diff options
| author | Alan Modra <amodra@gmail.com> | 2018-01-31 13:34:18 +1030 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2018-01-31 16:58:26 +1030 |
| commit | ab1fadc6b2f057b817e1fc093650b63d9f6dd6c5 (patch) | |
| tree | e55f2c97682850714204488b0b4bcd859f416ac6 /gas/app.c | |
| parent | 29236ca20ad953ead58ab791ec376ee7921624b8 (diff) | |
PR22714, Assembler preprocessor loses track of \@
The PR22714 testcase is such that the input buffer processed by
do_scrub_chars ends on this line
1: bug "Returning to usermode but unexpected PSR bits set?", \@
right at the backslash. (The line is part of a macro definition.)
The next input buffer then starts with '@' which starts a comment on
ARM, and the check for \@ fails due to to == tostart. Now it would be
possible to simply access to[-1] in this particular case, but that's
ugly, and to be absolutely safe from people deliberately trying to
crash gas we'd need the read.c:read_a_source_file buffer passed to
do_scrub_chars to have a single byte pad at the start.
PR 22714
* app.c (last_char): New static var.
(struct app_save): Add last_char field.
(app_push, app_pop): Handle it.
(do_scrub_chars): Use last_char in test for "\@". Set last_char.
Diffstat (limited to 'gas/app.c')
| -rw-r--r-- | gas/app.c | 22 |
1 files changed, 21 insertions, 1 deletions
@@ -55,6 +55,9 @@ static const char mri_pseudo[] = ".mri 0"; static const char symver_pseudo[] = ".symver"; static const char * symver_state; #endif +#ifdef TC_ARM +static char last_char; +#endif static char lex[256]; static const char symbol_chars[] = @@ -242,6 +245,9 @@ struct app_save #if defined TC_ARM && defined OBJ_ELF const char * symver_state; #endif +#ifdef TC_ARM + char last_char; +#endif }; char * @@ -271,6 +277,9 @@ app_push (void) #if defined TC_ARM && defined OBJ_ELF saved->symver_state = symver_state; #endif +#ifdef TC_ARM + saved->last_char = last_char; +#endif /* do_scrub_begin() is not useful, just wastes time. */ @@ -310,6 +319,9 @@ app_pop (char *arg) #if defined TC_ARM && defined OBJ_ELF symver_state = saved->symver_state; #endif +#ifdef TC_ARM + last_char = saved->last_char; +#endif free (arg); } @@ -1285,7 +1297,7 @@ do_scrub_chars (size_t (*get) (char *, size_t), char *tostart, size_t tolen) #ifdef TC_ARM /* For the ARM, care is needed not to damage occurrences of \@ by stripping the @ onwards. Yuck. */ - if (to > tostart && *(to - 1) == '\\') + if ((to > tostart ? to[-1] : last_char) == '\\') /* Do not treat the @ as a start-of-comment. */ goto de_fault; #endif @@ -1465,6 +1477,10 @@ do_scrub_chars (size_t (*get) (char *, size_t), char *tostart, size_t tolen) fromeof: /* We have reached the end of the input. */ +#ifdef TC_ARM + if (to > tostart) + last_char = to[-1]; +#endif return to - tostart; tofull: @@ -1478,5 +1494,9 @@ do_scrub_chars (size_t (*get) (char *, size_t), char *tostart, size_t tolen) else saved_input = NULL; +#ifdef TC_ARM + if (to > tostart) + last_char = to[-1]; +#endif return to - tostart; } |