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This repository was archived by the owner on Nov 26, 2025. It is now read-only.
zig translate-c fails to translate compound literals like &(float){0.5} #75
Description
Zig Version
0.14.0-dev.2064+b5cafe223
Steps to Reproduce and Observed Behavior
void main() {
float * p = &(float){0.5};
}Expected Behavior
translate-c fails to process the compound literal &(float){0.5}, which is a standard C feature allowing in-line temporary variables. Zig translate-c does not generate an equivalent expression in Zig.
The translated Zig code should ideally create a temporary variable for the literal and then assign its address to p.
pub export fn main() void {
var temp: f32 = @as(f32, @floatCast(0.5));
_ = &temp;
var x: [*c]f32 = &temp;
_ = &x;
}
Activity
mlugg commentedon Oct 30, 2024
translate-c fails to translate and demotes the function to extern:
rohlem commentedon Oct 30, 2024
See https://en.cppreference.com/w/c/language/compound_literal for details - note that afaiu the value is not bound the current sub-expression / statement (the closest meaning of "temporary"), but instead to the current scope/block.
Even if used in an expression (f.e. a function call), it has to translate to a stack location with lifetime until the end of the current block.
Yeaseen commentedon Oct 30, 2024
Thank you for the explanation! @rohlem That makes sense regarding the scope and the lifetime of the temporary variable. Just to clarify my main concern,
translate-cdoesn’t directly translate the compound literal&(float){0.5}in a way that maintains its temporary nature within the current scope or block.To be more specific, C compound literals like
&(float){0.5}create a temporary value with an addressable location that exists until the end of the current block, and it would be ideal iftranslate-ccould mimic this behavior by using a stack-allocated temporary variable. For example, generating something likevar temp: f32 = 0.5;in Zig and then assigningpto&tempwould produce the expected result and ensure that the temporary exists for the correct scope.