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Diffstat (limited to 'gcc/doc/tm.texi')
| -rw-r--r-- | gcc/doc/tm.texi | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index b36c764..72ea14c 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -10647,6 +10647,12 @@ convention when processing system header files, but when processing user files @code{__STDC__} will always expand to 1. @end defmac +@deftypefn {C Target Hook} {const char *} TARGET_C_PREINCLUDE (void) +Define this hook to return the name of a header file to be included at the start of all compilations, as if it had been included with @code{#include <@var{file}>}. If this hook returns @code{NULL}, or is not defined, or the header is not found, or if the user specifies @option{-ffreestanding} or @option{-nostdinc}, no header is included. + + This hook can be used together with a header provided by the system C library to implement ISO C requirements for certain macros to be predefined that describe properties of the whole implementation rather than just the compiler. +@end deftypefn + @defmac NO_IMPLICIT_EXTERN_C Define this macro if the system header files support C++ as well as C@. This macro inhibits the usual method of using system header files in |