diff options
Diffstat (limited to 'gcc/doc/cppopts.texi')
| -rw-r--r-- | gcc/doc/cppopts.texi | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/gcc/doc/cppopts.texi b/gcc/doc/cppopts.texi index 68bd439..7a2ce50 100644 --- a/gcc/doc/cppopts.texi +++ b/gcc/doc/cppopts.texi @@ -204,10 +204,13 @@ When used with the driver options @option{-MD} or @option{-MMD}, @item -MG @opindex MG -When used with @option{-M} or @option{-MM}, @option{-MG} says to treat missing -header files as generated files and assume they live in the same -directory as the source file. It suppresses preprocessed output, as a -missing header file is ordinarily an error. +In conjunction with an option such as @option{-M} requesting +dependency generation, @option{-MG} assumes missing header files are +generated files and adds them to the dependency list without raising +an error. The dependency filename is taken directly from the +@code{#include} directive without prepending any path. @option{-MG} +also suppresses preprocessed output, as a missing header file renders +this useless. This feature is used in automatic updating of makefiles. |