Add patchfile support to getdeps

Summary:
This adds the ability to specify a patch file to be applied on top of any library in getdeps.

For example, zlib doesn't support static linking with CMake, but there's a small patch that can be applied to support static linking. This is the specific use case this diff is intended to support.

Reviewed By: bigfootjon

Differential Revision: D35410512

fbshipit-source-id: d1af0ddf9ec45ef28aa902c06735af86817ac194

build/fbcode_builder/getdeps/builder.py

@@ -7,6 +7,7 @@
 import glob
 import json
 import os
+import pathlib
 import shutil
 import stat
 import subprocess
@@ -38,6 +39,8 @@ class BuilderBase(object):
         if subdir:
             src_dir = os.path.join(src_dir, subdir)
 
+        self.patchfile = manifest.get("build", "patchfile", ctx=ctx)
+        self.patchfile_opts = manifest.get("build", "patchfile_opts", ctx=ctx) or ""
         self.ctx = ctx
         self.src_dir = src_dir
         self.build_dir = build_dir or src_dir
@@ -93,14 +96,39 @@ class BuilderBase(object):
                 reconfigure = True
         return reconfigure
 
+    def _apply_patchfile(self) -> None:
+        # Only implemented patch support for linux
+        if not self.build_opts.is_linux() or self.patchfile is None:
+            return
+        patched_sentinel_file = pathlib.Path(self.src_dir + "/.getdeps_patched")
+        if patched_sentinel_file.exists():
+            return
+        old_wd = os.getcwd()
+        os.chdir(self.src_dir)
+        print(f"Patching {self.manifest.name} with {self.patchfile} in {self.src_dir}")
+        retval = os.system(
+            "patch "
+            + self.patchfile_opts
+            + " < "
+            + self.build_opts.fbcode_builder_dir
+            + "/patches/"
+            + self.patchfile
+        )
+        if retval != 0:
+            raise ValueError(f"Failed to apply patch to {self.manifest.name}")
+        os.chdir(old_wd)
+        patched_sentinel_file.touch()
+
     def prepare(self, install_dirs, reconfigure: bool) -> None:
         print("Preparing %s..." % self.manifest.name)
         reconfigure = self._reconfigure(reconfigure)
+        self._apply_patchfile()
         self._prepare(install_dirs=install_dirs, reconfigure=reconfigure)
 
     def build(self, install_dirs, reconfigure: bool) -> None:
         print("Building %s..." % self.manifest.name)
         reconfigure = self._reconfigure(reconfigure)
+        self._apply_patchfile()
         self._prepare(install_dirs=install_dirs, reconfigure=reconfigure)
         self._build(install_dirs=install_dirs, reconfigure=reconfigure)