This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
C++ PATCH for c++/86201, diagnostic routines re-entered crash
- From: Marek Polacek <polacek at redhat dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>, Jason Merrill <jason at redhat dot com>
- Date: Tue, 3 Jul 2018 12:08:01 -0400
- Subject: C++ PATCH for c++/86201, diagnostic routines re-entered crash
This is an ICE of kind "Error reporting routines re-entered". From the PR:
The problem here is that we report the missing return value:
9224 permerror (input_location, "return-statement with no value, in "
9225 "function returning %qT", valtype);
but permerror will end up calling print_instantiation_full_context, which ends
up calling dump_template_bindings and then tsubst -> tsubst_copy_and_build ->
build_functional_cast -> ... -> ocp_convert which has (complain is tf_none)
829 if (complain & tf_warning)
830 return cp_truthvalue_conversion (e);
831 else
832 {
833 /* Prevent bogus -Wint-in-bool-context warnings coming
834 from c_common_truthvalue_conversion down the line. */
835 warning_sentinel w (warn_int_in_bool_context);
836 return cp_truthvalue_conversion (e);
837 }
So we call cp_truthvalue_conversion -> c_common_truthvalue_conversion ->
build_binary_op which only calls cp_build_binary_op but with
tf_warning_or_error. So even though the warning
4736 if ((complain & tf_warning)
4737 && (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1)))
4738 warning (OPT_Wfloat_equal,
4739 "comparing floating point with == or != is unsafe");
is properly guarded, we still re-enter the diagnostic routines.
But since we're parsing decltype we can check c_inhibit_evaluation_warnings
which means we won't call warning().
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2018-07-03 Marek Polacek <polacek@redhat.com>
PR c++/86201
* typeck.c (cp_build_binary_op): Check c_inhibit_evaluation_warnings.
* g++.dg/diagnostic/pr86201.C: New test.
diff --git gcc/cp/typeck.c gcc/cp/typeck.c
index 3a4f1cdf479..ea4ce9649cd 100644
--- gcc/cp/typeck.c
+++ gcc/cp/typeck.c
@@ -4734,6 +4734,7 @@ cp_build_binary_op (location_t location,
if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
goto vector_compare;
if ((complain & tf_warning)
+ && c_inhibit_evaluation_warnings == 0
&& (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1)))
warning (OPT_Wfloat_equal,
"comparing floating point with == or != is unsafe");
diff --git gcc/testsuite/g++.dg/diagnostic/pr86201.C gcc/testsuite/g++.dg/diagnostic/pr86201.C
index e69de29bb2d..e7019c22d95 100644
--- gcc/testsuite/g++.dg/diagnostic/pr86201.C
+++ gcc/testsuite/g++.dg/diagnostic/pr86201.C
@@ -0,0 +1,12 @@
+// PR c++/86201
+// { dg-do compile { target c++11 } }
+
+template <class U, class V>
+auto fn1 (V&& v) -> decltype(U(v))
+{
+ return; // { dg-error "return-statement with no value" }
+}
+void fn2 ()
+{
+ fn1<bool>(1.0);
+}