gresource-tool: fix build in case libelf is available on Windows. Fix…

…es #1466

The gresource code uses libelf if available but that also depends on mmap but isn't
guarded with HAVE_MMAP. This can make the build fail under MSYS2 where a mingw version
of libelf exists but there is no mmap.

Instead of guarting the libelf code with HAVE_LIBELF add a new macro named USE_LIBELF
which is only defined if libelf and mmap support are available.

Also install the mingw libelf version for CI so we catch similar errors in the future.

.gitlab-ci/test-msys2.sh

@@ -21,7 +21,8 @@ pacman --noconfirm -S --needed \
     mingw-w64-$MSYS2_ARCH-python3 \
     mingw-w64-$MSYS2_ARCH-python3-pip \
     mingw-w64-$MSYS2_ARCH-toolchain \
-    mingw-w64-$MSYS2_ARCH-zlib
+    mingw-w64-$MSYS2_ARCH-zlib \
+    mingw-w64-$MSYS2_ARCH-libelf
 
 curl -O -J -L "https://github.com/linux-test-project/lcov/releases/download/v1.13/lcov-1.13.tar.gz"
 echo "44972c878482cc06a05fe78eaa3645cbfcbad6634615c3309858b207965d8a23  lcov-1.13.tar.gz" | sha256sum -c

gio/gresource-tool.c

@@ -31,6 +31,9 @@
 #ifdef HAVE_LIBELF
 #include <libelf.h>
 #include <gelf.h>
+#endif
+
+#ifdef HAVE_MMAP
 #include <sys/mman.h>
 #endif
 
@@ -42,6 +45,10 @@
 #include "glib/glib-private.h"
 #endif
 
+#if defined(HAVE_LIBELF) && defined(HAVE_MMAP)
+#define USE_LIBELF
+#endif
+
 /* GResource functions {{{1 */
 static GResource *
 get_resource (const gchar *file)
@@ -133,7 +140,7 @@ extract_resource (GResource   *resource,
 
 /* Elf functions {{{1 */
 
-#ifdef HAVE_LIBELF
+#ifdef USE_LIBELF
 
 static Elf *
 get_elf (const gchar *file,
@@ -353,7 +360,7 @@ print_section_name (GElf_Shdr   *shdr,
   return TRUE;
 }
 
-#endif /* HAVE_LIBELF */
+#endif /* USE_LIBELF */
 
   /* Toplevel commands {{{1 */
 
@@ -365,7 +372,7 @@ cmd_sections (const gchar *file,
 {
   GResource *resource;
 
-#ifdef HAVE_LIBELF
+#ifdef USE_LIBELF
 
   Elf *elf;
   gint fd;
@@ -388,7 +395,7 @@ cmd_sections (const gchar *file,
   else
     {
       g_printerr ("Don't know how to handle %s\n", file);
-#ifndef HAVE_LIBELF
+#ifndef USE_LIBELF
       g_printerr ("gresource is built without elf support\n");
 #endif
     }
@@ -402,7 +409,7 @@ cmd_list (const gchar *file,
 {
   GResource *resource;
 
-#ifdef HAVE_LIBELF
+#ifdef USE_LIBELF
   Elf *elf;
   int fd;
 
@@ -424,7 +431,7 @@ cmd_list (const gchar *file,
   else
     {
       g_printerr ("Don't know how to handle %s\n", file);
-#ifndef HAVE_LIBELF
+#ifndef USE_LIBELF
       g_printerr ("gresource is built without elf support\n");
 #endif
     }
@@ -438,7 +445,7 @@ cmd_extract (const gchar *file,
 {
   GResource *resource;
 
-#ifdef HAVE_LIBELF
+#ifdef USE_LIBELF
 
   Elf *elf;
   int fd;
@@ -461,7 +468,7 @@ cmd_extract (const gchar *file,
   else
     {
       g_printerr ("Don't know how to handle %s\n", file);
-#ifndef HAVE_LIBELF
+#ifndef USE_LIBELF
       g_printerr ("gresource is built without elf support\n");
 #endif
     }