[PATCH] c: Fix pragma inside a pragma [PR97991}

[Andrew Pinski]

After r0-72806-gbc4071dd66fd4d, c_parser_consume_token will
assert if we get a pragma inside c_parser_consume_token but
pragma processing will call pragma_lex which then calls
c_parser_consume_token. In the case of pragma with expansion
(redefine_extname, message and sometimes pack [and some target
specific pragmas]) we get the expanded tokens that includes
CPP_PRAGMA. We should just allow it instead of doing an assert.
This follows what the C++ front-end does even and we no longer
have an ICE.

Bootstrapped and tested on x86_64-linux-gnu.

        PR c/97991

gcc/c/ChangeLog:

        * c-parser.cc (c_parser_consume_token): Allow
        CPP_PRAGMA if inside a pragma.

gcc/testsuite/ChangeLog:

        * c-c++-common/cpp/pr97991-1.c: New test.

Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
---
 gcc/c/c-parser.cc                          | 6 +++++-
 gcc/testsuite/c-c++-common/cpp/pr97991-1.c | 3 +++
 2 files changed, 8 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/c-c++-common/cpp/pr97991-1.c

diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 106a5b48093..ff4a15aebce 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -929,7 +929,11 @@ c_parser_consume_token (c_parser *parser)
   gcc_assert (parser->tokens_avail >= 1);
   gcc_assert (parser->tokens[0].type != CPP_EOF);
   gcc_assert (!parser->in_pragma || parser->tokens[0].type != CPP_PRAGMA_EOL);
-  gcc_assert (parser->error || parser->tokens[0].type != CPP_PRAGMA);
+  /* CPP_PRAGMA should not show up here except if there was an error or inside
+     another pragma.  */
+  gcc_assert (parser->in_pragma
+             || parser->error
+             || parser->tokens[0].type != CPP_PRAGMA);
   parser->last_token_location = parser->tokens[0].location;
   if (parser->tokens != &parser->tokens_buf[0])
     parser->tokens++;
diff --git a/gcc/testsuite/c-c++-common/cpp/pr97991-1.c 
b/gcc/testsuite/c-c++-common/cpp/pr97991-1.c
new file mode 100644
index 00000000000..afdfd8a51b2
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/cpp/pr97991-1.c
@@ -0,0 +1,3 @@
+/* { dg-do compile } */
+/* Make sure malformed redefine_extname with a pragma inside does not cause an 
ICE. */
+#pragma redefine_extname _Pragma ("pack(bar)") /* { dg-warning "" } */
-- 
2.43.0