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Re: [PATCH] Cygwin: Build cygwin-console-helper with correct compiler

Corinna Vinschen wrote:
On Jun 26 01:48, Mark Geisert wrote:
Corinna Vinschen wrote:
On Jun 25 00:54, Mark Geisert wrote:
   winsup/utils/ | 2 +-
   1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/utils/ b/winsup/utils/
index b64f457e7..cebf39572 100644
--- a/winsup/utils/
+++ b/winsup/utils/
@@ -64,7 +64,7 @@ MINGW_BINS := ${addsuffix .exe,cygcheck cygwin-console-helper ldh strace}
   # List all objects to be compiled in MinGW mode.  Any object not on this
   # list will will be compiled in Cygwin mode implicitly, so there is no
   # need for a CYGWIN_OBJS.
-MINGW_OBJS := bloda.o cygcheck.o dump_setup.o ldh.o path.o strace.o
+MINGW_OBJS := bloda.o cygcheck.o cygwin-console-helper.o dump_setup.o ldh.o path.o strace.o
   CYGCHECK_OBJS:=cygcheck.o bloda.o path.o dump_setup.o

Careful!  This leads to a warning when building on 64 bit: In function 'int main(int, char**)': warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
     HANDLE h = (HANDLE) strtoul (argv[1], &end, 0);
                                                  ^ warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
     h = (HANDLE) strtoul (argv[2], &end, 0);

Note that strtoul returns an unsigned long.  Mingw compiles
for native Windows, which is LLP64 rather than LP64:

    mingw:sizeof(long) == 4
    cygwin:sizeof(long) == 8

This needs fixing as well (use strtoull).

I appreciate the comments.  These warnings have "always" been present.

I have to amend my statement. Warnings during whole-tree builds in general have "always" been present but I cannot be 100% sure this particular warning was present. I looked through my most recent make log and there are only compiler warnings in newlib, not in winsup. Sorry for my confusion.

I don't see any warning in terms of building cygwin-console-helper in
the current state.  However, it suddenly occured to me that, even without
a warning, this was always wrong.  The compiler generates code for 8 byte
long and the linker links against libs expecting 4 byte longs.

The fact that this works is ... not exactly magic, but first, the
arguments and return values are in registers anyway, and second, HANDLEs
are only using the lower 4 bytes even though they are 8 bytes in size.

I didn't make clear the reason for this one-line patch to A
'make -j 6' over the Cygwin source tree would sometimes fail because the
link step for cygwin-console-helper uses a different gcc than the compile
step did in parallel builds.

Huh, really?  I'm building with make -j42 on a 32 core machine, but I
never saw this problem.

Well that's a very good counterexample. I attributed it to parallel make steps but it was rare even with that condition. When the build failed it was because linking with cygwin-console-helper.o was provoking an error something like "file format not recognized". Which now appears to me to possibly be a 32/64 issue of mismatched tools.

Let's drop this report for now and I'll be sure to report more accurately if it happens again.

   Can you accept this patch as-is for what it
does for builds?

Yes, we can do that, but it might be a good idea to order the patches
so that the *first* patch fixes the actual problem in cygwin-console-helper
and the *second* patch fixes the Makefile.  Consider this patch approved,
I just wait for the other one, ok?

I've now submitted a patch for the actual problem separately. Thanks for patiently helping me help where I can.


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