[PATCH] Handle no_sanitize attribute values in the right way (PR sanitizer/85556).

[Martin Liška <mliska at suse dot cz>]

Hi.

Parsing of no_sanitize attribute now supports
__attribute__((no_sanitize("address,undefined")))
which is wrong. And on the other hand this is not recognized:
__attribute__((no_sanitize("address", "undefined")))

Patch can bootstrap on x86_64-linux-gnu and survives regression tests. Then I would like
to backport that to GCC 8 branch.

Ready to be installed?
Martin

gcc/ChangeLog:

2018-05-10  Martin Liska  <mliska@suse.cz>

        PR sanitizer/85556
	* opts.c (parse_no_sanitize_attribute): Handle only a sinle
	option value.

gcc/c-family/ChangeLog:

2018-05-10  Martin Liska  <mliska@suse.cz>

        PR sanitizer/85556
	* c-attribs.c (handle_no_sanitize_attribute): Iterate all
	TREE_LIST values.

gcc/testsuite/ChangeLog:

2018-05-10  Martin Liska  <mliska@suse.cz>

        PR sanitizer/85556
	* c-c++-common/ubsan/attrib-6.c: New test.
---
 gcc/c-family/c-attribs.c                    | 20 +++++++++++--------
 gcc/opts.c                                  | 30 +++++++++++------------------
 gcc/testsuite/c-c++-common/ubsan/attrib-6.c | 22 +++++++++++++++++++++
 3 files changed, 45 insertions(+), 27 deletions(-)
 create mode 100644 gcc/testsuite/c-c++-common/ubsan/attrib-6.c


diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index e0630885cca..744315eec86 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -403,7 +403,7 @@ const struct attribute_spec c_common_attribute_table[] =
 			      0, 0, true, false, false, false,
 			      handle_no_address_safety_analysis_attribute,
 			      NULL },
-  { "no_sanitize",	      1, 1, true, false, false, false,
+  { "no_sanitize",	      1, -1, true, false, false, false,
 			      handle_no_sanitize_attribute, NULL },
   { "no_sanitize_address",    0, 0, true, false, false, false,
 			      handle_no_sanitize_address_attribute, NULL },
@@ -683,22 +683,26 @@ static tree
 handle_no_sanitize_attribute (tree *node, tree name, tree args, int,
 			      bool *no_add_attrs)
 {
+  unsigned int flags = 0;
   *no_add_attrs = true;
-  tree id = TREE_VALUE (args);
   if (TREE_CODE (*node) != FUNCTION_DECL)
     {
       warning (OPT_Wattributes, "%qE attribute ignored", name);
       return NULL_TREE;
     }
 
-  if (TREE_CODE (id) != STRING_CST)
+  for (; args; args = TREE_CHAIN (args))
     {
-      error ("no_sanitize argument not a string");
-      return NULL_TREE;
-    }
+      tree id = TREE_VALUE (args);
+      if (TREE_CODE (id) != STRING_CST)
+	{
+	  error ("no_sanitize argument not a string");
+	  return NULL_TREE;
+	}
 
-  char *string = ASTRDUP (TREE_STRING_POINTER (id));
-  unsigned int flags = parse_no_sanitize_attribute (string);
+      char *string = ASTRDUP (TREE_STRING_POINTER (id));
+      flags |= parse_no_sanitize_attribute (string);
+    }
 
   add_no_sanitize_value (*node, flags);
 
diff --git a/gcc/opts.c b/gcc/opts.c
index 33efcc0d6e7..f999dccd009 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -1748,33 +1748,25 @@ parse_sanitizer_options (const char *p, location_t loc, int scode,
   return flags;
 }
 
-/* Parse string values of no_sanitize attribute passed in VALUE.
-   Values are separated with comma.  */
+/* Parse string value of no_sanitize attribute passed in VALUE.  */
 
 unsigned int
 parse_no_sanitize_attribute (char *value)
 {
   unsigned int flags = 0;
   unsigned int i;
-  char *q = strtok (value, ",");
 
-  while (q != NULL)
-    {
-      for (i = 0; sanitizer_opts[i].name != NULL; ++i)
-	if (strcmp (sanitizer_opts[i].name, q) == 0)
-	  {
-	    flags |= sanitizer_opts[i].flag;
-	    if (sanitizer_opts[i].flag == SANITIZE_UNDEFINED)
-	      flags |= SANITIZE_UNDEFINED_NONDEFAULT;
-	    break;
-	  }
-
-      if (sanitizer_opts[i].name == NULL)
-	warning (OPT_Wattributes,
-		 "%<%s%> attribute directive ignored", q);
+  for (i = 0; sanitizer_opts[i].name != NULL; ++i)
+    if (strcmp (sanitizer_opts[i].name, value) == 0)
+      {
+	flags |= sanitizer_opts[i].flag;
+	if (sanitizer_opts[i].flag == SANITIZE_UNDEFINED)
+	  flags |= SANITIZE_UNDEFINED_NONDEFAULT;
+	break;
+      }
 
-      q = strtok (NULL, ",");
-    }
+  if (sanitizer_opts[i].name == NULL)
+    warning (OPT_Wattributes, "%<%s%> attribute directive ignored", value);
 
   return flags;
 }
diff --git a/gcc/testsuite/c-c++-common/ubsan/attrib-6.c b/gcc/testsuite/c-c++-common/ubsan/attrib-6.c
new file mode 100644
index 00000000000..ac08dc219ec
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/ubsan/attrib-6.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=undefined" } */
+
+static void __attribute__((no_sanitize("foobar")))
+foo (void) { /* { dg-warning "attribute directive ignored" } */
+}
+
+static void __attribute__((no_sanitize("address,undefined")))
+foo2 (void) { /* { dg-warning ".address,undefined. attribute directive ignored" } */
+}
+
+static void __attribute__((no_sanitize("address", "undefined")))
+foo3 (void) {
+}
+
+static void __attribute__((no_sanitize("address", "address", "")))
+foo4 (void) { /* { dg-warning ".. attribute directive ignored" } */
+}
+
+static void __attribute__((no_sanitize("address", "address", "address,address")))
+foo5 (void) { /* { dg-warning ".address,address. attribute directive ignored" } */
+}