mlugg 93cb44c805 translate-c: support GCC/Clang pointer subtraction extension
Pointer subtraction on `void *` or function pointers is UB by the C
spec, but is permitted by GCC and Clang as an extension. So, avoid
crashing translate-c in such cases, and follow the extension behavior --
there's nothing else that could really be intended.
2024-08-27 06:43:40 +01:00
..

Test Case Quick Reference

Use comments at the end of the file to indicate metadata about the test case. Here are examples of different kinds of tests:

Compile Error Test

If you want it to be run with zig test and match expected error messages:

// error
// is_test=true
//
// :4:13: error: 'try' outside function scope

Execution

This will do zig run on the code and expect exit code 0.

// run

Translate-c

If you want to test translating C code to Zig use translate-c:

// translate-c
// c_frontend=aro,clang
// target=x86_64-linux
//
// pub const foo = 1;
// pub const immediately_after_foo = 2;
//
// pub const somewhere_else_in_the_file = 3:

Run Translated C

If you want to test translating C code to Zig and then executing it use run-translated-c:

// run-translated-c
// c_frontend=aro,clang
// target=x86_64-linux
//
// Hello world!

Incremental Compilation

Make multiple files that have ".", and then an integer, before the ".zig" extension, like this:

hello.0.zig
hello.1.zig
hello.2.zig

Each file can be a different kind of test, such as expecting compile errors, or expecting to be run and exit(0). The test harness will use these to simulate incremental compilation.

At the time of writing there is no way to specify multiple files being changed as part of an update.

Subdirectories

Subdirectories do not have any semantic meaning but they can be used for organization since the test harness will recurse into them. The full directory path will be prepended as a prefix on the test case name.

Limiting which Backends and Targets are Tested

// run
// backend=stage2,llvm
// target=x86_64-linux,x86_64-macos

Possible backends are:

  • stage1: equivalent to -fstage1.
  • stage2: equivalent to passing -fno-stage1 -fno-LLVM.
  • llvm: equivalent to -fLLVM -fno-stage1.