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ctor-eval fixes (WebAssembly#996)
* fix wasm-ctor-eval, we need to look for the STACKTOP etc. imports, they may not be named, if this build is not with -g * pack memory after ctor evalling, since we merge it up which is less efficient * do some useful opts after ctor-evalling, to clean things up
1 parent 7ba0e4e commit 0b8acfc

19 files changed

Lines changed: 171 additions & 34 deletions

‎src/ast/global-utils.h‎

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/*
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* Copyright 2017 WebAssembly Community Group participants
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef wasm_ast_global_h
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#define wasm_ast_global_h
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#include <algorithm>
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#include <vector>
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#include "literal.h"
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#include "wasm.h"
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namespace wasm {
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namespace GlobalUtils {
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// find a global initialized to the value of an import, or null if no such global
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inline Global* getGlobalInitializedToImport(Module&wasm, Name module, Name base) {
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// find the import
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Name imported;
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for (auto& import : wasm.imports) {
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if (import->module == module && import->base == base) {
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imported = import->name;
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break;
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}
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}
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if (imported.isNull()) return nullptr;
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// find a global inited to it
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for (auto& global : wasm.globals) {
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if (auto* init = global->init->dynCast<GetGlobal>()) {
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if (init->name == imported) {
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return global.get();
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}
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}
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}
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return nullptr;
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}
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};
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} // namespace wasm
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#endif // wasm_ast_global_h
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‎src/tools/wasm-ctor-eval.cpp‎

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@@ -32,6 +32,7 @@
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#include "wasm-interpreter.h"
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#include "wasm-builder.h"
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#include "ast/memory-utils.h"
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#include "ast/global-utils.h"
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using namespace wasm;
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@@ -153,10 +154,14 @@ class EvallingModuleInstance : public ModuleInstanceBase<EvallingGlobalManager,
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// prepare scratch memory
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stack.resize(STACK_SIZE);
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// fill usable values for stack imports
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auto total = STACK_START + STACK_SIZE;
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globals["STACKTOP"] = Literal(int32_t(STACK_START));
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globals["STACK_MAX"] = Literal(int32_t(STACK_START + STACK_SIZE));
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if (auto* stackTop = GlobalUtils::getGlobalInitializedToImport(wasm, "env", "STACKTOP")) {
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globals[stackTop->name] = Literal(int32_t(STACK_START));
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}
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if (auto* stackMax = GlobalUtils::getGlobalInitializedToImport(wasm, "env", "STACK_MAX")) {
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globals[stackMax->name] = Literal(int32_t(STACK_START));
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}
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// tell the module to accept writes up to the stack end
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auto total = STACK_START + STACK_SIZE;
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memorySize = total / Memory::kPageSize;
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}
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@@ -398,6 +403,17 @@ int main(int argc, const char* argv[]) {
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}
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evalCtors(wasm, ctors);
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// Do some useful optimizations after the evalling
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{
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PassRunner passRunner(&wasm);
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passRunner.add("memory-packing"); // we flattened it, so re-optimize
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passRunner.add("remove-unused-names");
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passRunner.add("dce");
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passRunner.add("merge-blocks");
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passRunner.add("vacuum");
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passRunner.run();
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}
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if (options.extra.count("output") > 0) {
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if (options.debug) std::cerr << "writing..." << std::endl;
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ModuleWriter writer;

‎test/ctor-eval/bad-indirect-call.wast.out‎

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(table 1 1 anyfunc)
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(elem (i32.const 0) $call-indirect)
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(memory $0 256 256)
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(data (i32.const 0) "\00\00\00\00\00\00\00\00\00\00waka waka waka waka waka")
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(data (i32.const 10) "waka waka waka waka waka")
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(export "test1" (func $test1))
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(func $test1 (type $v)
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(call_indirect $v

‎test/ctor-eval/bad-indirect-call2.wast.out‎

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(table 2 2 anyfunc)
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(elem (i32.const 0) $_abort $call-indirect)
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(memory $0 256 256)
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(data (i32.const 0) "\00\00\00\00\00\00\00\00\00\00waka waka waka waka waka")
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(data (i32.const 10) "waka waka waka waka waka")
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(export "test1" (func $test1))
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(func $test1 (type $v)
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(call_indirect $v

‎test/ctor-eval/basics-flatten.wast.out‎

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(table 1 1 anyfunc)
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(elem (i32.const 0) $call-indirect)
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(memory $0 256 256)
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(data (i32.const 0) "\00\00\00\00\00\00\00\00\00\00nas\00\00\00aka\00yzkx waka wakm\00\00\00\00\00\00C")
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(data (i32.const 10) "nas\00\00\00aka\00yzkx waka wakm\00\00\00\00\00\00C")
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(export "test1" (func $test1))
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(export "test2" (func $test2))
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(export "test3" (func $test3))
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(nop)
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)
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(func $safe-to-call (type $v)
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(drop
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(i32.const 1)
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)
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(i32.store8
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(i32.const 10)
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(i32.const 110)

‎test/ctor-eval/basics.wast.out‎

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@@ -3,7 +3,7 @@
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(table 1 1 anyfunc)
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(elem (i32.const 0) $call-indirect)
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(memory $0 256 256)
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(data (i32.const 0) "\00\00\00\00\00\00\00\00\00\00nas\00\00\00aka yzkx waka wakm\00\00\00\00\00\00C")
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(data (i32.const 10) "nas\00\00\00aka yzkx waka wakm\00\00\00\00\00\00C")
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(export "test1" (func $test1))
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(export "test2" (func $test2))
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(export "test3" (func $test3))
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(nop)
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)
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(func $safe-to-call (type $v)
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(drop
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(i32.const 1)
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)
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(i32.store8
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(i32.const 10)
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(i32.const 110)

‎test/ctor-eval/imported-min.wast‎

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(module
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(memory 256 256)
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(data (i32.const 10) "waka waka waka waka waka")
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;; stack imports are special
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(import "env" "STACKTOP" (global $STACKTOP$asm2wasm$import i32))
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(import "env" "STACK_MAX" (global $STACK_MAX$asm2wasm$import i32))
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;; other imports must not be touched!
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(import "env" "tempDoublePtr" (global $tempDoublePtr i32))
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(export "test1" $test1)
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(export "test2" $test2)
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(export "test3" $test3)
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;; ok to modify a global, if we keep it the same value
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(global $mine (mut i32) (i32.const 1))
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;; stack imports are ok to use. their uses are the same as other
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;; globals - must keep the same value (which means, unwind the stack)
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;; here the global names are "minified"
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(global $global0 (mut i32) (get_global $STACKTOP$asm2wasm$import))
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(global $global1 (mut i32) (get_global $STACK_MAX$asm2wasm$import))
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;; a global initialized by an import, so bad, but ok if not used
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(global $do-not-use (mut i32) (get_global $tempDoublePtr))
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(func $test1
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(local $temp i32)
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(set_global $mine (i32.const 1))
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(set_local $temp (get_global $global0))
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(set_global $global0 (i32.const 1337)) ;; bad
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(set_global $global0 (get_local $temp)) ;; save us
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(set_global $global1 (i32.const 913370)) ;; bad
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(set_global $global1 (get_local $temp)) ;; save us
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;; use the stack memory
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(i32.store (get_local $temp) (i32.const 1337))
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(if
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(i32.ne
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(i32.load (get_local $temp))
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(i32.const 1337)
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)
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(unreachable) ;; they should be equal, never get here
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)
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;; finally, do a valid store
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(i32.store8 (i32.const 12) (i32.const 115))
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)
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(func $test2
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(set_global $tempDoublePtr (i32.const 1)) ;; bad!
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(i32.store8 (i32.const 13) (i32.const 115))
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)
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(func $test3
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(i32.store8 (i32.const 14) (i32.const 115))
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)
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)

‎test/ctor-eval/imported-min.wast.ctors‎

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test1,test2,test3

‎test/ctor-eval/imported-min.wast.out‎

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(module
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(type $0 (func))
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(import "env" "STACKTOP" (global $STACKTOP$asm2wasm$import i32))
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(import "env" "STACK_MAX" (global $STACK_MAX$asm2wasm$import i32))
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(import "env" "tempDoublePtr" (global $tempDoublePtr i32))
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(global $mine (mut i32) (i32.const 1))
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(global $global0 (mut i32) (get_global $STACKTOP$asm2wasm$import))
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(global $global1 (mut i32) (get_global $STACK_MAX$asm2wasm$import))
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(global $do-not-use (mut i32) (get_global $tempDoublePtr))
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(memory $0 256 256)
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(data (i32.const 10) "wasa waka waka waka waka")
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(export "test1" (func $test1))
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(export "test2" (func $test2))
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(export "test3" (func $test3))
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(func $test1 (type $0)
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(local $temp i32)
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(nop)
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)
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(func $test2 (type $0)
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(set_global $tempDoublePtr
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(i32.const 1)
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)
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(i32.store8
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(i32.const 13)
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(i32.const 115)
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)
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)
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(func $test3 (type $0)
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(i32.store8
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(i32.const 14)
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(i32.const 115)
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)
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)
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)

‎test/ctor-eval/imported.wast.out‎

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@@ -8,7 +8,7 @@
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(global $STACK_MAX (mut i32) (get_global $STACK_MAX$asm2wasm$import))
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(global $do-not-use (mut i32) (get_global $tempDoublePtr))
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(memory $0 256 256)
11-
(data (i32.const 0) "\00\00\00\00\00\00\00\00\00\00wasa waka waka waka waka")
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(data (i32.const 10) "wasa waka waka waka waka")
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(export "test1" (func $test1))
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(export "test2" (func $test2))
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(export "test3" (func $test3))

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