[gcc r12-3315] Improve -Wuninitialized note location.

[gcc r12-3315] Improve -Wuninitialized note location.

[Martin Sebor]

https://gcc.gnu.org/g:9695e1c23be5b5c55d572ced152897313ddb96ae

commit r12-3315-g9695e1c23be5b5c55d572ced152897313ddb96ae
Author: Martin Sebor <msebor@redhat.com>
Date:   Thu Sep 2 09:20:09 2021 -0600

    Improve -Wuninitialized note location.
    
    Related:
    PR tree-optimization/17506 - warning about uninitialized variable points to wrong location
    PR testsuite/37182 - Revision 139286 caused gcc.dg/pr17506.c and gcc.dg/uninit-15.c
    
    gcc/ChangeLog:
    
            PR tree-optimization/17506
            PR testsuite/37182
            * tree-ssa-uninit.c (warn_uninit): Remove conditional guarding note.
    
    gcc/testsuite/ChangeLog:
    
            PR tree-optimization/17506
            PR testsuite/37182
            * gcc.dg/diagnostic-tree-expr-ranges-2.c: Add expected output.
            * gcc.dg/uninit-15-O0.c: Remove xfail.
            * gcc.dg/uninit-15.c: Same.

Diff:
---
 .../gcc.dg/diagnostic-tree-expr-ranges-2.c         | 26 +++++++++++++---------
 gcc/testsuite/gcc.dg/uninit-15-O0.c                |  2 +-
 gcc/testsuite/gcc.dg/uninit-15.c                   |  2 +-
 gcc/tree-ssa-uninit.c                              |  9 +-------
 4 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/diagnostic-tree-expr-ranges-2.c b/gcc/testsuite/gcc.dg/diagnostic-tree-expr-ranges-2.c
index 302e233a04a..1cbcad5ac7d 100644
--- a/gcc/testsuite/gcc.dg/diagnostic-tree-expr-ranges-2.c
+++ b/gcc/testsuite/gcc.dg/diagnostic-tree-expr-ranges-2.c
@@ -3,21 +3,25 @@
 
 int test_uninit_1 (void)
 {
-  int result;
-  return result;  /* { dg-warning "uninitialized" } */
-/* { dg-begin-multiline-output "" }
-   return result;
-          ^~~~~~
+  int result_1;     /* { dg-message "declared here" } */
+  return result_1;  /* { dg-warning "uninitialized" } */
+  /* { dg-begin-multiline-output "" }
+   return result_1;
+          ^~~~~~~~
+   int result_1;
+       ^~~~~~~~
    { dg-end-multiline-output "" } */
 }
 
 int test_uninit_2 (void)
 {
-  int result;
-  result += 3; /* { dg-warning "uninitialized" } */
-/* { dg-begin-multiline-output "" }
-   result += 3;
-   ~~~~~~~^~~~
+  int result_2;     /* { dg-message "declared here" } */
+  result_2 += 3;    /* { dg-warning "uninitialized" } */
+  /* { dg-begin-multiline-output "" }
+   result_2 += 3;
+   ~~~~~~~~~^~~~
+   int result_2;
+       ^~~~~~~~
    { dg-end-multiline-output "" } */
-  return result;
+  return result_2;
 }
diff --git a/gcc/testsuite/gcc.dg/uninit-15-O0.c b/gcc/testsuite/gcc.dg/uninit-15-O0.c
index 36d96348617..1ddddee1388 100644
--- a/gcc/testsuite/gcc.dg/uninit-15-O0.c
+++ b/gcc/testsuite/gcc.dg/uninit-15-O0.c
@@ -14,7 +14,7 @@ void baz();
 
 void bar()
 {
-    int j;           /* { dg-message "was declared here" {} { xfail *-*-* } } */
+    int j;              /* { dg-message "declared here" } */
     for (; foo(j); ++j) /* { dg-warning "is used uninitialized" } */
         baz();
 }
diff --git a/gcc/testsuite/gcc.dg/uninit-15.c b/gcc/testsuite/gcc.dg/uninit-15.c
index 85cb116f349..7352662f627 100644
--- a/gcc/testsuite/gcc.dg/uninit-15.c
+++ b/gcc/testsuite/gcc.dg/uninit-15.c
@@ -20,7 +20,7 @@ void baz (void);
 void
 bar (void)
 {
-  int j; /* { dg-message "note: 'j' was declared here" "" { xfail *-*-* } } */
+  int j;                /* { dg-message "note: 'j' was declared here" } */
   for (; foo (j); ++j)  /* { dg-warning "'j' is used uninitialized" } */
     baz ();
 }
diff --git a/gcc/tree-ssa-uninit.c b/gcc/tree-ssa-uninit.c
index 394dbf40c9c..cb6d1145202 100644
--- a/gcc/tree-ssa-uninit.c
+++ b/gcc/tree-ssa-uninit.c
@@ -206,14 +206,7 @@ warn_uninit (opt_code opt, tree t, tree var, const char *gmsgid,
   if (location == var_loc)
     return;
 
-  location_t cfun_loc = DECL_SOURCE_LOCATION (cfun->decl);
-  expanded_location xloc = expand_location (location);
-  expanded_location floc = expand_location (cfun_loc);
-  if (xloc.file != floc.file
-      || linemap_location_before_p (line_table, location, cfun_loc)
-      || linemap_location_before_p (line_table, cfun->function_end_locus,
-					location))
-    inform (var_loc, "%qD was declared here", var);
+  inform (var_loc, "%qD was declared here", var);
 }
 
 struct check_defs_data