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This program produces the following output:
$ CC EXAMPLE.C[Return] $ LINK EXAMPLE.OBJ[Return] $ RUN EXAMPLE.EXE[Return] I'm being compiled with DEC C on an OpenVMS system. $ CC/UNDEFINE="<double_uscore>DECC" EXAMPLE [Return] $ LINK EXAMPLE.OBJ[Return] $ RUN EXAMPLE.EXE[Return] I'm being compiled on some other compiler. |
It controls whether big or little endian ordering of bytes is carried out in character constants. For example, consider the following declaration:
int foo = 'ABCD'; |
Specifying /ENDIAN=LITTLE places 'A' in the first byte, 'B' in the second byte, and so on.
Specifying /ENDIAN=BIG places 'D' in the first byte, 'C' in the second byte, and so on.
The default is /ENDIAN=LITTLE.
The default is /ERROR_LIMIT=30, which specifies that compilation terminates after 31 error messages.
For example, assume the command line contains the following qualifiers:
/EXTERN_MODEL=STRICT_REFDEF="MYDATA"/NOSHARE |
The compiler will behave as if the program begins with the following line:
#pragma extern_model strict_refdef "MYDATA" noshr |
Table 1-6 describes the /EXTERN_MODEL qualifier options.
| Option | Usage |
|---|---|
| COMMON_BLOCK | Sets the compiler's extern_model to the common_block model. This is the model traditionally used for extern data by VAX C. |
| RELAXED_REFDEF |
Sets the compiler's
extern_model
to the
relaxed_refdef
model. Some declarations are references and some are definitions.
Multiple uninitialized definitions for the same object are allowed and
are resolved into one by the linker. However, a reference requires that
at least one definition exist.
This is the model used by the portable C compiler ( pcc ) on UNIX systems. |
| STRICT_REFDEF [=" name"] |
Sets the compiler's
extern_model
to the
strict_refdef
model. Some declarations are references and some are definitions. There
must be exactly one definition in the program for any symbol
referenced. The optional
name, in quotation marks, is the name of the psect for any
definitions.
This is the model specified by ANSI C. Use it in a program that is to be a strict ANSI C conforming program. This model is the preferred alternative to the nonstandard storage-class keywords globaldef and globalref . |
| GLOBALVALUE |
Sets the compiler's
extern_model
to the
globalvalue
model. This model is similar to the
strict_refdef
model except that these global objects have no storage; instead, they
are link-time constant values. There are two cases:
This model is the preferred alternative to the nonstandard storage-class keyword globalvalue . |
The default is /EXTERN_MODEL=RELAXED_REFDEF. This is different from VAX C, which uses the common block model for external objects.
On OpenVMS Alpha systems, representation of double variables defaults to G_floating format if not overridden by another format specified with the /FLOAT or /[NO]G_FLOAT qualifier.
If you are linking against object-module libraries, and /PREFIX=ALL is not specified on the command line:
The VAXCRTLX.OLB, VAXCRTLDX.OLB, and VAXCRTLTX.OLB libraries are used for the same floating-point formats, respectively, but include support for X_FLOAT format (/L_DOUBLE_SIZE=128). (ALPHA ONLY)
If /PREFIX=ALL is specified, then there is no need to link to the above-mentioned *.OLB object libraries. All the symbols you need are in STARLET.OLB. (ALPHA ONLY)
On OpenVMS VAX systems, representation of double variables defaults to D_floating format if not overridden by another format specified with the /FLOAT or /[NO]G_FLOAT qualifier. There is one exception: if /STANDARD=MIA is specified, G_floating is the default. If you are linking against object-module libraries, a program compiled with G_floating format must be linked with the object library DECCRTLG.OLB. (VAX ONLY)
Table 1-7 describes the /FLOAT qualifier options.
| Option | Usage |
|---|---|
| D_FLOAT | double variables are represented in D_floating format. |
| G_FLOAT | double variables are represented in G_floating format. |
| IEEE_FLOAT (ALPHA ONLY) | float and double variables are represented in IEEE floating-point format (S_float and T_float, respectively). Use the /IEEE_MODE qualifier for controlling the handling of IEEE exceptional values. If /IEEE_MODE is not specified, the default behavior is /IEEE_MODE=FAST. |
If you specify /G_FLOAT, double variables are represented in G_floating format.
If you specify /NOG_FLOAT, double variables are represented in D_floating format. (See Section 4.5 for more information on the floating formats.)
On OpenVMS Alpha systems, representation of double variables defaults to G_floating format if not overridden by another format specified with the /FLOAT or /[NO]G_FLOAT qualifier.
If you are linking against object-module libraries, and /PREFIX=ALL is not specified on the command line:
The VAXCRTLX.OLB, VAXCRTLDX.OLB, and VAXCRTLTX.OLB libraries are used for the same floating-point formats, respectively, but include support for X_FLOAT format (/L_DOUBLE_SIZE=128). (ALPHA ONLY)
If /PREFIX=ALL is specified, then there is no need to link to the above-mentioned *.OLB object libraries. All the symbols you need are in STARLET.OLB. (ALPHA ONLY)
On OpenVMS VAX systems, representation of double variables defaults to D_floating format if not overridden by another format specified with the /FLOAT or /[NO]G_FLOAT qualifier. There is one exception: if /STANDARD=MIA is specified, G_floating is the default. If you are linking against object-module libraries, a program compiled with G_floating format must be linked with the object library DECCRTLG.OLB. (VAX ONLY)
Granularity has two aspects: references inside a particular data segment and references between data segments.
The options are:
The default is /GRANULARITY=QUADWORD.
Table 1-8 describes the /IEEE_MODE options.
| 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. This is the default option. |
| UNDERFLOW_TO_ZERO | Generate infinities and NaNs. Flush denormalized results and underflow to zero without exceptions. |
| DENORM_RESULTS | Same as UNDERFLOW_TO_ZERO, except that denorms are generated. |
| INEXACT | Same as DENORM_RESULTS, except that inexact values are trapped. This is the slowest mode, and is not appropriate for any sort of general-purpose computations. |
The default is /IEEE_MODE=FAST.
If one of the places is specified as an empty string, the compiler does not search any of its conventionally-named places:
Instead, it searches only places specified explicitly on the command line by the /INCLUDE_DIRECTORY and /LIBRARY qualifiers (or by the location of the primary source file, depending on the /NESTED_INCLUDE_DIRECTORY qualifier). This behavior is similar to that obtained by specifying -I without a directory name to the Digital UNIX cc command.
The basic search order depends on the form of the header-file name (after macro expansion). Additional aspects of the search order are controlled by other command-line qualifiers and the presence or absence of logical name definitions.
Only the portable forms of the #include directive are affected by the pathnames specified on an /INCLUDE_DIRECTORY qualifier:
However, an empty string also affects the text-module form specific to OpenVMS systems (example: #include stdio ).
Except where otherwise specified, searching a "place" means that the string designating the place is used as the default file-spec in a call to an RMS system service (for example, $SEARCH/$PARSE). The file-spec consists of the name in the #include directive without enclosing delimiters. The search terminates successfully as soon as a file can be opened for reading.
Prior to OpenVMS VAX Version 7.1, the operating system did not provide a SYS$LIBRARY:SYS$STARLET_C.TLB nor the headers contained therein. Instead, the compiler installation generated these headers and placed them in SYS$LIBRARY:DECC$RTLDEF.TLB. |
Quoted Form
For the quoted form of inclusion, the search order is:
Angle-Bracketed Form
For the angle-bracketed form of inclusion, the search order is:
The compiler installation does not create these directories of header files. Instead, it creates [DECC$LIB.REFERENCE] for your convenience. But if you choose to create and populate SYS$COMMON:[DECC$LIB.INCLUDE.DECC$RTLDEF] or SYS$COMMON:[DECC$LIB.INCLUDE.SYS$STARLET_C].H, the compiler will search them. |
Text-Module Form
For the text-module (nonportable) form of inclusion, the name can only be an identifier. It, therefore, has no associated file type.
The identifier is used as a module name to search the following:
The default for this qualifer is /NOINCLUDE_DIRECTORY.
The default is /INSTRUCTION_SET=FLOATING_POINT.
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=128 treats all long double references as X_FLOAT.
The default is /L_DOUBLE_SIZE=128.
$ CC ONE + TWO + THREE/LIBRARY[Return] |
Files ONE.C and TWO.C can contain references to modules in THREE.TLB. Consider the following example:
$ CC ONE + TWO + THREE/LIBRARY, FOUR[Return] |
The file FOUR.C cannot contain references to modules in THREE.TLB since FOUR.C is located in a separate compilation unit separated by a comma. The placement of the library file specification does not matter. The following command lines are equivalent:
$ CC THREE/LIBRARY + ONE + TWO[Return] $ CC ONE + THREE/LIBRARY + TWO[Return] $ CC ONE + TWO + THREE/LIBRARY[Return] |
The default is /LINE_DIRECTIVES.
By default, /LIST creates a listing file with the same name as the source file and with a file extension of .LIS. If you include a file specification with the /LIST qualifier, the compiler uses that specification to name the listing file.
In interactive mode, the default is /NOLIST. In batch mode, the default is /LIST. See the descriptions of the qualifiers /[NO]MACHINE_CODE, and /SHOW for related information. (For example, to suppress compiler messages to the terminal or to a batch log file, use the /SHOW=NOTERMINAL qualifier.)
On OpenVMS VAX systems, several formats exist to list machine code. Table 1-9 describes the /MACHINE_CODE qualifier options.
| Option | Usage |
|---|---|
| AFTER | Causes the lines of machine code produced during compilation to print after all the source code in the listing. |
| BEFORE | Causes lines of machine code produced during compilation to print before any source code in the listing. |
| INTERSPERSED | Produces a listing consisting of lines of source code followed by the corresponding lines of machine code. This is the default option. |
On OpenVMS Alpha sytems, the format of the generated machine code listing is similar to what you would get using the AFTER keyword on OpenVMS VAX systems.
The default is /NOMACHINE_CODE.
Any 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).
On OpenVMS Alpha systems, the default is /MEMBER_ALIGNMENT.
On OpenVMS VAX systems, the default is /NOMEMBER_ALIGNMENT.
See the description of #pragma [no]member_alignment in Section 5.4.10.
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>) |
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