bisect-runner.pl must patch Makefile.SH to avoid parallel make problems.

Patch in all 4 "extra_dep" rules for XS modules if any are needed as it
simplifies the implementation. It does no harm to have dependency rules for
XS modules "from the future", as they are ignored if the module is not
present. None were needed before Cwd was first converted to an XS module,
so use that as the test for applicability.

Remove a short-lived set of Makefile rules that attempted to run the regen
scripts if needed (commits 9fec149bb652b6e9 and 5bab1179608f81d8), as they
obscure whether correctly regenerated headers were checked in, and can cause
spurious rebuilds or timing-related parallel make failures.

Remove the code to explicitly set @INC in POSIX's Makefile.PL, as the @INC
it sets will cause build failures with make_ext.pl if Cwd isn't built first,
whereas the @INC set by make_ext.pl has no such issue.

diff --git a/Porting/bisect-runner.pl b/Porting/bisect-runner.pl
index 80598dc..0caa64e 100755 (executable)
--- a/Porting/bisect-runner.pl
+++ b/Porting/bisect-runner.pl
@@ -623,13 +623,16 @@ index 3d2e8b9..6ce7766 100755
 EOPATCH
 }
 
-if ($major < 10 && -d 'ext/Unicode/Normalize/'
-    && !extract_from_file('Configure', qr/^extra_dep=''$/)) {
-    # The Makefile.PL for Unicode::Normalize needs
-    # lib/unicore/CombiningClass.pl. Even without a parallel build, we need
-    # a dependency to ensure that it builds. This is a variant of commit
-    # 9f3ef600c170f61e
-    apply_patch(<<'EOPATCH');
+# Cwd.xs added in commit 0d2079faa739aaa9. Cwd.pm moved to ext/ 8 years later
+# in commit 403f501d5b37ebf0
+if ($major > 0 && <*/Cwd/Cwd.xs>) {
+    if ($major < 10 && !extract_from_file('Makefile.SH', qr/^extra_dep=''$/)) {
+        # The Makefile.PL for Unicode::Normalize needs
+        # lib/unicore/CombiningClass.pl. Even without a parallel build, we need
+        # a dependency to ensure that it builds. This is a variant of commit
+        # 9f3ef600c170f61e. Putting this for earlier versions gives us a spot
+        # on which to hang the edits below
+        apply_patch(<<'EOPATCH');
 diff --git a/Makefile.SH b/Makefile.SH
 index f61d0db..6097954 100644
 --- a/Makefile.SH
@@ -667,6 +670,43 @@ index f61d0db..6097954 100644
 +$spitshell >>Makefile <<'!NO!SUBS!'
  
 EOPATCH
+    }
+    if ($major < 14) {
+        # Commits dc0655f797469c47 and d11a62fe01f2ecb2
+        edit_file('Makefile.SH', sub {
+                      my $code = shift;
+                      foreach my $ext (qw(Encode SDBM_File)) {
+                          next if $code =~ /\b$ext\) extra_dep=/s;
+                          $code =~ s!(\) extra_dep="\$extra_dep
+\$this_target: .*?" ;;)
+(    esac
+)!$1
+       $ext) extra_dep="\$extra_dep
+\$this_target: lib/auto/Cwd/Cwd.\$dlext" ;;
+$2!;
+                      }
+                      return $code;
+                  });
+    }
+}
+if ($major == 7) {
+    # Remove commits 9fec149bb652b6e9 and 5bab1179608f81d8, which add/amend
+    # rules to automatically run regen scripts that rebuild C headers. These
+    # cause problems because a git checkout doesn't preserve relative file
+    # modification times, hence the regen scripts may fire. This will obscure
+    # whether the repository had the correct generated headers checked in.
+    # Also, the dependency rules for running the scripts were not correct,
+    # which could cause spurious re-builds on re-running make, and can cause
+    # complete build failures for a parallel make.
+    if (extract_from_file('Makefile.SH',
+                          qr/Writing it this way gives make a big hint to always run opcode\.pl before/)) {
+        system 'git show 70c6e6715e8fec53 | patch -p1'
+            and die;
+    } elsif (extract_from_file('Makefile.SH',
+                               qr/^opcode\.h opnames\.h pp_proto\.h pp\.sym: opcode\.pl$/)) {
+        system 'git show 9fec149bb652b6e9 | patch -p1 -R'
+            and die;
+    }
 }
 
 # There was a bug in makedepend.SH which was fixed in version 96a8704c.
@@ -1214,6 +1254,30 @@ EOFIX
               });
 }
 
+if (-f 'ext/POSIX/Makefile.PL'
+    && extract_from_file('ext/POSIX/Makefile.PL',
+                         qr/Explicitly avoid including/)) {
+    # commit 6695a346c41138df, which effectively reverts 170888cff5e2ffb7
+
+    # PERL5LIB is populated by make_ext.pl with paths to the modules we need
+    # to run, don't override this with "../../lib" since that may not have
+    # been populated yet in a parallel build.
+    apply_patch(<<'EOPATCH');
+diff --git a/ext/POSIX/Makefile.PL b/ext/POSIX/Makefile.PL
+index 392b6fb..9e6d091 100644
+--- a/ext/POSIX/Makefile.PL
++++ b/ext/POSIX/Makefile.PL
+@@ -1,7 +1,3 @@
+-# Explicitly avoid including '.' in @INC; autoloader gets confused since it
+-# can find POSIX.pm, but can't find autosplit.ix.
+-BEGIN { @INC = '../../lib';}
+-#
+ use ExtUtils::MakeMaker;
+ use ExtUtils::Constant 0.11 'WriteConstants';
+ use Config;
+EOPATCH
+}
+
 # Parallel build for miniperl is safe
 system "make $j miniperl </dev/null";