[libcxx] Add support for building and testing with an ABI library not along linker paths

Summary:
This patch adds support for building/testing libc++ with an ABI library that the linker would not normally find.

- `CMAKE_LIBRARY_PATH` is used to specify the list of search directories.
- The ABI library is now found using `find_library` instead of assuming its along the linker's search path.
- `CMAKE_LIBRARY_PATH` is passed to our LIT config as `library_paths`.
- For each path in `library_paths` the following flags are added `-L<path> -Wl,-rpath -Wl,<path>`

Some changes in existing behavior were also added:
- `target_link_libraries` is now passed the ABI library file instead of the library name. Ex `target_link_libraries(cxx "/usr/lib/libc++abi.so")` vs `target_link_libraries(cxx "c++abi")`.
- `-Wl,-rpath -Wl,<path>` is now used on OSX to link to libc++ instead of env['DYLD_LIBRARY_PATH'] if `use_system_lib=False`.




Reviewers: mclow.lists, danalbert, EricWF

Reviewed By: EricWF

Subscribers: emaste, cfe-commits

Differential Revision: http://reviews.llvm.org/D5038

llvm-svn: 220118

2 files changed, 19 insertions, 11 deletions

diff --git a/libcxx/test/lit.cfg b/libcxx/test/lit.cfg
index fbeb827597b..6d30e5fcd91 100644
--- a/libcxx/test/lit.cfg
+++ b/libcxx/test/lit.cfg
@@ -197,6 +197,7 @@ class Configuration(object):
         self.obj_root = None
         self.env = {}
         self.compile_flags = []
+        self.library_paths = []
         self.link_flags = []
         self.use_system_lib = False
         self.use_clang_verify = False
@@ -366,9 +367,19 @@ class Configuration(object):
         # Configure extra compiler flags.
         self.compile_flags += ['-I' + self.src_root + '/include',
                                '-I' + self.src_root + '/test/support']
+        if sys.platform == 'linux2':
+            self.compile_flags += ['-D__STDC_FORMAT_MACROS',
+                                   '-D__STDC_LIMIT_MACROS',
+                                   '-D__STDC_CONSTANT_MACROS']
 
     def configure_link_flags(self):
-        self.link_flags += ['-L' + self.obj_root + '/lib', '-lc++']
+        # Configure library search paths
+        lpaths = self.get_lit_conf('library_paths', '').split(';')
+        lpaths = [l for l in lpaths if l.strip()]
+        self.link_flags += ['-L' + self.obj_root + '/lib']
+        self.link_flags += ['-L' + l for l in lpaths]
+        # Configure libraries
+        self.link_flags += ['-lc++']
         link_flags_str = self.get_lit_conf('link_flags')
         if link_flags_str is None:
             cxx_abi = self.get_lit_conf('cxx_abi', 'libcxxabi')
@@ -394,22 +405,18 @@ class Configuration(object):
             elif sys.platform.startswith('freebsd'):
                 self.link_flags += ['-lc', '-lm', '-pthread', '-lgcc_s']
             else:
-                self.lit_config.fatal("unrecognized system")
+                self.lit_config.fatal("unrecognized system: %r" % sys.platform)
 
             self.lit_config.note(
                 "inferred link_flags as: %r" % self.link_flags)
         if link_flags_str:
             self.link_flags += shlex.split(link_flags_str)
 
-        if sys.platform == 'linux2':
-            if not self.use_system_lib:
-                self.link_flags += ['-Wl,-R', self.obj_root + '/lib']
-            self.compile_flags += ['-D__STDC_FORMAT_MACROS',
-                                   '-D__STDC_LIMIT_MACROS',
-                                   '-D__STDC_CONSTANT_MACROS']
-        elif sys.platform.startswith('freebsd'):
-            if not self.use_system_lib:
-                self.link_flags += ['-Wl,-R', self.obj_root + '/lib']
+        # Configure library runtime search paths
+        if not self.use_system_lib:
+            self.link_flags += ['-Wl,-rpath', '-Wl,' + self.obj_root + '/lib']
+        for l in lpaths:
+            self.link_flags += ['-Wl,-rpath', '-Wl,' + l]
 
     def configure_std_flag(self):
         # Try and get the std version from the command line. Fall back to
diff --git a/libcxx/test/lit.site.cfg.in b/libcxx/test/lit.site.cfg.in
index 3362d99e09e..0c5f2609874 100644
--- a/libcxx/test/lit.site.cfg.in
+++ b/libcxx/test/lit.site.cfg.in
@@ -7,6 +7,7 @@ config.python_executable     = "@PYTHON_EXECUTABLE@"
 config.enable_shared         = @LIBCXX_ENABLE_SHARED@
 config.cxx_abi               = "@LIBCXX_CXX_ABI_LIBNAME@"
 config.llvm_use_sanitizer    = "@LLVM_USE_SANITIZER@"
+config.library_paths         = "@CMAKE_LIBRARY_PATH@"
 
 # Let the main config do the real work.
 lit_config.load_config(config, "@LIBCXX_SOURCE_DIR@/test/lit.cfg")