[PATCH] Fix PR56694

[Richard Biener]

This fixes PR56694 - the code keeping BLOCKs live is not looking
at the EH tree for references.  In the must-not-throw failure_loc
such references can now appear.

Fixed by reverting that to 4.7 behavior.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk
and 4.8 branch.

Richard.

2013-03-25  Richard Biener  <rguent...@suse.de>

        PR middle-end/56694
        * tree-eh.c (lower_eh_must_not_throw): Strip BLOCKs from the
        must-not-throw stmt location.

        * g++.dg/torture/pr56694.C: New testcase.

Index: gcc/tree-eh.c
===================================================================
*** gcc/tree-eh.c       (revision 197029)
--- gcc/tree-eh.c       (working copy)
*************** lower_eh_must_not_throw (struct leh_stat
*** 1855,1861 ****
        this_region = gen_eh_region_must_not_throw (state->cur_region);
        this_region->u.must_not_throw.failure_decl
        = gimple_eh_must_not_throw_fndecl (inner);
!       this_region->u.must_not_throw.failure_loc = gimple_location (tp);
  
        /* In order to get mangling applied to this decl, we must mark it
         used now.  Otherwise, pass_ipa_free_lang_data won't think it
--- 1855,1862 ----
        this_region = gen_eh_region_must_not_throw (state->cur_region);
        this_region->u.must_not_throw.failure_decl
        = gimple_eh_must_not_throw_fndecl (inner);
!       this_region->u.must_not_throw.failure_loc
!       = LOCATION_LOCUS (gimple_location (tp));
  
        /* In order to get mangling applied to this decl, we must mark it
         used now.  Otherwise, pass_ipa_free_lang_data won't think it
Index: gcc/testsuite/g++.dg/torture/pr56694.C
===================================================================
*** gcc/testsuite/g++.dg/torture/pr56694.C      (revision 0)
--- gcc/testsuite/g++.dg/torture/pr56694.C      (working copy)
***************
*** 0 ****
--- 1,30 ----
+ // { dg-do compile }
+ // { dg-options "-fopenmp" }
+ 
+ class GException {
+ public:
+     class vector_mismatch {
+     public:
+       vector_mismatch(int size1, int size2);
+     };
+ };
+ class GVector{
+ public:
+     GVector& operator+=(const GVector& v);
+     int m_num;
+     double* m_data;
+ };
+ inline GVector& GVector::operator+= (const GVector& v)
+ {
+   if (m_num != v.m_num)
+     throw GException::vector_mismatch(m_num, v.m_num);
+   for (int i = 0; i < m_num; ++i)  m_data[i] += v.m_data[i];
+ };
+ void eval(GVector* m_gradient, GVector* vect_cpy_grad, int n)
+ {
+ #pragma omp sections
+     {
+       for (int i = 0; i < n; ++i)
+       *m_gradient += vect_cpy_grad[i];
+     }
+ }