Oops, consider the typo in the subject line fixed. Also ...
On Wed, 15 Apr 2020, Patrick Palka wrote:
> Here we're ICE'ing in do_narrow during error-recovery, because ocp_convert
> returns error_mark_node after it attempts to reduce a const decl to its
> erroneous DECL_INITIAL via scalar_constant_value, and we later pass this
> error_mark_node to fold_build2 which isn't prepared to handle
> error_mark_nodes.
>
> We could fix this ICE in do_narrow by checking if ocp_convert returns
> error_mark_node, but for the sake of consistency and for better error recovery
> it seems it'd be better if ocp_convert didn't care that a const decl's
> initializer is erroneous and would instead proceed as if the decl was not
> const,
> which is the approach that this patch takes.
>
> Passes 'make check-c++', does this look OK to commit after full bootstrap and
> regtest?
>
> gcc/cp/ChangeLog:
>
> PR c++/94475
> * cvt.c (ocp_convert): If the result of scalar_constant_value is
> erroneous, discard it and carry on with the original expression.
>
> gcc/testsuite/ChangeLog:
>
> PR c++/94475
> * g++.dg/conversion/err-recover2.C: New test.
> * g++.dg/diagnostic/pr84138.C: Remove now-bogus warning.
> * g++.dg/warn/Wsign-compare-8.C: Remove now-bogus warning.
> ---
> gcc/cp/cvt.c | 6 +++---
> gcc/testsuite/g++.dg/conversion/err-recover2.C | 10 ++++++++++
> gcc/testsuite/g++.dg/diagnostic/pr84138.C | 2 +-
> gcc/testsuite/g++.dg/warn/Wsign-compare-8.C | 2 +-
> 4 files changed, 15 insertions(+), 5 deletions(-)
> create mode 100644 gcc/testsuite/g++.dg/conversion/err-recover2.C
>
> diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c
> index a3b80968b33..b94231a6d08 100644
> --- a/gcc/cp/cvt.c
> +++ b/gcc/cp/cvt.c
> @@ -723,10 +723,10 @@ ocp_convert (tree type, tree expr, int convtype, int
> flags,
> if (!CLASS_TYPE_P (type))
> {
> e = mark_rvalue_use (e);
> - e = scalar_constant_value (e);
> + tree v = scalar_constant_value (e);
> + if (!error_operand_p (v))
> + e = v;
> }
> - if (error_operand_p (e))
> - return error_mark_node;
Removing this error_operand_p check might make an error_mark_node slip
through and get processed by the rest of ocp_convert, if the call to
mark_rvalue_use above returns error_mark_node.
In light of that, please consider this patch instead which restores that
error_operand_p check:
-- >8 --
Subject: [PATCH] c++: Error recovery with erroneous DECL_INITIAL [PR94475]
gcc/cp/ChangeLog:
PR c++/94475
* cvt.c (ocp_convert): If the result of scalar_constant_value is
erroneous, ignore it and use the original expression.
gcc/testsuite/ChangeLog:
PR c++/94475
* g++.dg/conversion/err-recover2.C: New test.
* g++.dg/diagnostic/pr84138.C: Remove now-bogus warning.
* g++.dg/warn/Wsign-compare-8.C: Remove now-bogus warning.
---
gcc/cp/cvt.c | 4 +++-
gcc/testsuite/g++.dg/conversion/err-recover2.C | 10 ++++++++++
gcc/testsuite/g++.dg/diagnostic/pr84138.C | 2 +-
gcc/testsuite/g++.dg/warn/Wsign-compare-8.C | 2 +-
4 files changed, 15 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/conversion/err-recover2.C
diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c
index a3b80968b33..656e7fd3ec0 100644
--- a/gcc/cp/cvt.c
+++ b/gcc/cp/cvt.c
@@ -723,7 +723,9 @@ ocp_convert (tree type, tree expr, int convtype, int flags,
if (!CLASS_TYPE_P (type))
{
e = mark_rvalue_use (e);
- e = scalar_constant_value (e);
+ tree v = scalar_constant_value (e);
+ if (!error_operand_p (v))
+ e = v;
}
if (error_operand_p (e))
return error_mark_node;
diff --git a/gcc/testsuite/g++.dg/conversion/err-recover2.C
b/gcc/testsuite/g++.dg/conversion/err-recover2.C
new file mode 100644
index 00000000000..437e1a919ea
--- /dev/null
+++ b/gcc/testsuite/g++.dg/conversion/err-recover2.C
@@ -0,0 +1,10 @@
+// PR c++/94475
+// { dg-do compile }
+
+unsigned char
+sr ()
+{
+ const unsigned char xz = EI; // { dg-error "not declared" }
+
+ return xz - (xz >> 1);
+}
diff --git a/gcc/testsuite/g++.dg/diagnostic/pr84138.C
b/gcc/testsuite/g++.dg/diagnostic/pr84138.C
index 5c48b9b164a..00352306a56 100644
--- a/gcc/testsuite/g++.dg/diagnostic/pr84138.C
+++ b/gcc/testsuite/g++.dg/diagnostic/pr84138.C
@@ -5,4 +5,4 @@ foo()
{
const int i = 0 = 0; // { dg-error "lvalue required as left operand" }
return 1 ? 0 : (char)i;
-} // { dg-warning "control reaches" }
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wsign-compare-8.C
b/gcc/testsuite/g++.dg/warn/Wsign-compare-8.C
index 237ba84d526..4d2688157fc 100644
--- a/gcc/testsuite/g++.dg/warn/Wsign-compare-8.C
+++ b/gcc/testsuite/g++.dg/warn/Wsign-compare-8.C
@@ -5,4 +5,4 @@ bool foo (char c)
{
const int i = 0 = 0; // { dg-error "lvalue" }
return c = i;
-} // { dg-warning "control reaches" }
+}
--
2.26.1.107.gefe3874640
