This commit makes it possible to obtain pointers to `extern` variables
at comptime.
- `ir_get_var_ptr` employs several checks to determine if the given
variable is eligible for obtaining its pointer at comptime. This
commit alters these checks to consider `extern` variables, which have
runtime values, as eligible.
- After this change, it's now possible for `render_const_val` to be
called for `extern` variables. This commit modifies
`render_const_val` to suppress the value generation for `extern`
variables.
- `do_code_gen` now creates `ZigValue::llvm_global` of `extern`
variables before iterating through module-level variables so that
other module-level variables can refer to them.
This solution is incomplete since there are several cases still
failing:
- `global_var.array[n..m]`
- `&global_var.array[i]`
- `&global_var.inner_struct.value`
- `&global_array[i]`
Closes#5349
* Take advantage of coercing anonymous struct literals to struct types.
* Reworks Module to favor Zig source as the primary use case.
Breaks ZIR compilation, which will have to be restored in a future commit.
* Decl uses src_index rather then src, pointing to an AST Decl node
index, or ZIR Module Decl index, rather than a byte offset.
* ZIR instructions have an `analyzed_inst` field instead of Module
having a hash table.
* Module.Fn loses the `fn_type` field since it is redundant with
its `owner_decl` `TypedValue` type.
* Implement Type and Value copying. A ZIR Const instruction's TypedValue
is copied to the Decl arena during analysis, which allows freeing the
ZIR text instructions post-analysis.
* Don't flush the ELF file if there are compilation errors.
* Function return types allow arbitrarily complex expressions.
* AST->ZIR for function calls and return statements.
This will allow the developer to request additional memory pages
from the runtime to be allocated for the Wasm app. Typical usage:
```zig
var wasm_pages = @wasmMemorySize();
@wasmMemoryGrow(1);
@import("std").debug.assert((wasm_pages + 1) == @wasmMemorySize());
```
This will allow the developer to poll the runtime for currently
allocated memory in the number of Wasm pages. Typical usage:
```zig
var wasm_pages = @wasmMemorySize();
@import("std").debug.assert(wasm_pages > 0);
```
Consider a (legal according to the `@bitCast` rules) conversion from u16
to [2]u8: since the former is a scalar and the latter is a pointer
(arrays are represented at pointers in the codegen phase) we have to
allocate a temporary slot on the stack and then bitcast the resulting
pointer to the desired destination type.
Beware that this means the lifetime of the resulting value is the same
of the function it's contained in and for all intents and purposes
should be regarded as a local (eg. it should not escape).
Closes#4395Closes#5121
The codegen would sometimes change the LLVM type for some constants to
an unnamed structure in order to accomodate extra padding. This is fine
as long as the alignment of each field is still respected and it was not
the case for structure types, leading to ill-formed constants being
generated.
Optional types suffer from this to a lower extent as their layout is
quite lucky, the only missing piece was the tail padding.
Closes#4530Closes#4594Closes#4295
Closes my will to live
Before, this would cause a link failure when mixing Zig and C code for
RISC-V targets.
Now, the ABIs match and Zig and C code can be mixed successfully.
I will file a follow-up issue for the ability to deal more explicitly
with ABIs.
closes#4863
Make fallthrough an error when compiler supports it. This requires a new
macro that is defined with such compilers to be used as a statement, at
all fallthrough sites:
switch (...) {
case 0:
...
ZIG_FALLTHROUGH;
case 1:
...
break;
default:
...
break;
}
If we ever move to C++17 as minimal requirement, then the macro can be
replaced with `[[fallthrough]];` at statement sites.
This caused link errors in c++ code because it was not correct to pass
these flags to child codegens. And that was the only reason to detect
these flags. Otherwise we can safely rely on non-explicitly-detected
flag forwarding.
Andrew Kelley