Patchwork C++ PATCH for c++/56481 (time hog with repeated &&)

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Submitter Jason Merrill
Date March 17, 2013, 1:34 a.m.
Message ID <51451DAE.3050801@redhat.com>
Download mbox | patch
Permalink /patch/228257/
State New
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Comments

Jason Merrill - March 17, 2013, 1:34 a.m.
It is also the case that using 'this' in a non-constexpr function should 
prevent the expression from being constant.

Tested x86_64-pc-linux-gnu, applying to trunk.

Patch

commit e0f26a1998f2cb404e58bcf8a9f22e29401312e0
Author: Jason Merrill <jason@redhat.com>
Date:   Thu Feb 28 11:58:44 2013 -0500

    	PR c++/56481
    	* semantics.c (potential_constant_expression_1): Use of 'this' in
    	a non-constexpr function makes the expression not potentially
    	constant.

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 1cf060e..9d2f3f4 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -8497,6 +8497,13 @@  potential_constant_expression_1 (tree t, bool want_rval, tsubst_flags_t flags)
         STRIP_NOPS (x);
         if (is_this_parameter (x))
 	  {
+	    if (DECL_CONTEXT (x)
+		&& !DECL_DECLARED_CONSTEXPR_P (DECL_CONTEXT (x)))
+	      {
+		if (flags & tf_error)
+		  error ("use of %<this%> in a constant expression");
+		return false;
+	      }
 	    if (want_rval && DECL_CONTEXT (x)
 		&& DECL_CONSTRUCTOR_P (DECL_CONTEXT (x)))
 	      {