Re: Possible fix for mingw32 directory relocation problems

[Doug Evans <dje@google.com>]

[-- Attachment #1: Type: text/plain, Size: 2570 bytes --]

On Mon, Jan 16, 2012 at 7:03 AM, Pierre Muller
<pierre.muller@ics-cnrs.unistra.fr> wrote:
>  After some debugging,
> we finally managed to find out that
> mingw32 specific directory relocations are related
> to msys -> mingw32 argument conversions.

Thanks for the detective work!

> http://sourceware.org/ml/gdb-patches/2012-01/msg00537.html
>
> This is explained in:
>
> http://www.mingw.org/wiki/Posix_path_conversion
>
> This page also allows to understand why
> using mingw32 style paths for prefix at configure
> level works and avoid the troubles encountered.
>
> This conversion concerns defines passed by command line arguments
> to gcc, which are specific to main.o
> compilation, as found in gdb/Makefile.in
> 1520-
> 1521:# main.o needs an explicit build rule to get TARGET_SYSTEM_ROOT and
> BINDIR.
> 1522-main.o: $(srcdir)/main.c
> 1523:   $(COMPILE) $(TARGET_SYSTEM_ROOT_DEFINE) -DBINDIR=\"$(bindir)\"
> $(srcdir)/main.c
> 1524-   $(POSTCOMPILE)
> 1525-
>
>  But this leads to a conversion:
>  -DBINDIR="/usr/local/bin\"
> gets transformed into '-D' 'BINDIR="E:/msys/mingw32/msys/1.0/local/bin"'
>
>  While other pates used in relocate_gdb_directory calls
> are macros defined inside gdb/config.h
>
> config.h:#define DEBUGDIR "/usr/local/lib/debug"
> config.h:#define GDB_DATADIR "/usr/local/share/gdb"
> config.h:#define JIT_READER_DIR "/usr/local/lib/gdb"
>
> Those are of course not affected by msys command-line argument conversion.
>
>  The first question is:
> Why do we need to pass BINDIR (and TARGET_SYSTEM_ROOT_DEFINE)
> at the command line instead of inside config.h as for other
> directories?

We don't need to pass them on the command line.

>  If the answer to the first question is "we don't",
> then I need help about how to convert those
> Makefile.in variables into new entries of generated config.h file.

Possible patch is attached.
Can you try it?  I don't know that it will fix things, but based on
what you've said it seems reasonable to try.

There is an open issue that the current --with-sysroot relocatability
computation is different than what GDB_AC_WITH_DIR does.  We should
fix that regardless.  I've left that as a separate issue.  [We should
resolve it before checkin, but at this point I'm willing to just
experiment until we know what the right fix is.]

>  I don't have enough knowledge about autoconf scripts to
> handle this...
>  An extra bonus of this change would be that it would
> render the special rule for main.o compilation unnecessary.

[-- Attachment #2: mingw-config.patch --]
[-- Type: application/octet-stream, Size: 3884 bytes --]

2012-01-16  Doug Evans  <dje@sebabeach.org>

	* Makefile.in (TARGET_SYSTEM_ROOT, TARGET_SYSTEM_ROOT_DEFINE): Delete.
	(main.o): Remove rule.
	* configure.ac (BINDIR): Define in config.h.
	(--with-sysroot): Define using GDB_AC_WITH_DIR.
	* configure: Regenerate.
	* config.in: Regenerate.

Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.1186
diff -u -p -r1.1186 Makefile.in
--- Makefile.in	10 Jan 2012 16:30:43 -0000	1.1186
+++ Makefile.in	17 Jan 2012 06:42:31 -0000
@@ -166,10 +166,6 @@ INTL = @LIBINTL@
 INTL_DEPS = @LIBINTL_DEP@
 INTL_CFLAGS = @INCINTL@
 
-# Did the user give us a --with-sysroot option?
-TARGET_SYSTEM_ROOT = @TARGET_SYSTEM_ROOT@
-TARGET_SYSTEM_ROOT_DEFINE = @TARGET_SYSTEM_ROOT_DEFINE@
-
 # Did the user give us a --with-gdb-datadir option?
 GDB_DATADIR = @GDB_DATADIR@
 
@@ -1518,11 +1514,6 @@ ALLDEPFILES = \
 # Some files need explicit build rules (due to -Werror problems) or due
 # to sub-directory fun 'n' games.
 
-# main.o needs an explicit build rule to get TARGET_SYSTEM_ROOT and BINDIR.
-main.o: $(srcdir)/main.c
-	$(COMPILE) $(TARGET_SYSTEM_ROOT_DEFINE) -DBINDIR=\"$(bindir)\" $(srcdir)/main.c
-	$(POSTCOMPILE)
-
 # FIXME: cagney/2003-08-10: "monitor.c" gets -Wformat-nonliteral
 # errors.  It turns out that that is the least of monitor.c's
 # problems.  The function print_vsprintf appears to be using
Index: configure.ac
===================================================================
RCS file: /cvs/src/src/gdb/configure.ac,v
retrieving revision 1.152
diff -u -p -r1.152 configure.ac
--- configure.ac	4 Jan 2012 08:17:00 -0000	1.152
+++ configure.ac	17 Jan 2012 06:42:32 -0000
@@ -125,6 +125,14 @@ GDB_AC_WITH_DIR(DEBUGDIR, separate-debug
     [look for global separate debug info in this path @<:@LIBDIR/debug@:>@],
     [${libdir}/debug])
 
+# We can't pass paths as command line arguments.
+# Mingw32 tries to be clever and will convert the paths for us.
+# For example -DBINDIR="/usr/local/bin" passed on the command line may get
+# converted to  -DBINDIR="E:/msys/mingw32/msys/1.0/local/bin".
+# This breaks GDB's relocatable path conversions since paths passed in
+# config.h do not get so translated.
+AC_DEFINE_DIR(BINDIR, bindir, [Directory of programs.])
+
 # GDB's datadir relocation
 
 GDB_AC_WITH_DIR(GDB_DATADIR, gdb-datadir,
@@ -1753,42 +1761,12 @@ fi
 
 dnl Handle optional features that can be enabled.
 
-target_sysroot_reloc=0
-AC_ARG_WITH(sysroot,
-AS_HELP_STRING([--with-sysroot@<:@=DIR@:>@], [search for usr/lib et al within DIR]),
-[
- case ${with_sysroot} in
- yes) TARGET_SYSTEM_ROOT='${exec_prefix}/${target_alias}/sys-root' ;;
- *) TARGET_SYSTEM_ROOT=$with_sysroot ;;
- esac
-
- TARGET_SYSTEM_ROOT_DEFINE='-DTARGET_SYSTEM_ROOT=\"$(TARGET_SYSTEM_ROOT)\"'
-
- if test "x$prefix" = xNONE; then
-  test_prefix=/usr/local
- else
-  test_prefix=$prefix
- fi
- if test "x$exec_prefix" = xNONE || test "x$exec_prefix" = 'x${prefix}'; then
-  test_exec_prefix=$test_prefix
- else
-  test_exec_prefix=$exec_prefix
- fi
- case ${TARGET_SYSTEM_ROOT} in
- "${test_prefix}"|"${test_prefix}/"*|\
- "${test_exec_prefix}"|"${test_exec_prefix}/"*|\
- '${prefix}'|'${prefix}/'*|\
- '${exec_prefix}'|'${exec_prefix}/'*)
-   target_sysroot_reloc=1
-   ;;
- esac
-], [
- TARGET_SYSTEM_ROOT=
- TARGET_SYSTEM_ROOT_DEFINE='-DTARGET_SYSTEM_ROOT=\"\"'
-])
-TARGET_SYSTEM_ROOT_DEFINE="$TARGET_SYSTEM_ROOT_DEFINE -DTARGET_SYSTEM_ROOT_RELOCATABLE=$target_sysroot_reloc"
-AC_SUBST(TARGET_SYSTEM_ROOT)
-AC_SUBST(TARGET_SYSTEM_ROOT_DEFINE)
+if test "x$with_sysroot" = xyes; then
+  with_sysroot="${exec_prefix}/${target_alias}/sys-root"
+fi
+GDB_AC_WITH_DIR(TARGET_SYSTEM_ROOT, sysroot,
+    [search for usr/lib et al within PATH],
+    [])
 
 GDB_AC_WITH_DIR(SYSTEM_GDBINIT, system-gdbinit,
     [automatically load a system-wide gdbinit file],