fix(codegen): null-terminate untyped variadic argument lists - #1887
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ghaith wants to merge 2 commits into
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fix(codegen): null-terminate untyped variadic argument lists#1887ghaith wants to merge 2 commits into
ghaith wants to merge 2 commits into
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Problem: A call to an untyped variadic (`args : ...`) passes only the
arguments the caller wrote. A C callee that walks the list until a
terminator cannot find its end and reads past the arguments, which
segfaults, most visibly when the call carries no variadic argument at all.
Solution: Append a null pointer to every untyped variadic call.
Format-directed and count-directed callees read only the arguments they
expect and never see it, and a terminator written by the caller still ends
the list first. Sized (`{sized} T...`) and typed (`T...`) variadics keep
their exact argument list, because both have a callee signature that an
added argument would break.
Refs: PRG-4282
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Build Artifacts🐧 Linux
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Problem: The variadic suite calls only C functions that declare a named parameter and read their arguments with the two-argument `va_start`, so it says nothing about the forms C23 allows. Solution: Add a second lane that calls variadic functions with no named parameter at all, reading their arguments with the single-argument `va_start`. The lane probes the compiler for `-std=c23` or `-std=c2x` and reports itself unsupported when neither is accepted. Refs: PRG-4282 Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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Problem: A call to an untyped variadic (
args : ...) passes only the arguments the caller wrote. A C callee that walks the argument list until a terminator cannot find its end, so it reads past the arguments and segfaults. A call that carries no variadic argument at all crashes on its first read.Solution: Append a null pointer to every untyped variadic call. Format-directed and count-directed callees read only the arguments they expect and never see it, and a terminator written by the caller still ends the list first. Sized (
{sized} T...) and typed (T...) variadics keep their exact argument list, because both have a callee signature that an extra argument would break.Refs: PRG-4282
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