From: Markus Trippelsdorf <markus@trippelsdorf.de>
Date: Wed, 25 Nov 2015 16:40:16 +0000 (+0000)
Subject: re PR c++/68087 (ICE with constexpr in array with negative index)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=c2127564efc152de34ea1a15ce9b20e8ddccfc2c;p=gcc.git

re PR c++/68087 (ICE with constexpr in array with negative index)

/cp
2015-11-25  Markus Trippelsdorf  <markus@trippelsdorf.de>
	    Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/68087
	* constexpr.c (cxx_eval_array_reference): Use tree_fits_shwi_p before
	tree_to_shwi to avoid ICEs.

/testsuite
2015-11-25  Markus Trippelsdorf  <markus@trippelsdorf.de>
	    Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/68087
	* g++.dg/cpp0x/constexpr-array13.C: New.

Co-Authored-By: Paolo Carlini <paolo.carlini@oracle.com>

From-SVN: r230886
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index a4aa01e3b2a..c94ae5f1cc4 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2015-11-25  Markus Trippelsdorf  <markus@trippelsdorf.de>
+	    Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/68087
+	* constexpr.c (cxx_eval_array_reference): Use tree_fits_shwi_p before
+	tree_to_shwi to avoid ICEs.
+
 2015-11-24  Ilya Verbin  <ilya.verbin@intel.com>
 
 	* parser.c (cp_parser_oacc_declare): Replace "ifdef ENABLE_OFFLOADING"
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index 459173dec07..42e99021f11 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -1799,8 +1799,8 @@ cxx_eval_array_reference (const constexpr_ctx *ctx, tree t,
       gcc_unreachable ();
     }
 
-  i = tree_to_shwi (index);
-  if (i < 0)
+  if (!tree_fits_shwi_p (index)
+      || (i = tree_to_shwi (index)) < 0)
     {
       if (!ctx->quiet)
 	error ("negative array subscript");
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 58bd40ab404..e0b16f592e7 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2015-11-25  Markus Trippelsdorf  <markus@trippelsdorf.de>
+	    Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/68087
+	* g++.dg/cpp0x/constexpr-array13.C: New.
+
 2015-11-25  Ilmir Usmanov <me@ilmir.us>
 	    Cesar Philippidis  <cesar@codesourcery.com>
 
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-array13.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-array13.C
new file mode 100644
index 00000000000..13ab5a724b5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-array13.C
@@ -0,0 +1,6 @@
+// PR c++/68087
+// { dg-do compile { target c++11 } }
+
+constexpr char c[] = "hello";
+constexpr const char *p = c;
+constexpr char ch = *(p-1);  // { dg-error "negative array subscript" }