a7fe165684
"pure" universally means side-effect-free (GCC __attribute__((pure)), FP purity, D's pure) — the opposite of a register-clobbering context switch. The concept is "naked": no compiler-generated prologue/epilogue, body is raw asm that emits its own ret. That is the established term everywhere (LLVM's naked function attribute — which we literally emit — plus Zig callconv(.naked), Rust #[naked], GCC/Clang __attribute__ ((naked))). Rename the keyword + everything keyed off it so concept, surface, field, and the emitted LLVM attribute all agree. - ast.zig: ABI enum variant pure -> naked (+ doc). - parser: accept abi(.naked); error text updated. - IR Function.is_pure -> is_naked; type_resolver/decl/generic/pack/ emit_llvm references updated; diagnostics say abi(.naked). - examples 1800-1803 renamed *-pure-* -> *-naked-* (source + expected/ snapshots; .ir/.exit/.stdout/.stderr are byte-identical — the emitted IR is unchanged, only the keyword spelling differs). - docs (PLAN-FIBERS, CHECKPOINT-FIBERS, PLAN-POST-METATYPE, the design roadmap, the compiler-API checkpoint/design) updated; the naming rationale now records why .naked over .pure. No semantic change — pure cosmetics. Suite green (725/0).
26 lines
1.1 KiB
Plaintext
26 lines
1.1 KiB
Plaintext
// Stream B1 (fibers) — `abi(.pure)` emits a naked function end-to-end.
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//
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// An `abi(.pure)` function has no calling-convention prologue/epilogue/frame
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// and no implicit `__sx_ctx`: its body is a single asm block that sets the
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// return register and emits its own `ret`. This is the substrate the per-arch
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// fiber context-switch is built on (design §4.6) — a `.c` epilogue would
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// restore SP from the wrong stack across a switch (SP-in ≠ SP-out by design).
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//
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// Lowered via LLVM's `naked` function attribute: the body is emitted verbatim
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// (the inline asm + its own `ret`) with NO frame setup; the IR shows
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// `attributes #N = { naked noinline nounwind }` and the bare asm. aarch64-pinned
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// (the asm body is per-arch); runs end-to-end here (exit 42), ir-only on a
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// mismatch. See the x86_64 sibling 1802. NOTE: the `.ir` proves the `naked`
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// keyword + asm emitted, NOT register-save correctness (that's the B1.3
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// switch-stress harness's job).
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answer :: () -> i64 abi(.pure) {
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asm volatile {
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#string ASM
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mov x0, #42
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ret
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ASM
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};
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}
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main :: () -> i64 { return answer(); }
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