analyzer: log the stashing of named constants [PR107711]

PR analyzer/107711 seems to be a bug in how named constants are looked up
by the analyzer in the C frontend.

To help debug this, this patch extends -fdump-analyzer and
-fdump-analyzer-stderr so that they dump this part of the analyzer's
startup.

gcc/analyzer/ChangeLog:
	PR analyzer/107711
	* analyzer-language.cc: Include "diagnostic.h".
	(maybe_stash_named_constant): Add logger param and use it to log
	the name being looked up, and the result.
	(stash_named_constants): New, splitting out from...
	(on_finish_translation_unit): ...this function.  Call
	get_or_create_logfile and use the result to create a logger
	instance, passing it to stash_named_constants.
	* analyzer.h (get_or_create_any_logfile): New decl.
	* engine.cc (dump_fout, owns_dump_fout): New globals, split out
	from run_checkers.
	(get_or_create_any_logfile): New function, split out from...
	(run_checkers): ...here, so that the logfile can be opened by
	on_finish_translation_unit.  Clear the globals when closing the
	dump file.

gcc/testsuite/ChangeLog:
	PR analyzer/107711
	* gcc.dg/analyzer/fdump-analyzer-1.c: New test.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

gcc/analyzer/analyzer-language.cc

@@ -27,6 +27,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "analyzer/analyzer.h"
 #include "analyzer/analyzer-language.h"
 #include "analyzer/analyzer-logging.h"
+#include "diagnostic.h"
 
 /* Map from identifier to INTEGER_CST.  */
 static GTY (()) hash_map <tree, tree> *analyzer_stashed_constants;
@@ -39,8 +40,12 @@ namespace ana {
    If found, stash its value within analyzer_stashed_constants.  */
 
 static void
-maybe_stash_named_constant (const translation_unit &tu, const char *name)
+maybe_stash_named_constant (logger *logger,
+			    const translation_unit &tu,
+			    const char *name)
 {
+  LOG_FUNC_1 (logger, "name: %qs", name);
+
   if (!analyzer_stashed_constants)
     analyzer_stashed_constants = hash_map<tree, tree>::create_ggc ();
 
@@ -49,7 +54,30 @@ maybe_stash_named_constant (const translation_unit &tu, const char *name)
     {
       gcc_assert (TREE_CODE (t) == INTEGER_CST);
       analyzer_stashed_constants->put (id, t);
+      if (logger)
+	logger->log ("%qs: %qE", name, t);
     }
+  else
+    {
+      if (logger)
+	logger->log ("%qs: not found", name);
+    }
+}
+
+/* Call into TU to try to find values for the names we care about.
+   If found, stash their values within analyzer_stashed_constants.  */
+
+static void
+stash_named_constants (logger *logger, const translation_unit &tu)
+{
+  LOG_SCOPE (logger);
+
+  /* Stash named constants for use by sm-fd.cc  */
+  maybe_stash_named_constant (logger, tu, "O_ACCMODE");
+  maybe_stash_named_constant (logger, tu, "O_RDONLY");
+  maybe_stash_named_constant (logger, tu, "O_WRONLY");
+  maybe_stash_named_constant (logger, tu, "SOCK_STREAM");
+  maybe_stash_named_constant (logger, tu, "SOCK_DGRAM");
 }
 
 /* Hook for frontend to call into analyzer when TU finishes.
@@ -68,12 +96,12 @@ on_finish_translation_unit (const translation_unit &tu)
   if (!flag_analyzer)
     return;
 
-  /* Stash named constants for use by sm-fd.cc  */
-  maybe_stash_named_constant (tu, "O_ACCMODE");
-  maybe_stash_named_constant (tu, "O_RDONLY");
-  maybe_stash_named_constant (tu, "O_WRONLY");
-  maybe_stash_named_constant (tu, "SOCK_STREAM");
-  maybe_stash_named_constant (tu, "SOCK_DGRAM");
+  FILE *logfile = get_or_create_any_logfile ();
+  log_user the_logger (NULL);
+  if (logfile)
+    the_logger.set_logger (new logger (logfile, 0, 0,
+				       *global_dc->printer));
+  stash_named_constants (the_logger.get_logger (), tu);
 }
 
 /* Lookup NAME in the named constants stashed when the frontend TU finished.

gcc/analyzer/analyzer.h

@@ -324,6 +324,8 @@ public:
 extern tree get_stashed_constant_by_name (const char *name);
 extern void log_stashed_constants (logger *logger);
 
+extern FILE *get_or_create_any_logfile ();
+
 } // namespace ana
 
 extern bool is_special_named_call_p (const gcall *call, const char *funcname,

gcc/analyzer/engine.cc

@@ -6144,6 +6144,34 @@ impl_run_checkers (logger *logger)
   delete purge_map;
 }
 
+/* Handle -fdump-analyzer and -fdump-analyzer-stderr.  */
+static FILE *dump_fout = NULL;
+
+/* Track if we're responsible for closing dump_fout.  */
+static bool owns_dump_fout = false;
+
+/* If dumping is enabled, attempt to create dump_fout if it hasn't already
+   been opened.  Return it.  */
+
+FILE *
+get_or_create_any_logfile ()
+{
+  if (!dump_fout)
+    {
+      if (flag_dump_analyzer_stderr)
+	dump_fout = stderr;
+      else if (flag_dump_analyzer)
+	{
+	  char *dump_filename = concat (dump_base_name, ".analyzer.txt", NULL);
+	  dump_fout = fopen (dump_filename, "w");
+	  free (dump_filename);
+	  if (dump_fout)
+	    owns_dump_fout = true;
+	}
+     }
+  return dump_fout;
+}
+
 /* External entrypoint to the analysis "engine".
    Set up any dumps, then call impl_run_checkers.  */
 
@@ -6153,23 +6181,9 @@ run_checkers ()
   /* Save input_location.  */
   location_t saved_input_location = input_location;
 
-  /* Handle -fdump-analyzer and -fdump-analyzer-stderr.  */
-  FILE *dump_fout = NULL;
-  /* Track if we're responsible for closing dump_fout.  */
-  bool owns_dump_fout = false;
-  if (flag_dump_analyzer_stderr)
-    dump_fout = stderr;
-  else if (flag_dump_analyzer)
-    {
-      char *dump_filename = concat (dump_base_name, ".analyzer.txt", NULL);
-      dump_fout = fopen (dump_filename, "w");
-      free (dump_filename);
-      if (dump_fout)
-	owns_dump_fout = true;
-    }
-
   {
     log_user the_logger (NULL);
+    get_or_create_any_logfile ();
     if (dump_fout)
       the_logger.set_logger (new logger (dump_fout, 0, 0,
 					 *global_dc->printer));
@@ -6182,7 +6196,11 @@ run_checkers ()
   }
 
   if (owns_dump_fout)
-    fclose (dump_fout);
+    {
+      fclose (dump_fout);
+      owns_dump_fout = false;
+      dump_fout = NULL;
+    }
 
   /* Restore input_location.  Subsequent passes may assume that input_location
      is some arbitrary value *not* in the block tree, which might be violated

gcc/testsuite/gcc.dg/analyzer/fdump-analyzer-1.c

@@ -0,0 +1,14 @@
+/* { dg-additional-options "-fdump-analyzer" } */
+
+void test (void)
+{
+}
+
+/* Verify that we log the named constants that we look up in the TU
+   (before the analysis pass runs).
+     { dg-final { scan-file fdump-analyzer-1.c.analyzer.txt "maybe_stash_named_constant: name: 'O_ACCMODE'" } }
+
+   Verify that we log the main part of the analysis (part of the
+   analysis pass):
+     { dg-final { scan-file fdump-analyzer-1.c.analyzer.txt "ana::run_checkers" } }
+ */