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[ORC] Move all pass config into MachOPlatformPlugin::modifyPassConfig.
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NFC, this just makes it easier to see and reason about pass ordering.
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@lhames
lhames committed Oct 30, 2021
1 parent efa5cad commit afeb1e4
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Showing 2 changed files with 112 additions and 120 deletions.
11 changes: 5 additions & 6 deletions llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
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Expand Up @@ -153,15 +153,12 @@ class MachOPlatform : public Platform {
using InitSymbolDepMap =
DenseMap<MaterializationResponsibility *, JITLinkSymbolSet>;

void addInitializerSupportPasses(MaterializationResponsibility &MR,
jitlink::PassConfiguration &Config);

void addMachOHeaderSupportPasses(MaterializationResponsibility &MR,
jitlink::PassConfiguration &Config);

void addEHAndTLVSupportPasses(MaterializationResponsibility &MR,
jitlink::PassConfiguration &Config);

Error associateJITDylibHeaderSymbol(jitlink::LinkGraph &G,
MaterializationResponsibility &MR);

Error preserveInitSections(jitlink::LinkGraph &G,
MaterializationResponsibility &MR);

Expand All @@ -172,6 +169,8 @@ class MachOPlatform : public Platform {

Error fixTLVSectionsAndEdges(jitlink::LinkGraph &G, JITDylib &JD);

Error registerEHAndTLVSections(jitlink::LinkGraph &G);

std::mutex PluginMutex;
MachOPlatform &MP;
DenseMap<JITDylib *, std::pair<uint32_t, uint32_t>> ObjCImageInfos;
Expand Down
221 changes: 107 additions & 114 deletions llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
View file
Expand Up @@ -603,21 +603,48 @@ void MachOPlatform::MachOPlatformPlugin::modifyPassConfig(
MaterializationResponsibility &MR, jitlink::LinkGraph &LG,
jitlink::PassConfiguration &Config) {

// If the initializer symbol is the MachOHeader start symbol then just add
// the macho header support passes.
if (MR.getInitializerSymbol() == MP.MachOHeaderStartSymbol) {
addMachOHeaderSupportPasses(MR, Config);
// The header materialization unit doesn't require any other support, so we
// can bail out early.
return;
// --- Handle Initializers ---
if (auto InitSymbol = MR.getInitializerSymbol()) {

// If the initializer symbol is the MachOHeader start symbol then just
// register it and then bail out -- the header materialization unit
// definitely doesn't need any other passes.
if (InitSymbol == MP.MachOHeaderStartSymbol) {
Config.PostAllocationPasses.push_back([this, &MR](jitlink::LinkGraph &G) {
return associateJITDylibHeaderSymbol(G, MR);
});
return;
}

// If the object contains an init symbol other than the header start symbol
// then add passes to preserve, process and register the init
// sections/symbols.
Config.PrePrunePasses.push_back([this, &MR](jitlink::LinkGraph &G) {
if (auto Err = preserveInitSections(G, MR))
return Err;
return processObjCImageInfo(G, MR);
});

Config.PostFixupPasses.push_back(
[this, &JD = MR.getTargetJITDylib()](jitlink::LinkGraph &G) {
return registerInitSections(G, JD);
});
}

// If the object contains initializers then add passes to record them.
if (MR.getInitializerSymbol())
addInitializerSupportPasses(MR, Config);
// --- Add passes for eh-frame and TLV support ---

// Insert TLV lowering at the start of the PostPrunePasses, since we want
// it to run before GOT/PLT lowering.
Config.PostPrunePasses.insert(
Config.PostPrunePasses.begin(),
[this, &JD = MR.getTargetJITDylib()](jitlink::LinkGraph &G) {
return fixTLVSectionsAndEdges(G, JD);
});

// Add passes for eh-frame and TLV support.
addEHAndTLVSupportPasses(MR, Config);
// Add a pass to register the final addresses of the eh-frame and TLV sections
// with the runtime.
Config.PostFixupPasses.push_back(
[this](jitlink::LinkGraph &G) { return registerEHAndTLVSections(G); });
}

ObjectLinkingLayer::Plugin::SyntheticSymbolDependenciesMap
Expand All @@ -634,110 +661,22 @@ MachOPlatform::MachOPlatformPlugin::getSyntheticSymbolDependencies(
return SyntheticSymbolDependenciesMap();
}

void MachOPlatform::MachOPlatformPlugin::addInitializerSupportPasses(
MaterializationResponsibility &MR, jitlink::PassConfiguration &Config) {

/// Preserve init sections.
Config.PrePrunePasses.push_back([this, &MR](jitlink::LinkGraph &G) {
if (auto Err = preserveInitSections(G, MR))
return Err;
return processObjCImageInfo(G, MR);
});

Config.PostFixupPasses.push_back(
[this, &JD = MR.getTargetJITDylib()](jitlink::LinkGraph &G) {
return registerInitSections(G, JD);
});
}

void MachOPlatform::MachOPlatformPlugin::addMachOHeaderSupportPasses(
MaterializationResponsibility &MR, jitlink::PassConfiguration &Config) {

Config.PostAllocationPasses.push_back([this, &JD = MR.getTargetJITDylib()](
jitlink::LinkGraph &G) -> Error {
auto I = llvm::find_if(G.defined_symbols(), [this](jitlink::Symbol *Sym) {
return Sym->getName() == *MP.MachOHeaderStartSymbol;
});
assert(I != G.defined_symbols().end() &&
"Missing MachO header start symbol");
{
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
JITTargetAddress HeaderAddr = (*I)->getAddress();
MP.HeaderAddrToJITDylib[HeaderAddr] = &JD;
assert(!MP.InitSeqs.count(&JD) && "InitSeq entry for JD already exists");
MP.InitSeqs.insert(std::make_pair(
&JD,
MachOJITDylibInitializers(JD.getName(), ExecutorAddr(HeaderAddr))));
}
return Error::success();
});
}

void MachOPlatform::MachOPlatformPlugin::addEHAndTLVSupportPasses(
MaterializationResponsibility &MR, jitlink::PassConfiguration &Config) {

// Insert TLV lowering at the start of the PostPrunePasses, since we want
// it to run before GOT/PLT lowering.
Config.PostPrunePasses.insert(
Config.PostPrunePasses.begin(),
[this, &JD = MR.getTargetJITDylib()](jitlink::LinkGraph &G) {
return fixTLVSectionsAndEdges(G, JD);
});

// Add a pass to register the final addresses of the eh-frame and TLV sections
// with the runtime.
Config.PostFixupPasses.push_back([this](jitlink::LinkGraph &G) -> Error {
MachOPerObjectSectionsToRegister POSR;

if (auto *EHFrameSection = G.findSectionByName(EHFrameSectionName)) {
jitlink::SectionRange R(*EHFrameSection);
if (!R.empty())
POSR.EHFrameSection = {ExecutorAddr(R.getStart()),
ExecutorAddr(R.getEnd())};
}

// Get a pointer to the thread data section if there is one. It will be used
// below.
jitlink::Section *ThreadDataSection =
G.findSectionByName(ThreadDataSectionName);

// Handle thread BSS section if there is one.
if (auto *ThreadBSSSection = G.findSectionByName(ThreadBSSSectionName)) {
// If there's already a thread data section in this graph then merge the
// thread BSS section content into it, otherwise just treat the thread
// BSS section as the thread data section.
if (ThreadDataSection)
G.mergeSections(*ThreadDataSection, *ThreadBSSSection);
else
ThreadDataSection = ThreadBSSSection;
}

// Having merged thread BSS (if present) and thread data (if present),
// record the resulting section range.
if (ThreadDataSection) {
jitlink::SectionRange R(*ThreadDataSection);
if (!R.empty())
POSR.ThreadDataSection = {ExecutorAddr(R.getStart()),
ExecutorAddr(R.getEnd())};
}

if (POSR.EHFrameSection.Start || POSR.ThreadDataSection.Start) {

// If we're still bootstrapping the runtime then just record this
// frame for now.
if (!MP.RuntimeBootstrapped) {
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
MP.BootstrapPOSRs.push_back(POSR);
return Error::success();
}

// Otherwise register it immediately.
if (auto Err = MP.registerPerObjectSections(POSR))
return Err;
}
Error MachOPlatform::MachOPlatformPlugin::associateJITDylibHeaderSymbol(
jitlink::LinkGraph &G, MaterializationResponsibility &MR) {

return Error::success();
auto I = llvm::find_if(G.defined_symbols(), [this](jitlink::Symbol *Sym) {
return Sym->getName() == *MP.MachOHeaderStartSymbol;
});
assert(I != G.defined_symbols().end() && "Missing MachO header start symbol");

auto &JD = MR.getTargetJITDylib();
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
JITTargetAddress HeaderAddr = (*I)->getAddress();
MP.HeaderAddrToJITDylib[HeaderAddr] = &JD;
assert(!MP.InitSeqs.count(&JD) && "InitSeq entry for JD already exists");
MP.InitSeqs.insert(std::make_pair(
&JD, MachOJITDylibInitializers(JD.getName(), ExecutorAddr(HeaderAddr))));
return Error::success();
}

Error MachOPlatform::MachOPlatformPlugin::preserveInitSections(
Expand Down Expand Up @@ -942,5 +881,59 @@ Error MachOPlatform::MachOPlatformPlugin::fixTLVSectionsAndEdges(
return Error::success();
}

Error MachOPlatform::MachOPlatformPlugin::registerEHAndTLVSections(
jitlink::LinkGraph &G) {
MachOPerObjectSectionsToRegister POSR;

if (auto *EHFrameSection = G.findSectionByName(EHFrameSectionName)) {
jitlink::SectionRange R(*EHFrameSection);
if (!R.empty())
POSR.EHFrameSection = {ExecutorAddr(R.getStart()),
ExecutorAddr(R.getEnd())};
}

// Get a pointer to the thread data section if there is one. It will be used
// below.
jitlink::Section *ThreadDataSection =
G.findSectionByName(ThreadDataSectionName);

// Handle thread BSS section if there is one.
if (auto *ThreadBSSSection = G.findSectionByName(ThreadBSSSectionName)) {
// If there's already a thread data section in this graph then merge the
// thread BSS section content into it, otherwise just treat the thread
// BSS section as the thread data section.
if (ThreadDataSection)
G.mergeSections(*ThreadDataSection, *ThreadBSSSection);
else
ThreadDataSection = ThreadBSSSection;
}

// Having merged thread BSS (if present) and thread data (if present),
// record the resulting section range.
if (ThreadDataSection) {
jitlink::SectionRange R(*ThreadDataSection);
if (!R.empty())
POSR.ThreadDataSection = {ExecutorAddr(R.getStart()),
ExecutorAddr(R.getEnd())};
}

if (POSR.EHFrameSection.Start || POSR.ThreadDataSection.Start) {

// If we're still bootstrapping the runtime then just record this
// frame for now.
if (!MP.RuntimeBootstrapped) {
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
MP.BootstrapPOSRs.push_back(POSR);
return Error::success();
}

// Otherwise register it immediately.
if (auto Err = MP.registerPerObjectSections(POSR))
return Err;
}

return Error::success();
}

} // End namespace orc.
} // End namespace llvm.

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