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d11bbde5f9
This commit reworks how anonymous struct literals and tuples work.
Previously, an untyped anonymous struct literal
(e.g. `const x = .{ .a = 123 }`) was given an "anonymous struct type",
which is a special kind of struct which coerces using structural
equivalence. This mechanism was a holdover from before we used
RLS / result types as the primary mechanism of type inference. This
commit changes the language so that the type assigned here is a "normal"
struct type. It uses a form of equivalence based on the AST node and the
type's structure, much like a reified (`@Type`) type.
Additionally, tuples have been simplified. The distinction between
"simple" and "complex" tuple types is eliminated. All tuples, even those
explicitly declared using `struct { ... }` syntax, use structural
equivalence, and do not undergo staged type resolution. Tuples are very
restricted: they cannot have non-`auto` layouts, cannot have aligned
fields, and cannot have default values with the exception of `comptime`
fields. Tuples currently do not have optimized layout, but this can be
changed in the future.
This change simplifies the language, and fixes some problematic
coercions through pointers which led to unintuitive behavior.
Resolves: #16865
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.