From: Jakub Jelinek <jakub@redhat.com>
Date: Mon, 25 Jun 2018 17:01:10 +0000 (+0200)
Subject: backport: re PR c++/79650 (ICE on invalid c++ code with label arithmetic in convert_n... 
X-Git-Tag: releases/gcc-6.5.0~238
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c3598e1dc10f7b224e4154833d62c7427831dd1a;p=thirdparty%2Fgcc.git

backport: re PR c++/79650 (ICE on invalid c++ code with label arithmetic in convert_nontype_argument (pt.c:6515))

	Backported from mainline
	2017-12-14  Jakub Jelinek  <jakub@redhat.com>

	PR c++/79650
	* pt.c (convert_nontype_argument): Diagnose
	reduced_constant_expression_p expressions that aren't INTEGER_CST.

	* g++.dg/template/pr79650.C: New test.

From-SVN: r262045
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 045e5e127a44..4113b0a394d5 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,6 +1,12 @@
 2018-06-25  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2017-12-14  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/79650
+	* pt.c (convert_nontype_argument): Diagnose
+	reduced_constant_expression_p expressions that aren't INTEGER_CST.
+
 	2017-12-06  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/80259
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 9dbf17ba4d88..3f57c6afc689 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -6411,7 +6411,20 @@ convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
 		return NULL_TREE;
 	      /* else cxx_constant_value complained but gave us
 		 a real constant, so go ahead.  */
-	      gcc_assert (TREE_CODE (expr) == INTEGER_CST);
+	      if (TREE_CODE (expr) != INTEGER_CST)
+		{
+		  /* Some assemble time constant expressions like
+		     (intptr_t)&&lab1 - (intptr_t)&&lab2 or
+		     4 + (intptr_t)&&var satisfy reduced_constant_expression_p
+		     as we can emit them into .rodata initializers of
+		     variables, yet they can't fold into an INTEGER_CST at
+		     compile time.  Refuse them here.  */
+		  gcc_checking_assert (reduced_constant_expression_p (expr));
+		  location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
+		  error_at (loc, "template argument %qE for type %qT not "
+				 "a constant integer", expr, type);
+		  return NULL_TREE;
+		}
 	    }
 	  else
 	    return NULL_TREE;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b9b51dce3921..ca38ff3f0af9 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,6 +1,11 @@
 2018-06-25  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2017-12-14  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/79650
+	* g++.dg/template/pr79650.C: New test.
+
 	2017-12-08  Joseph Myers  <joseph@codesourcery.com>
 		    Alexander Monakov  <amonakov@ispras.ru>
 		    Jakub Jelinek  <jakub@redhat.com>
diff --git a/gcc/testsuite/g++.dg/template/pr79650.C b/gcc/testsuite/g++.dg/template/pr79650.C
new file mode 100644
index 000000000000..72c781409426
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/pr79650.C
@@ -0,0 +1,20 @@
+// PR c++/79650
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+typedef __INTPTR_TYPE__ intptr_t;
+template<intptr_t> struct A {};
+
+void
+foo ()
+{
+  static int a, b;
+lab1:
+lab2:
+  A<(intptr_t)&&lab1 - (__INTPTR_TYPE__)&&lab2> c;	// { dg-error "not a constant integer" }
+  A<(intptr_t)&&lab1 - (__INTPTR_TYPE__)&&lab1> d;
+  A<(intptr_t)&a - (intptr_t)&b> e;			// { dg-error "is not a constant expression" }
+  A<(intptr_t)&a - (intptr_t)&a> f;
+  A<(intptr_t)sizeof(a) + (intptr_t)&a> g;		// { dg-error "not a constant integer" }
+  A<(intptr_t)&a> h;					// { dg-error "conversion from pointer type" }
+}