Preserve OPTIMIZE in hints

Some extensions hints files (B, Digest-MD5, PerlIO-via) forcefully
overwrite OPTIMIZE in order to work around compiler mishaps with high level
optimizations. However, this loses whatever extra flags are listed in
OPTIMIZE, such as compiler warnings flags or PERL_POISON, and makes them
difficult to run under a debugger since a minimal level of optimization
(usually -O1) is always enforced. This has became visible recently with
new XS handshake facility.

Instead, we chose to just follow Storable's strategy of lowering the
optimization level with a substitution, while keeping all the other flags
untouched. If other compiler flags are deemed problematic (such as
-mcpu/-march on gcc), they ought to be addressed separately.

Only B and PerlIO-via hints files are fixed by this change. The case of
Digest-MD5 will be addressed on the CPAN.

This fixes [RT #124038].

1 files changed, 5 insertions, 1 deletions

diff --git a/ext/PerlIO-via/hints/aix.pl b/ext/PerlIO-via/hints/aix.pl
index 960a8fdfe0..2b23ab3be7 100644
--- a/ext/PerlIO-via/hints/aix.pl
+++ b/ext/PerlIO-via/hints/aix.pl
@@ -1,2 +1,6 @@
 # compilation may hang at -O3 level
-$self->{OPTIMIZE} = '-O';
+use Config;
+
+my $optimize = $Config{optimize};
+$optimize =~ s/(^| )-O[2-9]\b/$1-O/g
+             and $self->{OPTIMIZE} = $optimize;