[perl #91354] win32/makefile.mk needs patching for gcc-4.x.x

The current win32/makefile.mk wants us to edit it when we are using
the gcc-4.x.x compiler. Firstly, we have to signify that we are using
gcc-4.x.x, then we have to nominate (from a supplied list) the name of
the helper dll that needs to be copied to the t folder (in order that
the taint.t tests can pass).

The supplied list of candidates is deficient - the name of the helper
dll from one of my gcc compilers is not listed there. Also, I'm now
finding that a second dll (libstdc++-6.dll) needs to be copied to the
t folder - otherwise the taint.t test still crashes.

The attached makefile.mk patch addresses these issues in such a way
that we don't have to do any editting (re the using of gcc-4.x.x) of
the makefile.mk at all.

There's a small discussion about this on the p5p mailing list in the
thread "win32/makefile.mk patch" (15 may 2011).

This change to the makefile.mk means that README.win32 needs a
slight modification - and the attached README.win32 patch addresses
that issue.

The README.win32 patch also alters the link to the 64-bit (mingw64)
compiler made available by kmx. This has nothing to do with the
subject of this bug report, but I don't see why that correction to
the link (as suggested to me by kmx, in private correspondence)
can't be made.

2 files changed, 14 insertions, 23 deletions

diff --git a/README.win32 b/README.win32
index ba9f69a1b5..106d6990cb 100644
--- a/README.win32
+++ b/README.win32
@@ -80,7 +80,7 @@ The Windows SDK can be downloaded from L<http://www.microsoft.com/>.
 The MinGW64 compiler is available at L<http://sourceforge.net/projects/mingw-w64>.
 The latter is actually a cross-compiler targeting Win64. There's also a trimmed
 down compiler (no java, or gfortran) suitable for building perl available at:
-L<http://strawberryperl.com/package/kmx/64_gcctoolchain/mingw64-w64-20100123-kmx-v2.zip>
+L<http://strawberryperl.com/package/kmx/64_gcctoolchain/>
 
 NOTE: If you're using a 32-bit compiler to build perl on a 64-bit Windows
 operating system, then you should set the WIN64 environment variable to "undef".
@@ -362,9 +362,7 @@ may end up building against the installed perl's lib/CORE directory rather
 than the one being tested.
 
 You will have to make sure that CCTYPE is set correctly and that
-CCHOME points to wherever you installed your compiler. If building with
-gcc-4.x.x, you'll also need to uncomment the assignment to GCC_4XX and
-uncomment the assignment to the appropriate GCCHELPERDLL in the makefile.mk.
+CCHOME points to wherever you installed your compiler.
 
 If building with the cross-compiler provided by
 mingw-w64.sourceforge.net you'll need to uncomment the line that sets
diff --git a/win32/makefile.mk b/win32/makefile.mk
index 069e8ed9fa..2cbcdeaa76 100644
--- a/win32/makefile.mk
+++ b/win32/makefile.mk
@@ -200,22 +200,6 @@ CCHOME		*= $(MSVCDIR)
 .ENDIF
 
 #
-# If building with gcc-4.x.x (or x86_64-w64-mingw32-gcc-4.x.x), then
-# uncomment  the following assignment to GCC_4XX, make sure that CCHOME
-# has been set correctly above, and uncomment the appropriate
-# GCCHELPERDLL line.
-# The name of the dll can change, depending upon which vendor has supplied
-# your 4.x.x compiler, and upon the values of "x".
-# (The dll will be in your mingw/bin folder, so check there if you're
-# unsure about the correct name.)
-# Without these corrections, the op/taint.t test script will fail.
-#
-#GCC_4XX		*= define
-#GCCHELPERDLL	*= $(CCHOME)\bin\libgcc_s_sjlj-1.dll
-#GCCHELPERDLL	*= $(CCHOME)\bin\libgcc_s_dw2-1.dll
-#GCCHELPERDLL	*= $(CCHOME)\bin\libgcc_s_1.dll
-
-#
 # uncomment this if you are using x86_64-w64-mingw32 cross-compiler
 # ie if your gcc executable is called 'x86_64-w64-mingw32-gcc'
 # instead of the usual 'gcc'.
@@ -1623,10 +1607,19 @@ test-prep : all utils ..\pod\perltoc.pod
 .ELSE
 	$(XCOPY) $(GLOBEXE) ..\t\$(NULL)
 .ENDIF
+
 .IF "$(CCTYPE)" == "GCC"
-.IF "$(GCC_4XX)" == "define"
-	$(XCOPY) $(GCCHELPERDLL) ..\t\$(NULL)
-.ENDIF
+# If building with gcc versions 4.x.x or greater, then
+# the GCC helper DLL will also need copied to the test directory.
+# The name of the dll can change, depending upon which vendor has supplied
+# your compiler, and upon the values of "x".
+# libstdc++-6.dll is copied if it exists as it, too, may then be needed.
+# Without this copying, the op/taint.t test script will fail.
+	if exist $(CCHOME)\bin\libgcc_s_sjlj-1.dll $(XCOPY) $(CCHOME)\bin\libgcc_s_sjlj-1.dll ..\t\$(NULL)
+	if exist $(CCHOME)\bin\libgcc_s_dw2-1.dll $(XCOPY) $(CCHOME)\bin\libgcc_s_dw2-1.dll ..\t\$(NULL)
+	if exist $(CCHOME)\bin\libgcc_s_1.dll $(XCOPY) $(CCHOME)\bin\libgcc_s_1.dll ..\t\$(NULL)
+	if exist $(CCHOME)\bin\w64gcc_s_sjlj-1.dll $(XCOPY) $(CCHOME)\bin\w64gcc_s_sjlj-1.dll ..\t\$(NULL)
+	if exist $(CCHOME)\bin\libstdc++-6.dll $(XCOPY) $(CCHOME)\bin\libstdc++-6.dll ..\t\$(NULL)
 .ENDIF
 
 test : $(RIGHTMAKE) test-prep