[PATCH] [libstdc++] [prettyprint] add local std::string use to more tests

[PATCH] [libstdc++] [prettyprint] add local std::string use to more tests

[Alexandre Oliva]

We're getting regressions after ugprading to GDB 13 in a few of the
libstdc++ pretty-printing tests.  It might seem like a GDB regression,
but that update has a new symbol reader, and Tom Tromey says it
exposes a latent problem in the pretty-printer, namely, when a name is
not defined locally in the local translation unit, GDB will look for
it in other units, and if multiple different definitions are
available, there are no guarantees as to which one it will find.

Since libstdc++ contains units in which std::string maps to different
types, in order to ensure the tests get the std::string definition we
expect, we need std::string to be present in the debug information for
the test itself, as we already do in other tests.

Regstrapped on x86_64-linux-gnu.  Ok to install?


for  libstdc++-v3/ChangeLog

	* testsuite/libstdc++-pretty-printers/80276.cc: Add
	std::string to debug info.
	* testsuite/libstdc++-pretty-printers/libfundts.cc: Likewise.


Change-Id: I928617d44679c63d634c26f6db17d7580a9bcd8f
TN: W223-034
---
 .../testsuite/libstdc++-prettyprinters/80276.cc    |    5 +++++
 .../libstdc++-prettyprinters/libfundts.cc          |    6 ++++++
 2 files changed, 11 insertions(+)

diff --git a/libstdc++-v3/testsuite/libstdc++-prettyprinters/80276.cc b/libstdc++-v3/testsuite/libstdc++-prettyprinters/80276.cc
index db4de593808e3..1d6b0207106a6 100644
--- a/libstdc++-v3/testsuite/libstdc++-prettyprinters/80276.cc
+++ b/libstdc++-v3/testsuite/libstdc++-prettyprinters/80276.cc
@@ -36,6 +36,11 @@ int
 main()
 {
   using namespace std;
+  // Ensure debug info for std::string is issued in the local
+  // translation unit, so that GDB won't pick up any alternate
+  // std::string notion that might be present in libstdc++.so.
+  string bah = "hi";
+  (void)bah;
   unique_ptr<vector<unique_ptr<vector<int>*>>> p1;
   unique_ptr<vector<unique_ptr<set<int>*>>[]> p2;
   unique_ptr<set<unique_ptr<vector<int>*>>[10]> p3;
diff --git a/libstdc++-v3/testsuite/libstdc++-prettyprinters/libfundts.cc b/libstdc++-v3/testsuite/libstdc++-prettyprinters/libfundts.cc
index b1c91033cc8e6..29e8bc8f194e3 100644
--- a/libstdc++-v3/testsuite/libstdc++-prettyprinters/libfundts.cc
+++ b/libstdc++-v3/testsuite/libstdc++-prettyprinters/libfundts.cc
@@ -32,6 +32,12 @@ using std::experimental::string_view;
 int
 main()
 {
+  // Ensure debug info for std::string is issued in the local
+  // translation unit, so that GDB won't pick up any alternate
+  // std::string notion that might be present in libstdc++.so.
+  std::string bah = "hi";
+  (void)bah;
+
   string_view str = "string";
 // { dg-final { note-test str "\"string\"" } }
 

-- 
Alexandre Oliva, happy hacker                https://FSFLA.org/blogs/lxo/
   Free Software Activist                       GNU Toolchain Engineer
Disinformation flourishes because many people care deeply about injustice
but very few check the facts.  Ask me about <https://stallmansupport.org>

Re: [PATCH] [libstdc++] [prettyprint] add local std::string use to more tests

[Jonathan Wakely]

[-- Attachment #1: Type: text/plain, Size: 916 bytes --]

On Fri, 3 Mar 2023 at 17:50, Alexandre Oliva via Libstdc++ <
libstdc++@gcc.gnu.org> wrote:

>
> We're getting regressions after ugprading to GDB 13 in a few of the
> libstdc++ pretty-printing tests.  It might seem like a GDB regression,
> but that update has a new symbol reader, and Tom Tromey says it
> exposes a latent problem in the pretty-printer, namely, when a name is
> not defined locally in the local translation unit, GDB will look for
> it in other units, and if multiple different definitions are
> available, there are no guarantees as to which one it will find.
>
> Since libstdc++ contains units in which std::string maps to different
> types, in order to ensure the tests get the std::string definition we
> expect, we need std::string to be present in the debug information for
> the test itself, as we already do in other tests.
>
> Regstrapped on x86_64-linux-gnu.  Ok to install?
>

OK, thanks.