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Diffstat (limited to 'gcc/doc/extend.texi')
| -rw-r--r-- | gcc/doc/extend.texi | 33 |
1 files changed, 24 insertions, 9 deletions
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 5f0d7624a04..795b6bf7a34 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -12590,15 +12590,30 @@ option. #pragma GCC diagnostic ignored "-Wformat" @end example -Note that these pragmas override any command-line options. Also, -while it is syntactically valid to put these pragmas anywhere in your -sources, the only supported location for them is before any data or -functions are defined. Doing otherwise may result in unpredictable -results depending on how the optimizer manages your sources. If the -same option is listed multiple times, the last one specified is the -one that is in effect. This pragma is not intended to be a general -purpose replacement for command-line options, but for implementing -strict control over project policies. +Note that these pragmas override any command-line options. GCC keeps +track of the location of each pragma, and issues diagnostics according +to the state as of that point in the source file. Thus, pragmas occurring +after a line do not affect diagnostics caused by that line. + +@item #pragma GCC diagnostic push +@itemx #pragma GCC diagnostic pop + +Causes GCC to remember the state of the diagnostics as of each +@code{push}, and restore to that point at each @code{pop}. If a +@code{pop} has no matching @code{push}, the command line options are +restored. + +@example +#pragma GCC diagnostic error "-Wuninitialized" + foo(a); /* error is given for this one */ +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wuninitialized" + foo(b); /* no diagnostic for this one */ +#pragma GCC diagnostic pop + foo(c); /* error is given for this one */ +#pragma GCC diagnostic pop + foo(d); /* depends on command line options */ +@end example @end table |