Flag Cleaner Skill
Fixes build errors caused by compiler flags that are not supported by the current toolchain.
Detection Patterns
- •
unknown argument: '-fX' - •
unsupported option '-fX' - •
unknown warning option '-Wno-X' - •
unrecognized command line option
Strategy
- •Extract Flag: Parse the unsupported flag from the error.
- •Locate Build File: Find where the flag is defined.
- •Remove Flag: Delete the flag from the build configuration.
Instructions
Step 1: Identify the Flag
From error: clang: error: unknown argument: '-fno-strict-overflow'
Flag: -fno-strict-overflow
Step 2: Find the Build File
Search for the flag in build files:
bash
grep -r "fno-strict-overflow" --include="*.bp" --include="*.gn" --include="CMakeLists.txt"
Step 3: Remove the Flag
In Android.bp:
json
// Before cflags: ["-Wall", "-fno-strict-overflow", "-O2"], // After cflags: ["-Wall", "-O2"],
In BUILD.gn:
gn
// Before cflags = [ "-Wall", "-fno-strict-overflow" ] // After cflags = [ "-Wall" ]
In CMakeLists.txt:
cmake
# Before
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-strict-overflow")
# After
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
Common Problematic Flags
| Flag | Issue |
|---|---|
-fno-strict-overflow | GCC-only, not in Clang |
-Wno-unused-but-set-* | GCC-only warning |
-fstack-protector-strong | Older toolchains |