Fix va_start related location

In gcc/testsuite/gcc.dg/pr30457.c, the first warning was not being
emitted because the relevant location was inside the var_start macro
defined in a system header.  It can even point to a token for a
builtin macro there.  This patch unwinds to the first token in real
source code in that case.

Tested on x86_64-unknown-linux-gnu against trunk.

	* builtins.c (fold_builtin_next_arg): Unwinds to the first
	location in real source code.

From-SVN: r186975

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5544d667392e5fdcbf41273e680cebf415554c2a..c47ba21dde5882a12a805c19e96d12c9c3e80161 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2012-04-30  Dodji Seketeli  <dodji@redhat.com>
 
+       Fix va_start related location
+       * builtins.c (fold_builtin_next_arg): Unwinds to the first
+       location in real source code.
+
        Make conversion warnings work on NULL with -ftrack-macro-expansion
        * input.h (expansion_point_location_if_in_system_header): Declare
        new function.

diff --git a/gcc/builtins.c b/gcc/builtins.c
index b47f2180527aebc69240270bd7b6bef22fd947f8..5ddc47bd7ea651a7481a11888fc1553056aebaa9 100644 (file)
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -12095,6 +12095,13 @@ fold_builtin_next_arg (tree exp, bool va_start_p)
   tree fntype = TREE_TYPE (current_function_decl);
   int nargs = call_expr_nargs (exp);
   tree arg;
+  /* There is good chance the current input_location points inside the
+     definition of the va_start macro (perhaps on the token for
+     builtin) in a system header, so warnings will not be emitted.
+     Use the location in real source code.  */
+  source_location current_location =
+    linemap_unwind_to_first_non_reserved_loc (line_table, input_location,
+                                             NULL);
 
   if (!stdarg_p (fntype))
     {
@@ -12119,7 +12126,9 @@ fold_builtin_next_arg (tree exp, bool va_start_p)
        {
          /* Evidently an out of date version of <stdarg.h>; can't validate
             va_start's second argument, but can still work as intended.  */
-         warning (0, "%<__builtin_next_arg%> called without an argument");
+         warning_at (current_location,
+                     0,
+                     "%<__builtin_next_arg%> called without an argument");
          return true;
        }
       else if (nargs > 1)
@@ -12154,7 +12163,9 @@ fold_builtin_next_arg (tree exp, bool va_start_p)
             argument.  We just warn and set the arg to be the last
             argument so that we will get wrong-code because of
             it.  */
-         warning (0, "second parameter of %<va_start%> not last named argument");
+         warning_at (current_location,
+                     0,
+                     "second parameter of %<va_start%> not last named argument");
        }
 
       /* Undefined by C99 7.15.1.4p4 (va_start):
@@ -12164,8 +12175,12 @@ fold_builtin_next_arg (tree exp, bool va_start_p)
          the default argument promotions, the behavior is undefined."
       */
       else if (DECL_REGISTER (arg))
-        warning (0, "undefined behaviour when second parameter of "
-                 "%<va_start%> is declared with %<register%> storage");
+       {
+         warning_at (current_location,
+                     0,
+                     "undefined behaviour when second parameter of "
+                     "%<va_start%> is declared with %<register%> storage");
+       }
 
       /* We want to verify the second parameter just once before the tree
         optimizers are run and then avoid keeping it in the tree,