Add meson.override_dependency()

Similar to meson.override_find_program() but overrides the result of the
dependency() function.

Also ensure that dependency() always returns the same result when
looking for the same dependency, this fixes cases where parts of the
project could be using a system library and other parts use the library
provided by a subproject.

4 files changed, 28 insertions, 7 deletions

diff --git a/test cases/common/102 subproject subdir/meson.build b/test cases/common/102 subproject subdir/meson.build
index ec9fad123..fc54db18f 100644
--- a/test cases/common/102 subproject subdir/meson.build
+++ b/test cases/common/102 subproject subdir/meson.build
@@ -4,3 +4,16 @@ libSub = dependency('sub', fallback: ['sub', 'libSub'])
 
 exe = executable('prog', 'prog.c', dependencies: libSub)
 test('subproject subdir', exe)
+
+# Verify the subproject has placed dependency override.
+dependency('sub-1.0')
+
+# Verify we can now take 'sub' dependency without fallback, but only version 1.0.
+dependency('sub')
+d = dependency('sub', version : '>=2.0', required : false)
+assert(not d.found(), 'version should not match')
+
+# Verify that not-found does not get cached, we can still fallback afterward.
+dependency('sub2', required : false)
+d = dependency('sub2', fallback: ['sub', 'libSub'])
+assert(d.found(), 'Should fallback even if a previous call returned not-found')
diff --git a/test cases/common/102 subproject subdir/subprojects/sub/lib/meson.build b/test cases/common/102 subproject subdir/subprojects/sub/lib/meson.build
index 731d22bfb..53233ab4e 100644
--- a/test cases/common/102 subproject subdir/subprojects/sub/lib/meson.build
+++ b/test cases/common/102 subproject subdir/subprojects/sub/lib/meson.build
@@ -1,2 +1,3 @@
 lib = static_library('sub', 'sub.c')
 libSub = declare_dependency(include_directories: include_directories('.'), link_with: lib)
+meson.override_dependency('sub-1.0', libSub)
diff --git a/test cases/common/102 subproject subdir/subprojects/sub/meson.build b/test cases/common/102 subproject subdir/subprojects/sub/meson.build
index bf69c25b7..d8c4dce70 100644
--- a/test cases/common/102 subproject subdir/subprojects/sub/meson.build
+++ b/test cases/common/102 subproject subdir/subprojects/sub/meson.build
@@ -1,2 +1,2 @@
-project('sub', 'c')
+project('sub', 'c', version : '1.0')
 subdir('lib')
diff --git a/test cases/linuxlike/5 dependency versions/meson.build b/test cases/linuxlike/5 dependency versions/meson.build
index 087db5ff7..cb58a64d7 100644
--- a/test cases/linuxlike/5 dependency versions/meson.build
+++ b/test cases/linuxlike/5 dependency versions/meson.build
@@ -38,32 +38,32 @@ somelibver = dependency('somelib',
   fallback : ['somelibnover', 'some_dep'])
 assert(somelibver.type_name() == 'internal', 'somelibver should be of type "internal", not ' + somelibver.type_name())
 # Find an internal dependency again with the same name and a specific version
-somelib = dependency('somelib',
+somelib = dependency('somelib2',
   version : '== 0.1',
   fallback : ['somelib', 'some_dep'])
 # Find an internal dependency again even if required = false
-somelib_reqfalse = dependency('somelib',
+somelib_reqfalse = dependency('somelib3',
   required: false,
   fallback : ['somelib', 'some_dep'])
 assert(somelib_reqfalse.found(), 'somelib should have been found')
 # Find an internal dependency again with the same name and incompatible version
-somelibver = dependency('somelib',
+somelibver = dependency('somelib4',
   version : '>= 0.3',
   fallback : ['somelibver', 'some_dep'])
 # Find an internal dependency again with impossible multi-version
-somelibver = dependency('somelib',
+somelibver = dependency('somelib5',
   version : ['>= 0.3', '<0.3'],
   required : false,
   fallback : ['somelibver', 'some_dep'])
 assert(not somelibver.found(), 'Dependency should not be found')
 # Find somelib again, but with a fallback that will fail because subproject does not exist
-somelibfail = dependency('somelib',
+somelibfail = dependency('somelib6',
   version : '>= 0.2',
   required : false,
   fallback : ['somelibfail', 'some_dep'])
 assert(somelibfail.found() == false, 'somelibfail found via wrong fallback')
 # Find somelib again, but with a fallback that will fail because dependency does not exist
-somefail_dep = dependency('somelib',
+somefail_dep = dependency('somelib7',
   version : '>= 0.2',
   required : false,
   fallback : ['somelib', 'somefail_dep'])
@@ -79,6 +79,13 @@ fakezlib_dep = dependency('fakezlib',
   fallback : ['somelib', 'fakezlib_dep'])
 assert(fakezlib_dep.type_name() == 'internal', 'fakezlib_dep should be of type "internal", not ' + fakezlib_dep.type_name())
 
+# Verify that once we got a system dependency, we won't fallback if a newer
+# version is requested.
+d = dependency('zlib', version: '>= 999',
+  fallback : ['somelib', 'some_dep'],
+  required: false)
+assert(not d.found(), 'version should not match and it should not fallback')
+
 # Check that you can find a dependency by not specifying a version after not
 # finding it by specifying a version. We add `static: true` here so that the
 # previously cached zlib dependencies don't get checked.