https://gcc.gnu.org/g:d241835c8f47031259280930449a3ba4d8eb8eea
commit r11-11495-gd241835c8f47031259280930449a3ba4d8eb8eea
Author: Jakub Jelinek <ja...@redhat.com>
Date: Thu Feb 22 19:32:02 2024 +0100
c: Handle scoped attributes in __has*attribute and scoped attribute parsing
changes in -std=c11 etc. modes [PR114007]
We aren't able to parse __has_attribute (vendor::attr) (and
__has_c_attribute
and __has_cpp_attribute) in strict C < C23 modes. While in -std=gnu* modes
or in -std=c23 there is CPP_SCOPE token, in -std=c* (except for -std=c23)
there are is just a pair of CPP_COLON tokens.
The c-lex.cc hunk adds support for that, but always returns 0 in that case
unlike the GCC 14+ version.
2024-02-22 Jakub Jelinek <ja...@redhat.com>
PR c/114007
gcc/c-family/
* c-lex.c (c_common_has_attribute): Parse 2 CPP_COLONs with
the first one with COLON_SCOPE flag the same as CPP_SCOPE but
ensure 0 is returned then.
gcc/testsuite/
* gcc.dg/c23-attr-syntax-8.c: New test.
libcpp/
* include/cpplib.h (COLON_SCOPE): Define to PURE_ZERO.
* lex.c (_cpp_lex_direct): When lexing CPP_COLON with another
colon after it, if !CPP_OPTION (pfile, scope) set COLON_SCOPE
flag on the first CPP_COLON token.
(cherry picked from commit 37127ed975e09813eaa2d1cf1062055fce45dd16)
Diff:
---
gcc/c-family/c-lex.c | 32 ++++++++++++++++++++++++++++++--
gcc/testsuite/gcc.dg/c23-attr-syntax-8.c | 12 ++++++++++++
libcpp/include/cpplib.h | 1 +
libcpp/lex.c | 9 +++++++--
4 files changed, 50 insertions(+), 4 deletions(-)
diff --git a/gcc/c-family/c-lex.c b/gcc/c-family/c-lex.c
index 88ec7a48fcf1..97ddc797a4a1 100644
--- a/gcc/c-family/c-lex.c
+++ b/gcc/c-family/c-lex.c
@@ -327,9 +327,28 @@ c_common_has_attribute (cpp_reader *pfile, bool std_syntax)
do
nxt_token = cpp_peek_token (pfile, idx++);
while (nxt_token->type == CPP_PADDING);
- if (nxt_token->type == CPP_SCOPE)
+ if (!c_dialect_cxx ()
+ && nxt_token->type == CPP_COLON
+ && (nxt_token->flags & COLON_SCOPE) != 0)
+ {
+ const cpp_token *prev_token = nxt_token;
+ do
+ nxt_token = cpp_peek_token (pfile, idx++);
+ while (nxt_token->type == CPP_PADDING);
+ if (nxt_token->type == CPP_COLON)
+ {
+ /* __has_attribute (vendor::attr) in -std=c17 etc. modes.
+ :: isn't CPP_SCOPE but 2 CPP_COLON tokens, where the
+ first one should have COLON_SCOPE flag to distinguish
+ it from : :. */
+ have_scope = true;
+ get_token_no_padding (pfile); // Eat first colon.
+ }
+ else
+ nxt_token = prev_token;
+ }
+ if (nxt_token->type == CPP_SCOPE || have_scope)
{
- have_scope = true;
get_token_no_padding (pfile); // Eat scope.
nxt_token = get_token_no_padding (pfile);
if (nxt_token->type == CPP_NAME)
@@ -347,6 +366,15 @@ c_common_has_attribute (cpp_reader *pfile, bool std_syntax)
"attribute identifier required after scope");
attr_name = NULL_TREE;
}
+ if (have_scope)
+ {
+ /* The parser in this case won't be able to parse
+ [[vendor::attr]], so ensure 0 is returned. */
+ result = 0;
+ attr_name = NULL_TREE;
+ }
+ else
+ have_scope = true;
}
else
{
diff --git a/gcc/testsuite/gcc.dg/c23-attr-syntax-8.c
b/gcc/testsuite/gcc.dg/c23-attr-syntax-8.c
new file mode 100644
index 000000000000..6fff160dff03
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c23-attr-syntax-8.c
@@ -0,0 +1,12 @@
+/* PR c/114007 */
+/* { dg-do compile } */
+/* { dg-options "-std=c11" } */
+
+#if __has_c_attribute (gnu::unused)
+[[gnu::unused]]
+#endif
+int i;
+#if __has_cpp_attribute (gnu::unused)
+[[gnu::unused]]
+#endif
+int j;
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 41d75d9e731b..93cc7c07b021 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -193,6 +193,7 @@ struct GTY(()) cpp_string {
#define BOL (1 << 6) /* Token at beginning of line. */
#define PURE_ZERO (1 << 7) /* Single 0 digit, used by the C++ frontend,
set in c-lex.c. */
+#define COLON_SCOPE PURE_ZERO /* Adjacent colons in C < 23. */
#define SP_DIGRAPH (1 << 8) /* # or ## token was a digraph. */
#define SP_PREV_WHITE (1 << 9) /* If whitespace before a ##
operator, or before this token
diff --git a/libcpp/lex.c b/libcpp/lex.c
index 0cdd846bbc33..a450058ad6e5 100644
--- a/libcpp/lex.c
+++ b/libcpp/lex.c
@@ -3344,8 +3344,13 @@ _cpp_lex_direct (cpp_reader *pfile)
case ':':
result->type = CPP_COLON;
- if (*buffer->cur == ':' && CPP_OPTION (pfile, scope))
- buffer->cur++, result->type = CPP_SCOPE;
+ if (*buffer->cur == ':')
+ {
+ if (CPP_OPTION (pfile, scope))
+ buffer->cur++, result->type = CPP_SCOPE;
+ else
+ result->flags |= COLON_SCOPE;
+ }
else if (*buffer->cur == '>' && CPP_OPTION (pfile, digraphs))
{
buffer->cur++;
