Bug 1045783 - Move OS_LIBS from a passthrough to a more fully supported variable. r=gps

build/docs/defining-binaries.rst

@@ -158,6 +158,33 @@ Similar to ``SIMPLE_PROGRAMS``, is ``CPP_UNIT_TESTS``, which defines, with the
 same rules, C++ unit tests programs.
 
 
+Linking with system libraries
+=============================
+
+Programs and libraries usually need to link with system libraries, such as a
+widget toolkit, etc. Those required dependencies can be given with the
+``OS_LIBS`` variable.
+
+   OS_LIBS += [
+       'foo',
+       'bar',
+   ]
+
+This expands to ``foo.lib bar.lib`` when building with MSVC, and
+``-lfoo -lbar`` otherwise.
+
+For convenience with ``pkg-config``, ``OS_LIBS`` can also take linker flags
+such as ``-L/some/path`` and ``-llib``, such that it is possible to directly
+assign ``LIBS`` variables from ``CONFIG``, such as:
+
+   OS_LIBS += CONFIG['MOZ_PANGO_LIBS']
+
+(assuming ``CONFIG['MOZ_PANGO_LIBS']`` is a list, not a string)
+
+Like ``USE_LIBS``, this variable applies to static and shared libraries, as
+well as programs.
+
+
 Building both static and shared libraries
 =========================================
 

ipc/chromium/chromium-config.mozbuild

@@ -14,7 +14,11 @@ GENERATED_INCLUDES += [
 ]
 
 if CONFIG['OS_ARCH'] == 'WINNT':
-    OS_LIBS += [ '$(call EXPAND_LIBNAME,psapi shell32 dbghelp)' ]
+    OS_LIBS += [
+        'psapi',
+        'shell32',
+        'dbghelp',
+    ]
 
     DEFINES.update({
         'UNICODE': True,

python/mozbuild/mozbuild/backend/recursivemake.py

@@ -1196,13 +1196,15 @@ class RecursiveMakeBackend(CommonBackend):
             self.environment.topobjdir), obj.KIND)
 
     def _process_linked_libraries(self, obj, backend_file):
-        def recursive_get_shared_libs(lib):
+        def write_shared_and_system_libs(lib):
             for l in lib.linked_libraries:
                 if isinstance(l, StaticLibrary):
-                    for q in recursive_get_shared_libs(l):
-                        yield q
+                    write_shared_and_system_libs(l)
                 else:
-                    yield l
+                    backend_file.write_once('SHARED_LIBS += %s/%s\n'
+                        % (pretty_relpath(l), l.import_name))
+            for l in lib.linked_system_libs:
+                backend_file.write_once('OS_LIBS += %s\n' % l)
 
         def pretty_relpath(lib):
             return '$(DEPTH)/%s' % mozpath.relpath(lib.objdir, topobjdir)
@@ -1238,9 +1240,7 @@ class RecursiveMakeBackend(CommonBackend):
                     backend_file.write_once('STATIC_LIBS += %s/%s\n'
                                         % (relpath, lib.import_name))
                     if isinstance(obj, SharedLibrary):
-                        for l in recursive_get_shared_libs(lib):
-                            backend_file.write_once('SHARED_LIBS += %s/%s\n'
-                                        % (pretty_relpath(l), l.import_name))
+                        write_shared_and_system_libs(lib)
                 elif isinstance(obj, SharedLibrary):
                     assert lib.variant != lib.COMPONENT
                     backend_file.write_once('SHARED_LIBS += %s/%s\n'
@@ -1249,9 +1249,7 @@ class RecursiveMakeBackend(CommonBackend):
                 if isinstance(lib, StaticLibrary):
                     backend_file.write_once('STATIC_LIBS += %s/%s\n'
                                         % (relpath, lib.import_name))
-                    for l in recursive_get_shared_libs(lib):
-                        backend_file.write_once('SHARED_LIBS += %s/%s\n'
-                                        % (pretty_relpath(l), l.import_name))
+                    write_shared_and_system_libs(lib)
                 else:
                     assert lib.variant != lib.COMPONENT
                     backend_file.write_once('SHARED_LIBS += %s/%s\n'
@@ -1261,6 +1259,12 @@ class RecursiveMakeBackend(CommonBackend):
                 backend_file.write_once('HOST_LIBS += %s/%s\n'
                                    % (relpath, lib.import_name))
 
+        for lib in obj.linked_system_libs:
+            if obj.KIND == 'target':
+                backend_file.write_once('OS_LIBS += %s\n' % lib)
+            else:
+                backend_file.write_once('HOST_EXTRA_LIBS += %s\n' % lib)
+
     def _write_manifests(self, dest, manifests):
         man_dir = mozpath.join(self.environment.topobjdir, '_build_manifests',
             dest)

python/mozbuild/mozbuild/frontend/data.py

@@ -328,11 +328,15 @@ class LinkageWrongKindError(Exception):
 
 class Linkable(SandboxDerived):
     """Generic sandbox container object for programs and libraries"""
-    __slots__ = ('linked_libraries')
+    __slots__ = (
+        'linked_libraries',
+        'linked_system_libs',
+    )
 
     def __init__(self, sandbox):
         SandboxDerived.__init__(self, sandbox)
         self.linked_libraries = []
+        self.linked_system_libs = []
 
     def link_library(self, obj):
         assert isinstance(obj, BaseLibrary)
@@ -344,6 +348,20 @@ class Linkable(SandboxDerived):
         self.linked_libraries.append(obj)
         obj.refs.append(self)
 
+    def link_system_library(self, lib):
+        # The '$' check is here as a special temporary rule, allowing the
+        # inherited use of make variables, most notably in TK_LIBS.
+        if not lib.startswith('$') and not lib.startswith('-'):
+            if self.config.substs.get('GNU_CC'):
+                lib = '-l%s' % lib
+            else:
+                lib = '%s%s%s' % (
+                    self.config.import_prefix,
+                    lib,
+                    self.config.import_suffix,
+                )
+        self.linked_system_libs.append(lib)
+
 
 class BaseProgram(Linkable):
     """Sandbox container object for programs, which is a unicode string.

python/mozbuild/mozbuild/frontend/emitter.py

@@ -314,6 +314,10 @@ class TreeMetadataEmitter(LoggingMixin):
                 self._static_linking_shared.add(obj)
             obj.link_library(candidates[0])
 
+        # Link system libraries from OS_LIBS/HOST_OS_LIBS.
+        for lib in sandbox.get(variable.replace('USE', 'OS'), []):
+            obj.link_system_library(lib)
+
     def emit_from_sandbox(self, sandbox):
         """Convert a MozbuildSandbox to tree metadata objects.
 
@@ -381,7 +385,6 @@ class TreeMetadataEmitter(LoggingMixin):
             'IS_GYP_DIR',
             'MSVC_ENABLE_PGO',
             'NO_DIST_INSTALL',
-            'OS_LIBS',
             'PYTHON_UNIT_TESTS',
             'RCFILE',
             'RESFILE',

python/mozbuild/mozbuild/frontend/sandbox_symbols.py

@@ -332,6 +332,10 @@ VARIABLES = {
         """List of libraries to link to host programs and libraries.
         """, None),
 
+    'HOST_OS_LIBS': (List, list,
+        """List of system libraries for host programs and libraries.
+        """, None),
+
     'LOCAL_INCLUDES': (StrictOrderingOnAppendList, list,
         """Additional directories to be searched for include files by the compiler.
         """, None),

python/mozbuild/mozbuild/test/backend/data/variable_passthru/moz.build

@@ -10,8 +10,6 @@ EXTRA_PP_COMPONENTS = ['bar.pp.js', 'foo.pp.js']
 HOST_SOURCES += ['bar.cpp', 'foo.cpp']
 HOST_SOURCES += ['bar.c', 'foo.c']
 
-OS_LIBS = ['foo.so', '-l123', 'bar.a']
-
 SOURCES += ['bar.c', 'foo.c']
 
 SOURCES += ['bar.mm', 'foo.mm']

python/mozbuild/mozbuild/test/backend/test_recursivemake.py

@@ -290,11 +290,6 @@ class TestRecursiveMakeBackend(BackendTester):
             'MSVC_ENABLE_PGO': [
                 'MSVC_ENABLE_PGO := 1',
             ],
-            'OS_LIBS': [
-                'OS_LIBS += foo.so',
-                'OS_LIBS += -l123',
-                'OS_LIBS += bar.a',
-            ],
             'SSRCS': [
                 'SSRCS += baz.S',
                 'SSRCS += foo.S',

python/mozbuild/mozbuild/test/frontend/data/variable-passthru/moz.build

@@ -10,8 +10,6 @@ EXTRA_PP_COMPONENTS=['fans.pp.js', 'tans.pp.js']
 HOST_SOURCES += ['fans.cpp', 'tans.cpp']
 HOST_SOURCES += ['fans.c', 'tans.c']
 
-OS_LIBS += ['foo.so', '-l123', 'aaa.a']
-
 SOURCES += ['fans.c', 'tans.c']
 
 SOURCES += ['fans.mm', 'tans.mm']

python/mozbuild/mozbuild/test/frontend/test_emitter.py

@@ -159,7 +159,6 @@ class TestEmitterBasic(unittest.TestCase):
             HOST_CSRCS=['fans.c', 'tans.c'],
             MSVC_ENABLE_PGO=True,
             NO_DIST_INSTALL=True,
-            OS_LIBS=['foo.so', '-l123', 'aaa.a'],
             SSRCS=['bans.S', 'fans.S'],
             VISIBILITY_FLAGS='',
             DELAYLOAD_LDFLAGS=['-DELAYLOAD:foo.dll', '-DELAYLOAD:bar.dll'],