Evict selftest tempfiles from the diagnostics file cache

Selftests can use class selftest::temp_source_file to write out files
for testing input-handling, and the files are unlinked in the dtor.

This leads to stale entries in input.c's cache of file content, which
could lead to errors if a temporary filename gets reused during a run
of the selftests.

We don't normally expect files to be "deleted from under us", so
special-case this by adding a special way for temp_source_file's
dtor to purge any cache entries referring to it.

gcc/ChangeLog:
	* input.c (diagnostics_file_cache_forcibly_evict_file): New
	function.
	* input.h (diagnostics_file_cache_forcibly_evict_file): New
	declaration.
	* selftest.c (selftest::temp_source_file::~temp_source_file):
	Evict m_filename from the diagnostic file cache.

From-SVN: r239570

1 files changed, 26 insertions, 0 deletions

diff --git a/gcc/input.c b/gcc/input.c
index 172d13a8ad7..76a33077bc2 100644
--- a/gcc/input.c
+++ b/gcc/input.c
@@ -249,6 +249,32 @@ lookup_file_in_cache_tab (const char *file_path)
   return r;
 }
 
+/* Purge any mention of FILENAME from the cache of files used for
+   printing source code.  For use in selftests when working
+   with tempfiles.  */
+
+void
+diagnostics_file_cache_forcibly_evict_file (const char *file_path)
+{
+  gcc_assert (file_path);
+
+  fcache *r = lookup_file_in_cache_tab (file_path);
+  if (!r)
+    /* Not found.  */
+    return;
+
+  r->file_path = NULL;
+  if (r->fp)
+    fclose (r->fp);
+  r->fp = NULL;
+  r->nb_read = 0;
+  r->line_start_idx = 0;
+  r->line_num = 0;
+  r->line_record.truncate (0);
+  r->use_count = 0;
+  r->total_lines = 0;
+}
+
 /* Return the file cache that has been less used, recently, or the
    first empty one.  If HIGHEST_USE_COUNT is non-null,
    *HIGHEST_USE_COUNT is set to the highest use count of the entries