Preprocessor directive
Syntax
#pragma option [ = value ]
Or
#pragma push ( option [, value ] )
Or
#pragma pop ( option )
Parameters
Possible values for
option and related
values:
| Option | Value | Description |
| msbitfields | false | Use bitfields compatible with gcc (default) |
| msbitfields | true | Use bitfields compatible with those used in Microsoft C compilers |
| once | N/A | cause the source file in which the pragma appears to behave as though it was included with #include once ... |
| constness | false | disable 'CONST qualifier discarded' warning in current source |
| constness | true | enable 'CONST qualifier discarded' warning in current source |
| lookup108 | false | use normal symbol lookups for unqualified symbol names |
| lookup108 | true | use fbc-1.08.x or earlier symbol lookups for unqualified symbol names |
| gui | false | compile in console subsystem mode |
| gui | true | compile in GUI subsystem mode |
| private | false | allow procedures in sources to be compiled as separate modules with public linkage |
| private | true | allow procedures in sources to be compiled as privately included with minimal overhead for changing desired linkage |
| profile | false | profiling code is not generated |
| profile | true | profiling code is generated |
If
value is not given, the compiler assumes
True (
-1). A zero (
0) value may be used in place of
False. A non-zero (for example,
-1) value may be used in place of
True.
Description
Allows the setting of compiler options inside the source code.
Push saves the current value of the
option onto a stack, then assigns the new
value (or
True) to it.
Pop restores the
option to its previous value, and removes it from the stack. This mechanism allows options to be changed for a certain part of source code, regardless of the setting used by the context, which is especially useful inside #include header files.
gui sets the same GUI/console subsystem mode represented by the
-s compiler option and
__FB_GUI__. This pragma must be used at module level.
constness pragma is added for testing fbc compiler. It will be removed in future at should not be relied upon.
Example
'' MSVC-compatible bitfields: save the current setting and then enable them
#pragma push(msbitfields)
'' do something that requires MS-compatible bitfields here
'' restore original setting
#pragma pop(msbitfields)
Version
- #pragma gui added in version 1.20.1
- #pragma private and #pragma profile added in version 1.20.0
- #pragma lookup108 added in version 1.09.0, and to be removed in next minor release
Differences from QB
See also