pkgconfig: Don't expose internal libraries in .pc files

Libraries that have been linked with link_whole: are internal
implementation details and should never be exposed to the outside
world in either Libs: or Libs.private:

Closes https://github.com/mesonbuild/meson/issues/3509

mesonbuild/build.py

@@ -817,16 +817,22 @@ This will become a hard error in a future Meson release.''')
     def get_extra_args(self, language):
         return self.extra_args.get(language, [])
 
-    def get_dependencies(self, exclude=None):
+    def get_dependencies(self, exclude=None, internal=True):
         transitive_deps = []
         if exclude is None:
             exclude = []
-        for t in itertools.chain(self.link_targets, self.link_whole_targets):
+        if internal:
+            link_targets = itertools.chain(self.link_targets, self.link_whole_targets)
+        else:
+            # We don't want the 'internal' libraries when generating the
+            # `Libs:` and `Libs.private:` lists in pkg-config files.
+            link_targets = self.link_targets
+        for t in link_targets:
             if t in transitive_deps or t in exclude:
                 continue
             transitive_deps.append(t)
             if isinstance(t, StaticLibrary):
-                transitive_deps += t.get_dependencies(transitive_deps + exclude)
+                transitive_deps += t.get_dependencies(transitive_deps + exclude, internal)
         return transitive_deps
 
     def get_source_subdir(self):

mesonbuild/modules/pkgconfig.py

@@ -123,10 +123,10 @@ class DependenciesHelper:
                     if not hasattr(obj, 'generated_pc'):
                         obj.generated_pc = self.name
                 if isinstance(obj, build.StaticLibrary) and public:
-                    self.add_pub_libs(obj.get_dependencies())
+                    self.add_pub_libs(obj.get_dependencies(internal=False))
                     self.add_pub_libs(obj.get_external_deps())
                 else:
-                    self.add_priv_libs(obj.get_dependencies())
+                    self.add_priv_libs(obj.get_dependencies(internal=False))
                     self.add_priv_libs(obj.get_external_deps())
             elif isinstance(obj, str):
                 processed_libs.append(obj)

run_unittests.py

@@ -3108,11 +3108,12 @@ endian = 'little'
         self.init(testdir)
         myenv = os.environ.copy()
         myenv['PKG_CONFIG_PATH'] = self.privatedir
-        ro = subprocess.run(['pkg-config', '--libs', 'libsomething'], stdout=subprocess.PIPE,
-                            env=myenv)
-        self.assertEqual(ro.returncode, 0)
-        self.assertIn(b'-lgobject-2.0', ro.stdout)
-        self.assertIn(b'-lgio-2.0', ro.stdout)
+        stdo = subprocess.check_output(['pkg-config', '--libs-only-l', 'libsomething'], env=myenv)
+        deps = [b'-lgobject-2.0', b'-lgio-2.0', b'-lglib-2.0', b'-lsomething']
+        if is_windows() or is_cygwin():
+            # On Windows, libintl is a separate library
+            deps.append(b'-lintl')
+        self.assertEqual(set(deps), set(stdo.split()))
 
 class LinuxArmCrossCompileTests(BasePlatformTests):
     '''

test cases/unit/31 pkgconfig format/meson.build

@@ -8,10 +8,11 @@ endif
 
 pkgg = import('pkgconfig')
 
-l = shared_library('something', 'somelib.c')
+s = static_library('returner', 'someret.c')
+l = library('something', 'somelib.c', link_whole: s)
 
 pkgg.generate(libraries: l,
               version: '1.0',
               name: 'libsomething',
               description: 'A library that does something',
-              requires: 'gobject-2.0 >= 2.54, gio-2.0 >= 2.54')
+              requires: 'gobject-2.0 >= 2.0, gio-2.0 >= 2.0')

test cases/unit/31 pkgconfig format/somelib.c

@@ -1,5 +1,7 @@
 #include<stdio.h>
 
+int get_returnvalue (void);
+
 int some_func() {
-    return 0;
+    return get_returnvalue();
 }

test cases/unit/31 pkgconfig format/someret.c

@@ -0,0 +1,3 @@
+int get_returnvalue (void) {
+  return 0;
+}