diff options
Diffstat (limited to 'src/regex.c')
| -rw-r--r-- | src/regex.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/src/regex.c b/src/regex.c index 4bb30f7e214..06c1bb0b72e 100644 --- a/src/regex.c +++ b/src/regex.c @@ -881,13 +881,22 @@ static const char *re_error_msg[] = using the relocating allocator routines, then malloc could cause a relocation, which might (if the strings being searched are in the ralloc heap) shift the data out from underneath the regexp - routines. */ + routines. + + Here's another reason to avoid allocation: Emacs insists on + processing input from X in a signal handler; processing X input may + call malloc; if input arrives while a matching routine is calling + malloc, then we're scrod. But Emacs can't just block input while + calling matching routines; then we don't notice interrupts when + they come in. So, Emacs blocks input around all regexp calls + except the matching calls, which it leaves unprotected, in the + faith that they will not malloc. */ /* Normally, this is fine. */ #define MATCH_MAY_ALLOCATE /* But under some circumstances, it's not. */ -#if defined (REL_ALLOC) && defined (C_ALLOCA) +#if defined (emacs) || (defined (REL_ALLOC) && defined (C_ALLOCA)) #undef MATCH_MAY_ALLOCATE #endif |