Add --shared-libs arg to getdeps.py

Summary:
This diffs adds
* `--shared-libs` command line argument to the `build` command which enables building shared libraries for supported projects (cmake-based projects, boost, libevent)
* this flag overrides `BUILD_SHARED_LIBS` cmake flags in manifest files and from `--extra-cmake-defines`
* adds `shared_libs=on` expression support in manifest files
* for boost, the flag enables building shared libraries **in addition to** statically linked ones

Reviewed By: simonmar

Differential Revision: D27462289

fbshipit-source-id: d22ab434f7228c30472611bc323830d88efba0a5

build/fbcode_builder/getdeps.py

@@ -100,6 +100,9 @@ class ProjectCmdBase(SubCmd):
         else:
             ctx_gen.set_value_for_project(args.project, "test", "off")
 
+        if opts.shared_libs:
+            ctx_gen.set_value_for_all_projects("shared_libs", "on")
+
         loader = ManifestLoader(opts, ctx_gen)
         self.process_project_dir_arguments(args, loader)
 
@@ -709,6 +712,12 @@ class BuildCmd(ProjectCmdBase):
                 'e.g: \'{"CMAKE_CXX_FLAGS": "--bla"}\''
             ),
         )
+        parser.add_argument(
+            "--shared-libs",
+            help="Build shared libraries if possible",
+            action="store_true",
+            default=False,
+        )
 
 
 @cmd("fixup-dyn-deps", "Adjusts dynamic dependencies for packaging purposes")

build/fbcode_builder/getdeps/builder.py

@@ -486,6 +486,8 @@ if __name__ == "__main__":
         if extra_cmake_defines:
             self.defines.update(extra_cmake_defines)
         self.loader = loader
+        if build_opts.shared_libs:
+            self.defines["BUILD_SHARED_LIBS"] = "ON"
 
     def _invalidate_cache(self):
         for name in [
@@ -968,7 +970,7 @@ class Boost(BuilderBase):
     def _build(self, install_dirs, reconfigure):
         env = self._compute_env(install_dirs)
         linkage = ["static"]
-        if self.build_opts.is_windows():
+        if self.build_opts.is_windows() or self.build_opts.shared_libs:
             linkage.append("shared")
 
         args = []
@@ -1118,7 +1120,7 @@ install(FILES sqlite3.h sqlite3ext.h DESTINATION include)
 
         defines = {
             "CMAKE_INSTALL_PREFIX": self.inst_dir,
-            "BUILD_SHARED_LIBS": "OFF",
+            "BUILD_SHARED_LIBS": "ON" if self.build_opts.shared_libs else "OFF",
             "CMAKE_BUILD_TYPE": "RelWithDebInfo",
         }
         define_args = ["-D%s=%s" % (k, v) for (k, v) in defines.items()]

build/fbcode_builder/getdeps/buildopts.py

@@ -56,6 +56,7 @@ class BuildOptions(object):
         vcvars_path=None,
         allow_system_packages=False,
         lfs_path=None,
+        shared_libs=False,
     ):
         """fbcode_builder_dir - the path to either the in-fbsource fbcode_builder dir,
                              or for shipit-transformed repos, the build dir that
@@ -69,6 +70,7 @@ class BuildOptions(object):
         num_jobs - the level of concurrency to use while building
         use_shipit - use real shipit instead of the simple shipit transformer
         vcvars_path - Path to external VS toolchain's vsvarsall.bat
+        shared_libs - whether to build shared libraries
         """
         if not num_jobs:
             import multiprocessing
@@ -103,6 +105,7 @@ class BuildOptions(object):
         self.use_shipit = use_shipit
         self.allow_system_packages = allow_system_packages
         self.lfs_path = lfs_path
+        self.shared_libs = shared_libs
         if vcvars_path is None and is_windows():
 
             try:
@@ -183,6 +186,7 @@ class BuildOptions(object):
                 "distro_vers": host_type.distrovers,
                 "fb": "on" if facebook_internal else "off",
                 "test": "off",
+                "shared_libs": "on" if self.shared_libs else "off",
             }
         )
 
@@ -455,20 +459,30 @@ def setup_build_options(args, host_type=None):
     if not is_windows():
         scratch_dir = os.path.realpath(scratch_dir)
 
-    # Save any extra cmake defines passed by the user in an env variable, so it
+    # Save these args passed by the user in an env variable, so it
     # can be used while hashing this build.
     os.environ["GETDEPS_CMAKE_DEFINES"] = getattr(args, "extra_cmake_defines", "") or ""
 
     host_type = _check_host_type(args, host_type)
 
+    build_args = {
+        k: v
+        for (k, v) in vars(args).items()
+        if k
+        in {
+            "num_jobs",
+            "use_shipit",
+            "vcvars_path",
+            "allow_system_packages",
+            "lfs_path",
+            "shared_libs",
+        }
+    }
+
     return BuildOptions(
         fbcode_builder_dir,
         scratch_dir,
         host_type,
         install_dir=args.install_prefix,
-        num_jobs=args.num_jobs,
-        use_shipit=args.use_shipit,
-        vcvars_path=args.vcvars_path,
-        allow_system_packages=args.allow_system_packages,
-        lfs_path=args.lfs_path,
+        **build_args
     )

build/fbcode_builder/getdeps/load.py

@@ -263,6 +263,7 @@ class ManifestLoader(object):
         env["os"] = self.build_opts.host_type.ostype
         env["distro"] = self.build_opts.host_type.distro
         env["distro_vers"] = self.build_opts.host_type.distrovers
+        env["shared_libs"] = str(self.build_opts.shared_libs)
         for name in [
             "CXXFLAGS",
             "CPPFLAGS",

build/fbcode_builder/getdeps/manifest.py

@@ -588,7 +588,7 @@ class ManifestContext(object):
     This object should be passed as the `ctx` parameter in ManifestParser.get() calls.
     """
 
-    ALLOWED_VARIABLES = {"os", "distro", "distro_vers", "fb", "test"}
+    ALLOWED_VARIABLES = {"os", "distro", "distro_vers", "fb", "test", "shared_libs"}
 
     def __init__(self, ctx_dict):
         assert set(ctx_dict.keys()) == self.ALLOWED_VARIABLES

build/fbcode_builder/manifests/libevent

@@ -25,5 +25,8 @@ EVENT__DISABLE_BENCHMARK = ON
 EVENT__DISABLE_SAMPLES = ON
 EVENT__DISABLE_REGRESS = ON
 
+[cmake.defines.shared_libs=on]
+EVENT__BUILD_SHARED_LIBRARIES = ON
+
 [dependencies.not(os=linux)]
 openssl