mlugg 4976b58ab1
Prevent analysis of functions only referenced at comptime
The idea here is that there are two ways we can reference a function at runtime:

* Through a direct call, i.e. where the function is comptime-known
* Through a function pointer

This means we can easily perform a form of rudimentary escape analysis
on functions. If we ever see a `decl_ref` or `ref` of a function, we
have a function pointer, which could "leak" into runtime code, so we
emit the function; but for a plain `decl_val`, there's no need to.

This change means that `comptime { _ = f; }` no longer forces a function
to be emitted, which was used for some things (mainly tests). These use
sites have been replaced with `_ = &f;`, which still triggers analysis
of the function body, since you're taking a pointer to the function.

Resolves: #6256
Resolves: #15353
2023-05-29 23:06:08 +01:00
..
2022-12-13 13:14:20 +02:00

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=1
//
// :4:13: error: 'try' outside function scope

Execution

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

// run

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.

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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.