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[WebAssembly] Update WebAssemblyLowerEmscriptenEHSjLj to handle separ…
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…ate compilation

Previously we were assuming whole program compilation. Now that
separate compilation is a thing we need to update this pass.
Firstly, it can no longer assert on the existence of malloc and free.
This functions might not be in the current translation unit.  If we
need them then we will generate not imports for them.

Secondly the global helper function we create should be marked as
weak since we will be generating a separate copy in each translation
unit.

Finally the names of the symbols used must be unique and fixed since
they need to agree across translation units.

Differential Revision: https://reviews.llvm.org/D49263

llvm-svn: 337301
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@sbc100
sbc100 committed Jul 17, 2018
1 parent c4c3633 commit 28b3e99
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Showing 3 changed files with 51 additions and 72 deletions.
55 changes: 17 additions & 38 deletions llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
View file
Expand Up @@ -225,13 +225,8 @@ static cl::list<std::string>

namespace {
class WebAssemblyLowerEmscriptenEHSjLj final : public ModulePass {
static const char *ThrewGVName;
static const char *ThrewValueGVName;
static const char *TempRet0GVName;
static const char *ResumeFName;
static const char *EHTypeIDFName;
static const char *SetThrewFName;
static const char *SetTempRet0FName;
static const char *EmLongjmpFName;
static const char *EmLongjmpJmpbufFName;
static const char *SaveSetjmpFName;
Expand Down Expand Up @@ -300,14 +295,9 @@ class WebAssemblyLowerEmscriptenEHSjLj final : public ModulePass {
};
} // End anonymous namespace

const char *WebAssemblyLowerEmscriptenEHSjLj::ThrewGVName = "__THREW__";
const char *WebAssemblyLowerEmscriptenEHSjLj::ThrewValueGVName = "__threwValue";
const char *WebAssemblyLowerEmscriptenEHSjLj::TempRet0GVName = "__tempRet0";
const char *WebAssemblyLowerEmscriptenEHSjLj::ResumeFName = "__resumeException";
const char *WebAssemblyLowerEmscriptenEHSjLj::EHTypeIDFName =
"llvm_eh_typeid_for";
const char *WebAssemblyLowerEmscriptenEHSjLj::SetThrewFName = "setThrew";
const char *WebAssemblyLowerEmscriptenEHSjLj::SetTempRet0FName = "setTempRet0";
const char *WebAssemblyLowerEmscriptenEHSjLj::EmLongjmpFName =
"emscripten_longjmp";
const char *WebAssemblyLowerEmscriptenEHSjLj::EmLongjmpJmpbufFName =
Expand Down Expand Up @@ -343,15 +333,13 @@ static bool canThrow(const Value *V) {
return true;
}

// Returns an available name for a global value.
// If the proposed name already exists in the module, adds '_' at the end of
// the name until the name is available.
static inline std::string createGlobalValueName(const Module &M,
const std::string &Propose) {
std::string Name = Propose;
while (M.getNamedGlobal(Name))
Name += "_";
return Name;
static GlobalVariable *createGlobalVariableI32(Module &M, IRBuilder<> &IRB,
const char *Name) {
if (M.getNamedGlobal(Name))
report_fatal_error(Twine("variable name is reserved: ") + Name);

return new GlobalVariable(M, IRB.getInt32Ty(), false,
GlobalValue::WeakODRLinkage, IRB.getInt32(0), Name);
}

// Simple function name mangler.
Expand Down Expand Up @@ -613,11 +601,13 @@ void WebAssemblyLowerEmscriptenEHSjLj::createSetThrewFunction(Module &M) {
LLVMContext &C = M.getContext();
IRBuilder<> IRB(C);

assert(!M.getNamedGlobal(SetThrewFName) && "setThrew already exists");
if (M.getNamedGlobal("setThrew"))
report_fatal_error("setThrew already exists");

Type *Params[] = {IRB.getInt32Ty(), IRB.getInt32Ty()};
FunctionType *FTy = FunctionType::get(IRB.getVoidTy(), Params, false);
Function *F =
Function::Create(FTy, GlobalValue::ExternalLinkage, SetThrewFName, &M);
Function::Create(FTy, GlobalValue::WeakODRLinkage, "setThrew", &M);
Argument *Arg1 = &*(F->arg_begin());
Argument *Arg2 = &*std::next(F->arg_begin());
Arg1->setName("threw");
Expand Down Expand Up @@ -648,11 +638,12 @@ void WebAssemblyLowerEmscriptenEHSjLj::createSetTempRet0Function(Module &M) {
LLVMContext &C = M.getContext();
IRBuilder<> IRB(C);

assert(!M.getNamedGlobal(SetTempRet0FName) && "setTempRet0 already exists");
if (M.getNamedGlobal("setTempRet0"))
report_fatal_error("setTempRet0 already exists");
Type *Params[] = {IRB.getInt32Ty()};
FunctionType *FTy = FunctionType::get(IRB.getVoidTy(), Params, false);
Function *F =
Function::Create(FTy, GlobalValue::ExternalLinkage, SetTempRet0FName, &M);
Function::Create(FTy, GlobalValue::WeakODRLinkage, "setTempRet0", &M);
F->arg_begin()->setName("value");
BasicBlock *EntryBB = BasicBlock::Create(C, "entry", F);
IRB.SetInsertPoint(EntryBB);
Expand Down Expand Up @@ -699,15 +690,9 @@ bool WebAssemblyLowerEmscriptenEHSjLj::runOnModule(Module &M) {

// Create global variables __THREW__, threwValue, and __tempRet0, which are
// used in common for both exception handling and setjmp/longjmp handling
ThrewGV = new GlobalVariable(M, IRB.getInt32Ty(), false,
GlobalValue::ExternalLinkage, IRB.getInt32(0),
createGlobalValueName(M, ThrewGVName));
ThrewValueGV = new GlobalVariable(
M, IRB.getInt32Ty(), false, GlobalValue::ExternalLinkage, IRB.getInt32(0),
createGlobalValueName(M, ThrewValueGVName));
TempRet0GV = new GlobalVariable(M, IRB.getInt32Ty(), false,
GlobalValue::ExternalLinkage, IRB.getInt32(0),
createGlobalValueName(M, TempRet0GVName));
ThrewGV = createGlobalVariableI32(M, IRB, "__THREW__");
ThrewValueGV = createGlobalVariableI32(M, IRB, "__threwValue");
TempRet0GV = createGlobalVariableI32(M, IRB, "__tempRet0");

bool Changed = false;

Expand Down Expand Up @@ -736,12 +721,6 @@ bool WebAssemblyLowerEmscriptenEHSjLj::runOnModule(Module &M) {
if (DoSjLj) {
Changed = true; // We have setjmp or longjmp somewhere

Function *MallocF = M.getFunction("malloc");
Function *FreeF = M.getFunction("free");
if (!MallocF || !FreeF)
report_fatal_error(
"malloc and free must be linked into the module if setjmp is used");

// Register saveSetjmp function
FunctionType *SetjmpFTy = SetjmpF->getFunctionType();
SmallVector<Type *, 4> Params = {SetjmpFTy->getParamType(0),
Expand Down
38 changes: 19 additions & 19 deletions llvm/test/CodeGen/WebAssembly/lower-em-exceptions.ll
View file
Expand Up @@ -5,9 +5,9 @@ target triple = "wasm32-unknown-unknown"

@_ZTIi = external constant i8*
@_ZTIc = external constant i8*
; CHECK-DAG: @[[__THREW__:__THREW__.*]] = global i32 0
; CHECK-DAG: @[[THREWVALUE:__threwValue.*]] = global i32 0
; CHECK-DAG: @[[TEMPRET0:__tempRet0.*]] = global i32 0
; CHECK-DAG: __THREW__ = weak_odr global i32 0
; CHECK-DAG: __threwValue = weak_odr global i32 0
; CHECK-DAG: __tempRet0 = weak_odr global i32 0

; Test invoke instruction with clauses (try-catch block)
define void @clause() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
Expand All @@ -16,10 +16,10 @@ entry:
invoke void @foo(i32 3)
to label %invoke.cont unwind label %lpad
; CHECK: entry:
; CHECK-NEXT: store i32 0, i32* @[[__THREW__]]
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: call void @__invoke_void_i32(void (i32)* @foo, i32 3)
; CHECK-NEXT: %[[__THREW__VAL:.*]] = load i32, i32* @[[__THREW__]]
; CHECK-NEXT: store i32 0, i32* @[[__THREW__]]
; CHECK-NEXT: %[[__THREW__VAL:.*]] = load i32, i32* @__THREW__
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: %cmp = icmp eq i32 %[[__THREW__VAL]], 1
; CHECK-NEXT: br i1 %cmp, label %lpad, label %invoke.cont

Expand All @@ -36,7 +36,7 @@ lpad: ; preds = %entry
; CHECK: lpad:
; CHECK-NEXT: %[[FMC:.*]] = call i8* @__cxa_find_matching_catch_4(i8* bitcast (i8** @_ZTIi to i8*), i8* null)
; CHECK-NEXT: %[[IVI1:.*]] = insertvalue { i8*, i32 } undef, i8* %[[FMC]], 0
; CHECK-NEXT: %[[TEMPRET0_VAL:.*]] = load i32, i32* @[[TEMPRET0]]
; CHECK-NEXT: %[[TEMPRET0_VAL:.*]] = load i32, i32* @__tempRet0
; CHECK-NEXT: %[[IVI2:.*]] = insertvalue { i8*, i32 } %[[IVI1]], i32 %[[TEMPRET0_VAL]], 1
; CHECK-NEXT: extractvalue { i8*, i32 } %[[IVI2]], 0
; CHECK-NEXT: %[[CDR:.*]] = extractvalue { i8*, i32 } %[[IVI2]], 1
Expand Down Expand Up @@ -72,10 +72,10 @@ entry:
invoke void @foo(i32 3)
to label %invoke.cont unwind label %lpad
; CHECK: entry:
; CHECK-NEXT: store i32 0, i32* @[[__THREW__]]
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: call void @__invoke_void_i32(void (i32)* @foo, i32 3)
; CHECK-NEXT: %[[__THREW__VAL:.*]] = load i32, i32* @[[__THREW__]]
; CHECK-NEXT: store i32 0, i32* @[[__THREW__]]
; CHECK-NEXT: %[[__THREW__VAL:.*]] = load i32, i32* @__THREW__
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: %cmp = icmp eq i32 %[[__THREW__VAL]], 1
; CHECK-NEXT: br i1 %cmp, label %lpad, label %invoke.cont

Expand All @@ -91,7 +91,7 @@ lpad: ; preds = %entry
; CHECK: lpad:
; CHECK-NEXT: %[[FMC:.*]] = call i8* @__cxa_find_matching_catch_4(i8* bitcast (i8** @_ZTIi to i8*), i8* bitcast (i8** @_ZTIc to i8*))
; CHECK-NEXT: %[[IVI1:.*]] = insertvalue { i8*, i32 } undef, i8* %[[FMC]], 0
; CHECK-NEXT: %[[TEMPRET0_VAL:.*]] = load i32, i32* @[[TEMPRET0]]
; CHECK-NEXT: %[[TEMPRET0_VAL:.*]] = load i32, i32* @__tempRet0
; CHECK-NEXT: %[[IVI2:.*]] = insertvalue { i8*, i32 } %[[IVI1]], i32 %[[TEMPRET0_VAL]], 1
; CHECK-NEXT: extractvalue { i8*, i32 } %[[IVI2]], 0
; CHECK-NEXT: extractvalue { i8*, i32 } %[[IVI2]], 1
Expand Down Expand Up @@ -123,7 +123,7 @@ entry:
%0 = invoke noalias i8* @bar(i8 signext 1, i8 zeroext 2)
to label %invoke.cont unwind label %lpad
; CHECK: entry:
; CHECK-NEXT: store i32 0, i32* @[[__THREW__]]
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: %0 = call noalias i8* @"__invoke_i8*_i8_i8"(i8* (i8, i8)* @bar, i8 signext 1, i8 zeroext 2)

invoke.cont: ; preds = %entry
Expand Down Expand Up @@ -173,22 +173,22 @@ declare void @__cxa_call_unexpected(i8*)
; CHECK-DAG: declare i8* @__cxa_find_matching_catch_4(i8*, i8*)

; setThrew function creation
; CHECK-LABEL: define void @setThrew(i32 %threw, i32 %value) {
; CHECK-LABEL: define weak_odr void @setThrew(i32 %threw, i32 %value) {
; CHECK: entry:
; CHECK-NEXT: %[[__THREW__]].val = load i32, i32* @[[__THREW__]]
; CHECK-NEXT: %cmp = icmp eq i32 %[[__THREW__]].val, 0
; CHECK-NEXT: %__THREW__.val = load i32, i32* @__THREW__
; CHECK-NEXT: %cmp = icmp eq i32 %__THREW__.val, 0
; CHECK-NEXT: br i1 %cmp, label %if.then, label %if.end
; CHECK: if.then:
; CHECK-NEXT: store i32 %threw, i32* @[[__THREW__]]
; CHECK-NEXT: store i32 %value, i32* @[[THREWVALUE]]
; CHECK-NEXT: store i32 %threw, i32* @__THREW__
; CHECK-NEXT: store i32 %value, i32* @__threwValue
; CHECK-NEXT: br label %if.end
; CHECK: if.end:
; CHECK-NEXT: ret void
; CHECK: }

; setTempRet0 function creation
; CHECK-LABEL: define void @setTempRet0(i32 %value) {
; CHECK-LABEL: define weak_odr void @setTempRet0(i32 %value) {
; CHECK: entry:
; CHECK-NEXT: store i32 %value, i32* @[[TEMPRET0]]
; CHECK-NEXT: store i32 %value, i32* @__tempRet0
; CHECK-NEXT: ret void
; CHECK: }
30 changes: 15 additions & 15 deletions llvm/test/CodeGen/WebAssembly/lower-em-sjlj.ll
View file
Expand Up @@ -6,9 +6,9 @@ target triple = "wasm32-unknown-unknown"
%struct.__jmp_buf_tag = type { [6 x i32], i32, [32 x i32] }

@global_var = hidden global i32 0, align 4
; CHECK-DAG: @[[__THREW__:__THREW__.*]] = global i32 0
; CHECK-DAG: @[[THREWVALUE:__threwValue.*]] = global i32 0
; CHECK-DAG: @[[TEMPRET0:__tempRet0.*]] = global i32 0
; CHECK-DAG: __THREW__ = weak_odr global i32 0
; CHECK-DAG: __threwValue = weak_odr global i32 0
; CHECK-DAG: __tempRet0 = weak_odr global i32 0

; Test a simple setjmp - longjmp sequence
define hidden void @setjmp_longjmp() {
Expand All @@ -28,18 +28,18 @@ entry:
; CHECK-NEXT: %[[BUF:.*]] = alloca [1 x %struct.__jmp_buf_tag]
; CHECK-NEXT: %[[ARRAYDECAY:.*]] = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %[[BUF]], i32 0, i32 0
; CHECK-NEXT: %[[SETJMP_TABLE1:.*]] = call i32* @saveSetjmp(%struct.__jmp_buf_tag* %[[ARRAYDECAY]], i32 1, i32* %[[SETJMP_TABLE]], i32 %[[SETJMP_TABLE_SIZE]])
; CHECK-NEXT: %[[SETJMP_TABLE_SIZE1:.*]] = load i32, i32* @[[TEMPRET0]]
; CHECK-NEXT: %[[SETJMP_TABLE_SIZE1:.*]] = load i32, i32* @__tempRet0
; CHECK-NEXT: br label %entry.split

; CHECK: entry.split:
; CHECK-NEXT: phi i32 [ 0, %entry ], [ %[[LONGJMP_RESULT:.*]], %if.end ]
; CHECK-NEXT: %[[ARRAYDECAY1:.*]] = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %[[BUF]], i32 0, i32 0
; CHECK-NEXT: store i32 0, i32* @[[__THREW__]]
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: call void @"__invoke_void_%struct.__jmp_buf_tag*_i32"(void (%struct.__jmp_buf_tag*, i32)* @emscripten_longjmp_jmpbuf, %struct.__jmp_buf_tag* %[[ARRAYDECAY1]], i32 1)
; CHECK-NEXT: %[[__THREW__VAL:.*]] = load i32, i32* @[[__THREW__]]
; CHECK-NEXT: store i32 0, i32* @[[__THREW__]]
; CHECK-NEXT: %[[__THREW__VAL:.*]] = load i32, i32* @__THREW__
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: %[[CMP0:.*]] = icmp ne i32 %__THREW__.val, 0
; CHECK-NEXT: %[[THREWVALUE_VAL:.*]] = load i32, i32* @[[THREWVALUE]]
; CHECK-NEXT: %[[THREWVALUE_VAL:.*]] = load i32, i32* @__threwValue
; CHECK-NEXT: %[[CMP1:.*]] = icmp ne i32 %[[THREWVALUE_VAL]], 0
; CHECK-NEXT: %[[CMP:.*]] = and i1 %[[CMP0]], %[[CMP1]]
; CHECK-NEXT: br i1 %[[CMP]], label %if.then1, label %if.else1
Expand All @@ -59,7 +59,7 @@ entry:

; CHECK: if.end:
; CHECK-NEXT: %[[LABEL_PHI:.*]] = phi i32 [ %[[LABEL:.*]], %if.end2 ], [ -1, %if.else1 ]
; CHECK-NEXT: %[[LONGJMP_RESULT]] = load i32, i32* @[[TEMPRET0]]
; CHECK-NEXT: %[[LONGJMP_RESULT]] = load i32, i32* @__tempRet0
; CHECK-NEXT: switch i32 %[[LABEL_PHI]], label %entry.split.split [
; CHECK-NEXT: i32 1, label %entry.split
; CHECK-NEXT: ]
Expand All @@ -69,7 +69,7 @@ entry:
; CHECK-NEXT: unreachable

; CHECK: if.end2:
; CHECK-NEXT: store i32 %[[THREWVALUE_VAL]], i32* @[[TEMPRET0]]
; CHECK-NEXT: store i32 %[[THREWVALUE_VAL]], i32* @__tempRet0
; CHECK-NEXT: br label %if.end
}

Expand Down Expand Up @@ -105,12 +105,12 @@ entry:
to label %try.cont unwind label %lpad

; CHECK: entry.split:
; CHECK: store i32 0, i32* @[[__THREW__]]
; CHECK: store i32 0, i32* @__THREW__
; CHECK-NEXT: call void @__invoke_void(void ()* @foo)
; CHECK-NEXT: %[[__THREW__VAL:.*]] = load i32, i32* @[[__THREW__]]
; CHECK-NEXT: store i32 0, i32* @[[__THREW__]]
; CHECK-NEXT: %[[__THREW__VAL:.*]] = load i32, i32* @__THREW__
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: %[[CMP0:.*]] = icmp ne i32 %[[__THREW__VAL]], 0
; CHECK-NEXT: %[[THREWVALUE_VAL:.*]] = load i32, i32* @[[THREWVALUE]]
; CHECK-NEXT: %[[THREWVALUE_VAL:.*]] = load i32, i32* @__threwValue
; CHECK-NEXT: %[[CMP1:.*]] = icmp ne i32 %[[THREWVALUE_VAL]], 0
; CHECK-NEXT: %[[CMP:.*]] = and i1 %[[CMP0]], %[[CMP1]]
; CHECK-NEXT: br i1 %[[CMP]], label %if.then1, label %if.else1
Expand Down Expand Up @@ -152,7 +152,7 @@ if.then: ; preds = %entry
; CHECK: if.then:
; CHECK: %[[VAR0:.*]] = load i32, i32* @global_var, align 4
; CHECK: %[[SETJMP_TABLE1:.*]] = call i32* @saveSetjmp(
; CHECK-NEXT: %[[SETJMP_TABLE_SIZE1:.*]] = load i32, i32* @[[TEMPRET0]]
; CHECK-NEXT: %[[SETJMP_TABLE_SIZE1:.*]] = load i32, i32* @__tempRet0

; CHECK: if.then.split:
; CHECK: %[[VAR1:.*]] = phi i32 [ %[[VAR0]], %if.then ], [ %[[VAR2:.*]], %if.end3 ]
Expand Down

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