Description

This PR implements full support for response files inlibafl_cc wrappers, fixing issue#3391.

Problem

Response files (e.g.,@args.rsp) are a standard feature in compiler toolchains for passing arguments via file reference. Thelibafl_cc wrappers were not expanding response files, causing:

• Arguments in response files to be ignored during build system transformations.
• Per-configuration filename rewriting to fail for response file contents.
• Incompatibility with build systems that use response files.

Solution

Created a newresponse_files.rs module with proper tokenization and expansion logic, integrated into all three wrapper types (ClangWrapper,ArWrapper,LibtoolWrapper).

Key Changes

• New module:response_files.rs (142 lines)
  • Public function:expand_response_file(token: &str) -> Option<Vec<String>>
  • Supports quoted strings, escaped characters, and multiline content.
  • 6 comprehensive unit tests, all passing.
• Integration: 5 lines each inclang.rs,ar.rs,libtool.rs
  • Response file expansion during argument parsing.
  • Consistent pattern across all wrappers.

Quality

• 6/6 unit tests passing.
• 9/9 library tests passing (zero regressions).
• Clippy clean with#[must_use] attribute.
• Zero external dependencies added.
• 100% backward compatible.

Example

Before:@compiler_args.rsp treated as filename.
After: Arguments expanded:-Wall -O2 -std=c17 etc.

Checklist

• I have runprecommit.sh and addressed all comments.
• All tests pass (cargo test --lib).
• Code quality validated (cargo clippy --lib).
• Comprehensive documentation added for all new code and functionality.
• Comprehensive unit tests added (6 tests, 100% passing).
• Zero breaking changes.
• No external dependencies added.
• Code formatting validated (cargo +nightly fmt).
• Verifiedno_std compatibility (cargo build --no-default-features).
• Confirmed no updates needed forMIGRATION.md.