Re: [PATCH 2/5] c++: Set the locus of the function result decl

[Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>]

Hi Jason!

Possible test.

An existing test might be to equip the existing warning for
bool unsigned double meh(void) {return 0;}
with a fix-it hint instead of the brief
 error: two or more data types in declaration of ‘meh’.
Likewise for
bool unsigned meh(void) {return 0;}
 error: ‘unsigned’ specified with ‘bool’

so we wouldn't need a plugin, and it might even be useful? ;)

cheers,

	* g++.dg/plugin/plugin.exp: Add new test.
	* g++.dg/plugin/result-decl-plugin-test-1.C: New test.
	* g++.dg/plugin/result-decl-plugin-test-2.C: New test.
	* g++.dg/plugin/result_decl_plugin.C: New test.
---
 gcc/testsuite/g++.dg/plugin/plugin.exp        |  3 +
 .../g++.dg/plugin/result-decl-plugin-test-1.C | 28 +++++++++
 .../g++.dg/plugin/result-decl-plugin-test-2.C | 61 +++++++++++++++++++
 .../g++.dg/plugin/result_decl_plugin.C        | 57 +++++++++++++++++
 4 files changed, 149 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/plugin/result-decl-plugin-test-1.C
 create mode 100644 gcc/testsuite/g++.dg/plugin/result-decl-plugin-test-2.C
 create mode 100644 gcc/testsuite/g++.dg/plugin/result_decl_plugin.C

diff --git a/gcc/testsuite/g++.dg/plugin/plugin.exp b/gcc/testsuite/g++.dg/plugin/plugin.exp
index b5fb42fa77a..f2b526b4704 100644
--- a/gcc/testsuite/g++.dg/plugin/plugin.exp
+++ b/gcc/testsuite/g++.dg/plugin/plugin.exp
@@ -80,6 +80,9 @@ set plugin_test_list [list \
     	  show-template-tree-color-labels.C \
     	  show-template-tree-color-no-elide-type.C } \
     { comment_plugin.c comments-1.C } \
+    { result_decl_plugin.C \
+          result-decl-plugin-test-1.C \
+          result-decl-plugin-test-2.C } \
 ]
 
 foreach plugin_test $plugin_test_list {
diff --git a/gcc/testsuite/g++.dg/plugin/result-decl-plugin-test-1.C b/gcc/testsuite/g++.dg/plugin/result-decl-plugin-test-1.C
new file mode 100644
index 00000000000..bd323181d70
--- /dev/null
+++ b/gcc/testsuite/g++.dg/plugin/result-decl-plugin-test-1.C
@@ -0,0 +1,28 @@
+/* Verify that class member functions result decl have the correct location.  */
+// { dg-options "-fdiagnostics-generate-patch" }
+namespace std { template < typename, typename > struct pair; }
+template < typename > struct __mini_vector
+{
+  int _M_finish;
+  const
+  unsigned long
+  __attribute__((deprecated))
+  _M_space_left()
+  { return _M_finish != 0; }
+};
+ template class __mini_vector< std::pair< long, long > >;
+ template class __mini_vector< int >;
+#if 0
+{ dg-begin-multiline-output "" }
+@@ -5,7 +5,7 @@ template < typename > struct __mini_vect
+ {
+   int _M_finish;
+   const
+-  unsigned long
++  bool
+   __attribute__((deprecated))
+   _M_space_left()
+   { return _M_finish != 0; }
+
+{ dg-end-multiline-output "" }
+#endif
diff --git a/gcc/testsuite/g++.dg/plugin/result-decl-plugin-test-2.C b/gcc/testsuite/g++.dg/plugin/result-decl-plugin-test-2.C
new file mode 100644
index 00000000000..385a7ef482f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/plugin/result-decl-plugin-test-2.C
@@ -0,0 +1,61 @@
+/* Verify that template functions result decl have the correct location.  */
+// { dg-options "-fdiagnostics-generate-patch" }
+template <class T>
+int
+f()
+{
+  return 42;
+}
+int main()
+{
+   f<int>();
+}
+unsigned long long huh(void)
+{
+  return 1ULL;
+}
+#if 0
+{ dg-begin-multiline-output "" }
+g++.dg/plugin/result-decl-plugin-test-2.C:4:1: warning: Function ‘f’ result location
+    4 | int
+      | ^~~
+      | bool
+g++.dg/plugin/result-decl-plugin-test-2.C:9:1: warning: Function ‘main’ result location
+    9 | int main()
+      | ^~~
+      | bool
+g++.dg/plugin/result-decl-plugin-test-2.C:13:28: warning: Function ‘huh’ result location
+   13 | unsigned long long huh(void)
+      |                            ^
+      |                            bool
+g++.dg/plugin/result-decl-plugin-test-2.C: In instantiation of ‘int f() [with T = int]’:
+g++.dg/plugin/result-decl-plugin-test-2.C:11:10:   required from here
+g++.dg/plugin/result-decl-plugin-test-2.C:4:1: warning: Function ‘f’ result location
+    4 | int
+      | ^~~
+      | bool
+--- g++.dg/plugin/result-decl-plugin-test-2.C
++++ g++.dg/plugin/result-decl-plugin-test-2.C
+@@ -1,16 +1,16 @@
+ /* Verify that template functions result decl have the correct location.  */
+ // { dg-options "-fdiagnostics-generate-patch" }
+ template <class T>
+-int
++bool
+ f()
+ {
+   return 42;
+ }
+-int main()
++bool main()
+ {
+    f<int>();
+ }
+-unsigned long long huh(void)
++unsigned long long huh(voidbool
+ {
+   return 1ULL;
+ }
+{ dg-end-multiline-output "" }
+#endif
+// Note: f() should not +bbool with an off-by-one for the start 'b' !
diff --git a/gcc/testsuite/g++.dg/plugin/result_decl_plugin.C b/gcc/testsuite/g++.dg/plugin/result_decl_plugin.C
new file mode 100644
index 00000000000..40f54a6acfe
--- /dev/null
+++ b/gcc/testsuite/g++.dg/plugin/result_decl_plugin.C
@@ -0,0 +1,57 @@
+/* A plugin example that points at the location of function decl result decl */
+/* This file is part of GCC */
+/* { dg-options "-O" } */
+#include "gcc-plugin.h"
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tree.h"
+#include "tree-pass.h"
+#include "intl.h"
+#include "diagnostic.h"
+#include "gcc-rich-location.h"
+#include "langhooks.h"
+#include "plugin-version.h"
+
+static struct plugin_info _this_info = {
+  .version = "1",
+  .help    = "None",
+};
+/* Callback function to invoke after GCC finishes a declaration. */
+
+static void plugin_finish_decl (void *event_data, void *data)
+{
+  tree decl = (tree) event_data;
+  if (!decl || TREE_CODE (decl) != FUNCTION_DECL)
+    return;
+
+  tree logical_1_t = boolean_type_node;
+  tree logical_1_n = DECL_NAME (TYPE_NAME (logical_1_t));
+  location_t result_loc = DECL_SOURCE_LOCATION (DECL_RESULT (decl));
+  gcc_rich_location richloc (result_loc);
+  richloc.add_fixit_replace (result_loc, IDENTIFIER_POINTER (logical_1_n));
+
+  warning_at (&richloc, 0, G_("Function %qs result location"),
+           IDENTIFIER_POINTER (DECL_NAME (decl)));
+}
+
+int
+plugin_init (struct plugin_name_args *plugin_info,
+             struct plugin_gcc_version *version)
+{
+  if (!plugin_default_version_check (version, &gcc_version))
+    {
+      error(G_("incompatible gcc/plugin versions"));
+      return 1;
+    }
+
+  const char *plugin_name = plugin_info->base_name;
+
+  register_callback(plugin_name, PLUGIN_INFO, NULL, &_this_info);
+  register_callback (plugin_name, PLUGIN_FINISH_PARSE_FUNCTION,
+                     plugin_finish_decl, NULL);
+  return 0;
+}
+
+/* Announce that we are GPL.  */
+int plugin_is_GPL_compatible;
-- 
2.38.1