From 601dbf2a799f691688dfe78250b5bea2717b5b5e Mon Sep 17 00:00:00 2001 From: Lewis Hyatt Date: Fri, 15 Sep 2023 13:31:51 -0400 Subject: libcpp: Fix ICE on #include after a line marker directive [PR61474] As noted in the PR, GCC will segfault if a file name is first seen in a linemarker directive, and then later seen in a normal #include. This is because the fake include process adds the file to the cache with a null PATH member. The normal #include finds this file in the cache and then attempts to use the null PATH. Resolve by adding the file to the cache with a unique starting directory, so that the fake entry will only be found by a subsequent fake include, not by a real one. libcpp/ChangeLog: PR preprocessor/61474 * files.cc (_cpp_find_file): Set DONT_READ to TRUE for fake include files. (_cpp_fake_include): Pass a unique cpp_dir* address so the fake file will not be found when looked up for real. gcc/testsuite/ChangeLog: PR preprocessor/61474 * c-c++-common/cpp/pr61474-2.h: New test. * c-c++-common/cpp/pr61474.c: New test. * c-c++-common/cpp/pr61474.h: New test. --- libcpp/files.cc | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'libcpp/files.cc') diff --git a/libcpp/files.cc b/libcpp/files.cc index 43a8894..27301d7 100644 --- a/libcpp/files.cc +++ b/libcpp/files.cc @@ -541,7 +541,9 @@ _cpp_find_file (cpp_reader *pfile, const char *fname, cpp_dir *start_dir, = (kind == _cpp_FFK_PRE_INCLUDE || (pfile->buffer && pfile->buffer->file->implicit_preinclude)); - if (kind != _cpp_FFK_FAKE) + if (kind == _cpp_FFK_FAKE) + file->dont_read = true; + else /* Try each path in the include chain. */ for (;;) { @@ -1490,7 +1492,12 @@ cpp_clear_file_cache (cpp_reader *pfile) void _cpp_fake_include (cpp_reader *pfile, const char *fname) { - _cpp_find_file (pfile, fname, pfile->buffer->file->dir, 0, _cpp_FFK_FAKE, 0); + /* It does not matter what are the contents of fake_source_dir, it will never + be inspected; we just use its address to uniquely signify that this file + was added as a fake include, so a later call to _cpp_find_file (to include + the file for real) won't find the fake one in the hash table. */ + static cpp_dir fake_source_dir; + _cpp_find_file (pfile, fname, &fake_source_dir, 0, _cpp_FFK_FAKE, 0); } /* Not everyone who wants to set system-header-ness on a buffer can -- cgit v1.1