Use cmake-file-api

CMake’s File API provides detailed build information that results in more accurate Bazel file generation.

Why Use cmake-file-api?

The default CMakeLists.txt parser works well for most projects, but cmake-file-api provides:

• Exact source lists - Including generated files
• Resolved paths - Absolute include directories
• Actual compiler flags - As CMake would use them
• Configuration-specific settings - Debug vs Release

Prerequisites

• CMake 3.14 or later
• An existing CMake build directory (or ability to create one)

1. Configure your CMake project

   cd myproject
   cmake -S . -B build

   For a specific configuration:

   cmake -S . -B build -DCMAKE_BUILD_TYPE=Release

2. Run migration with File API

   rebaze migrate . --cmake-build-dir build

   For a specific configuration:

   rebaze migrate . --cmake-build-dir build --cmake-config Release

3. Require File API (optional)

   To fail if File API isn’t available:

   rebaze migrate . --cmake-build-dir build --cmake-file-api-only

How It Works

1. rebaze reads the .cmake/api/v1/reply/ directory
2. Parses the codemodel JSON files
3. Extracts targets, sources, includes, and dependencies
4. Generates Bazel files from this accurate data

Troubleshooting

”Failed to load cmake-file-api”

Ensure CMake was configured with version 3.14+:

cmake --version

Re-run CMake configuration:

cmake -S . -B build

Missing targets

Some targets may only exist in certain configurations:

cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug
rebaze migrate . --cmake-build-dir build --cmake-config Debug

Tip

Best Practices:

1. Always configure CMake before migration
2. Match configurations between CMake and rebaze
3. Use --cmake-file-api-only in CI for consistency