From 06eb1211986901a74817d619bde855508c7cb7bd Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Sun, 10 Sep 2023 12:49:39 +1000
Subject: [PATCH 1/2] _cc_is_clang: allow for a vendor prefix on the --version
 output

Several distributions build clang with CLANG_VENDOR defined:

https://github.com/llvm/llvm-project/blob/444abb39/clang/lib/Basic/Version.cpp#L96

For example:

  tony@enceladus:~$ grep PRETTY_NAME /etc/os-release
  PRETTY_NAME="Debian GNU/Linux 12 (bookworm)"
  tony@enceladus:~$ clang --version | head -n1
  Debian clang version 14.0.6

  tony@enceladus:~$ grep PRETTY_NAME /etc/os-release
  PRETTY_NAME="Ubuntu 22.04.3 LTS"
  tony@enceladus:~$ clang --version | head -n1
  Ubuntu clang version 14.0.0-1ubuntu1.1

  openbsd69$ uname -a
  OpenBSD openbsd69.tony.develop-help.com 6.9 GENERIC#464 amd64
  openbsd69$ cc --version | head -n1
  OpenBSD clang version 10.0.1

  enceladus:~$ clang-15 --version | head -n1
  Alpine clang version 15.0.7
  enceladus:~$ clang --version | head -n1
  Alpine clang version 15.0.7
  enceladus:~$ grep PRETTY_NAME /etc/os-release
  PRETTY_NAME="Alpine Linux v3.17"

From https://trac.macports.org/wiki/XcodeVersionInfo :

  Apple clang version 14.0.0 (clang-1400.0.29.202)

so adjust the regexp to allow a leading vendor.  It's possible
for the vendor to contain spaces, but I haven't found any examples
of that in the wild.

Keep the match tight by checking for the following " version".
---
 lib/ExtUtils/CppGuess.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/ExtUtils/CppGuess.pm b/lib/ExtUtils/CppGuess.pm
index 0be5783..0a92fdf 100644
--- a/lib/ExtUtils/CppGuess.pm
+++ b/lib/ExtUtils/CppGuess.pm
@@ -405,7 +405,7 @@ sub _cc_is_clang {
     $self->{is_clang} = 0;
     my $cc_version = _capture( "$cc --version" );
     if (
-         $cc_version =~ m/\A(?:clang|apple llvm)/i
+         $cc_version =~ m/\A(?:(?:\S+ )?clang version|apple llvm)/i
       || $cc eq 'clang' # because why would they lie?
       || (($self->_config->{gccversion} || '') =~ /Clang|Apple LLVM/),
     ) {

From 5e475041d53fa09b55b1e357cd4ba4590d0d6a20 Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Sun, 10 Sep 2023 13:40:55 +1000
Subject: [PATCH 2/2] 002_iccp.t: mock some --version output to test clang
 changes

---
 t/002_icpp.t | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/t/002_icpp.t b/t/002_icpp.t
index 90b42a6..2d9b0d0 100644
--- a/t/002_icpp.t
+++ b/t/002_icpp.t
@@ -95,6 +95,61 @@ my @METHODS = qw(
 
 run_test(@$_) for @DATA;
 
+# mock some compiler output
+my $old_capture = \&ExtUtils::CppGuess::_capture;
+our $CAPTURES;
+{
+  no warnings "redefine";
+  *ExtUtils::CppGuess::_capture =
+    sub {
+      my @cmd = @_;
+      if (my $result = $CAPTURES->{"@cmd"}) {
+        note "Mocking output of @cmd: $result";
+        return $result;
+      }
+      goto &$old_capture;
+    };
+}
+my @CAPS =
+    (
+     [
+       { cc => "cc", config => { ccflags => '' } },
+       {
+         is_sunstudio => 0,
+         is_msvc => undef, is_gcc => undef, is_clang => 1,
+         compiler_command => 'clang++ -xc++ -Wno-reserved-user-defined-literal',
+         linker_flags => '-lstdc++',
+       },
+       { "cc --version" => "OpenBSD clang version 10.0.1" },
+     ],
+     [
+       { cc => "clang-15", config => { ccflags => '' } },
+       {
+         is_sunstudio => 0,
+         is_msvc => undef, is_gcc => undef, is_clang => 1,
+         compiler_command => 'clang++ -xc++ -Wno-reserved-user-defined-literal',
+         linker_flags => '-lstdc++',
+       },
+       { "clang-15 --version" => "Debian clang version 15.0.7" },
+     ],
+     [
+       { cc => "cc", config => { ccflags => '' } },
+       {
+         is_sunstudio => 0,
+         is_msvc => undef, is_gcc => 1, is_clang => 0,
+         compiler_command => 'g++ -xc++',
+         linker_flags => '-lstdc++',
+       },
+       { "cc --version" => "cc (Debian 12.2.0-14) 12.2.0" },
+     ],
+    );
+
+for my $test (@CAPS) {
+    my ($args, $expect, $cap) = @$test;
+    local $CAPTURES = $cap;
+    run_test($args, $expect);
+}
+
 done_testing;
 
 sub run_test {