Patchwork C++ PATCH for c++/55520 (ICE with lambda capture of VLA)

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Submitter Jason Merrill
Date June 7, 2013, 3:12 a.m.
Message ID <51B14FA4.8030401@redhat.com>
Download mbox | patch
Permalink /patch/249588/
State New
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Comments

Jason Merrill - June 7, 2013, 3:12 a.m.
I recently implemented capture of C++14 VLAs, but the VLA in this 
testcase is not valid C++14, so capturing it isn't supported.  But we 
still shouldn't ICE.

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

Patch

commit c0ecc17471e7859ba36f3f8d095e5666e525f84f
Author: Jason Merrill <jason@redhat.com>
Date:   Thu Jun 6 22:41:32 2013 -0400

    	PR c++/55520
    	* semantics.c (add_capture): Diagnose capture of variable-size
    	type that is not a C++1y array of runtime bound.

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 048a7db..b5c3b0a 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -9487,6 +9487,15 @@  add_capture (tree lambda, tree id, tree initializer, bool by_reference_p,
 					  nelts_field, array_type_nelts (type));
       type = ctype;
     }
+  else if (variably_modified_type_p (type, NULL_TREE))
+    {
+      error ("capture of variable-size type %qT that is not a C++1y array "
+	     "of runtime bound", type);
+      if (TREE_CODE (type) == ARRAY_TYPE
+	  && variably_modified_type_p (TREE_TYPE (type), NULL_TREE))
+	inform (input_location, "because the array element type %qT has "
+		"variable size", TREE_TYPE (type));
+    }
   else if (by_reference_p)
     {
       type = build_reference_type (type);
diff --git a/gcc/testsuite/g++.dg/cpp1y/vla7.C b/gcc/testsuite/g++.dg/cpp1y/vla7.C
new file mode 100644
index 0000000..df34c82
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/vla7.C
@@ -0,0 +1,12 @@ 
+// PR c++/55520
+// { dg-options "-Wno-vla" }
+// { dg-require-effective-target c++11 }
+
+int main(int argc, char** argv)
+{
+  int x[1][argc];
+
+  [&x](int i) {			// { dg-error "variable.size" }
+    x[0][i] = 0;	     	// { dg-prune-output "assignment" }
+  }(5);
+}