Hi!
The first part of the following testcase (m1-m3 macros and its use)
regressed with my PR89971 fix, but as the m1,m4-m5 and its use part shows,
the problem isn't new, we can emit a CPP_PADDING token to avoid it from
being adjacent to whatever comes after the __VA_OPT__ (in this case there
is nothing afterwards, true).
In most cases these CPP_PADDING tokens don't matter, all other
callers of cpp_get_token_with_location either ignore CPP_PADDING tokens
completely (e.g. c_lex_with_flags) or they just remember them and
take them into account when printing stuff whether there should be
added whitespace or not (scan_translation_unit + token_streamer::stream).
So, I think we should just ignore CPP_PADDING tokens the same way in
_cpp_parse_expr.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2022-05-27 Jakub Jelinek <ja...@redhat.com>
PR preprocessor/105732
* expr.cc (_cpp_parse_expr): Handle CPP_PADDING by just another
token.
* c-c++-common/cpp/va-opt-10.c: New test.
--- libcpp/expr.cc.jj 2022-01-18 11:59:00.258972399 +0100
+++ libcpp/expr.cc 2022-05-26 15:39:54.348780446 +0200
@@ -1366,6 +1366,10 @@ _cpp_parse_expr (cpp_reader *pfile, bool
op.op = CPP_UMINUS;
break;
+ case CPP_PADDING:
+ lex_count--;
+ continue;
+
default:
if ((int) op.op <= (int) CPP_EQ || (int) op.op >= (int) CPP_PLUS_EQ)
SYNTAX_ERROR2_AT (op.loc,
--- gcc/testsuite/c-c++-common/cpp/va-opt-10.c.jj 2022-05-26
15:54:40.279766330 +0200
+++ gcc/testsuite/c-c++-common/cpp/va-opt-10.c 2022-05-26 15:54:24.028928687
+0200
@@ -0,0 +1,18 @@
+/* PR preprocessor/105732 */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99" { target c } } */
+/* { dg-options "-std=c++20" { target c++ } } */
+
+#define m1(p1, p2, p3) p3
+#define m2(p1, ...) 1##__VA_OPT__(foo)
+#define m3(...) m1(1, 2, m2)
+#define m4(p1, ...) 1 __VA_OPT__()
+#define m5(...) m1(1, 2, m4)
+#if m3(,)(,)
+#else
+#error
+#endif
+#if m5(,)(,)
+#else
+#error
+#endif
Jakub
