[Bug middle-end/88397] attribute malloc ignored on function pointers when alloc_size is accepted

["msebor at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88397

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2018-12-07
           Assignee|unassigned at gcc dot gnu.org      |msebor at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Based on quick review of c-attribs.c it looks like attributes noreturn and
nothrow suffer from the same limitation as malloc.  It should be easy to fix. 
I'm testing the patch below.  If it doesn't cause major problems I'll add
tests, update the manual, and post it.

Index: gcc/c-family/c-attribs.c
===================================================================
--- gcc/c-family/c-attribs.c    (revision 266881)
+++ gcc/c-family/c-attribs.c    (working copy)
@@ -257,7 +257,7 @@ const struct attribute_spec c_common_attribute_tab
      would require all the places in the compiler that use TREE_THIS_VOLATILE
      on a decl to identify non-returning functions to be located and fixed
      to check the function type instead.  */
-  { "noreturn",               0, 0, true,  false, false, false,
+  { "noreturn",               0, 0, false, true, true, false,
                              handle_noreturn_attribute,
                              attr_noreturn_exclusions },
   { "volatile",               0, 0, true,  false, false, false,
@@ -330,7 +330,7 @@ const struct attribute_spec c_common_attribute_tab
   { "no_profile_instrument_function",  0, 0, true, false, false, false,
                              handle_no_profile_instrument_function_attribute,
                              NULL },
-  { "malloc",                 0, 0, true,  false, false, false,
+  { "malloc",                 0, 0, false, true, true, false,
                              handle_malloc_attribute, attr_alloc_exclusions },
   { "returns_twice",          0, 0, true,  false, false, false,
                              handle_returns_twice_attribute,
@@ -372,7 +372,7 @@ const struct attribute_spec c_common_attribute_tab
                              handle_nonnull_attribute, NULL },
   { "nonstring",              0, 0, true, false, false, false,
                              handle_nonstring_attribute, NULL },
-  { "nothrow",                0, 0, true,  false, false, false,
+  { "nothrow",                0, 0, false, true, true, false,
                              handle_nothrow_attribute, NULL },
   { "may_alias",             0, 0, false, true, false, false, NULL, NULL },
   { "cleanup",               1, 1, true, false, false, false,