type T can point to objects of the same type, ignoring type qualifiers such as const, unaligned, or volatile, or whether the object is signed or unsigned. Pointers to a type T can also point to structures, unions, or array members whose type follows the rules above.
The aliasing rules are further explained in Section 3.3, paragraphs 20 and 25, of the ANSI C89 Standard (Section 6.3 of the ISO version, same paragraphs).
/ARCHITECTURE=option
Determines the Alpha or Intel processor instruction set to be used by the compiler. The /ARCHITECTURE qualifier uses the same keyword options (keywords) as the /OPTIMIZE=TUNE qualifier.
/ARCHITECTURE=GENERIC (D)Where the /OPTIMIZE=TUNE qualifier is primarily used by certain higher-level optimizations for instruction scheduling purposes, the /ARCHITECTURE qualifier determines the type of code instructions generated for the program unit being compiled.
OpenVMS Version 7.1 and subsequent releases provide an operating system kernel that includes an instruction emulator. This emulator allows new instructions, not implemented on the host processor chip, to execute and produce correct results. Applications using emulated instructions will run correctly, but may incur significant software emulation overhead at runtime.
All Alpha processors implement a core set of instructions. Certain Alpha processor versions include additional instruction extensions.
Select one of the /ARCHITECTURE qualifier options shown in the following table.
Option Usage GENERIC Generates code that is appropriate for all processor generations. This is the default. HOST Generates code for the processor generation in use on the system being used for compilation. Running programs compiled with this option on other implementations of the Alpha architecture may encounter instruction-emulation overhead.
ITANIUM2 (I64 ONLY) Generates code for the Intel Itanium 2 processor family. For use on I64 systems only. EV4 (ALPHA ONLY) Generates code for the 21064, 21064A, 21066, and 21068 implementations of the Alpha architecture. Programs compiled with the EV4 option run without instruction-emulation overhead on all Alpha processors.
EV5 (ALPHA ONLY) Generates code for some 21164 chip implementations of the Alpha architecture that use only the base set of Alpha instructions (no extensions). Programs compiled with the EV5 option will without instruction-emulation overhead on all Alpha processors.
EV56 (ALPHA ONLY) Generates code for some 21164 chip implementations that use the byte and word-manipulation instruction extensions of the Alpha architecture. Running programs compiled with the EV56 option might incur emulation overhead on EV4 and EV5 processors, but will still run correctly on OpenVMS Version 7.1 (or higher) systems.
PCA56 (ALPHA ONLY) Generates code for the 21164PC chip implementation that uses the byte- and word-manipulation instruction extensions and multimedia instruction extensions of the Alpha architecture. Programs compiled with the PCA56 option might incur emulation overhead on EV4, EV5, and EV56 processors, but still run correctly on OpenVMS Version 7.1 (or higher) systems.
EV6 (ALPHA ONLY) Generates code for the 21264 implementation of the Alpha architecture. EV68 (ALPHA ONLY) Generates code for the 21264/EV68 implementation of the Alpha architecture. EV7 (ALPHA ONLY) Generates code for the EV7 implementation of the Alpha architecture. See also /OPTIMIZE=TUNE, which is a more typical option. Note that if /ARCHITECTURE is explicitly specified and /OPTIMIZE=TUNE is not, the tuning processor defaults to the architecture processor; for example, /ARCHITECTURE=EV6 implies /OPTIMIZE=TUNE=EV6.
/ASSUME
Controls compiler assumptions. You may select the following options:
/ASSUME=(option[,...])
Option Usage [NO]WRITABLE_STRING_LITERALS Stores string constants in a writable psect. Otherwise, such constants are placed in a nonwriteable psect. The default is NOWRITABLE_STRING_LITERALS. [NO]ACCURACY_SENSITIVE Specifies whether certain code transformations that affect floating-point operations are allowed. These changes may or may not affect the accuracy of the program's results. If you specify NOACCURACY_SENSITIVE, the compiler is free to reorder floating-point operations based on algebraic identities (inverses, associativity, and distribution). This allows the compiler to move divide operations outside of loops, which improves performance.
The default, ACCURACY_SENSITIVE, directs the compiler to use only certain scalar rules for calculations. This setting can prevent some optimization.
[NO]ALIGNED_OBJECTS Controls an optimization for dereferencing pointers. Dereferencing a pointer to a longword- or quadword-aligned object is more efficient than dereferencing a pointer to a byte- or word-aligned object. Therefore, the compiler can generate more optimized code if it makes the assumption that a pointer object of an aligned pointer type does point to an aligned object.
Because the compiler determines the alignment of the dereferenced object from the type of the pointer, and the program is allowed to compute a pointer that references an unaligned object (even though the pointer type indicates that it references an aligned object), the compiler must assume that the dereferenced object's alignment matches or exceeds the alignment indicated by the pointer type.
The default, /ASSUME=ALIGNED_OBJECTS, allows the compiler to make such an assumption. With this assumption made, the compiler can generate more efficient code for pointer dereferences of aligned pointer types.
To prevent the compiler from assuming the pointer type's alignment for objects to which it points, use the /ASSUME=NOALIGNED_OBJECTS qualifier. This option causes the compiler to generate longer code sequences to perform indirect load and store operations to avoid hardware alignment faults for arbitrarily aligned addresses. Although /ASSUME=NOALIGNED_OBJECTS might generate less efficient code than the default /ASSUME=ALIGNED_OBJECTS option, by avoiding hardware alignment faults, it speeds the execution of programs that reference unaligned data.
[NO]GLOBAL_ARRAY_NEW Controls whether calls to global array new and delete are generated as specified by ANSI. Pre-ANSI global array new generated calls to operator new(). According to ANSI, use of global array new generates calls to operator new()[]. The GLOBAL_ARRAY_NEW option also defines the macro __GLOBAL_ARRAY_NEW. GLOBAL_ARRAY_NEW generates calls to operator new()[] for global array new expressions such as new int[4]; this is the default when compiling /STANDARD=RELAXED, /STANDARD=STRICT_ANSI,
/STANDARD=GNU, and /STANDARD=MS.NOGLOBAL_ARRAY_NEW generates calls to operator new() for global array new expressions such as new int[4]; and preserves compatibility with Version 5.n; this is the default when compiling /STANDARD=ARM.
[NO]HEADER_TYPE_DEFAULT Controls whether the compiler appends a file extension to a file name. The default is /ASSUME=NOHEADER_TYPE_DEFAULT. To prevent the compiler from appending a file extension to files (such as STL header files that must not have file extensions) use the /ASSUME=NOHEADER_TYPE_DEFAULT qualifier. [NO]MATH_ERRNO Controls whether intrinsic code is generated for math functions that set the errno variable. The default is /ASSUME=MATH_ERRNO, which does not allow intrinsic code for such math functions to be generated, even if /OPTIMIZE=INTRINSICS is in effect. Their prototypes and call formats, however, are still checked. [NO]POINTERS_TO_GLOBALS Controls whether the compiler can safely assume that global variables have not had their addresses taken in code that is not visible to the current compilation. The default is /ASSUME=POINTERS_TO_GLOBALS, which directs the compiler to assume that global variables have had their addresses taken in separately compiled modules and that, in general, any pointer dereference could be accessing the same memory as any global variable. This is often a significant barrier to optimization.
While the /ANSI_ALIAS option allows some resolution based on data type, /ASSUME=POINTERS_TO_GLOBALS provides significant additional resolution and improved optimization in many cases.
The /ASSUME=NOPOINTERS_TO_GLOBALS option tells the compiler that any global variable accessed through a pointer in the compilation must have had its address taken within that compilation. The compiler can see any code that takes the address of an extern variable. If it does not see the address of the variable being taken, the compiler can assume that no pointer points to the variable.
Note that /ASSUME=NOPOINTERS_TO_GLOBALS does not tell the compiler that the compilation never uses pointers to access global variables.
Also note that on I64 systems, the NOPOINTERS_TO_GLOBALS option is ignored and should not cause any behavior changes.
[NO]STDNEW Controls whether calls are generated to the ANSI or pre-ANSI implementation of the operator new(). On memory allocation failure, the ANSI implementation throws std::bad_alloc , while the pre-ANSI implementation returns 0. /ASSUME=STDNEW generates calls to the ANSI new() implementation; this is the default when compiling with /STANDARD=RELAXED, /STANDARD= STRICT_ANSI, and /STANDARD=GNU.
/ASSUME=NOSTDNEW generates calls to the pre-ANSI new() implementation; this is the default when compiling with /STANDARD=ARM and /STANDARD=MS.
[NO]TRUSTED_SHORT_ALIGNMENT Allows the compiler additional assumptions about the alignment of short types that, although thought to be naturally aligned, might cross a quadword boundary. The TRUSTED_SHORT_ALIGNMENT option indicates that the compiler should assume any datatype accessed through a pointer is naturally aligned. This generates the fastest code, but can silently generate the wrong results when an unaligned short object crosses a quadword boundary.
Note that on I64 systems, the TRUSTED_SHORT_ALIGNMENT option is ignored and should not cause any behavior changes.
The NOTRUSTED_SHORT_ALIGNMENT tells the compiler that short objects might not be naturally aligned. The compiler generates slightly larger (and slower) code that gives the correct result, regardless of the actual alignment of the data. This is the default.
Note that the NOTRUSTED_SHORT_ALIGNMENT option does not override the __unaligned type qualifier or the /ASSUME=NOALIGNED_OBJECTS option.
[NO]WHOLE_PROGRAM Tells the compiler that except for well-behaved library routines, the whole program consists only of the single object module being produced by this compilation. The optimizations enabled by /ASSUME=WHOLE_PROGRAM include all those enabled by /ASSUME=NOPOINTERS_TO_GLOBALS and possibly other optimizations. Note that on I64 systems, the WHOLE_PROGRAM option is ignored and should not cause any behavior changes.
The default is /ASSUME=NOWHOLE_PROGRAM.
/CHECK
Use this qualifier as a debugging aid.
/CHECK[=([NO]UNINITIALIZED_VARIABLES)] (ALPHA ONLY)
/NOCHECK (D)Use /CHECK=UNINITIALIZED_VARIABLES to initialize all automatic variables to the value 0x7ff580057ff58005. This value is a floating NaN and, if used, causes a floating-point trap. If used as a pointer, this value is likely to cause an ACCVIO.
Note that on I64 systems, /CHECK=UNINITIALIZED_VARIABLES emits a warning and is ignored.
/COMMENTS
Specifies whether comments appear in preprocessor output files. If comments do not appear, this qualifier specifies what replaces them. The options are:
/COMMENTS[=option]
/COMMENTS=SPACE (D)
/NOCOMMENTS
Option Usage AS_IS Specifies that the comment appear in the output file. This is the default if you use the /COMMENTS qualifier without specifying an option. SPACE Specifies that a single space replaces the comment in the output file. This is the default if you do not specify the /COMMENTS qualifier at all. Specifying /NOCOMMENTS tells the preprocessor that nothing replaces the comment in the output file. This may result in inadvertent token pasting.
The preprocessor may replace a comment at the end of a line or replace a line by itself with nothing, even if you specify /COMMENTS=SPACE. Specifying /COMMENTS=SPACE cannot change the meaning of the program.
/DEBUG
Requests that information be included in the object module for use with the OpenVMS Debugger. You can select the following options:
/DEBUG[=(option[,...])]
/DEBUG=(TRACEBACK,NOSYMBOLS) (D)
/NODEBUG
Option Usage ALL Includes all possible debugging information. /DEBUG=ALL is equivalent to /DEBUG=(TRACEBACK,SYMBOLS), which on I64 systems is equivalent to /DEBUG=(TRACEBACK, SYMBOLS=NOBRIEF). NONE Excludes all debugging information. This option is equivalent to specifying /NODEBUG, which is equivalent to /DEBUG=(NOTRACEBACK,NOSYMBOLS). NOSYMBOLS Turns off symbol generation SYMBOLS Generates symbol-table records. On I64 systems, /DEBUG= SYMBOLS is equivalent to /DEBUG=SYMBOLS=BRIEF. On Alpha systems, /DEBUG=SYMBOLS is effectively equivalent to /DEBUG=NOBRIEF. SYMBOLS=BRIEF (I64 ONLY) Generates debug information with unreferenced labels and types pruned out to produce smaller object sizes. On Alpha systems, BRIEF is ignored. SYMBOLS=NOBRIEF (I64 ONLY) Generates complete debug information. On Alpha systems, the NOBRIEF keyword is ignored, but you still get complete debug information. NOTRACEBACK Excludes traceback records. This option is equivalent to specifying /NODEBUG and is used to avoid generating extraneous information from thoroughly debugged program modules. TRACEBACK Includes only traceback records. This option is the default if you do not specify the /DEBUG qualifier on the command line. On Alpha systems /DEBUG is equivalent to /DEBUG=(TRACEBACK,SYMBOLS).
On I64 systems /DEBUG is equivalent to /DEBUG=(TRACEBACK,SYMBOLS), which is equivalent to /DEBUG=(TRACEBACK,SYMBOLS=BRIEF).
/DEFINE
Performs the same function as the #define preprocessor directive. That is, /DEFINE defines a token string or macro to be substituted for every occurrence of a given identifier in the program.
/DEFINE=(identifier[=definition][,...])
/NODEFINE (D)DCL converts all input to uppercase unless it is enclosed in quotation marks.
The simplest form of a /DEFINE definition is as follows:
/DEFINE=trueThis results in a definition like the one that would result from the following definition:
#define TRUE 1When more than one /DEFINE is present on the CXX command line or in a single compilation unit, only the last /DEFINE is used.
When both /DEFINE and /UNDEFINE are present on a command line, /DEFINE is evaluated before /UNDEFINE.
/DEFINE=__FORCE_INSTANTIATIONS (ALPHA ONLY)
Forces the standard library template preinstantiations to be created in the user's repository. Normally these instantiations are suppressed because the library already contains them.
/NODEFINE=__FORCE_INSTANTIATIONS (D)On I64 systems, defining __FORCE_INSTANTIATIONS has no effect.
/DEFINE=__[NO_]USE_STD_IOSTREAM
Use or do not use the standard iostreams. Specifying /DEFINE=__USE_STD_IOSTREAM forces the inclusion of the ANSI standard version of the iostream header file. This is the default in STRICT_ANSI mode. Otherwise, the pre-standard AT&T-compatible version of iostreams is used.
/DEFINE=__NO_USE_STD_IOSTREAM (D)/DIAGNOSTICS
Creates a file containing compiler diagnostic messages. The default file extension for a diagnostics file is .DIA. The diagnostics file is used with the DEC Language-Sensitive Editor (LSE). To display a diagnostics file, enter the command REVIEW/FILE=file-spec while in LSE.
/DIAGNOSTICS[=file-spec]
/NODIAGNOSTICS (D)/DISTINGUISH_NESTED_ENUMS
Causes the compiler, when forming a mangled name, to include the name of any enclosing classes within which an enum is nested, thereby preventing different functions from receiving the same mangled name.
/NODISTINGUISH_NESTED_ENUMS (D)This qualifier has no meaning on I64 systems because it modifies the behavior of programs compiled with /MODEL=ARM, and that model is not supported on I64 systems.
/ENDIAN
Controls whether big or little endian ordering of bytes is carried out in character constants.
/ENDIAN={BIG | LITTLE}
/ENDIAN=LITTLE (D)/ERROR_LIMIT
Limits the number of error-level diagnostic messages that are acceptable during program compilation. Compilation terminates when the limit (number) is exceeded. /NOERROR_LIMIT specifies that there is no limit on error messages.
/ERROR_LIMIT[=number]
/ERROR_LIMIT=30 (D)
/NOERROR_LIMITThe default is /ERROR_LIMIT=30, which specifies that compilation terminates after issuing 30 error messages.
/EXCEPTIONS
Controls whether support for C++ exceptions is enabled or disabled. C++ exceptions are enabled by default (equivalent to /EXCEPTIONS=CLEANUP). When C++ exceptions are enabled, the compiler generates code for throw expressions, try blocks, and catch statements. The compiler also generates special code for main programs so that the terminate() routine is called for unhandled exceptions. You can select from the following options:
/EXCEPTIONS=CLEANUP (D)
/EXCEPTIONS=NOCLEANUP (ALPHA ONLY)
/EXCEPTIONS=EXPLICIT (D)
/EXCEPTIONS=IMPLICIT (ALPHA ONLY)
/NOEXCEPTIONS
CLEANUP Generate cleanup code for automatic objects. When an exception is handled at run-time and control passes from a throw-point to a handler, call the destructors for all automatic objects that were constructed because the try-block containing the handler was entered. NOCLEANUP (ALPHA ONLY) Do not generate cleanup code. Using this option can reduce the size of your executable when you want to throw and handle exceptions and cleanup of automatic objects during exception processing is not important for your application. The NOCLEANUP option is ignored on I64 systems.
EXPLICIT Tells the compiler to assume the standard C++ rules about exceptions. Catch clauses can catch only those exceptions resulting from the evaluation of a throw expression within the body of the catch clause's try block or from within a procedure called from within the catch clause's try block. IMPLICIT (ALPHA ONLY) On Alpha systems, tells the compiler that an exception might be thrown at any time the program is executing code within the body of the try block. These exceptions might be the result of a throw expression, hardware errors, or software errors (such as dereferencing an invalid pointer). Specifying /EXCEPTIONS=IMPLICIT seriously interferes with the compiler's ability to optimize code. When the compiler optimizes a function, it must ensure that the values of all variables after an exception is caught remain the same as they were at the point where the exception was throw. The optimizer is therefore limited in its ability to rearrange stores and expressions that might cause an exception to be thrown.
With /EXCEPTIONS=EXPLICIT, this is not a serious restriction, because the compiler cannot rearrange stores and expressions around the code that explicitly raises an exception. In implicit exception mode, however, almost any code has the potential to cause an exception to be thrown, thereby dramatically reducing the optimizer's ability to rearrange code.
Also, if the compiler can determine that no throw expressions occur within a try block, it can eliminate the exception handling overhead the try block introduces, including all code within the catch clauses associated with the try block. Because no exceptions can occur during the execution of the code within the try block, no code within the catch clauses can ever be executed. The compiler cannot do this with /EXCEPTIONS=IMPLICIT.
Use /EXCEPTIONS=IMPLICIT if your program converts signals to C++ exceptions by calling cxxl$set_condition(cxx_exception). Failure to do so may result in your code not catching the exceptions produced by signals.
For example, consider the following routine:
void f(int *p) { try { *p = 2; } catch (...) { ... } }Failure to compile the routine with /EXCEPTIONS=IMPLICIT may result in a failure to catch the exception generated by the SIGBUS signal that occurs if p is 0. This is because the compiler sees that there are no throws nor procedure calls within f and therefore optimizes away the try block leaving:
void f(int *p) { *p = 2; }Except for those OpenVMS conditions that result in the delivery of signals, if you raise a condition explicitly using a mechanism such as LIB$SIGNAL, you may use /EXCEPTIONS=EXPLICIT.
The /NOEXCEPTIONS qualifier disables C++ exceptions as follows:
- The compiler issues errors for throw expressions, try blocks, and catch statements, but might generate code for these constructs.
- On Alpha systems, the compiler does not generate cleanup code for automatic objects.
- The compiler does not generate special code for main programs so that the terminate() function is called for unhandled exceptions.
The /EXCEPTIONS qualifer defines the macro __EXCEPTIONS.
/EXPORT_SYMBOLS=(OPTIONS_FILE=<name>
Creating OpenVMS shareable images that contain C++ code has long been a problem for users. When building a shareable image, you must specify a list of exported global symbols. For C++ code, determining this list can be very difficult for the following reasons:
[,EXCLUDE=<list of images>][,export_option] (I64 ONLY))
- Required C++ name mangling makes it difficult to know the name of the external symbol created for a C++ name.
- OpenVMS CRC encoding (to 31 characters) further complicates mapping source names to object names.
- Certain C++ constructs require compiler-generated names to be created and exported.
To help solve the problem, the HP C++ compiler provides the /EXPORT_SYMBOLS qualifier and __declspec(dllexport) declaration modifier.
The default file extension for the OPTIONS_FILE <name> is .OPT.
If the file exists, the compiler appends to it. If the file does not exist, the compiler creates it.
The output for the compilation is:
! ! Entries added for <module> ! <symbol vector> <symbol vector> . . .The output file is suitable input to a linker options file that can be used to build a shareable image containing the compiled object.
The format of each <symbol vector> is:
SYMBOL_VECTOR=(<global name>={DATA | PROCEDURE}) ! <comment field>The <comment field> format is:
<unmangled name> [<promoted static flag>] [<class information>]The <promoted static flag> is one of the following:
*PSDM* - for promoted static data members
*PTSDM* - for promoted template static data membersThe <promoted static flag> is output whenever the symbol is a promoted local static or a promoted template static data member. This is important because these variables, while declared static, actually become global symbols when compiled.
The <class information> field is present if the symbol is a member of a class. It contains the name of the class.
Notes
- When /EXPORT_SYMBOLS is specified, an object file must also be generated. So /EXPORT_SYMBOLS cannot be used with /NOOBJ.
- When the options file already exists, the compiler reads all the symbols that are listed there. If the current compilation also defines one of those symbols, that symbol will not be added to the options file. This is necessary to prevent SYMVALRDEF warnings from the linker.
- When the compiler reads the existing file, it treats SYMBOL_VECTOR directives that are in comments (of the form !SYMBOL_VECTOR...) as if they were not commented. In this way, if a user does not want to export a symbol, placing it in comments will prevent the compiler from emitting a directive for that symbol when it compiles other sources that might also define the symbol.
- The symbols placed in the options file are a subset of the symbols defined in the output object file. The export_option value controls exactly which symbols are placed there. There are three choices:
Export_option Value Usage ALL Place all symbols suitable for placement in a sharable image into the options file. The compiler knows that certain symbols are not suited for placement in a shareable image and excludes them from the options file. Some examples are certain compiler-generated constructor/destructor jackets and symbols in the unnamed namespace. EXPLICIT Place only those symbols marked with the
__declspec(dllexport) declaration modifier into the options file.AUTOMATIC(D) If the compiler processes a __declspec(dllexport) , then act as if EXPLICIT was specified. If the compiler does not process a __declspec(dllexport) , then act as if ALL was specified. - The EXCLUDE option of the /EXPORT_SYMBOLS qualifier can be used to specify a list of shareable images. The compiler searches these images for any symbols that it might want to place in the output options file. If it finds the symbol in the image, then that symbol will not be put into the options file.
Because shareable images almost always contain a number of objects, the commands for creating the options file the first time might be:
$ DELETE options_file.OPT;* $ CXX SOURCE1/EXPORT_SYMBOLS=OPTIONS_FILE=options_file $ CXX SOURCE2/EXPORT_SYMBOLS=OPTIONS_FILE=options_file $ CXX SOURCE3/EXPORT_SYMBOLS=OPTIONS_FILE=options_file . . . $ CXX SOURCEn/EXPORT_SYMBOLS=OPTIONS_FILE=options_fileWhere SOURCE1 - SOURCEn are the sources for the shareable. After the compilations, the options_file.OPT will contain correct symbol vector information for the shareable.
The first time this options file is created, it can be considered a candidate options file. It contains all the symbol vector entries for all the C++ globals that make sense to export from the C++ language point of view. A user can then edit this file to exclude (by commenting out) entries that should not be exported, based on the design of the library.
Once an options file is created, it should be maintained for input to subsequent compilations. In this way, any new symbols caused by a change in the source will be added to the end of the compilation. Any existing symbols will not be added, as described in the NOTES section above. This technique ensures that the order of symbols remains unchanged, and that future shared libraries are compatible with existing ones.
/EXTERN_MODEL
In conjunction with the /SHARE_GLOBALS qualifier, controls the initial extern model of the compiler. Conceptually, the compiler behaves as if the first line of the program being compiled was a #pragma extern_model directive with the model and psect name, if any, specified by the /EXTERN_MODEL qualifier and with the SHR or NOSHR keyword specified by the /SHARE_GLOBALS qualifier.
/EXTERN_MODEL=option
/EXTERN_MODEL=RELAXED_REFDEF (D)For example, assume the command line contains the following qualifier:
/EXTERN_MODEL=STRICT_REFDEF="MYDATA"/NOSHAREThe compiler acts as if the program began with the following line:
#pragma extern_model strict_refdef "MYDATA" noshrFor more information on the various models, see Section 2.1.1.4.
The /EXTERN_MODEL qualifier takes the following options, which have the same meaning as for the #pragma extern_model directive:
COMMON_BLOCK
RELAXED_REFDEF
STRICT_REFDEF=["NAME"]
GLOBALVALUEThe default is RELAXED_REFDEF.
Use of an /EXTERN_MODEL value other than RELAXED_REFDEF should be limited to compilations that either declare only POD (Plain Old Data) objects, or that carefully use the extern_model (and/or environment ) #pragma directives to ensure that declarations of non-POD objects appear only in source that is subject to the default extern_model of relaxed_refdef .
/FIRST_INCLUDE
Includes the specified files before any source files. This qualifier corresponds to the Tru64 UNIX -FI switch.
/FIRST_INCLUDE=(file[,...])
/NOFIRST_INCLUDE (D)When /FIRST_INCLUDE=file is specified, file is included in the source as if the line before the first line of the source were:
#include "file"If more than one file is specified, the files are included in their order of appearance on the command line.
This qualifier is useful if you have command lines to pass to the C compiler that are exceeding the DCL command-line length limit. Using the /FIRST_INCLUDE qualifier can help solve this problem by replacing lengthy /DEFINE and /WARNINGS qualifiers with #define and #pragma message preprocessor directives placed in a /FIRST_INCLUDE file.
The default is /NOFIRST_INCLUDE.
/FLOAT
Controls the format of floating-point variables. The options are:
/FLOAT=option
/FLOAT=G_FLOAT (ALPHA ONLY) (D)
/FLOAT=IEEE_FLOAT (I64 ONLY) (D)
Option Usage D_FLOAT double variables are represented in VAX D_floating format. float variables are represented in VAX F_floating format. The __D_FLOAT macro is predefined. G_FLOAT double variables are represented in VAX G_floating format. float variables are represented in VAX F_floating format. The __G_FLOAT macro is predefined. IEEE_FLOAT float and double variables are represented in IEEE floating-point format (S_float and T_float, respectively). The __IEEE_FLOAT macro is predefined. Use the /IEEE_MODE qualifier for controlling the handling of IEEE exceptional values. On Alpha systems, the default is /FLOAT=G_FLOAT.
On I64 systems, the default is /FLOAT=IEEE_FLOAT.
See Section 4.1.6 for additional information on floating-point representation on I64 and Alpha systems.
/GRANULARITY
/GRANULARITY=option
/GRANULARITY=QUADWORD (D)Controls the size of shared data in memory that can be safely accessed from different threads. The possible size values are BYTE, LONGWORD, and QUADWORD.
Specifying BYTE allows single bytes to be accessed from different threads sharing data in memory without corrupting surrounding bytes. This option will slow runtime performance.
Specifying LONGWORD allows naturally aligned 4-byte longwords to be accessed safely from different threads sharing data in memory. Accessing data items of 3 bytes or less, or unaligned data, may result in data items written from multiple threads being inconsistently updated.
Specifying QUADWORD allows naturally aligned 8-byte quadwords to be accessed safely from different threads sharing data in memory. Accessing data items of 7 bytes or less, or unaligned data, might result in data items written from multiple threads being inconsistently updated. This is the default.
/IEEE_MODE
Selects the IEEE floating-point mode to be used if the /FLOAT=IEEE_FLOAT qualifier is specified. The options are:
/IEEE_MODE=option
/IEEE_MODE=FAST (D) (ALPHA ONLY)
/IEEE_MODE=DENORM_RESULTS (D) (I64 ONLY)
Option Usage FAST During program execution, only finite values (no infinities, NaNs, or denorms) are created. Underflows and denormal values are flushed to zero. Exceptional conditions, such as floating-point overflow, divide-by-zero, or use of an IEEE exceptional operand are fatal. UNDERFLOW_TO_ZERO Generate infinities and NaNs. Flush denormalized results and underflow to zero without exceptions. DENORM_RESULTS Same as the UNDERFLOW_TO_ZERO option, except that denorms are generated. INEXACT Same as the DENORM_RESULTS option, except that inexact values are trapped. This is the slowest mode, and is not appropriate for any sort of general-purpose computations. On Alpha systems, the default is /IEEE_MODE=FAST.
On I64 systems, the default is /IEEE_MODE=DENORM_RESULTS.
The INFINITY and NAN macros defined in <math.h> are available to programs compiled with /FLOAT=IEEE and /IEEE_MODE={anything other than FAST}.
On Alpha sytems, the /IEEE_MODE qualifier generally has its greatest effect on the generated code of a compilation. When calls are made between functions compiled with different /IEEE_MODE qualifiers, each function produces the /IEEE_MODE behavior with which it was compiled.
On I64 systems, the /IEEE_MODE qualifier primarily affects only the setting of a hardware register at program startup. In general, the /IEEE_MODE behavior for a given function is controlled by the /IEEE_MODE option specified on the compilation that produced the main program: the startup code for the main program sets the hardware register according the command-line qualifiers used to compile the main program.
When applied to a compilation that does not contain a main program, the /IEEE_MODE qualifier does have some effect: it might affect the evaluation of floating-point constant expressions, and it is used to set the EXCEPTION_MODE used by the math library for calls from that compilation. But the qualifier has no effect on the exceptional behavior of floating-point calculations generated as inline code for that compilation. Therefore, if floating-point exceptional behavior is important to an application, all of its compilations, including the one containing the main program, should be compiled with the same /IEEE_MODE setting.
Even on Alpha systems, the particular setting of /IEEE_MODE=UNDERFLOW_TO_ZERO has this characteristic: its primary effect requires the setting of a runtime status register, and so it needs to be specified on the compilation containing the main program in order to be effective in other compilations.
Also see the /FLOAT qualifier.
/IMPLICIT_INCLUDE
/IMPLICIT_INCLUDE enables inclusion of source files as a method of finding definitions of template entities. By default it is enabled for normal compilation, and disabled for preprocessing only. The search rules for finding template definition files is the same as for include files.
/IMPLICIT_INCLUDE (D)
/NOIMPLICIT_INCLUDE/NOIMPLICIT_INCLUDE disables inclusion of source files as a method of finding definitions of template entities. You might want to use this option in conjunction with the /STANDARD=MS command line option, to match more closely the behavior on Microsoft C++.
/INCLUDE_DIRECTORY
Provides an additional level of search for user-defined include files. Each pathname argument can be either a logical name or a legal UNIX style directory in a quoted string. The default is /NOINCLUDE_DIRECTORY.
/INCLUDE_DIRECTORY=(place[,...])
/NOINCLUDE_DIRECTORY (D)The /INCLUDE_DIRECTORY qualifier provides functionality similar to the -I option of the cxx command on Tru64 UNIX systems. This qualifier allows you to specify additional locations to search for files to include. Putting an empty string in the specification prevents the compiler from searching any of the locations it normally searches but directs it to search only in locations you identify explicitly on the command line with the /INCLUDE_DIRECTORY And /LIBRARY qualifiers (or by way of the specification of the primary source file, depending on the /NESTED_INCLUDE_DIRECTORY qualifier).
The basic order for searching depends on the form of the header name (after macro expansion), with additional aspects controlled by other command line qualifiers as well as the presence or absence of logical name definitions. The valid possibilities for names are as follows:
- Enclosed in quotes. For example: "stdio.h"
- Enclosed in angle brackets. For example: <stdio.h>
Unless otherwise defined, searching a location means that the compiler uses the string specifying the location as the default file specification in a call to an RMS system service (that is, a $SEARCH/$PARSE) with a primary file specification consisting of the name in the #include (without enclosing delimiters). The search terminates successfully as soon as a file can be opened for reading.
Specifying a null string in the /INCLUDE qualifier causes the compiler to do a non-standard search. This search path is as follows:
- The current directory (quoted form only)
- Any directories specified in the /INCLUDE qualifier
- The directory of the primary input file
- Text libraries specified on the command line using /LIBRARY
For standard searches, the search order is as follows:
- Search the current directory (directory of the source being processed). If angle-bracket form, search only if no directories are specified with /INCLUDE_DIRECTORY.
- Search the locations specified in the /INCLUDE_DIRECTORY qualifier (if any).
- If CXX$SYSTEM_INCLUDE is defined as a logical name, search CXX$SYSTEM_INCLUDE:.HXX or just CXX$SYSTEM_INCLUDE:., depending on the qualifier /ASSUME=NOHEADER_TYPE_DEFAULT. If nothing is found, go to step 6.
- If CXX$LIBRARY_INCLUDE is defined as a logical name, CXX$LIBRARY_INCLUDE:.HXX or CXX$LIBRARY_INCLUDE:., depending on the qualifier /ASSUME=NOHEADER_TYPE_DEFAULT. If nothing is found, go to step 6.
- If /ASSUME=HEADER_TYPE_DEFAULT is not specified, search the default list of locations for plain-text copies of compiler header files as follows:
SYS$COMMON:[CXX$LIB.INCLUDE.CXXL$ANSI_DEF]
SYS$COMMON:[CXX$LIB.INCLUDE.DECC$RTLDEF_HXX].HXX
SYS$COMMON:[DECC$LIB.INCLUDE.DECC$RTLDEF].H
SYS$COMMON:[DECC$LIB.INCLUDE.SYS$STARLET_C].H
If /ASSUME=HEADER_TYPE_DEFAULT is specified, search the default list of locations for plain-text copies of compiler header files as follows:SYS$COMMON:[CXX$LIB.INCLUDE.DECC$RTLDEF_HXX].HXX
SYS$COMMON:[DECC$LIB.INCLUDE.DECC$RTLDEF].H
SYS$COMMON:[DECC$LIB.INCLUDE.SYS$STARLET_C].H
SYS$COMMON:[CXX$LIB.INCLUDE.CXXL$ANSI_DEF]- Search the directory of the primary input file.
- If quoted form, and CXX$USER_INCLUDE is defined as a logical name, search CXX$USER_INCLUDE:.HXX or CXX$USER_INCLUDE:., depending on the /ASSUME=NOHEADER_TYPE_DEFAULT qualifier.
- Search the text libraries. Extract the simple file name and file type from the #include specification, and use them to determine a module name for each text library. There are three forms of module names used by the compiler:
- type stripped:
The file type will be removed from the include file specification to form a library module name. Examples:
#include "foo.h" Module name "FOO" #include "foo" Module name "FOO" #include "foo" Module name "FOO" - type required:
The file type must be a part of the file name. Examples:
#include "foo.h" Module name "FOO.H" #include "foo" Module name "FOO." #include "foo" Module name "FOO." - type optional:
First an attempt is made to find a module with the type included in the module name. If this is unsuccessful, an attempt is made with the type stripped from the module name. If this is unsuccessful, the search moves on to the next library.
If /ASSUME=HEADER_TYPE_DEFAULT is specified, the following text libraries are searched in this order:Libraries specified on the command line with the /LIBRARY qualifier (all files, type stripped)
CXX$TEXT_LIBRARY (all files, type stripped)
DECC$RTLDEF (H files and unspecified files, type stripped)
SYS$STARLET_C (all files, type stripped)
CXXL$ANSI_DEF (unspecified files, type stripped)
Otherwise, these text libraries are searched in this order:Libraries specified on the command line with the /LIBRARY qualifier (all files, type optional)
CXX$TEXT_LIBRARY (all files, type optional)
CXXL$ANSI_DEF (all files, type required)
DECC$RTLDEF (H files and unspecified files, type stripped)
SYS$STARLET_C (all files, type stripped)
Two text library search examples (stop when something is found):
#include "foo"
- For each library specified via the /LIBRARY qualifier:
- Look for "FOO."
- Look for "FOO"- Look for "FOO." in CXX$TEXT_LIBRARY
- Look for "FOO" in CXX$TEXT_LIBRARY
- Look for "FOO." in CXXL$ANSI_DEF (Do not look for "FOO" because the type is required as part of the module name)
- Look for "FOO" in DECC$RTLDEF (not "FOO." because the type must not be part of the module name)
- Look for "FOO" in SYS$STARLET_C (not "FOO." because the type must not be part of the module name)
Example 2
#include "foo.h"
- For each library specified via the /LIBRARY qualifier:
- Look for "FOO.H"
- Look for "FOO"- Look for "FOO.H" in CXX$TEXT_LIBRARY
- Look for "FOO" in CXX$TEXT_LIBRARY
- Look for "FOO.H" in CXXL$ANSI_DEF (Do not look for "FOO" because the type is required as part of the module name)
- Look for "FOO" in DECC$RTLDEF (not "FOO.H" because the type must not be part of the module name)
- Look for "FOO" in SYS$STARLET_C (not "FOO.H" because the type must not be part of the module name)
- If neither CXX$LIBRARY_INCLUDE nor CXX$SYSTEM_INCLUDE is defined as a logical name, then search SYS$LIBRARY:.HXX.
/L_DOUBLE_SIZE
Determines how the compiler interprets the long double type. The qualifier options are 64 and 128.
/L_DOUBLE_SIZE=option
/L_DOUBLE_SIZE=128 (D)Specifying /L_DOUBLE_SIZE=64 treats all long double references as G_FLOAT, D_FLOAT, or T_FLOAT, depending on the value of the /FLOAT qualifier. Specifying /L_DOUBLE_SIZE=64 also defines the macro __X_FLOAT=0.
Note: The /L_DOUBLE_SIZE=64 option is not available on I64 systems. If it is specified, the compiler issues a warning message and uses /L_DOUBLE_SIZE=128.
Specifying /L_DOUBLE_SIZE=128 treats all long double references as X_FLOAT. The /L_DOUBLE_SIZE=128 option also defines the macro __X_FLOAT=1. This is the default.
/LIBRARY
Indicates that the associated input file is a text library containing source text modules specified in #include directives. The compiler searches the specified library for all #include module names that are not enclosed in angle brackets or quotation marks. The name of the library must be concatenated with the file specification using a plus sign. For example: CXX DATAB/LIBRARY+APPLICATION/LINE_DIRECTIVES
Controls whether #line directives appear in preprocessed output files.
/LINE_DIRECTIVES (D)
/NOLINE_DIRECTIVES/LIST
Controls whether a listing file is produced. The default output file extension is .LIS.
/LIST[=file-spec] (Batch default)
/NOLIST (Interactive default)/MACHINE_CODE
Controls whether the listing produced by the compiler includes the machine-language code generated during the compilation. If you use this qualifier you also need to use the /LIST qualifier. On Alpha systems, machine-language code is not added to the listing file when object-file generation is disabled (using the /NOOBJECT qualifier).
/NOMACHINE_CODE (D)/MAIN=POSIX_EXIT
Directs the compiler to call __posix_exit instead of exit when returning from main .
/MAIN=POSIX_EXIT
/NOMAIN (D)/MEMBER_ALIGNMENT
Directs the compiler to naturally align data structure members. This means that data structure members are aligned on the next boundary appropriate to the type of the member, rather than on the next byte. For instance, a long variable member is aligned on the next longword boundary; a short variable member is aligned on the next word boundary.
/MEMBER_ALIGNMENT (D)
/NOMEMBER_ALIGNMENTAny use of the #pragma member_alignment or #pragma nomember_alignment directives within the source code overrides the setting established by this qualifier. Specifying /NOMEMBER_ALIGNMENT causes data structure members to be byte-aligned (with the exception of bit-field members).
/MMS_DEPENDENCIES
Instructs the compiler to produce a dependency file. The format of the dependency file is as follows:
/MMS_DEPENDENCIES[=(option[,option)]]
/NOMMS_DEPENDENCIES (D)
object_file_name:<tab><source file name> object_file_name:<tab><full path to first include file> object_file_name:<tab><full path to second include file>You can specify none, one, or both of the following qualifier options:
FILE[=filespec] Specifies where to save the dependency file. The default file extension for a dependency file is .mms. Other than using a different default extension, this qualifier uses the same procedure that /OBJECT and /LIST use for determining the name of the output file. SYSTEM_INCLUDE_FILES Specifies whether to include dependency information about system include files (that is, those included with #include <filename>). The default is to include dependency information about system include files. /MODEL (ALPHA ONLY)
On Alpha systems, determines the layout of C++ classes, name mangling, and exception handling.
/MODEL={ANSI | ARM}
/MODEL=ARM (D)On I64 systems, the default (and only) object model & demangling scheme used is the I64 Application Binary Interface (ABI). The compiler accepts the /MODEL qualifier, but it has no effect.
On Alpha systems, /MODEL=ARM is the default and generates objects that are link compatible with all releases prior to HP C++ version 6.3, and with all objects compiled with the /MODEL=ARM qualifier in releases of HP C++ Version 6.3 or later. Specifying this option defines the macro __MODEL_ARM.
The /MODEL=ANSI qualifier supports the complete ISO/ANSI C++ specification, including distinct name mangling for templates. The ANSI model also reduces the size of C++ non-POD class objects. Note that this option generates objects that are not compatible with all prior and future releases of HP C++, or with objects compiled using the /MODEL=ARM qualifier.
If you specify the /MODEL=ANSI qualifier, you must recompile and relink (using CXXLINK/MODEL=ANSI) your entire application, including libraries. Specifying this option defines the macro __MODEL_ANSI.
/NAMES
Option1 converts all definitions and references of external symbols and psects to the case specified. Option1 values are:
/NAMES=(option1,option2)
/NAMES=(UPPERCASE,TRUNCATED) (D)
Option Usage UPPERCASE Converts to uppercase. AS_IS Leaves the case as specified in the source. Option2 controls whether or not external names greater than 31 characters get truncated or shortened. Option2 values are:
Option Usage /NAMES=TRUNCATED (default) Truncates long external names to the first 31 characters. /NAMES=SHORTENED Shortens long external names. A shortened name consists of the first 23 characters of the name followed by a 7-character Cyclic Redundancy Check (CRC) computed by looking at the full name, and then a "$".
The default is /NAMES=(UPPERCASE,TRUNCATED).
Note
The I64 C++ compiler has some additional encoding rules that are applied to symbol names after the ABI name mangling is determined. All symbols with C++ linkage have CRC encodings added to the name, are uppercased and shorten to 31 characters if necessary. Since the CRC is computed before the name is uppercased, the symbol name is case-sensitive even though the final name is in uppercase. /NAMES=AS_IS and /NAMES=UPPER are not applicable to these symbols.
All symbols without C++ linkage will have CRC encodings added if they are longer then 31 characters and /NAMES=SHORTEN is specified. Global variables with C++ linkage are treated as if they have non-C++ linkage for compatibility with C and older compilers./NESTED_INCLUDE_DIRECTORY
Controls the first step in the search algorithm the compiler uses when looking for files included using the quoted form of the #include preprocessing directive: #include "file-spec" The /NESTED_INCLUDE_DIRECTORY qualifier has the following options:
/NESTED_INCLUDE_DIRECTORY[=option]
/NESTED_INCLUDE_DIRECTORY=INCLUDE_FILE (D)
Option Usage PRIMARY_FILE Directs the compiler to search the default file type for headers using the context of the primary source file. This means that only the file type (".H" or ".") is used for the default file-spec but, in addition, the chain of "related file-specs" used to maintain the sticky defaults for processing the next top-level source file is applied when searching for the include file. INCLUDE_FILE Directs the compiler to search the directory containing the file in which the #include directive itself occurred. The meaning of "directory containing" is: the RMS "resultant string" obtained when the file in which the #include occurred was opened, except that the filename and subsequent components are replaced by the default file type for headers (".H", or just "." if /ASSUME=NOHEADER_TYPE_DEFAULT is in effect). The "resultant string" will not have translated any concealed device logical. NONE Directs the compiler to skip the first step of processing #include "file.h" directives. The compiler starts its search for the include file in the /INCLUDE_DIRECTORY directories. For more information on the search order for included files, see the /INCLUDE_DIRECTORY qualifier.
/OBJECT
Controls whether the compiler produces an output object module. The default output file extension is .OBJ.
/OBJECT[=file-spec]
/OBJECT=.OBJ (D)
/NOOBJECTNote that the /OBJECT qualifier has no impact on the output file of the /MMS_DEPENDENCIES qualifier.
/OPTIMIZE
Controls the level of code optimization that the compiler performs. The options are as follows:
/OPTIMIZE[=option]
/OPTIMIZE=(LEVEL=4,INLINE=AUTOMATIC,INTRINSICS,UNROLL=0,
NOOVERRIDE_LIMITS,TUNE=GENERIC) (D)
/NOOPTIMIZE
Option Usage LEVEL= n Selects the level of code optimization. Specify an integer from 0 (no optimization) to 5 (full optimization). [NO]INLINE Provides inline expansion of functions that yield optimized code when they are expanded. You can specify one of the following keywords to control inlining:
NONE No inlining is done, even if requested by the language syntax. MANUAL Inlines only those function calls for which the program explicitly requests inlining. AUTOMATIC Inlines all of the function calls in the MANUAL category, plus additional calls that the compiler determines are appropriate on this platform. On Alpha systems, the heuristics for AUTOMATIC are similar to those for SIZE; on I64 systems, they are more like those for SPEED. AUTOMATIC is the default. SIZE Inlines all of the function calls in the MANUAL category plus any additional calls that the compiler determines would improve run-time performance without significantly increasing the size of the program. SPEED Performs more aggressive inlining for run-time performance, even when it might significantly increase the size of the program. ALL Inlines every call that can be inlined while still generating correct code. Recursive routines, however, will not cause an infinite loop at compile time. On I64 systems, ALL is treated as if SIZE had been specified. Note that /OPT=INLINE=ALL is not recommended for general use, because it performs very aggressive inlining and can cause the compiler to exhaust virtual memory or take an unacceptably long time to compile.
[NO]OVERRIDE_LIMITS (I64 ONLY) Controls whether or not the compiler uses certain built-in limits on the size and complexity of a function to "throttle back" the amount of optimization performed in order to reduce the likelihood that the compiler will use excessive memory resources or CPU time attempting to optimize the code. The default is NOOVERRIDE_LIMITS, which means that when compiling a function that has an unusually large number of basic blocks, live variables, or other properties that tend to cause the optimizer to use extra resources, the informational message OPTLIMEXC might be issued to notify you that optimization has been reduced to avoid excessive resource use.
You can choose to ignore this message or disable it (the message is not issued on compilations with optimization disabled).
Or you can specify /OPTIMIZE=OVERRIDE_LIMITS, which instructs the compiler to not check the limits and to attempt full optimization no matter how large or complex the function, knowing that the compilation might exhaust memory or seem to be in a loop.
If using /OPTIMIZE=OVERRIDE_LIMITS does result in excessive resource use, you are sure that the compiler process has plenty of memory quota available, you are convinced that the compilation does not contain any unusually large or complex functions, and you can provide complete source code, then you might want to contact your support channel to see if there is a problem in the compiler causing it to use more resources than it should for the particular compilation at hand.
TUNE Specifies the preferred processor for execution. This option makes some decisions preferentially for the specified processor (for example, for code scheduling). Note that code valid only for the specified processor can be generated. However, parallel code can be generated for processors down to the specified architecture level if necessary; that is, tuning specifies the preferred target, while architecture level specifies a lower boundary on available processor features. For example, /ARCHITECTURE=EV56/OPTIMIZE=TUNE=EV6 specifies that the code does not need to run on a processor older than an EV56, and that the code will probably run on an EV6. The generated code will run on all EV56 and later systems without any emulation. The code might have run-time selected conditional regions specifically for EV6. Also, note that because emulation is provided, the code should run, but potentially at very significantly reduced speed, on pre-EV56 processors.
The options for TUNE are the same as the options for /ARCH. You can specify one of the following keywords:
GENERIC Selects instruction tuning that is appropriate for all implementations of the operating system architecture. This option is the default. HOST Selects instruction tuning that is appropriate for the machine on which the code is being compiled. ITANIUM2 (I64 ONLY) Selects instruction tuning for the Intel Itanium 2 processor. EV4 (ALPHA ONLY) Selects instruction tuning for the 21064, 21064A, 21066, and 21068 implementations of the operating system architecture. EV5 (ALPHA ONLY) Selects instruction tuning for the 21164 implementation of the operating system architecture. EV56 (ALPHA ONLY) Selects instruction tuning for 21164 chip implementations that use the byte- and word-manipulation instruction extensions of the Alpha architecture. Running programs compiled with the EV56 keyword might incur emulation overhead on EV4 and EV5 processors, but will still run correctly on OpenVMS Version 7.1 (or later) systems.
PCA56 (ALPHA ONLY) Selects instruction tuning for the 21164PC chip implementation that uses the byte- and word-manipulation instruction extensions and multimedia instruction extensions of the Alpha architecture. Programs compiled with the PCA56 keyword might incur emulation overhead on EV4, EV5, and EV56 processors, but will still run correctly on OpenVMS Version 7.1 (or later) systems.
EV6 (ALPHA ONLY) Selects instruction tuning for the first-generation 21264 implementation of the Alpha architecture. EV67 (ALPHA ONLY) Selects instruction tuning for the second-generation 21264 implementation of the Alpha architecture. [NO]INTRINSICS Controls whether certain functions are handled as intrinsic functions without explicitly enabling each of them as an intrinsic through the #pragma intrinsic preprocessor directive. Functions that can be handled as intrinsics are:
Main Group - ANSI:
abs atanl atan2l ceill cosl floorf memcpy sinf
atan atan ceil cos fabs floorl memmove sinl sin
atanf atan2f ceilf cosf floor labs memset strcpy strlen
Main Group - Non-ANSI:
alloca atand2 bzero sind
atand bcopy cosd
Printf functions:
fprintf printf sprintf
Printf non-ANSI:
snprintf
ANSI math functions that set errno, thereby requiring /ASSUME=NOMATH_ERRNO:
acos asinf coshl log log10f powl sqrt tanf
acosf asinl exp logf log10l sinh sqrtf tanl
acosl cosh expf logl pow sinhf sqrtl tanh tanhl
asin coshf expl log10 powf sinhl tan tanhf
Non-ANSI math functions that set errno, thereby requiring /ASSUME=NOMATH_ERRNO:
log2 tand
The /OPTIMZE=INTRINSICS qualifier works with /OPTIMIZE=LEVEL =n and some other qualifiers to determine how intrinsics are handled:
- If the optimization level specified is less than 4, the intrinsic-function prototypes and call formats are checked, but normal run-time calls are still made.
- If the optimization level is 4 or higher, intrinsic code is generated.
- Intrinsic code is not generated for math functions that set the errno variable unless /ASSUME=NOMATH_ERRNO is specified. Such math functions, however, do have their prototypes and call formats checked.
The default is /OPTIMIZE=INTRINSICS, which turns on this handling.
To turn it off, use /NOOPTIMIZE or /OPTIMIZE=NOINTRINSICS.
UNROLL= n Controls loop unrolling done by the optimizer. Specify a positive integer to indicate the number of times to unroll loop bodies. If you specify 0 or do not supply a value, the optimizer determines its own unroll amount. The default is UNROLL=0. Specifying UNROLL=1 effectively disables loop unrolling. On I64 systems, you do not have the ability to control the number of times a loop is unrolled. You can either disable loop unrolling with UNROLL=1, or accept the UNROLL=0 default, which lets the optimizer determine the unroll amount.
The default is /OPTIMIZE, which is equivalent to /OPTIMIZE=LEVEL=4.
/PENDING_INSTANTIATIONS
Limit the depth of recursive instantiations so that infinite instantiation loops can be detected before some resource is exhausted. The /PENDING_INSTANTIATIONS qualifier requires a positive non-zero value as argument and issues an error when n instantiations are pending for the same class template. The default value for n is 64.
/PENDING_INSTANTIATIONS[=n]
/PENDING_INSTANTIATIONS=64(D)/POINTER_SIZE
Controls whether pointer-size features are enabled, and whether pointers are 32 bits or 64 bits long.
/POINTER_SIZE=option
/NOPOINTER_SIZE (D)On both Alpha and I64 systems, the default is /NOPOINTER_SIZE, which disables pointer-size features, such as the ability to use #pragma pointer_size , and directs the compiler to assume that all pointers are 32-bit pointers. This default represents no change over previous versions of HP C++.
You can specify one of the following options:
SHORT The compiler assumes 32-bit pointers. 32 Same as SHORT. LONG The compiler assumes 64-bit pointers. 64 Same as LONG. Specifying /POINTER_SIZE=32 directs the compiler to assume that all pointers are 32-bit pointers. But unlike the default of /NOPOINTER_SIZE, /POINTER_SIZE=32 enables use of the #pragma pointer_size long and #pragma pointer_size short preprocessor directives to control pointer size throughout your program.
Specifying /POINTER_SIZE=64 directs the compiler to assume that all pointers are 64-bit pointers, and also enables use of the #pragma pointer_size directives.
/PREFIX_LIBRARY_ENTRIES
Controls C Run-Time Library (RTL) name prefixing. For user programs that do not include the ANSI header files but call the ANSI library, the compiler automatically adds a DECC$ prefix to all C RTL library calls just before the name for the external reference or global definition is put into the object file. The C RTL shareable image (DECC$SHR.EXE) resides in IMAGELIB.OLB with a DECC$ prefix for its entry points. Every external name in IMAGELIB.OLB has a DECC$ prefix, and, therefore, has an OpenVMS-conformant name space (a requirement for inclusion in IMAGELIB).
/PREFIX_LIBRARY_ENTRIES=(option,...)
/NOPREFIX_LIBRARY_ENTRIES
/PREFIX_LIBRARY_ENTRIES=ALL_ENTRIES (D)The options are as follows:
Option Usage EXCEPT=( name,...) The names specified are not prefixed. ALL_ENTRIES All HP C++ names are prefixed. Note: ALL_ENTRIES prefixes all functions defined by the C99 standard, including those that may not be supported in the current run-time library. So calling functions introduced in C99 that are not yet implemented in the OpenVMS C RTL will produce unresolved references to symbols prefixed by DECC$ when the program is linked. In addition, the compiler will issue a CC-W-NOTINCRTL message when it prefixes a name that is not in the current C RTL.
ANSI_C89_ENTRIES Only ANSI/ISO C library names are prefixed. RTL= name References to the C RTL, indicated by NAME, are generated. NAME must be 1017 characters or fewer. If you want no names prefixed, specify /NOPREFIX_LIBRARY_ENTRIES.
/PREPROCESS_ONLY
Causes the compiler to perform only the actions of the preprocessor phase and write the resulting processed text out to a file. The default output file extension is .IXX. Use of /PREPROCESS_ONLY prevents the generation of an object or XREF file.
/PREPROCESS_ONLY[=filename]
/NOPREPROCESS_ONLY (D)/PSECT_MODEL
Controls whether the compiler allocates the size of overlaid psects to ensure compatibility when the psect is shared by code created by other HP compilers.
/PSECT_MODEL=MULTILANGUAGE
/PSECT_MODEL=NOMULTILANGUAGE (D)This qualifier solves a problem that can occur when a psect generated by a Fortran COMMON block is overlaid with a psect consisting of a C struct. Because Fortran COMMON blocks are not padded, if the C struct is padded, the inconsistent psect sizes can cause linker error messages.
Compiling with /PSECT_MODEL=MULTILANGUAGE ensures that the compiler uses a consistent psect size allocation scheme. The corresponding Fortran squalifier is /ALIGN=COMMON=[NO]MULTILANGUAGE.
The default is /PSECT=NOMULTILANGUAGE, which should be sufficient for most applications.
/PURE_CNAME
Affects insertion of the names into the global namespace by <cname> headers.
/PURE_CNAME (D) (/STANDARD=STRICT_ANSI)
/NOPURE_CNAME (D) (All other modes)In /PURE_CNAME mode, the <cname> headers insert the names into the std namespace only, as defined by the C++ Standard. In this mode, the __PURE_CNAME and __HIDE_FORBIDDEN_NAMES macros are predefined by the compiler.
In /NOPURE_CNAME mode, the <cname> headers insert the name into the std namespace and also into the global namespace. In this mode, the __PURE_CNAME and __HIDE_FORBIDDEN_NAMES macros are not predefined by the compiler.
The default depends on the standard mode:
- In /STANDARD=STRICT_ANSI mode, the default is /PURE_CNAME.
- In all other standard modes, the default is /NOPURE_CNAME.
Inclusion of a <name> header instead of its <cname> counterpart (for example, <stdio.h> instead of <cstdio> ) results in inserting names defined in the header into both the std namespace and the global namespace. Effectively, this is the same as the inclusion of a <cname> header in /NOPURE_CNAME mode.
/QUIET
Specifying /QUIET causes the compiler to report errors like the Version 5.n compiler (issue fewer messages). This is the default for ARM mode (/STANDARD=ARM). All other modes default to /NOQUIET.
/QUIET
/NOQUIET (D)Use /WARNINGS=ENABLE to enable specific messages normally disabled with /QUIET.
/REENTRANCY
Controls the type of reentrancy that reentrant HP C RTL routines exhibit. (See also the DECC$SET_REENTRANCY RTL routine.)
/REENTRANCY=option
/REENTRANCY=TOLERANT (D)This qualifier is for use only with a module containing the main routine.
The reentrancy level is set at run time according to the /REENTRANCY qualifier specified while compiling the module containing the main routine. This option affects the behavior of the C RTL, but has no effect on the C++ libraries.
You can specify one of the following options:
Option Usage AST Uses the __TESTBITSSI built-in function to perform simple locking around critical sections of RTL code, and may additionally disable asynchronous system traps (ASTs) in locked region of codes. This type of locking should be used when AST code contains calls to DEC C RTL I/O routines. MULTITHREAD Designed to be used in conjunction with the DECthreads product. It performs DECthreads locking and never disables ASTs. NONE Gives optimal performance in the RTL, but does absolutely no locking around critical sections of RTL code. It should be used only in a single threaded environment when there is no chance that the thread of execution will be interrupted by an AST that would call the HP C RTL. TOLERANT Uses the __TESTBITSSI built-in function to perform simple locking around critical sections of RTL code, but ASTs are not disabled. This type of locking should be used when ASTs are used and must be delivered immediately. This is the default reentrancy type. /REPOSITORY
Specifies a repository that C++ uses to store requested template instantiations. The default is /REPOSITORY=[.CXX_REPOSITORY]. If multiple repositories are specified, only the first is considered writable and the default repository is ignored unless specified.
/REPOSITORY=(PATHNAME [,...])
/REPOSITORY=[.CXX_REPOSITORY] (D)/ROUNDING_MODE
Lets you select an IEEE rounding mode if /FLOAT=IEEE_FLOAT is specified. The options are as follows:
/ROUNDING_MODE=option
/ROUNDING_MODE=NEAREST (D)
Option Usage CHOPPED Rounds toward 0. DYNAMIC Sets the rounding mode for IEEE floating-point instructions dynamically, as determined from the contents of the floating-point control register. MINUS_INFINITY Rounds toward minus infinity. NEAREST Sets the normal rounding mode (unbiased round to nearest). This is the default. If you specify either /FLOAT=G_FLOAT or /FLOAT=D_FLOAT, then rounding defaults to /ROUNDING_MODE=NEAREST, with no other choice of rounding mode.
/RTTI
Enables or disables support for RTTI (runtime type identification) features: dynamic_cast and typeid. Disabling runtime type identification can also save space in your object file because static information to describe polymorphic C++ types is not generated. The default is to enable runtime type information features and generate static information in the object file. The /RTTI qualifier defines the macro __RTTI.
/RTTI (D)
/NORTTI (ALPHA ONLY)Note that specifying /NORTTI does not disable exception handling.
/SHARE_GLOBALS
Controls whether the initial extern_model is shared or not shared (for those extern_models where it is allowed). The initial extern_model of the compiler is a fictitious pragma constructed from the settings of the /EXTERN_MODEL and /SHARE_GLOBALS.
/SHARE_GLOBALS
/NOSHARE_GLOBALS (D)The default value is /NOSHARE_GLOBALS, which has the following effects:
- When linking old object files or object libraries with newly produced object files, you might get "conflicting attributes for psect" messages, which can be safely ignored as long as you are not building shareable libraries.
- The /noshare_globals default makes building shareable libraries easier.
/SHOW
Used with the /LIST qualifier to set or cancel specific listing options. You can select the following options:
/SHOW=(option[,...])
/SHOW=(HEADER,SOURCE) (D)
Option Usage ALL Print all listing information. [NO]HEADER Print/do not print header lines at the top of each page (D = HEADER) [NO]INCLUDE Print/do not print contents of #include files (D = NOINCLUDE) NONE Print no listing information [NO]SOURCE Print/do not print source file statements (D = SOURCE) [NO]STATISTICS Print/do not print compiler performance statistics (D = NOSTATISTICS). On I64 systems, the /SHOW=STATISTICS option is ignored. /STANDARD
The compiler implements the International ANSI C++ Standard. The /STANDARD qualifier directs the compiler to interpret source code according to certain nonstandard syntax conventions followed by other implementations of the C++ language. The options are:
/STANDARD=(option)
/STANDARD=RELAXED (D)For more information on the effect of the /STANDARD qualifier on HP C++ compile-time error checking, Section E.1.
/TEMPLATE_DEFINE=(option,...)
Controls compiler behavior pertaining to the instantiation of C++ templates. See Chapter 5 for details on how to instantiate templates using this qualifier.
/NOTEMPLATE_DEFINENote that you must specify a value for /TEMPLATE_DEFINE.
Select only one of the following optional values to determine the template instantiation model:
Option Usage ALL Instantiate all template entities declared or referenced in the compilation unit, including typedefs. For each fully instantiated template class, all its member functions and static data members are instantiated even if they were not used. Nonmember template functions are instantiated even if the only reference was a declaration. Instantiations are created with external linkage. Overrides /REPOSITORY at compile time. Instantiations are placed in the user's object file ALL_REPOSITORY Instantiate all templates declared or used in the source program and put the object code generated as separate object files in the repository. Instantiations caused by manual instantiation directives are also put in the repository. This is similar to /TEMPLATE_DEFINE=ALL except that explicit instantiations are also put in the repository, rather than than an external symbol being put in the main object file. This qualifier is useful for creating a pre-instantiation library. AUTOMATIC Directs the compiler to use the automatic instantiation model of C++ templates. /TEMPLATE_DEFINE=AUTOMATIC is the default. NOAUTOMATIC Directs the compiler to not implicitly instantiate templates. IMPLICIT_LOCAL Same as /TEMPLATE_DEFINE=LOCAL, except manually instantiated templates are placed in the repository with external linkage. This is useful for build systems that need to have explicit control of the template instantiation mechanism. This mode can suffer the same limitations as /TEMPLATE_DEFINE=LOCAL. This mode is the default when /STANDARD=GNU is specified. LOCAL Similar to /TEMPLATE_DEFINE=USED except that the functions are given internal linkage. This qualifier provides a simple mechanism for getting started with templates. The compiler instantiates as local functions the functions used in each compilation unit, and the program links and runs correctly (barring problems resulting from multiple copies of local static variables). However, because many copies of the instantiated functions can be generated, this qualifier might not be not suitable for production use. The /TEMPLATE_DEFINE=LOCAL qualifier cannot be used in conjunction with automatic template instantiation. If automatic instantiation is enabled by default, it is disabled by the /TEMPLATE_DEFINE=LOCAL qualifier. Explicit use of /TEMPLATE_DEFINE=LOCAL and /TEMPLATE_DEFINE=AUTO is an error.
USED Instantiate those template entities that were used in the compilation. This includes all static data members for which there are template definitions. Overrides /TEMPLATE_DEFINE=AUTO at compile time. USED_REPOSITORY Like ALL_REPOSITORY, but instantiates only templates used by the compilation. The explicit instantiations are also put into the repository as separate object files. The following /TEMPLATE_DEFINE optional values are independent of the model used and each other:
Option Usage DEFINITION_FILE_TYPE="file-type-list" Specifies a string that contains a list of file types that are valid for template definition files. Items in the list must be separated by commas and preceded by a period. A type is not allowed to exceed the OpenVMS limit of 31 characters. This qualifier is applicable only when automatic instantiation has been specified. The default is /TEMPLATE_DEFINE=DEF=".CXX,.C,.CC,.CPP". PRAGMA Determines whether the compiler ignores #pragma define_template directives encountered during the compilation. This qualifier lets you quickly switch to automatic instantiation without having to remove all the pragma directives from your program's code base. The default is /TEMPLATE_DEFINE=PRAGMA, which enables #pragma define_template . VERBOSE Turns on verbose or verify mode to display each phase of instantiation as it occurs. During the compilation phase, informational level diagnostics are generated to indicate which templates are automatically being instantiated. This qualifier is useful as a debugging aid. TIMESTAMP (ALPHA ONLY) only applicable if a repository is being used. Causes the compiler to create a timestamp file named TIMESTAMP. in the repository. Thereafter, instantiations are added or regenerated only if needed; that is, if they do not alreay exist, or if existing ones are older than the timestamp. Also see /REPOSITORY. Also see /PENDING_INSTANTIATIONS.
/UNDEFINE
Performs the same function as the #undefine preprocessor directive: it cancels a macro definition.
/UNDEFINE=(identifier[,...])
/NOUNDEFINE (D)The /UNDEFINE qualifier is useful for undefining the predefined C++ preprocessor constants. For example, if you use a preprocessor constant to conditionally compile segments of code specific to C++ for OpenVMS systems, you can undefine constants to see how the portable sections of your program execute. For example:
/UNDEFINE="deccxx"When both /DEFINE and /UNDEFINE are present on the CXX command line, /DEFINE is evaluated before /UNDEFINE.
/UNSIGNED_CHAR
The /UNSIGNED_CHAR qualifier changes the default for all char types from signed to unsigned. The /NOUNSIGNED_CHAR qualifier causes all plain char declarations to have the same representation and set of values as signed char declarations.
/UNSIGNED_CHAR
/NOUNSIGNED_CHAR (D)/USING_STD
Controls whether standard library header files are processed as though the compiled code were written as follows:
/USING_STD
/NOUSING_STD (D)
using namespace std; #include <header>These options are provided for compatibility for users who do not want to qualify use of each standard library name with std:: or put using namespace std; at the top of their sources.
/USING_STD turns implicit using namespace std on; this is the default when compiling /STANDARD=ARM, /STANDARD=GNU, /STANDARD=MS, or /STANDARD=RELAXED.
/NOUSING_STD turns implicit using namespace std off; this is the default when compiling /STANDARD=STRICT_ANSI.
/VERSION
Causes the compiler to identify (print out) its version and operating system. The listing file also contains the compiler version. You cannot specify this qualifier with any other qualifiers.
/VERSION
/NOVERSION (D)/WARNINGS
Controls the issuance of compiler diagnostic messages and lets you modify the severity of messages.
/WARNINGS[=(option[,...])]
/WARNINGS (D)
/NOWARNINGSThe default qualifier, /WARNINGS, outputs all enabled warning and informational messages for the compiler mode you are using. The /NOWARNINGS qualifier suppresses warning and informational messages.
Options apply only to warning and informational messages.
The message-list in the following table of options can be any one of the following:
- A single message identifier (within parentheses, or not). The message identifier is the name following the message severity letter on the first line of an issued message. For example, in the following message, the message identifier is GLOBALEXT:
%CC-W-GLOBALEXT, a storage class of globaldef, globalref, or globalvalue is a language extension.- A comma-separated list of message identifiers, enclosed in parentheses.
- The keyword ALL.
The options are processed and take effect in the following order:
NOWARNINGS Suppresses warnings. NOINFORMATIONALS Suppresses informational messages. ENABLE= message-list Enables issuance of the specified messages. Can be used to enable specific messages that normally would not be issued when using /QUIET or messages disabled with /WARNINGS=DISABLE. DISABLE= message-list Disables issuance of the specified messages. Can be used for any nonerror message specified by a message number or tag. Specify ALL to suppress all informationals and warnings. INFORMATIONALS= message-list Sets the severity of all specified messages to Informational. Fatal and Error messages cannot be made less severe. Can also be used to enable informationals that are disabled by default. Note: With C++ Version 7.1, using
/WARNINGS=INFORMATIONALS=<tag> no longer enables all other informational messages.WARNINGS= message-list Sets the severity of the specified messages to Warning. Fatal and Error messages cannot be made less severe. [NO]ANSI_ERRORS Issues error messages for all ANSI violations when in STRICT_ANSI mode. The default is /WARNINGS=NOANSI_ERRORS. [NO]TAGS Displays a descriptive tag at the end of each message. "D" indicates that the severity of the message can be controlled from the command line. The tag displayed can be used as the message identifier in the /WARNINGS qualifier options. ERRORS= message-list Sets the severity of the specified messages to Error. Supplied Error and Fatal messages cannot be made less severe. (Exception: A message can be upgraded from Error to Fatal, then later downgraded to Error again, but it can never be downgraded from Error.)
Warnings and Informationals can be made any severity.
FATALS= message-list Sets the severity of the specified messages to Fatal. Also see the #pragma message preprocessor directive.
/XREF (ALPHA ONLY)
Controls whether the compiler generates a file of source code analysis information. The default file name is the file name of the primary source file; the default file type is .XREF. Use the SCA IMPORT command to convert an .XREF file into an analysis data file that is ready for loading into an SCA library.
/XREF[=file-spec]
/NOXREF (D)
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