meson: add option to disable tests

During development it can be useful to disable unit testing. By default
tests are built if cmocka is found. To force enable tests run `meson
build -Dtests=enable`. To disable tests run `meson build
-Dtests=disabled`.

Change-Id: I384c904c577b265dfe36bf46bf07c641bc29de9b
Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/63832
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
Reviewed-by: Felix Singer <felixsinger@posteo.net>

meson.build

@@ -506,30 +506,35 @@ executable(
 
 subdir('util')
 
+# Use `.auto() or .enabled()` instead of `.allowed()` to keep the minimum meson version as low as possible.
+# `.allowed()` gets introduced in 0.59.0
+if get_option('tests').auto() or get_option('tests').enabled()
 # unit-test framework
 cmocka_dep = dependency(
-  'cmocka',
+    'cmocka',
-  fallback: ['cmocka', 'cmocka_dep'],
+    fallback: ['cmocka', 'cmocka_dep'],
-  required: false
+    required : get_option('tests')
-)
+  )
-flashrom_test_dep = declare_dependency(
-  include_directories : include_dir,
-  sources : [
-    srcs,
-    'cli_common.c',
-    'cli_output.c',
-    'flashrom.c',
-  ],
-  compile_args : [
-    '-includestdlib.h',
-    '-includeunittest_env.h',
-    '-includehwaccess_x86_io_unittest.h'
-  ],
-  dependencies : [
-    deps,
-  ],
-)
 
-if cmocka_dep.found()
+  flashrom_test_dep = declare_dependency(
-  subdir('tests')
+    include_directories : include_dir,
+    sources : [
+      srcs,
+      'cli_common.c',
+      'cli_output.c',
+      'flashrom.c',
+    ],
+    compile_args : [
+      '-includestdlib.h',
+      '-includeunittest_env.h',
+      '-includehwaccess_x86_io_unittest.h'
+    ],
+    dependencies : [
+      deps,
+    ],
+  )
+
+  if cmocka_dep.found()
+    subdir('tests')
+  endif
 endif

meson_options.txt

@@ -42,3 +42,4 @@ option('config_stlinkv3_spi', type : 'boolean', value : true, description : 'STM
 option('config_lspcon_i2c_spi', type : 'boolean', value : false, description : 'Parade lspcon USB-C to HDMI protocol translator')
 option('config_mediatek_i2c_spi', type : 'boolean', value : false, description : 'MediaTek LCD controller')
 option('config_realtek_mst_i2c_spi', type : 'boolean', value : true, description : 'Realtek MultiStream Transport MST')
+option('tests', type : 'feature', value : 'auto', description : 'Build unit tests')