Add -fdiagnostics-format={json-stderr|json-file}

This commit adds -fdiagnostics-format=json-file, writing to
DUMP_BASE_NAME.gcc.json, and adds -fdiagnostics-format=json-stderr,
a synonym for the existing -fdiagnostics-format=json.

gcc/ChangeLog:
	* common.opt (fdiagnostics-format=): Add json-stderr and json-file
	to description.
	(DIAGNOSTICS_OUTPUT_FORMAT_JSON): Rename to...
	(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR): ...this.
	(diagnostics_output_format): Add json-stderr and json-file.
	* diagnostic-format-json.cc (json_flush_to_file): New.
	(json_final_cb): Convert to...
	(json_flush_to_file): ...this, ...
	(json_stderr_final_cb): ...this, and...
	(json_file_final_cb): ...this.
	(diagnostic_output_format_init): Move to diagnostic.cc.
	(json_output_base_file_name): New.
	(diagnostic_output_format_init_json): New.
	(diagnostic_output_format_init_json_stderr): New.
	(diagnostic_output_format_init_json_file): New.
	* diagnostic.cc (diagnostic_output_format_init): Move here from
	diagnostic-format-json.cc; update for changes to enum.
	* diagnostic.h (enum diagnostics_output_format): Rename
	DIAGNOSTICS_OUTPUT_FORMAT_JSON to
	DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR, and add
	DIAGNOSTICS_OUTPUT_FORMAT_JSON_FILE.
	(diagnostic_output_format_init): Add base_file_name param.
	(diagnostic_output_format_init_json_stderr): New decl.
	(diagnostic_output_format_init_json_file): New dec.
	* doc/invoke.texi (-fdiagnostics-format=): Add "json-stderr" and
	"json-file".  Rewrite so that the existing "json" is a synonym of
	"json-stderr".
	* gcc.cc (driver_handle_option): Pass dump_base_name to
	diagnostic_output_format_init.
	* opts.cc (common_handle_option): Likewise.

gcc/testsuite/ChangeLog:
	* c-c++-common/diagnostic-format-json-file-1.c: New test.
	* c-c++-common/diagnostic-format-json-stderr-1.c: New test.

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

1 files changed, 76 insertions, 40 deletions

diff --git a/gcc/diagnostic-format-json.cc b/gcc/diagnostic-format-json.cc
index 62594eb..051fa6c 100644
--- a/gcc/diagnostic-format-json.cc
+++ b/gcc/diagnostic-format-json.cc
@@ -285,57 +285,93 @@ json_end_group (diagnostic_context *)
   cur_children_array = NULL;
 }
 
-/* Callback for final cleanup for JSON output.  */
+/* Flush the top-level array to OUTF.  */
 
 static void
-json_final_cb (diagnostic_context *)
+json_flush_to_file (FILE *outf)
 {
-  /* Flush the top-level array.  */
-  toplevel_array->dump (stderr);
-  fprintf (stderr, "\n");
+  toplevel_array->dump (outf);
+  fprintf (outf, "\n");
   delete toplevel_array;
   toplevel_array = NULL;
 }
 
-/* Set the output format for CONTEXT to FORMAT.  */
+/* Callback for final cleanup for JSON output to stderr.  */
 
-void
-diagnostic_output_format_init (diagnostic_context *context,
-			       enum diagnostics_output_format format)
+static void
+json_stderr_final_cb (diagnostic_context *)
+{
+  json_flush_to_file (stderr);
+}
+
+static char *json_output_base_file_name;
+
+/* Callback for final cleanup for JSON output to a file.  */
+
+static void
+json_file_final_cb (diagnostic_context *)
 {
-  switch (format)
+  char *filename = concat (json_output_base_file_name, ".gcc.json", NULL);
+  FILE *outf = fopen (filename, "w");
+  if (!outf)
     {
-    default:
-      gcc_unreachable ();
-    case DIAGNOSTICS_OUTPUT_FORMAT_TEXT:
-      /* The default; do nothing.  */
-      break;
-
-    case DIAGNOSTICS_OUTPUT_FORMAT_JSON:
-      {
-	/* Set up top-level JSON array.  */
-	if (toplevel_array == NULL)
-	  toplevel_array = new json::array ();
-
-	/* Override callbacks.  */
-	context->begin_diagnostic = json_begin_diagnostic;
-	context->end_diagnostic = json_end_diagnostic;
-	context->begin_group_cb = json_begin_group;
-	context->end_group_cb =  json_end_group;
-	context->final_cb =  json_final_cb;
-	context->print_path = NULL; /* handled in json_end_diagnostic.  */
-
-	/* The metadata is handled in JSON format, rather than as text.  */
-	context->show_cwe = false;
-
-	/* The option is handled in JSON format, rather than as text.  */
-	context->show_option_requested = false;
-
-	/* Don't colorize the text.  */
-	pp_show_color (context->printer) = false;
-      }
-      break;
+      const char *errstr = xstrerror (errno);
+      fnotice (stderr, "error: unable to open '%s' for writing: %s\n",
+	       filename, errstr);
+      free (filename);
+      return;
     }
+  json_flush_to_file (outf);
+  fclose (outf);
+  free (filename);
+}
+
+/* Populate CONTEXT in preparation for JSON output (either to stderr, or
+   to a file).  */
+
+static void
+diagnostic_output_format_init_json (diagnostic_context *context)
+{
+  /* Set up top-level JSON array.  */
+  if (toplevel_array == NULL)
+    toplevel_array = new json::array ();
+
+  /* Override callbacks.  */
+  context->begin_diagnostic = json_begin_diagnostic;
+  context->end_diagnostic = json_end_diagnostic;
+  context->begin_group_cb = json_begin_group;
+  context->end_group_cb =  json_end_group;
+  context->print_path = NULL; /* handled in json_end_diagnostic.  */
+
+  /* The metadata is handled in JSON format, rather than as text.  */
+  context->show_cwe = false;
+
+  /* The option is handled in JSON format, rather than as text.  */
+  context->show_option_requested = false;
+
+  /* Don't colorize the text.  */
+  pp_show_color (context->printer) = false;
+}
+
+/* Populate CONTEXT in preparation for JSON output to stderr.  */
+
+void
+diagnostic_output_format_init_json_stderr (diagnostic_context *context)
+{
+  diagnostic_output_format_init_json (context);
+  context->final_cb = json_stderr_final_cb;
+}
+
+/* Populate CONTEXT in preparation for JSON output to a file named
+   BASE_FILE_NAME.gcc.json.  */
+
+void
+diagnostic_output_format_init_json_file (diagnostic_context *context,
+					 const char *base_file_name)
+{
+  diagnostic_output_format_init_json (context);
+  context->final_cb = json_file_final_cb;
+  json_output_base_file_name = xstrdup (base_file_name);
 }
 
 #if CHECKING_P