re PR c/41182 (Revision 145254 caused ICE: tree check: expected integer_cst, have nop_expr in tree_int_cst_lt, at tree.c:5259)

	PR c/41182
	* c-common.c (c_fully_fold_internal): Strip nops from the result
	of recursive calls to c_fully_fold_internal.
	(c_wrap_maybe_const): New.
	(c_save_expr): Use c_wrap_maybe_const.
	* c-common.h (c_wrap_maybe_const): Declare.
	* c-typeck.c (build_conditional_expr, c_finish_stmt_expr,
	build_binary_op): Use c_wrap_maybe_const.

testsuite:
	* gcc.c-torture/compile/pr41182-1.c: New.

From-SVN: r152548

1 files changed, 37 insertions, 4 deletions

diff --git a/gcc/c-common.c b/gcc/c-common.c
index bf57cb8..fb2a84e 100644
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -1219,6 +1219,7 @@ c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
       op2 = TREE_OPERAND (expr, 2);
       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
 				   maybe_const_itself);
+      STRIP_TYPE_NOPS (op0);
       if (op0 != orig_op0)
 	ret = build3 (COMPONENT_REF, TREE_TYPE (expr), op0, op1, op2);
       if (ret != expr)
@@ -1235,8 +1236,10 @@ c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
       op3 = TREE_OPERAND (expr, 3);
       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
 				   maybe_const_itself);
+      STRIP_TYPE_NOPS (op0);
       op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
 				   maybe_const_itself);
+      STRIP_TYPE_NOPS (op1);
       op1 = decl_constant_value_for_optimization (op1);
       if (op0 != orig_op0 || op1 != orig_op1)
 	ret = build4 (ARRAY_REF, TREE_TYPE (expr), op0, op1, op2, op3);
@@ -1293,6 +1296,7 @@ c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
       orig_op1 = op1 = TREE_OPERAND (expr, 1);
       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
 				   maybe_const_itself);
+      STRIP_TYPE_NOPS (op0);
       if (code != MODIFY_EXPR
 	  && code != PREDECREMENT_EXPR
 	  && code != PREINCREMENT_EXPR
@@ -1304,6 +1308,7 @@ c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
       if (code != MODIFY_EXPR)
 	op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
 				     maybe_const_itself);
+      STRIP_TYPE_NOPS (op1);
       op1 = decl_constant_value_for_optimization (op1);
       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
 	ret = in_init
@@ -1333,6 +1338,7 @@ c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
       orig_op0 = op0 = TREE_OPERAND (expr, 0);
       op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
 				   maybe_const_itself);
+      STRIP_TYPE_NOPS (op0);
       if (code != ADDR_EXPR && code != REALPART_EXPR && code != IMAGPART_EXPR)
 	op0 = decl_constant_value_for_optimization (op0);
       if (op0 != orig_op0 || in_init)
@@ -1372,12 +1378,14 @@ c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
       orig_op0 = op0 = TREE_OPERAND (expr, 0);
       orig_op1 = op1 = TREE_OPERAND (expr, 1);
       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
+      STRIP_TYPE_NOPS (op0);
 
       unused_p = (op0 == (code == TRUTH_ANDIF_EXPR
 			  ? truthvalue_false_node
 			  : truthvalue_true_node));
       c_inhibit_evaluation_warnings += unused_p;
       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
+      STRIP_TYPE_NOPS (op1);
       c_inhibit_evaluation_warnings -= unused_p;
 
       if (op0 != orig_op0 || op1 != orig_op1 || in_init)
@@ -1409,12 +1417,15 @@ c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
       orig_op2 = op2 = TREE_OPERAND (expr, 2);
       op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self);
 
+      STRIP_TYPE_NOPS (op0);
       c_inhibit_evaluation_warnings += (op0 == truthvalue_false_node);
       op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self);
+      STRIP_TYPE_NOPS (op1);
       c_inhibit_evaluation_warnings -= (op0 == truthvalue_false_node);
 
       c_inhibit_evaluation_warnings += (op0 == truthvalue_true_node);
       op2 = c_fully_fold_internal (op2, in_init, &op2_const, &op2_const_self);
+      STRIP_TYPE_NOPS (op2);
       c_inhibit_evaluation_warnings -= (op0 == truthvalue_true_node);
 
       if (op0 != orig_op0 || op1 != orig_op1 || op2 != orig_op2)
@@ -3790,6 +3801,31 @@ pointer_int_sum (location_t loc, enum tree_code resultcode,
   return ret;
 }
 
+/* Wrap a C_MAYBE_CONST_EXPR around an expression that is fully folded
+   and if NON_CONST is known not to be permitted in an evaluated part
+   of a constant expression.  */
+
+tree
+c_wrap_maybe_const (tree expr, bool non_const)
+{
+  bool nowarning = TREE_NO_WARNING (expr);
+  location_t loc = EXPR_LOCATION (expr);
+
+  /* This should never be called for C++.  */
+  if (c_dialect_cxx ())
+    gcc_unreachable ();
+
+  /* The result of folding may have a NOP_EXPR to set TREE_NO_WARNING.  */
+  STRIP_TYPE_NOPS (expr);
+  expr = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (expr), NULL, expr);
+  C_MAYBE_CONST_EXPR_NON_CONST (expr) = non_const;
+  if (nowarning)
+    TREE_NO_WARNING (expr) = 1;
+  protected_set_expr_location (expr, loc);
+
+  return expr;
+}
+
 /* Wrap a SAVE_EXPR around EXPR, if appropriate.  Like save_expr, but
    for C folds the inside expression and wraps a C_MAYBE_CONST_EXPR
    around the SAVE_EXPR if needed so that c_fully_fold does not need
@@ -3804,10 +3840,7 @@ c_save_expr (tree expr)
   expr = c_fully_fold (expr, false, &maybe_const);
   expr = save_expr (expr);
   if (!maybe_const)
-    {
-      expr = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (expr), NULL, expr);
-      C_MAYBE_CONST_EXPR_NON_CONST (expr) = 1;
-    }
+    expr = c_wrap_maybe_const (expr, true);
   return expr;
 }