The issue here was that we were cp_folding a location wrapper around a
lambda capture proxy before it had been mark_rvalue_used. I considered
adding mark_rvalue_use calls to build_new_op_1, but it seems appropriate to
have them in cp_fold_maybe_rvalue when we know we're trying to produce an
rvalue.
The change to mark_use is for a related issue: when we change the operand of
the location wrapper from VAR_DECL to INTEGER_CST, we need the TREE_CODE of
the location wrapper to change as well, from VIEW_CONVERT_EXPR to
NON_LVALUE_EXPR.
Tested x86_64-cp-linux-gnu, applying to trunk.
* expr.c (mark_use): Fix location wrapper handling.
* cp-gimplify.c (cp_fold_maybe_rvalue): Call mark_rvalue_use.
---
gcc/cp/cp-gimplify.c | 2 ++
gcc/cp/expr.c | 17 +++++++++++++++--
.../g++.dg/cpp0x/lambda/lambda-const10.C | 11 +++++++++++
gcc/cp/ChangeLog | 6 ++++++
4 files changed, 34 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/lambda/lambda-const10.C
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index 726adac4f4e..121dfa41d8d 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -2124,6 +2124,8 @@ cp_fold_maybe_rvalue (tree x, bool rval)
while (true)
{
x = cp_fold (x);
+ if (rval)
+ x = mark_rvalue_use (x);
if (rval && DECL_P (x)
&& !TYPE_REF_P (TREE_TYPE (x)))
{
diff --git a/gcc/cp/expr.c b/gcc/cp/expr.c
index 071c6fb9205..9160043ed11 100644
--- a/gcc/cp/expr.c
+++ b/gcc/cp/expr.c
@@ -187,10 +187,23 @@ mark_use (tree expr, bool rvalue_p, bool read_p,
}
break;
- CASE_CONVERT:
case VIEW_CONVERT_EXPR:
if (location_wrapper_p (expr))
- loc = EXPR_LOCATION (expr);
+ {
+ loc = EXPR_LOCATION (expr);
+ tree op = TREE_OPERAND (expr, 0);
+ tree nop = RECUR (op);
+ if (nop == error_mark_node)
+ return error_mark_node;
+ TREE_OPERAND (expr, 0) = nop;
+ /* If we're replacing a DECL with a constant, we also need to change
+ the TREE_CODE of the location wrapper. */
+ if (op != nop && rvalue_p)
+ TREE_SET_CODE (expr, NON_LVALUE_EXPR);
+ return expr;
+ }
+ gcc_fallthrough();
+ CASE_CONVERT:
recurse_op[0] = true;
break;
diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-const10.C
b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-const10.C
new file mode 100644
index 00000000000..3112f08f5c2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-const10.C
@@ -0,0 +1,11 @@
+// PR c++/88613
+// { dg-do compile { target c++11 } }
+// { dg-additional-options -Wtautological-compare }
+
+void a() {
+ const int b = 5;
+ [=] {
+ if (b != 5)
+ ;
+ }();
+}
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 4b9fa821d74..74e4dff494e 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2019-01-11 Jason Merrill <ja...@redhat.com>
+
+ PR c++/88613 - ICE with use of const var in lambda.
+ * expr.c (mark_use): Fix location wrapper handling.
+ * cp-gimplify.c (cp_fold_maybe_rvalue): Call mark_rvalue_use.
+
2019-01-11 Paolo Carlini <paolo.carl...@oracle.com>
* decl.c (start_decl): Improve error location.
base-commit: ead1f4b6412011a79e84db928f6a98dd7cf09a3d
--
2.20.1
