Add `-Wl,-rpath-link` for secondary dependencies

10 files changed, 129 insertions, 3 deletions

diff --git a/mesonbuild/dependencies/base.py b/mesonbuild/dependencies/base.py
index b0f24c86b..e32f9838b 100644
--- a/mesonbuild/dependencies/base.py
+++ b/mesonbuild/dependencies/base.py
@@ -33,6 +33,7 @@ from .. import mesonlib
 from ..compilers import clib_langs
 from ..environment import BinaryTable, Environment, MachineInfo
 from ..cmake import CMakeExecutor, CMakeTraceParser, CMakeException
+from ..linkers import GnuLikeDynamicLinkerMixin
 from ..mesonlib import MachineChoice, MesonException, OrderedSet, PerMachine
 from ..mesonlib import Popen_safe, version_compare_many, version_compare, listify, stringlistify, extract_as_list, split_args
 from ..mesonlib import Version, LibType
@@ -712,16 +713,18 @@ class PkgConfigDependency(ExternalDependency):
                                       (self.name, out))
         self.compile_args = self._convert_mingw_paths(self._split_args(out))
 
-    def _search_libs(self, out, out_raw):
+    def _search_libs(self, out, out_raw, out_all):
         '''
         @out: PKG_CONFIG_ALLOW_SYSTEM_LIBS=1 pkg-config --libs
         @out_raw: pkg-config --libs
+        @out_all: pkg-config --libs --static
 
         We always look for the file ourselves instead of depending on the
         compiler to find it with -lfoo or foo.lib (if possible) because:
         1. We want to be able to select static or shared
         2. We need the full path of the library to calculate RPATH values
         3. De-dup of libraries is easier when we have absolute paths
+        4. We need to find the directories in which secondary dependencies reside
 
         Libraries that are provided by the toolchain or are not found by
         find_library() will be added with -L -l pairs.
@@ -755,6 +758,18 @@ class PkgConfigDependency(ExternalDependency):
                 continue
             if arg.startswith('-L') and arg[2:] not in prefix_libpaths:
                 system_libpaths.add(arg[2:])
+        # collect all secondary library paths
+        secondary_libpaths = OrderedSet()
+        all_args = self._convert_mingw_paths(shlex.split(out_all))
+        for arg in all_args:
+            if arg.startswith('-L') and not arg.startswith(('-L-l', '-L-L')):
+                path = arg[2:]
+                if not os.path.isabs(path):
+                    # Resolve the path as a compiler in the build directory would
+                    path = os.path.join(self.env.get_build_dir(), path)
+                if path not in prefix_libpaths and path not in system_libpaths:
+                    secondary_libpaths.add(path)
+
         # Use this re-ordered path list for library resolution
         libpaths = list(prefix_libpaths) + list(system_libpaths)
         # Track -lfoo libraries to avoid duplicate work
@@ -762,8 +777,12 @@ class PkgConfigDependency(ExternalDependency):
         # Track not-found libraries to know whether to add library paths
         libs_notfound = []
         libtype = LibType.STATIC if self.static else LibType.PREFER_SHARED
-        # Generate link arguments for this library
+        # Generate link arguments for this library, by
+        # first appending secondary link arguments for ld
         link_args = []
+        if self.clib_compiler and self.clib_compiler.linker and isinstance(self.clib_compiler.linker, GnuLikeDynamicLinkerMixin):
+            link_args = ['-Wl,-rpath-link,' + p for p in secondary_libpaths]
+
         for lib in full_args:
             if lib.startswith(('-L-l', '-L-L')):
                 # These are D language arguments, add them as-is
@@ -833,6 +852,26 @@ class PkgConfigDependency(ExternalDependency):
         libcmd = [self.name, '--libs']
         if self.static:
             libcmd.append('--static')
+        # We need to find *all* secondary dependencies of a library
+        #
+        # Say we have libA.so, located in /non/standard/dir1/, and
+        # libB.so, located in /non/standard/dir2/, which links to
+        # libA.so. Now when linking exeC to libB.so, the linker will
+        # walk the complete symbol tree to determine that all undefined
+        # symbols can be resolved. Because libA.so lives in a directory
+        # not known to the linker by default, you will get errors like
+        #
+        #   ld: warning: libA.so, needed by /non/standard/dir2/libB.so,
+        #       not found (try using -rpath or -rpath-link)
+        #   ld: /non/standard/dir2/libB.so: undefined reference to `foo()'
+        #
+        # To solve this, we load the -L paths of *all* dependencies, by
+        # relying on --static to provide us with a complete picture. All
+        # -L paths that are found via a --static lookup but that are not
+        # contained in the normal lookup have to originate from secondary
+        # dependencies. See also:
+        #   http://www.kaizou.org/2015/01/linux-libraries/
+        libcmd_all = [self.name, '--libs', '--static']
         # Force pkg-config to output -L fields even if they are system
         # paths so we can do manual searching with cc.find_library() later.
         env = os.environ.copy()
@@ -848,7 +887,10 @@ class PkgConfigDependency(ExternalDependency):
         if ret != 0:
             raise DependencyException('Could not generate libs for %s:\n\n%s' %
                                       (self.name, out_raw))
-        self.link_args, self.raw_link_args = self._search_libs(out, out_raw)
+        ret, out_all = self._call_pkgbin(libcmd_all)
+        if ret != 0:
+            mlog.warning('Could not determine complete list of dependencies for %s' % self.name)
+        self.link_args, self.raw_link_args = self._search_libs(out, out_raw, out_all)
 
     def get_pkgconfig_variable(self, variable_name, kwargs):
         options = ['--variable=' + variable_name, self.name]
diff --git a/run_unittests.py b/run_unittests.py
index f9ba01763..eedb087dd 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -5292,6 +5292,45 @@ endian = 'little'
             self.build()
 
     @skipIfNoPkgconfig
+    def test_pkgconfig_secondary_dependencies(self):
+        '''
+        Check that Meson gets -Wl,-rpath-link right for secondary dependencies
+
+        This test requires at least two libraries, as -Wl,-rpath-link is only
+        required for dependencies of dependencies (i.e. secondary dependencies).
+        '''
+        with tempfile.TemporaryDirectory() as tempdirname:
+            testdirbase = os.path.join(self.unit_test_dir, '63 rpath-link secondary')
+
+            # build libA
+            testdirlibA = os.path.join(testdirbase, 'libA')
+            testlibAprefix = os.path.join(tempdirname, 'libAprefix')
+            self.init(testdirlibA, extra_args=['--prefix=' + testlibAprefix,
+                                               '--libdir=lib',
+                                               '--default-library=shared'], default_args=False)
+            self.build()
+            self.install(use_destdir=False)
+
+            # build libB (uses libA)
+            pkg_dir = [os.path.join(testlibAprefix, 'lib/pkgconfig')]
+            self.new_builddir()
+            testdirlibB = os.path.join(testdirbase, 'libB')
+            testlibBprefix = os.path.join(tempdirname, 'libBprefix')
+            self.init(testdirlibB, extra_args=['--prefix=' + testlibBprefix,
+                                               '--libdir=lib',
+                                               '--default-library=shared'], default_args=False,
+                      override_envvars={'PKG_CONFIG_PATH': ':'.join(pkg_dir)})
+            self.build()
+            self.install(use_destdir=False)
+
+            # build executable (uses libB, secondary dependency on libA)
+            pkg_dir.append(os.path.join(testlibBprefix, 'lib/pkgconfig'))
+            self.new_builddir()
+            self.init(os.path.join(testdirbase, 'app'),
+                      override_envvars={'PKG_CONFIG_PATH': ':'.join(pkg_dir)})
+            self.build()
+
+    @skipIfNoPkgconfig
     def test_pkgconfig_formatting(self):
         testdir = os.path.join(self.unit_test_dir, '38 pkgconfig format')
         self.init(testdir)
diff --git a/test cases/unit/63 rpath-link secondary/app/app.c b/test cases/unit/63 rpath-link secondary/app/app.c
new file mode 100644
index 000000000..f33b1a99e
--- /dev/null
+++ b/test cases/unit/63 rpath-link secondary/app/app.c
@@ -0,0 +1,4 @@
+#include <stdio.h>
+#include <libb.h>
+
+int main() { printf("The answer is: %d\n", libB_func()); }
diff --git a/test cases/unit/63 rpath-link secondary/app/meson.build b/test cases/unit/63 rpath-link secondary/app/meson.build
new file mode 100644
index 000000000..3d85a32f4
--- /dev/null
+++ b/test cases/unit/63 rpath-link secondary/app/meson.build
@@ -0,0 +1,5 @@
+project('app', ['c'])
+
+b = dependency('test-b')
+
+executable('app', 'app.c', dependencies : [b])
diff --git a/test cases/unit/63 rpath-link secondary/libA/liba.c b/test cases/unit/63 rpath-link secondary/libA/liba.c
new file mode 100644
index 000000000..620a9949d
--- /dev/null
+++ b/test cases/unit/63 rpath-link secondary/libA/liba.c
@@ -0,0 +1 @@
+int libA_func() { return 42; }
diff --git a/test cases/unit/63 rpath-link secondary/libA/liba.h b/test cases/unit/63 rpath-link secondary/libA/liba.h
new file mode 100644
index 000000000..ed4fa7ddc
--- /dev/null
+++ b/test cases/unit/63 rpath-link secondary/libA/liba.h
@@ -0,0 +1 @@
+int libA_func();
diff --git a/test cases/unit/63 rpath-link secondary/libA/meson.build b/test cases/unit/63 rpath-link secondary/libA/meson.build
new file mode 100644
index 000000000..383bed026
--- /dev/null
+++ b/test cases/unit/63 rpath-link secondary/libA/meson.build
@@ -0,0 +1,14 @@
+project('lib', ['c'])
+
+a = library('test-a', 'liba.c', install: true)
+
+install_headers(files('liba.h'))
+
+import('pkgconfig').generate(
+    a,
+    version: '0.0',
+    description: 'test library',
+    filebase: 'test-a',
+    name: 'test library',
+    subdirs: ['.']
+)
diff --git a/test cases/unit/63 rpath-link secondary/libB/libb.c b/test cases/unit/63 rpath-link secondary/libB/libb.c
new file mode 100644
index 000000000..d097066c8
--- /dev/null
+++ b/test cases/unit/63 rpath-link secondary/libB/libb.c
@@ -0,0 +1,3 @@
+#include <liba.h>
+
+int libB_func() { return libA_func(); }
diff --git a/test cases/unit/63 rpath-link secondary/libB/libb.h b/test cases/unit/63 rpath-link secondary/libB/libb.h
new file mode 100644
index 000000000..c5de0c22d
--- /dev/null
+++ b/test cases/unit/63 rpath-link secondary/libB/libb.h
@@ -0,0 +1 @@
+int libB_func();
diff --git a/test cases/unit/63 rpath-link secondary/libB/meson.build b/test cases/unit/63 rpath-link secondary/libB/meson.build
new file mode 100644
index 000000000..3bfd0d22e
--- /dev/null
+++ b/test cases/unit/63 rpath-link secondary/libB/meson.build
@@ -0,0 +1,16 @@
+project('lib', ['c'])
+
+libA_dep = dependency('test-a')
+
+b = library('test-b', 'libb.c', install: true, dependencies : libA_dep)
+
+install_headers(files('libb.h'))
+
+import('pkgconfig').generate(
+    b,
+    version: '0.0',
+    description: 'test library',
+    filebase: 'test-b',
+    name: 'test library',
+    subdirs: ['.']
+)