Remove constant deparsing from 5.10.1

This was added post-5.10.0, but adds a significant perfomance penalty
to all deparsing. Remove for now, and maybe add back in a later 5.10.x
if it can be fixed.

The original code was added to blead with
    2990415a4519bc3988d7224ae15100c3e9e901ee
with a lot of follow-up tweaks.

2 files changed, 1 insertions, 50 deletions

diff --git a/ext/B/B/Deparse.pm b/ext/B/B/Deparse.pm
index 5685d0914f..85c4ef039e 100644
--- a/ext/B/B/Deparse.pm
+++ b/ext/B/B/Deparse.pm
@@ -606,25 +606,6 @@ sub new {
     }
 }
 
-sub scan_for_constants {
-    my ($self) = @_;
-    my %ret;
-
-    B::walksymtable(\%::, sub {
-        my ($gv) = @_;
-
-        my $cv = $gv->CV;
-        return if !$cv || class($cv) ne 'CV';
-
-        my $const = $cv->const_sv;
-        return if !$const || class($const) eq 'SPECIAL';
-
-        $ret{ 0 + $const->object_2svref } = $gv->NAME;
-    }, sub { 1 });
-
-    return \%ret;
-}
-
 # Initialise the contextual information, either from
 # defaults provided with the ambient_pragmas method,
 # or from perl's own defaults otherwise.
@@ -3658,13 +3639,6 @@ sub const {
     if (class($sv) eq "NULL") {
        return 'undef';
     }
-    if ($cx) {
-	unless ($self->{'inlined_constants'}) {
-	    $self->{'inlined_constants'} = $self->scan_for_constants;
-	}
-	my $const = $self->{'inlined_constants'}->{ 0 + $sv->object_2svref };
-        return $const if $const;
-    }
     # convert a version object into the "v1.2.3" string in its V magic
     if ($sv->FLAGS & SVs_RMG) {
 	for (my $mg = $sv->MAGIC; $mg; $mg = $mg->MOREMAGIC) {
diff --git a/ext/B/t/deparse.t b/ext/B/t/deparse.t
index d2e65d9cb6..921cecaed8 100644
--- a/ext/B/t/deparse.t
+++ b/ext/B/t/deparse.t
@@ -27,7 +27,7 @@ BEGIN {
     require feature;
     feature->import(':5.10');
 }
-use Test::More tests => 77;
+use Test::More tests => 71;
 use Config ();
 
 use B::Deparse;
@@ -519,29 +519,6 @@ if ($a == 1) { x(); } elsif ($b == 2) { z(); }
 if (do { foo(); GLIPP }) { x(); }
 if (do { ++$a; GLIPP }) { x(); }
 ####
-# 62 tests for deparsing constants
-warn PI;
-####
-# 63 tests for deparsing imported constants
-warn O_TRUNC;
-####
-# 64 tests for deparsing re-exported constants
-warn O_CREAT;
-####
-# 65 tests for deparsing imported constants that got deleted from the original namespace
-warn O_APPEND;
-####
-# TODO ? $Config::Config{useithreads} && "doesn't work with threads"
-# 66 tests for deparsing constants which got turned into full typeglobs
-# It might be fundamentally impossible to make this work on ithreads, in which
-# case the TODO should become a SKIP
-warn O_EXCL;
-eval '@Fcntl::O_EXCL = qw/affe tiger/;';
-warn O_EXCL;
-####
-# 67 tests for deparsing of blessed constant with overloaded numification
-warn OVERLOADED_NUMIFICATION;
-####
 # TODO Only strict 'refs' currently supported
 # 68 strict
 no strict;