Generate warning settings for Android framework

Bug: b/66996870

Android wants to build with warnings as errors. Keep the external/skia
warnings in sync with other Skia builds by pulling them from the json
generated by GN.

Fix a couple small errors that show up in the framework build.

Uploaded in response to AOSP's
https://android-review.googlesource.com/#/c/platform/external/skia/+/498211/

Change-Id: I4d791d43a9b00f9d6b79ecf16839716f241cba99
Reviewed-on: https://skia-review.googlesource.com/55703
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>

1 files changed, 27 insertions, 8 deletions

diff --git a/gn/gn_to_bp.py b/gn/gn_to_bp.py
index f0a28a8941..239fb020fd 100644
--- a/gn/gn_to_bp.py
+++ b/gn/gn_to_bp.py
@@ -21,14 +21,11 @@ bp = string.Template('''// This file is autogenerated by gn_to_bp.py.
 cc_library_static {
     name: "libskia",
     cflags: [
-        "-fexceptions",
-        "-fvisibility=hidden",
-        "-Wno-unused-parameter",
-        "-U_FORTIFY_SOURCE",
-        "-D_FORTIFY_SOURCE=1",
-        "-DSKIA_DLL",
-        "-DSKIA_IMPLEMENTATION=1",
-        "-DATRACE_TAG=ATRACE_TAG_VIEW",
+        $cflags
+    ],
+
+    cppflags:[
+        $cflags_cc
     ],
 
     export_include_dirs: [
@@ -185,6 +182,8 @@ def strip_slashes(lst):
   return {str(p.lstrip('/')) for p in lst}
 
 srcs            = strip_slashes(js['targets']['//:skia']['sources'])
+cflags          = strip_slashes(js['targets']['//:skia']['cflags'])
+cflags_cc       = strip_slashes(js['targets']['//:skia']['cflags_cc'])
 local_includes  = strip_slashes(js['targets']['//:skia']['include_dirs'])
 export_includes = strip_slashes(js['targets']['//:public']['include_dirs'])
 
@@ -217,6 +216,24 @@ srcs            = {s for s in srcs           if not s.endswith('.h')}
 dm_srcs         = {s for s in dm_srcs        if not s.endswith('.h')}
 nanobench_srcs  = {s for s in nanobench_srcs if not s.endswith('.h')}
 
+# Only use the generated flags related to warnings.
+cflags          = {s for s in cflags         if s.startswith('-W')}
+cflags_cc       = {s for s in cflags_cc      if s.startswith('-W')}
+# Add the rest of the flags we want.
+cflags = cflags.union([
+    "-fvisibility=hidden",
+    "-D_FORTIFY_SOURCE=1",
+    "-DSKIA_DLL",
+    "-DSKIA_IMPLEMENTATION=1",
+    "-DATRACE_TAG=ATRACE_TAG_VIEW",
+])
+cflags_cc.add("-fexceptions")
+
+# We need to undefine FORTIFY_SOURCE before we define it. Insert it at the
+# beginning after sorting.
+cflags = sorted(cflags)
+cflags.insert(0, "-U_FORTIFY_SOURCE")
+
 # Most defines go into SkUserConfig.h, where they're seen by Skia and its users.
 defines = [str(d) for d in js['targets']['//:skia']['defines']]
 defines.remove('NDEBUG')                 # Let the Android build control this.
@@ -259,6 +276,8 @@ with open('Android.bp', 'w') as f:
     'export_includes': bpfmt(8, export_includes),
     'local_includes':  bpfmt(8, local_includes),
     'srcs':            bpfmt(8, srcs),
+    'cflags':          bpfmt(8, cflags, False),
+    'cflags_cc':       bpfmt(8, cflags_cc),
 
     'arm_srcs':      bpfmt(16, scrub(defs['armv7'])),
     'arm_neon_srcs': bpfmt(20, scrub(defs['neon'])),