re PR c/65345 (ICE with _Generic selection on _Atomic int)

	PR c/65345
	* c-decl.c (set_labels_context_r): New function.
	(store_parm_decls): Call it via walk_tree_without_duplicates.
	* c-typeck.c (convert_lvalue_to_rvalue): Use create_tmp_var_raw
	instead of create_tmp_var.  Build TARGET_EXPR instead of
	COMPOUND_EXPR.
	(build_atomic_assign): Use create_tmp_var_raw instead of
	create_tmp_var.  Build TARGET_EXPRs instead of MODIFY_EXPR.

	* gcc.dg/pr65345-1.c: New test.
	* gcc.dg/pr65345-2.c: New test.

From-SVN: r222370

3 files changed, 57 insertions, 11 deletions

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index e5c19e0..c613e9d 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,14 @@
+2015-04-23  Marek Polacek  <polacek@redhat.com>
+
+	PR c/65345
+	* c-decl.c (set_labels_context_r): New function.
+	(store_parm_decls): Call it via walk_tree_without_duplicates.
+	* c-typeck.c (convert_lvalue_to_rvalue): Use create_tmp_var_raw
+	instead of create_tmp_var.  Build TARGET_EXPR instead of
+	COMPOUND_EXPR.
+	(build_atomic_assign): Use create_tmp_var_raw instead of
+	create_tmp_var.  Build TARGET_EXPRs instead of MODIFY_EXPR.
+
 2015-04-20  Ilya Verbin  <ilya.verbin@intel.com>
 
 	* c-parser.c (c_parser_oacc_enter_exit_data): Remove excess semicolon.
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index e28a294..27ecd8b 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -8796,6 +8796,21 @@ store_parm_decls_from (struct c_arg_info *arg_info)
   store_parm_decls ();
 }
 
+/* Called by walk_tree to look for and update context-less labels.  */
+
+static tree
+set_labels_context_r (tree *tp, int *walk_subtrees, void *data)
+{
+  if (TREE_CODE (*tp) == LABEL_EXPR
+      && DECL_CONTEXT (LABEL_EXPR_LABEL (*tp)) == NULL_TREE)
+    {
+      DECL_CONTEXT (LABEL_EXPR_LABEL (*tp)) = static_cast<tree>(data);
+      *walk_subtrees = 0;
+    }
+
+  return NULL_TREE;
+}
+
 /* Store the parameter declarations into the current function declaration.
    This is called after parsing the parameter declarations, before
    digesting the body of the function.
@@ -8850,7 +8865,21 @@ store_parm_decls (void)
      thus won't naturally see the SAVE_EXPR containing the increment.  All
      other pending sizes would be handled by gimplify_parameters.  */
   if (arg_info->pending_sizes)
-    add_stmt (arg_info->pending_sizes);
+    {
+      /* In very special circumstances, e.g. for code like
+	   _Atomic int i = 5;
+	   void f (int a[i += 2]) {}
+	 we need to execute the atomic assignment on function entry.
+	 But in this case, it is not just a straight store, it has the
+	 op= form, which means that build_atomic_assign has generated
+	 gotos, labels, etc.  Because at that time the function decl
+	 for F has not been created yet, those labels do not have any
+	 function context.  But we have the fndecl now, so update the
+	 labels accordingly.  gimplify_expr would crash otherwise.  */
+      walk_tree_without_duplicates (&arg_info->pending_sizes,
+				    set_labels_context_r, fndecl);
+      add_stmt (arg_info->pending_sizes);
+    }
 }
 
 /* Store PARM_DECLs in PARMS into scope temporarily.  Used for
diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
index ebe4c73..91735b5 100644
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -2039,7 +2039,7 @@ convert_lvalue_to_rvalue (location_t loc, struct c_expr exp,
       /* Remove the qualifiers for the rest of the expressions and
 	 create the VAL temp variable to hold the RHS.  */
       nonatomic_type = build_qualified_type (expr_type, TYPE_UNQUALIFIED);
-      tmp = create_tmp_var (nonatomic_type);
+      tmp = create_tmp_var_raw (nonatomic_type);
       tmp_addr = build_unary_op (loc, ADDR_EXPR, tmp, 0);
       TREE_ADDRESSABLE (tmp) = 1;
       TREE_NO_WARNING (tmp) = 1;
@@ -2055,7 +2055,8 @@ convert_lvalue_to_rvalue (location_t loc, struct c_expr exp,
       mark_exp_read (exp.value);
 
       /* Return tmp which contains the value loaded.  */
-      exp.value = build2 (COMPOUND_EXPR, nonatomic_type, func_call, tmp);
+      exp.value = build4 (TARGET_EXPR, nonatomic_type, tmp, func_call,
+			  NULL_TREE, NULL_TREE);
     }
   return exp;
 }
@@ -3686,10 +3687,11 @@ build_atomic_assign (location_t loc, tree lhs, enum tree_code modifycode,
      the VAL temp variable to hold the RHS.  */
   nonatomic_lhs_type = build_qualified_type (lhs_type, TYPE_UNQUALIFIED);
   nonatomic_rhs_type = build_qualified_type (rhs_type, TYPE_UNQUALIFIED);
-  val = create_tmp_var (nonatomic_rhs_type);
+  val = create_tmp_var_raw (nonatomic_rhs_type);
   TREE_ADDRESSABLE (val) = 1;
   TREE_NO_WARNING (val) = 1;
-  rhs = build2 (MODIFY_EXPR, nonatomic_rhs_type, val, rhs);
+  rhs = build4 (TARGET_EXPR, nonatomic_rhs_type, val, rhs, NULL_TREE,
+		NULL_TREE);
   SET_EXPR_LOCATION (rhs, loc);
   add_stmt (rhs);
 
@@ -3715,12 +3717,12 @@ build_atomic_assign (location_t loc, tree lhs, enum tree_code modifycode,
     }
 
   /* Create the variables and labels required for the op= form.  */
-  old = create_tmp_var (nonatomic_lhs_type);
+  old = create_tmp_var_raw (nonatomic_lhs_type);
   old_addr = build_unary_op (loc, ADDR_EXPR, old, 0);
   TREE_ADDRESSABLE (old) = 1;
   TREE_NO_WARNING (old) = 1;
 
-  newval = create_tmp_var (nonatomic_lhs_type);
+  newval = create_tmp_var_raw (nonatomic_lhs_type);
   newval_addr = build_unary_op (loc, ADDR_EXPR, newval, 0);
   TREE_ADDRESSABLE (newval) = 1;
 
@@ -3736,7 +3738,9 @@ build_atomic_assign (location_t loc, tree lhs, enum tree_code modifycode,
   params->quick_push (old_addr);
   params->quick_push (seq_cst);
   func_call = c_build_function_call_vec (loc, vNULL, fndecl, params, NULL);
-  add_stmt (func_call);
+  old = build4 (TARGET_EXPR, nonatomic_lhs_type, old, func_call, NULL_TREE,
+		NULL_TREE);
+  add_stmt (old);
   params->truncate (0);
 
   /* Create the expressions for floating-point environment
@@ -3755,12 +3759,14 @@ build_atomic_assign (location_t loc, tree lhs, enum tree_code modifycode,
 
   /* newval = old + val;  */
   rhs = build_binary_op (loc, modifycode, old, val, 1);
+  rhs = c_fully_fold (rhs, false, NULL);
   rhs = convert_for_assignment (loc, UNKNOWN_LOCATION, nonatomic_lhs_type,
 				rhs, NULL_TREE, ic_assign, false, NULL_TREE,
 				NULL_TREE, 0);
   if (rhs != error_mark_node)
     {
-      rhs = build2 (MODIFY_EXPR, nonatomic_lhs_type, newval, rhs);
+      rhs = build4 (TARGET_EXPR, nonatomic_lhs_type, newval, rhs, NULL_TREE,
+		    NULL_TREE);
       SET_EXPR_LOCATION (rhs, loc);
       add_stmt (rhs);
     }
@@ -3782,7 +3788,7 @@ build_atomic_assign (location_t loc, tree lhs, enum tree_code modifycode,
   stmt = build3 (COND_EXPR, void_type_node, func_call, goto_stmt, NULL_TREE);
   SET_EXPR_LOCATION (stmt, loc);
   add_stmt (stmt);
-  
+
   if (clear_call)
     add_stmt (clear_call);
 
@@ -3790,7 +3796,7 @@ build_atomic_assign (location_t loc, tree lhs, enum tree_code modifycode,
   goto_stmt  = build1 (GOTO_EXPR, void_type_node, loop_decl);
   SET_EXPR_LOCATION (goto_stmt, loc);
   add_stmt (goto_stmt);
- 
+
   /* done:  */
   add_stmt (done_label);