procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

libcpp: Fix up ##__VA_OPT__ handling [PR89971]

Browse source 
In the following testcase we incorrectly error about pasting / token
with padding token (which is a result of __VA_OPT__); instead we should
like e.g. for ##arg where arg is empty macro argument clear PASTE_LEFT
flag of the previous token if __VA_OPT__ doesn't add any real tokens
(which can happen either because the macro doesn't have any tokens
passed to ... (i.e. __VA_ARGS__ expands to empty) or when __VA_OPT__
doesn't have any tokens in between ()s).

2021-12-30  Jakub Jelinek  <jakub@redhat.com>

	PR preprocessor/89971
libcpp/
	* macro.c (replace_args): For ##__VA_OPT__, if __VA_OPT__ expands
	to no tokens at all, drop PASTE_LEFT flag from the previous token.
gcc/testsuite/
	* c-c++-common/cpp/va-opt-9.c: New test.
This commit is contained in:
Jakub Jelinek 2021-12-30 22:23:58 +01:00
parent be674bdd11
commit 5545d1edcb
2 changed files with 27 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
gcc/testsuite/c-c++-common/cpp/va-opt-9.c Normal file
View file

@ -0,0 +1,20 @@
/* PR preprocessor/89971 */
/* { dg-do compile } */
/* { dg-options "-std=gnu99" { target c } } */
/* { dg-options "-std=c++20" { target c++ } } */
int a, c;
#define m1(...) a /##__VA_OPT__(b) c
#define m2(...) a /##__VA_OPT__() c
#define m3(...) a##__VA_OPT__()##b = 1
#define m4(...) a##__VA_OPT__(b c d)##e = 2
int
foo (void)
{
int d = m1();
int e = m2(1);
int m3(1 2 3);
int m4();
return d + e + ab + ae;
}

8
libcpp/macro.c
View file

@ -2094,8 +2094,14 @@ replace_args (cpp_reader *pfile, cpp_hashnode *node, cpp_macro *macro,
tokens_buff_add_token (buff, virt_locs,
t, t->src_loc, t->src_loc,
NULL, 0);
continue;
}
else if (src->flags & PASTE_LEFT)
if (start && paste_flag == start && (*start)->flags & PASTE_LEFT)
/* If __VA_OPT__ expands to nothing (either because __VA_ARGS__
is empty or because it is __VA_OPT__() ), drop PASTE_LEFT
flag from previous token. */
copy_paste_flag (pfile, start, &pfile->avoid_paste);
if (src->flags & PASTE_LEFT)
{
/* Don't avoid paste after all. */
while (paste_flag && paste_flag != start