re PR tree-optimization/17506 (warning about uninitialized variable points to wrong location)

gcc:

2006-08-29  Nathan Sidwell  <nathan@codesourcery.com>
	    J"orn Rennecke  <joern.rennecke@st.com>

	PR tree-optimization/17506
	* tree-ssa.c (warn_uninit): If warning about a location outside of
	the current function, note where the variable was declared.

testsuite:

2006-08-29  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>
	    Kazu Hirata  <kazu@codesourcery.com>

	PR tree-optimization/17506
	* gcc.dg/pr17506.c: New.

From-SVN: r116564

gcc/ChangeLog

+2006-08-29  Nathan Sidwell  <nathan@codesourcery.com>
+	    J"orn Rennecke  <joern.rennecke@st.com>
+
+	PR tree-optimization/17506
+	* tree-ssa.c (warn_uninit): If warning about a location outside of
+	the current function, note where the variable was declared.
+
 2006-08-28  Zdenek Dvorak <dvorakz@suse.cz>
 
 	PR tree-optimization/28411

gcc/testsuite/ChangeLog

+2006-08-29  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>
+	    Kazu Hirata  <kazu@codesourcery.com>
+
+	PR tree-optimization/17506
+	* gcc.dg/pr17506.c: New.
+
 2006-08-29  J"orn Rennecke  <joern.rennecke@st.com>
 
 	PR c++/28139

gcc/testsuite/gcc.dg/pr17506.c

+/* PR tree-optimization/17506
+   We issue an uninitialized variable warning at a wrong location at
+   line 11, which is very confusing.  Make sure we print out a note to
+   make it less confusing.  */
+/* { dg-do compile } */
+/* { dg-options "-O1 -Wuninitialized" } */
+
+inline int
+foo (int i)
+{
+  if (i) /* { dg-warning "used uninitialized in this function" } */
+    return 1;
+  return 0;
+}
+
+void baz (void);
+
+void
+bar (void)
+{
+  int j; /* { dg-error "note: 'j' was declared here" } */
+  for (; foo (j); ++j)
+    baz ();
+}

gcc/tree-ssa.c

@@ -1154,7 +1154,7 @@ warn_uninit (tree t, const char *gmsgid, void *data)
   tree var = SSA_NAME_VAR (t);
   tree def = SSA_NAME_DEF_STMT (t);
   tree context = (tree) data;
-  location_t * locus;
+  location_t *locus, *fun_locus;
 
   /* Default uses (indicated by an empty definition statement),
      are uninitialized.  */
@@ -1178,6 +1178,12 @@ warn_uninit (tree t, const char *gmsgid, void *data)
 	   ? EXPR_LOCUS (context)
 	   : &DECL_SOURCE_LOCATION (var));
   warning (0, gmsgid, locus, var);
+  fun_locus = &DECL_SOURCE_LOCATION (cfun->decl);
+  if (locus->file != fun_locus->file
+      || locus->line < fun_locus->line
+      || locus->line > cfun->function_end_locus.line)
+    inform ("%J%qD was declared here", var, var);
+
   TREE_NO_WARNING (var) = 1;
 }