When erroring out due to an incomplete type, we add a contextual note
about the type. However, when the error is suppressed by
-Wno-template-body, the note remains, making the compiler output quite
puzzling.
This patch makes sure the note is suppressed if we're processing a
template declaration body with -Wno-template-body.
Successfully tested on x86_64-pc-linux-gnu.
PR c++/118163
gcc/cp/ChangeLog:
* cp-tree.h (get_current_template): Declare.
* error.cc (get_current_template): Make non static.
* typeck2.cc (cxx_incomplete_type_inform): Suppress note when
parsing a template declaration with -Wno-template-body.
gcc/testsuite/ChangeLog:
* g++.dg/diagnostic/incomplete-type-2.C: New test.
* g++.dg/diagnostic/incomplete-type-2a.C: New test.
---
gcc/cp/cp-tree.h | 1 +
gcc/cp/error.cc | 2 +-
gcc/cp/typeck2.cc | 6 ++++++
gcc/testsuite/g++.dg/diagnostic/incomplete-type-2.C | 7 +++++++
.../g++.dg/diagnostic/incomplete-type-2a.C | 13 +++++++++++++
5 files changed, 28 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/diagnostic/incomplete-type-2.C
create mode 100644 gcc/testsuite/g++.dg/diagnostic/incomplete-type-2a.C
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 6de8f64b5ee..52f954b63d9 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -7297,6 +7297,7 @@ struct decl_location_traits
typedef hash_map<tree, location_t, decl_location_traits> erroneous_templates_t;
extern GTY((cache)) erroneous_templates_t *erroneous_templates;
+extern tree get_current_template ();
extern bool cp_seen_error ();
#define seen_error() cp_seen_error ()
diff --git a/gcc/cp/error.cc b/gcc/cp/error.cc
index 8c0644fba7e..7fd03dd6d12 100644
--- a/gcc/cp/error.cc
+++ b/gcc/cp/error.cc
@@ -197,7 +197,7 @@ class cxx_format_postprocessor : public format_postprocessor
/* Return the in-scope template that's currently being parsed, or
NULL_TREE otherwise. */
-static tree
+tree
get_current_template ()
{
if (scope_chain && in_template_context && !current_instantiation ())
diff --git a/gcc/cp/typeck2.cc b/gcc/cp/typeck2.cc
index fce687e83b3..505c143dae7 100644
--- a/gcc/cp/typeck2.cc
+++ b/gcc/cp/typeck2.cc
@@ -273,6 +273,12 @@ cxx_incomplete_type_inform (const_tree type)
if (!TYPE_MAIN_DECL (type))
return;
+ /* When processing a template declaration body, the error generated by the
+ caller (if any) might have been suppressed by -Wno-template-body. If that
+ is the case, suppress the inform as well. */
+ if (!warn_template_body && get_current_template ())
+ return;
+
location_t loc = DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type));
tree ptype = strip_top_quals (CONST_CAST_TREE (type));
diff --git a/gcc/testsuite/g++.dg/diagnostic/incomplete-type-2.C
b/gcc/testsuite/g++.dg/diagnostic/incomplete-type-2.C
new file mode 100644
index 00000000000..e2fb20a4ae8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/diagnostic/incomplete-type-2.C
@@ -0,0 +1,7 @@
+// PR c++/118163
+// { dg-do "compile" }
+
+template<class T>
+struct S { // { dg-note "until the closing brace" }
+ S s; // { dg-error "has incomplete type" }
+};
diff --git a/gcc/testsuite/g++.dg/diagnostic/incomplete-type-2a.C
b/gcc/testsuite/g++.dg/diagnostic/incomplete-type-2a.C
new file mode 100644
index 00000000000..d13021d0b68
--- /dev/null
+++ b/gcc/testsuite/g++.dg/diagnostic/incomplete-type-2a.C
@@ -0,0 +1,13 @@
+// PR c++/118163
+// { dg-do "compile" }
+// { dg-additional-options "-Wno-template-body" }
+
+template<class T>
+struct S { // { dg-bogus "until the closing brace" }
+ S s; // { dg-bogus "has incomplete type" }
+};
+
+// Check that we don't suppress errors outside of the body.
+struct forward_decl; // { dg-note "forward declaration" }
+template<class T>
+void foo (forward_decl) {} // { dg-error "has incomplete type" }
--
2.44.0
