Re: Guile with win32 cross compiling

[Andy Wingo]

Hi Volker,

On Fri 01 Apr 2011 20:50, Volker Grabsch <address@hidden> writes:

>     "Portability fixes for win32 cross compiling"
>     http://www.mail-archive.com/address@hidden/msg05308.html

Ah yes.  Thanks for that link.  And thank you for your ongoing patience
:-)

> Gen-scmconfig is a code generator, so it has to be built using
> the native toolchain. However, it is supposed to write take its
> values from the <uniconv.h> of the cross tool chain. Thus, the
> "/usr/include" equivalent of the cross tool chain is added to
> the include path when compiling gen-scmconfig. And here the
> trouble starts, because mixing headers of various toolchains
> is never a good idea. Among others, basic headers like <stdio.h>
> are now taken from the cross toolchain, referring to objects that
> don't even exist in the native toolchain, causing the build to
> fail with all kinds of strange error messages.

Hmmm.  Well.  We have other code generators in Guile's build system;
notably the configure script (via config.h and other output files).
What do folks think about the attached patch?

Regards,

Andy

>From b03f8337ea62091208680fab901606c9af360a5d Mon Sep 17 00:00:00 2001
From: Andy Wingo <address@hidden>
Date: Tue, 12 Apr 2011 13:12:56 +0200
Subject: [PATCH] check for iconveh values at configure-time

* configure.ac: Check for the iconveh values here, instead of relying on
  gen-scmconfig to know them.  That doesn't work in general because
  gen-scmconfig runs on the build machine, not the target machine.

* libguile/Makefile.am (gen-scmconfig.$(OBJEXT)): Revert rule to the
  revision before 533d8212.

* libguile/gen-scmconfig.h.in (SCM_I_GSC_ICONVEH_ERROR):
  (SCM_I_GSC_ICONVEH_QUESTION_MARK):
  (SCM_I_GSC_ICONVEH_ESCAPE_SEQUENCE):
* libguile/gen-scmconfig.c: Use configure-time substitutions to set
  SCM_ICONVEH_ERROR_HANDLER et al.
---
 configure.ac                |   64 +++++++++++++++++++++++++++++++++++++++++++
 libguile/Makefile.am        |   12 +++-----
 libguile/gen-scmconfig.c    |    9 +++---
 libguile/gen-scmconfig.h.in |    3 ++
 4 files changed, 76 insertions(+), 12 deletions(-)

diff --git a/configure.ac b/configure.ac
index 45438c8..1f68e0f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1188,6 +1188,70 @@ GUILE_STRUCT_UTIMBUF
 
 #--------------------------------------------------------------------
 #
+# What values do the iconv error handlers have?
+#
+# The only place that we need iconv in our public interfaces is for
+# the error handlers, which are just ints.  So we weaken our
+# dependency by looking up those values at configure-time.
+#--------------------------------------------------------------------
+SCM_I_GSC_ICONVEH_ERROR=0
+SCM_I_GSC_ICONVEH_QUESTION_MARK=1
+SCM_I_GSC_ICONVEH_ESCAPE_SEQUENCE=2
+AC_MSG_CHECKING([for iconveh_error])
+AC_RUN_IFELSE([AC_LANG_SOURCE(
+[AC_INCLUDES_DEFAULT
+#include <uniconv.h>
+int
+main (int argc, char *argv[])
+{
+  if (argc > 1)
+    printf ("%d\n", (int)iconveh_error);
+  return 0;
+}])],
+              [SCM_I_GSC_ICONVEH_ERROR=`./conftest$EXEEXT pretty-please`
+                AC_MSG_RESULT([$SCM_I_GSC_ICONVEH_ERROR])],
+              [AC_MSG_FAILURE([failed to get iconveh_error])],
+              [AC_MSG_WARN([assuming $SCM_I_GSC_ICONVEH_ERROR for 
cross-compilation])])
+
+AC_MSG_CHECKING([for iconveh_question_mark])
+AC_RUN_IFELSE([AC_LANG_SOURCE(
+[AC_INCLUDES_DEFAULT
+#include <uniconv.h>
+int
+main (int argc, char *argv[])
+{
+  if (argc > 1)
+    printf ("%d\n", (int)iconveh_question_mark);
+  return 0;
+}])],
+              [SCM_I_GSC_ICONVEH_QUESTION_MARK=`./conftest$EXEEXT 
pretty-please`
+                AC_MSG_RESULT([$SCM_I_GSC_ICONVEH_QUESTION_MARK])],
+              [AC_MSG_FAILURE([failed to get iconveh_question_mark])],
+              [AC_MSG_WARN([assuming $SCM_I_GSC_ICONVEH_QUESTION_MARK for 
cross-compilation])])
+
+AC_MSG_CHECKING([for iconveh_escape_sequence])
+AC_RUN_IFELSE([AC_LANG_SOURCE(
+[AC_INCLUDES_DEFAULT
+#include <uniconv.h>
+int
+main (int argc, char *argv[])
+{
+  if (argc > 1)
+    printf ("%d\n", (int)iconveh_escape_sequence);
+  return 0;
+}])],
+              [SCM_I_GSC_ICONVEH_ESCAPE_SEQUENCE=`./conftest$EXEEXT 
pretty-please`
+                AC_MSG_RESULT([$SCM_I_GSC_ICONVEH_ESCAPE_SEQUENCE])],
+              [AC_MSG_FAILURE([failed to get iconveh_escape_sequence])],
+              [AC_MSG_WARN([assuming $SCM_I_GSC_ICONVEH_ESCAPE_SEQUENCE for 
cross-compilation])])
+
+AC_SUBST([SCM_I_GSC_ICONVEH_ERROR])
+AC_SUBST([SCM_I_GSC_ICONVEH_QUESTION_MARK])
+AC_SUBST([SCM_I_GSC_ICONVEH_ESCAPE_SEQUENCE])
+
+
+#--------------------------------------------------------------------
+#
 # Which way does the stack grow?
 #
 # Following code comes from Autoconf 2.61's internal _AC_LIBOBJ_ALLOCA
diff --git a/libguile/Makefile.am b/libguile/Makefile.am
index ac27eb8..ffb4059 100644
--- a/libguile/Makefile.am
+++ b/libguile/Makefile.am
@@ -55,13 +55,11 @@ gen_scmconfig_SOURCES = gen-scmconfig.c
 ## Override default rule; this should be compiled for BUILD host.
 ## For some reason, OBJEXT does not include the dot
 gen-scmconfig.$(OBJEXT): gen-scmconfig.c
-       $(AM_V_GEN)                                                     \
-       if [ "$(cross_compiling)" = "yes" ]; then                       \
-               $(CC_FOR_BUILD) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) \
-                 $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)     \
-                 -c -o $@ $<;                                          \
-       else                                                            \
-               $(COMPILE) -c -o $@ $<;                                 \
+       $(AM_V_GEN) \
+       if [ "$(cross_compiling)" = "yes" ]; then \
+               $(CC_FOR_BUILD) $(DEFS) $(DEFAULT_INCLUDES) $(AM_CPPFLAGS) -c 
-o $@ $<; \
+       else \
+               $(COMPILE) -c -o $@ $<; \
        fi
 
 ## Override default rule; this should run on BUILD host.
diff --git a/libguile/gen-scmconfig.c b/libguile/gen-scmconfig.c
index 5834346..176f25c 100644
--- a/libguile/gen-scmconfig.c
+++ b/libguile/gen-scmconfig.c
@@ -123,7 +123,6 @@
 
 #include <stdio.h>
 #include <string.h>
-#include <uniconv.h>
 
 #define pf printf
 
@@ -397,11 +396,11 @@ main (int argc, char *argv[])
 
   pf ("\n");
   pf ("/* Constants from uniconv.h.  */\n");
-  pf ("#define SCM_ICONVEH_ERROR %d\n", (int) iconveh_error);
-  pf ("#define SCM_ICONVEH_QUESTION_MARK %d\n", 
-      (int) iconveh_question_mark);
+  pf ("#define SCM_ICONVEH_ERROR %d\n", SCM_I_GSC_ICONVEH_ERROR);
+  pf ("#define SCM_ICONVEH_QUESTION_MARK %d\n",
+      SCM_I_GSC_ICONVEH_QUESTION_MARK);
   pf ("#define SCM_ICONVEH_ESCAPE_SEQUENCE %d\n",
-      (int) iconveh_escape_sequence);  
+      SCM_I_GSC_ICONVEH_ESCAPE_SEQUENCE);  
 
   printf ("#endif\n");
 
diff --git a/libguile/gen-scmconfig.h.in b/libguile/gen-scmconfig.h.in
index 125720a..30f43d7 100644
--- a/libguile/gen-scmconfig.h.in
+++ b/libguile/gen-scmconfig.h.in
@@ -31,6 +31,9 @@
 #define SCM_I_GSC_NEED_BRACES_ON_PTHREAD_MUTEX_INITIALIZER 
@SCM_I_GSC_NEED_BRACES_ON_PTHREAD_MUTEX_INITIALIZER@
 #define SCM_I_GSC_HAVE_THREAD_STORAGE_CLASS 
@SCM_I_GSC_HAVE_THREAD_STORAGE_CLASS@
 #define SCM_I_GSC_HAVE_STRUCT_DIRENT64 @SCM_I_GSC_HAVE_STRUCT_DIRENT64@
+#define SCM_I_GSC_ICONVEH_ERROR @SCM_I_GSC_ICONVEH_ERROR@
+#define SCM_I_GSC_ICONVEH_QUESTION_MARK @SCM_I_GSC_ICONVEH_QUESTION_MARK@
+#define SCM_I_GSC_ICONVEH_ESCAPE_SEQUENCE @SCM_I_GSC_ICONVEH_ESCAPE_SEQUENCE@
 
 /*
   Local Variables:
-- 
1.7.3.4

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