[PATCH] Do not error for no_sanitize attributes (PR sanitizer/82490).

[Martin Liška]

Hi.

This changes error to a warning:
warning: ‘foobar’ attribute directive ignored [-Wattributes]

Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.

Ready to be installed?
Martin

gcc/ChangeLog:

2017-10-10  Martin Liska  <mli...@suse.cz>

        PR sanitizer/82490
        * opts.c (parse_no_sanitize_attribute): Do not use error_value
        variable.
        * opts.h (parse_no_sanitize_attribute): Remove last argument.

gcc/c-family/ChangeLog:

2017-10-10  Martin Liska  <mli...@suse.cz>

        PR sanitizer/82490
        * c-attribs.c (handle_no_sanitize_attribute): Report directly
        Wattributes warning.

gcc/testsuite/ChangeLog:

2017-10-10  Martin Liska  <mli...@suse.cz>

        PR sanitizer/82490
        * c-c++-common/ubsan/attrib-5.c: New test.
---
 gcc/c-family/c-attribs.c                    |  9 +--------
 gcc/opts.c                                  |  8 ++++----
 gcc/opts.h                                  |  2 +-
 gcc/testsuite/c-c++-common/ubsan/attrib-5.c | 11 +++++++++++
 4 files changed, 17 insertions(+), 13 deletions(-)
 create mode 100644 gcc/testsuite/c-c++-common/ubsan/attrib-5.c



diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index 4e6754fba20..bd8ca306c2d 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -613,15 +613,8 @@ handle_no_sanitize_attribute (tree *node, tree name, tree args, int,
       return NULL_TREE;
     }
 
-  char *error_value = NULL;
   char *string = ASTRDUP (TREE_STRING_POINTER (id));
-  unsigned int flags = parse_no_sanitize_attribute (string, &error_value);
-
-  if (error_value)
-    {
-      error ("wrong argument: \"%s\"", error_value);
-      return NULL_TREE;
-    }
+  unsigned int flags = parse_no_sanitize_attribute (string);
 
   add_no_sanitize_value (*node, flags);
 
diff --git a/gcc/opts.c b/gcc/opts.c
index 5aa5d066dbe..adf3d89851d 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -1700,11 +1700,10 @@ parse_sanitizer_options (const char *p, location_t loc, int scode,
 }
 
 /* Parse string values of no_sanitize attribute passed in VALUE.
-   Values are separated with comma.  Wrong argument is stored to
-   WRONG_ARGUMENT variable.  */
+   Values are separated with comma.  */
 
 unsigned int
-parse_no_sanitize_attribute (char *value, char **wrong_argument)
+parse_no_sanitize_attribute (char *value)
 {
   unsigned int flags = 0;
   unsigned int i;
@@ -1722,7 +1721,8 @@ parse_no_sanitize_attribute (char *value, char **wrong_argument)
 	  }
 
       if (sanitizer_opts[i].name == NULL)
-	*wrong_argument = q;
+	warning (OPT_Wattributes,
+		 "%<%s%> attribute directive ignored", q);
 
       q = strtok (NULL, ",");
     }
diff --git a/gcc/opts.h b/gcc/opts.h
index 2774e2c8b40..10938615725 100644
--- a/gcc/opts.h
+++ b/gcc/opts.h
@@ -390,7 +390,7 @@ extern void handle_common_deferred_options (void);
 unsigned int parse_sanitizer_options (const char *, location_t, int,
 				      unsigned int, int, bool);
 
-unsigned int parse_no_sanitize_attribute (char *value, char **wrong_argument);
+unsigned int parse_no_sanitize_attribute (char *value);
 extern bool common_handle_option (struct gcc_options *opts,
 				  struct gcc_options *opts_set,
 				  const struct cl_decoded_option *decoded,
diff --git a/gcc/testsuite/c-c++-common/ubsan/attrib-5.c b/gcc/testsuite/c-c++-common/ubsan/attrib-5.c
new file mode 100644
index 00000000000..1dfe50dd0b4
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/ubsan/attrib-5.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=undefined" } */
+
+__attribute__((no_sanitize(("foobar"))))
+static void
+float_cast2 (void)
+{ /* { dg-warning "attribute directive ignored" } */
+  volatile double d = 300;
+  volatile signed char c;
+  c = d;
+}