[PATCH 03/17] meson, cutils: allow non-relocatable installs

[Paolo Bonzini <pbonzini@redhat.com>]

Suggested-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 meson.build                   | 21 +++++++++++++++++++++
 meson_options.txt             |  2 ++
 scripts/meson-buildoptions.sh |  3 +++
 util/cutils.c                 | 11 ++++++++---
 4 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/meson.build b/meson.build
index 010d2c649c2..251838f2609 100644
--- a/meson.build
+++ b/meson.build
@@ -2111,6 +2111,7 @@ config_host_data.set('CONFIG_OPENGL', opengl.found())
 config_host_data.set('CONFIG_PLUGIN', get_option('plugins'))
 config_host_data.set('CONFIG_RBD', rbd.found())
 config_host_data.set('CONFIG_RDMA', rdma.found())
+config_host_data.set('CONFIG_RELOCATABLE', get_option('relocatable'))
 config_host_data.set('CONFIG_SAFESTACK', get_option('safe_stack'))
 config_host_data.set('CONFIG_SDL', sdl.found())
 config_host_data.set('CONFIG_SDL_IMAGE', sdl_image.found())
@@ -4054,6 +4055,7 @@ if 'simple' in get_option('trace_backends')
 endif
 summary_info += {'D-Bus display':     dbus_display}
 summary_info += {'QOM debugging':     get_option('qom_cast_debug')}
+summary_info += {'Relocatable install': get_option('relocatable')}
 summary_info += {'vhost-kernel support': have_vhost_kernel}
 summary_info += {'vhost-net support': have_vhost_net}
 summary_info += {'vhost-user support': have_vhost_user}
@@ -4356,3 +4358,22 @@ if host_arch == 'unknown' or not supported_oses.contains(targetos)
   message('If you want to help supporting QEMU on this platform, please')
   message('contact the developers at qemu-devel@nongnu.org.')
 endif
+
+actually_reloc = get_option('relocatable')
+# check if get_relocated_path() is actually able to relocate paths
+if get_option('relocatable') and \
+  not (get_option('prefix') / get_option('bindir')).startswith(get_option('prefix') / '')
+  message()
+  warning('bindir not included within prefix, the installation will not be relocatable.')
+  message()
+  message('Use --disable-relocatable to remove this warning.')
+  actually_reloc = false
+endif
+if not actually_reloc and (targetos == 'windows' or get_option('relocatable'))
+  if targetos == 'windows'
+    message()
+    warning('Windows installs should usually be relocatable.')
+  endif
+  message()
+  message('QEMU will have to be installed under ' + get_option('prefix') + '.')
+endif
diff --git a/meson_options.txt b/meson_options.txt
index 6a17b909680..e237b268469 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -101,6 +101,8 @@ option('cfi_debug', type: 'boolean', value: false,
        description: 'Verbose errors in case of CFI violation')
 option('multiprocess', type: 'feature', value: 'auto',
        description: 'Out of process device emulation support')
+option('relocatable', type : 'boolean', value : 'true',
+       description: 'toggle relocatable install')
 option('vfio_user_server', type: 'feature', value: 'disabled',
        description: 'vfio-user server support')
 option('dbus_display', type: 'feature', value: 'auto',
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index 2a74b0275b3..d4b89e6b443 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -17,6 +17,7 @@ meson_options_help() {
   printf "%s\n" '                           code for the Hexagon frontend'
   printf "%s\n" '  --disable-install-blobs  install provided firmware blobs'
   printf "%s\n" '  --disable-qom-cast-debug cast debugging support'
+  printf "%s\n" '  --disable-relocatable    toggle relocatable install'
   printf "%s\n" '  --docdir=VALUE           Base directory for documentation installation'
   printf "%s\n" '                           (can be empty) [share/doc]'
   printf "%s\n" '  --enable-block-drv-whitelist-in-tools'
@@ -421,6 +422,8 @@ _meson_option_parse() {
     --disable-rbd) printf "%s" -Drbd=disabled ;;
     --enable-rdma) printf "%s" -Drdma=enabled ;;
     --disable-rdma) printf "%s" -Drdma=disabled ;;
+    --enable-relocatable) printf "%s" -Drelocatable=true ;;
+    --disable-relocatable) printf "%s" -Drelocatable=false ;;
     --enable-replication) printf "%s" -Dreplication=enabled ;;
     --disable-replication) printf "%s" -Dreplication=disabled ;;
     --enable-rng-none) printf "%s" -Drng_none=true ;;
diff --git a/util/cutils.c b/util/cutils.c
index c99d26c5e2d..64f817b477b 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -1178,9 +1178,11 @@ char *get_relocated_path(const char *dir)
 #else
         g_string_append(result, dir);
 #endif
-    } else if (!starts_with_prefix(dir) || !starts_with_prefix(bindir)) {
-        g_string_assign(result, dir);
-    } else {
+        goto out;
+    }
+
+    if (IS_ENABLED(CONFIG_RELOCATABLE) &&
+        starts_with_prefix(dir) && starts_with_prefix(bindir)) {
         g_string_assign(result, exec_dir);
 
         /* Advance over common components.  */
@@ -1203,7 +1205,10 @@ char *get_relocated_path(const char *dir)
             assert(G_IS_DIR_SEPARATOR(dir[-1]));
             g_string_append(result, dir - 1);
         }
+        goto out;
     }
 
+    g_string_assign(result, dir);
+out:
     return g_string_free(result, false);
 }
-- 
2.41.0