get__Pragma_string() in directives.cc is responsible for lexing the parens
and the string argument from a _Pragma("...") operator. This function does
not handle the case when the closing paren is not on the same line as the
string; in that case, libcpp will by default reuse the token buffer it
previously used for the string, so that the string token returned by
get__Pragma_string() may be corrupted, as shown in the testcase. Fix using
the existing keep_tokens mechanism that temporarily disables the reuse of
token buffers.
libcpp/ChangeLog:
PR preprocessor/67046
* directives.cc (_cpp_do__Pragma): Increment pfile->keep_tokens to
ensure the returned string token is valid.
gcc/testsuite/ChangeLog:
PR preprocessor/67046
* c-c++-common/cpp/pr67046.c: New test.
---
Notes:
Hello-
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67046
This fixes an old ICE in libcpp that can happen when lexing the tokens from
a
_Pragma operator. Bootstrapped+tested on x86-64 Linux with no
regressions. Please let me know if it's OK? Thanks...
-Lewis
gcc/testsuite/c-c++-common/cpp/pr67046.c | 10 ++++++++++
libcpp/directives.cc | 5 +++++
2 files changed, 15 insertions(+)
create mode 100644 gcc/testsuite/c-c++-common/cpp/pr67046.c
diff --git a/gcc/testsuite/c-c++-common/cpp/pr67046.c
b/gcc/testsuite/c-c++-common/cpp/pr67046.c
new file mode 100644
index 00000000000..f37f20c624e
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/cpp/pr67046.c
@@ -0,0 +1,10 @@
+/* { dg-do preprocess } */
+
+_Pragma(
+"message(\"msg\")"
+)
+
+_Pragma(
+"message(\"msg\")"
+#
+)
diff --git a/libcpp/directives.cc b/libcpp/directives.cc
index 9dc4363c65a..ffd262bce7d 100644
--- a/libcpp/directives.cc
+++ b/libcpp/directives.cc
@@ -1996,7 +1996,12 @@ destringize_and_run (cpp_reader *pfile, const cpp_string
*in,
int
_cpp_do__Pragma (cpp_reader *pfile, location_t expansion_loc)
{
+ /* Make sure we don't invalidate the string token, if the closing parenthesis
+ ended up on a different line. */
+ ++pfile->keep_tokens;
const cpp_token *string = get__Pragma_string (pfile);
+ --pfile->keep_tokens;
+
pfile->directive_result.type = CPP_PADDING;
if (string)
