6420f37926
Instead of maintaining per-function-invocation malloc()'ed tables to track which functions each label belongs to, store the equivalent info in jump buffers (jmp_buf) themselves.
Also, use a less emscripten-looking ABI symbols:
```
saveSetjmp -> __wasm_setjmp
testSetjmp -> __wasm_setjmp_test
getTempRet0 -> (removed)
__wasm_longjmp -> (no change)
```
While I want to use this for WASI, it should work for emscripten as well.
An example runtime and a few tests:
https://github.com/yamt/garbage/tree/wasm-sjlj-alt2/wasm/longjmp
wasi-libc version of the runtime:
https://github.com/WebAssembly/wasi-libc/pull/483
emscripten version of the runtime:
https://github.com/emscripten-core/emscripten/pull/21502
Discussion:
https://docs.google.com/document/d/1ZvTPT36K5jjiedF8MCXbEmYjULJjI723aOAks1IdLLg/edit
36 lines
996 B
LLVM
36 lines
996 B
LLVM
; RUN: opt < %s -wasm-lower-em-ehsjlj -enable-emscripten-sjlj -S | FileCheck %s
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target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
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target triple = "wasm32-unknown-emscripten"
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; Tests if an alias to a function (here malloc) is correctly handled as a
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; function that cannot longjmp.
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%struct.__jmp_buf_tag = type { [6 x i32], i32, [32 x i32] }
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@malloc = weak alias ptr (i32), ptr @dlmalloc
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; CHECK-LABEL: @malloc_test
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define void @malloc_test() {
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entry:
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; CHECK: alloca i32
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%retval = alloca i32, align 4
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%jmp = alloca [1 x %struct.__jmp_buf_tag], align 16
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store i32 0, ptr %retval, align 4
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%call = call i32 @setjmp(ptr %jmp) #0
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call void @foo()
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ret void
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}
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; This is a dummy dlmalloc implemenation only to make compiler pass, because an
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; alias (malloc) has to point an actual definition.
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define ptr @dlmalloc(i32) {
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%p = inttoptr i32 0 to ptr
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ret ptr %p
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}
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declare void @foo()
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; Function Attrs: returns_twice
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declare i32 @setjmp(ptr) #0
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attributes #0 = { returns_twice }
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