c++: Change __builtin_source_location to use __PRETTY_FUNCTION__ instead of __FUNCTION__ [PR80780]

On Tue, Dec 01, 2020 at 01:03:52PM +0000, Jonathan Wakely via Gcc-patches wrote:
> I mentioned in PR 80780 that a __builtin__PRETTY_FUNCTION would have
> been nice, because __FUNCTION__ isn't very useful for C++, because of
> overloading and namespace/class scopes. There are an unlimited number
> of functions that have __FUNCTION__ == "s", e.g. "ns::s(int)" and
> "ns::s()" and "another_scope::s::s<T...>(T...)" etc.
>
> Since __builtin_source_location() can do whatever it wants (without
> needing to add __builtin__PRETTY_FUNCTION) it might be nice to use the
> __PRETTY_FUNCTION__ string. JeanHeyd's tests would still need changes,
> because the name would be "s::s(void*)" not "s::s" but that still
> seems better for users.

When I've added template tests for the previous patch, I have noticed that
the current __builtin_source_location behavior is not really __FUNCTION__,
just close, because e.g. in function template __FUNCTION__ is still
"bar" but __builtin_source_location gave "bar<0>".

Anyway, this patch implements above request to follow __PRETTY_FUNCTION__
(on top of the earlier posted patch).

2020-12-04  Jakub Jelinek  <jakub@redhat.com>

	PR c++/80780
	* cp-gimplify.c (fold_builtin_source_location): Use 2 instead of 0
	as last argument to cxx_printable_name.

	* g++.dg/cpp2a/srcloc1.C (quux): Use __PRETTY_FUNCTION__ instead of
	function.
	* g++.dg/cpp2a/srcloc2.C (quux): Likewise.
	* g++.dg/cpp2a/srcloc15.C (S::S): Likewise.
	(bar): Likewise.  Adjust expected column.
	* g++.dg/cpp2a/srcloc17.C (S::S): Likewise.
	(bar): Likewise.  Adjust expected column.

	* testsuite/18_support/source_location/1.cc (main): Adjust for
	__builtin_source_location using __PRETTY_FUNCTION__-like names instead
	__FUNCTION__-like.
	* testsuite/18_support/source_location/consteval.cc (main): Likewise.

5 files changed, 13 insertions, 13 deletions

diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index bafcaf5..8bbcf01 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -3005,7 +3005,7 @@ fold_builtin_source_location (location_t loc)
 	      const char *name = "";
 
 	      if (current_function_decl)
-		name = cxx_printable_name (current_function_decl, 0);
+		name = cxx_printable_name (current_function_decl, 2);
 
 	      val = build_string_literal (strlen (name) + 1, name);
 	    }
diff --git a/gcc/testsuite/g++.dg/cpp2a/srcloc1.C b/gcc/testsuite/g++.dg/cpp2a/srcloc1.C
index 6e19ff7..029a037 100644
--- a/gcc/testsuite/g++.dg/cpp2a/srcloc1.C
+++ b/gcc/testsuite/g++.dg/cpp2a/srcloc1.C
@@ -88,7 +88,7 @@ quux ()
   const char *file1 = source_location::current ().file_name ();
   const char *file2 = __FILE__;
   const char *function1 = source_location::current ().function_name ();
-  const char *function2 = __FUNCTION__;
+  const char *function2 = __PRETTY_FUNCTION__;
   int line1 = source_location::current ().line ();
   int line2 = __LINE__ - 1;
   int column
diff --git a/gcc/testsuite/g++.dg/cpp2a/srcloc15.C b/gcc/testsuite/g++.dg/cpp2a/srcloc15.C
index 30e5845..d02617e 100644
--- a/gcc/testsuite/g++.dg/cpp2a/srcloc15.C
+++ b/gcc/testsuite/g++.dg/cpp2a/srcloc15.C
@@ -44,12 +44,12 @@ struct S {
   source_location loc = source_location::current ();
 
   constexpr S (int l, source_location loc = source_location::current ())
-  : func(__FUNCTION__), line(l), loc(loc)
+  : func(__PRETTY_FUNCTION__), line(l), loc(loc)
   {}
 
   constexpr S (double)
-  : func(__FUNCTION__), line(__LINE__)
-  //                                 ^ column 38
+  : func(__PRETTY_FUNCTION__), line(__LINE__)
+  //                                        ^ column 45
   {}
 };
 
@@ -73,7 +73,7 @@ bar ()
   //                                            ^ column 49
   const source_location *d[3] = { &a, &b, &c };
   const char *file1 = __FILE__;
-  const char *function1 = __FUNCTION__;
+  const char *function1 = __PRETTY_FUNCTION__;
   for (int j = 0; j < 3; j++)
     {
       int i= 0;
@@ -104,7 +104,7 @@ bar ()
     return false;
   if (e.loc.column () != 9)
     return false;
-  if (f.loc.column () != 38)
+  if (f.loc.column () != 45)
     return false;
   return true;
 }
diff --git a/gcc/testsuite/g++.dg/cpp2a/srcloc17.C b/gcc/testsuite/g++.dg/cpp2a/srcloc17.C
index 16704d0..a02ea48 100644
--- a/gcc/testsuite/g++.dg/cpp2a/srcloc17.C
+++ b/gcc/testsuite/g++.dg/cpp2a/srcloc17.C
@@ -46,12 +46,12 @@ struct S {
   source_location loc = source_location::current ();
 
   constexpr S (int l, source_location loc = source_location::current ())
-  : func(__FUNCTION__), line(l), loc(loc)
+  : func(__PRETTY_FUNCTION__), line(l), loc(loc)
   {}
 
   constexpr S (double)
-  : func(__FUNCTION__), line(__LINE__)
-  //                                 ^ column 38
+  : func(__PRETTY_FUNCTION__), line(__LINE__)
+  //                                        ^ column 45
   {}
 };
 
@@ -76,7 +76,7 @@ bar ()
   //                                           ^ column 48
   const source_location *d[3] = { &a, &b, &c };
   const char *file1 = __FILE__;
-  const char *function1 = b.function_name ();
+  const char *function1 = __PRETTY_FUNCTION__;
   for (int j = 0; j < 3; j++)
     {
       int i= 0;
@@ -107,7 +107,7 @@ bar ()
     return false;
   if (e.loc.column () != 8)
     return false;
-  if (f.loc.column () != 38)
+  if (f.loc.column () != 45)
     return false;
   return true;
 }
diff --git a/gcc/testsuite/g++.dg/cpp2a/srcloc2.C b/gcc/testsuite/g++.dg/cpp2a/srcloc2.C
index 5ef09bb..4e0b960 100644
--- a/gcc/testsuite/g++.dg/cpp2a/srcloc2.C
+++ b/gcc/testsuite/g++.dg/cpp2a/srcloc2.C
@@ -92,7 +92,7 @@ quux ()
   const char *file1 = source_location::current ().file_name ();
   const char *file2 = __FILE__;
   const char *function1 = source_location::current ().function_name ();
-  const char *function2 = __FUNCTION__;
+  const char *function2 = __PRETTY_FUNCTION__;
   int line1 = source_location::current ().line ();
   int line2 = __LINE__ - 1;
   int column