meson: fix warnings about comparing unlike types
In the old days (0.42.x), when mesa's meson system was written the
recommendation for handling conditional dependencies was to define them
as empty lists. When meson would evaluate the dependencies of a target
it would recursively flatten all of the arguments, and empty lists would
be removed. There are some problems with this, among them that lists and
dependencies have different methods (namely .found()), so the
recommendation changed to use `dependency('', required : false)` for
such cases. This has the advantage of providing a .found() method, so
there is no need to do things like `dep_foo != [] and dep_foo.found()`,
such a dependency should never exist.
I've tested this with 0.42 (the minimum we claim to support) and 0.45.
On 0.45 this removes warnings about comparing unlike types, such as:
meson.build:1337: WARNING: Trying to compare values of different types
(DependencyHolder, list) using !=.
v2: - Use dependency('', required : false) instead of
declare_dependency(), the later will always report that it is
found, which is not what we want.
Signed-off-by: Dylan Baker <dylan.c.baker@intel.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
diff --git a/meson.build b/meson.build
index ee2b415..7b01d0a 100644
--- a/meson.build
+++ b/meson.build
@@ -29,6 +29,8 @@
default_options : ['buildtype=debugoptimized', 'c_std=c99', 'cpp_std=c++11']
)
+null_dep = dependency('', required : false)
+
system_has_kms_drm = ['openbsd', 'netbsd', 'freebsd', 'dragonfly', 'linux'].contains(host_machine.system())
# Arguments for the preprocessor, put these in a separate array from the C and
@@ -422,7 +424,7 @@
_vdpau = 'true'
endif
with_gallium_vdpau = _vdpau == 'true'
-dep_vdpau = []
+dep_vdpau = null_dep
if with_gallium_vdpau
dep_vdpau = dependency('vdpau', version : '>= 1.1')
dep_vdpau = declare_dependency(
@@ -461,7 +463,7 @@
_xvmc = 'true'
endif
with_gallium_xvmc = _xvmc == 'true'
-dep_xvmc = []
+dep_xvmc = null_dep
if with_gallium_xvmc
dep_xvmc = dependency('xvmc', version : '>= 1.0.6')
endif
@@ -491,7 +493,8 @@
error('OMX state tracker requires at least one of the following gallium drivers: r600, radeonsi, nouveau.')
endif
endif
-dep_omx = []
+with_gallium_omx = _omx
+dep_omx = null_dep
dep_omx_other = []
if ['auto', 'bellagio'].contains(_omx)
dep_omx = dependency(
@@ -579,7 +582,7 @@
_va = 'true'
endif
with_gallium_va = _va == 'true'
-dep_va = []
+dep_va = null_dep
if with_gallium_va
dep_va = dependency('libva', version : '>= 0.38.0')
dep_va_headers = declare_dependency(
@@ -638,7 +641,7 @@
with_gallium_opencl = true
with_opencl_icd = _opencl == 'icd'
else
- dep_clc = []
+ dep_clc = null_dep
with_gallium_opencl = false
with_gallium_icd = false
endif
@@ -831,7 +834,7 @@
endif
# Check for GCC style atomics
-dep_atomic = declare_dependency()
+dep_atomic = null_dep
if cc.compiles('int main() { int n; return __atomic_load_n(&n, __ATOMIC_ACQUIRE); }',
name : 'GCC atomic builtins')
@@ -976,7 +979,7 @@
# check for dl support
if cc.has_function('dlopen')
- dep_dl = []
+ dep_dl = null_dep
else
dep_dl = cc.find_library('dl')
endif
@@ -995,7 +998,7 @@
# Determine whether or not the rt library is needed for time functions
if cc.has_function('clock_gettime')
- dep_clock = []
+ dep_clock = null_dep
else
dep_clock = cc.find_library('rt')
endif
@@ -1013,7 +1016,7 @@
dep_elf = cc.find_library('elf')
endif
else
- dep_elf = []
+ dep_elf = null_dep
endif
dep_expat = dependency('expat')
# this only exists on linux so either this is linux and it will be found, or
@@ -1024,12 +1027,12 @@
# but we always want to use the same version for all libdrm modules. That means
# even if driver foo requires 2.4.0 and driver bar requires 2.4.3, if foo and
# bar are both on use 2.4.3 for both of them
-dep_libdrm_amdgpu = []
-dep_libdrm_radeon = []
-dep_libdrm_nouveau = []
-dep_libdrm_etnaviv = []
-dep_libdrm_freedreno = []
-dep_libdrm_intel = []
+dep_libdrm_amdgpu = null_dep
+dep_libdrm_radeon = null_dep
+dep_libdrm_nouveau = null_dep
+dep_libdrm_etnaviv = null_dep
+dep_libdrm_freedreno = null_dep
+dep_libdrm_intel = null_dep
_drm_amdgpu_ver = '2.4.91'
_drm_radeon_ver = '2.4.71'
@@ -1114,7 +1117,7 @@
dep_llvm = dependency('llvm', version : _llvm_version, modules : llvm_modules)
with_llvm = true
else
- dep_llvm = []
+ dep_llvm = null_dep
with_llvm = false
endif
if with_llvm
@@ -1144,7 +1147,7 @@
error('The following drivers require LLVM: Radv, RadeonSI, SWR. One of these is enabled, but LLVM is disabled.')
endif
-dep_glvnd = []
+dep_glvnd = null_dep
if with_glvnd
dep_glvnd = dependency('libglvnd', version : '>= 0.2.0')
pre_args += '-DUSE_LIBGLVND=1'
@@ -1156,7 +1159,7 @@
pre_args += '-DHAVE_VALGRIND'
endif
else
- dep_valgrind = []
+ dep_valgrind = null_dep
endif
# pthread stubs. Lets not and say we didn't
@@ -1164,7 +1167,7 @@
prog_bison = find_program('bison', required : with_any_opengl)
prog_flex = find_program('flex', required : with_any_opengl)
-dep_selinux = []
+dep_selinux = null_dep
if get_option('selinux')
dep_selinux = dependency('libselinux')
pre_args += '-DMESA_SELINUX'
@@ -1178,7 +1181,7 @@
pre_args += '-DHAVE_LIBUNWIND'
endif
else
- dep_unwind = []
+ dep_unwind = null_dep
endif
# TODO: gallium-hud
@@ -1217,29 +1220,29 @@
pre_args += ['-DHAVE_WAYLAND_PLATFORM', '-DWL_HIDE_DEPRECATED']
else
prog_wl_scanner = []
- dep_wl_protocols = []
- dep_wayland_client = []
- dep_wayland_server = []
+ dep_wl_protocols = null_dep
+ dep_wayland_client = null_dep
+ dep_wayland_server = null_dep
wayland_dmabuf_xml = ''
endif
-dep_x11 = []
-dep_xext = []
-dep_xdamage = []
-dep_xfixes = []
-dep_x11_xcb = []
-dep_xcb = []
-dep_xcb_glx = []
-dep_xcb_dri2 = []
-dep_xcb_dri3 = []
-dep_dri2proto = []
-dep_glproto = []
-dep_xxf86vm = []
-dep_xcb_dri3 = []
-dep_xcb_present = []
-dep_xcb_sync = []
-dep_xcb_xfixes = []
-dep_xshmfence = []
+dep_x11 = null_dep
+dep_xext = null_dep
+dep_xdamage = null_dep
+dep_xfixes = null_dep
+dep_x11_xcb = null_dep
+dep_xcb = null_dep
+dep_xcb_glx = null_dep
+dep_xcb_dri2 = null_dep
+dep_xcb_dri3 = null_dep
+dep_dri2proto = null_dep
+dep_glproto = null_dep
+dep_xxf86vm = null_dep
+dep_xcb_dri3 = null_dep
+dep_xcb_present = null_dep
+dep_xcb_sync = null_dep
+dep_xcb_xfixes = null_dep
+dep_xshmfence = null_dep
if with_platform_x11
if with_glx == 'xlib' or with_glx == 'gallium-xlib'
dep_x11 = dependency('x11')
@@ -1299,7 +1302,7 @@
pre_args += '-DHAVE_LIBSENSORS=1'
endif
else
- dep_lmsensors = []
+ dep_lmsensors = null_dep
endif
# TODO: gallium tests
@@ -1334,7 +1337,7 @@
if dep_libdrm.found()
gl_priv_reqs += 'libdrm >= 2.4.75'
endif
-if dep_xxf86vm != [] and dep_xxf86vm.found()
+if dep_xxf86vm.found()
gl_priv_reqs += 'xxf86vm'
endif
if with_dri_platform == 'drm'
@@ -1348,7 +1351,7 @@
if dep_m.found()
gl_priv_libs += '-lm'
endif
-if dep_dl != [] and dep_dl.found()
+if dep_dl.found()
gl_priv_libs += '-ldl'
endif