[llvm] 45a4aae - [NFC][XCOFF] Refactor Csect creation into TargetLoweringObjectFile
David Tenty via llvm-commits
llvm-commits at lists.llvm.org
Wed Jan 22 09:09:17 PST 2020
Author: David Tenty
Date: 2020-01-22T12:09:11-05:00
New Revision: 45a4aaea7fdf21a139b35ad6d25f6c4a150e065f
URL: https://github.com/llvm/llvm-project/commit/45a4aaea7fdf21a139b35ad6d25f6c4a150e065f
DIFF: https://github.com/llvm/llvm-project/commit/45a4aaea7fdf21a139b35ad6d25f6c4a150e065f.diff
LOG: [NFC][XCOFF] Refactor Csect creation into TargetLoweringObjectFile
Summary:
We create a number of standard types of control sections in multiple places for
things like the function descriptors, external references and the TOC anchor
among others, so it is possible for their properties to be defined
inconsistently in different places. This refactor moves their creation and
properties into functions in the TargetLoweringObjectFile class hierarchy, where
functions for retrieving various special types of sections typically seem
to reside.
Note: There is one case in PPCISelLowering which is specific to function entry
points which we don't address since we don't have access to the TLOF there.
Reviewers: DiggerLin, jasonliu, hubert.reinterpretcast
Reviewed By: jasonliu, hubert.reinterpretcast
Subscribers: wuzish, nemanjai, hiraditya, kbarton, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72347
Added:
Modified:
llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
llvm/include/llvm/MC/MCObjectFileInfo.h
llvm/include/llvm/Target/TargetLoweringObjectFile.h
llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
llvm/lib/MC/MCObjectFileInfo.cpp
llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h b/llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
index 4f58df93b93e..790e16ffa9eb 100644
--- a/llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
+++ b/llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
@@ -243,6 +243,15 @@ class TargetLoweringObjectFileXCOFF : public TargetLoweringObjectFile {
unsigned &Align) const override;
static XCOFF::StorageClass getStorageClassForGlobal(const GlobalObject *GO);
+
+ MCSection *getSectionForFunctionDescriptor(const MCSymbol *) const override;
+ MCSection *getSectionForTOCEntry(const MCSymbol *Sym) const override;
+
+ /// For external functions, this will always return a function descriptor
+ /// csect.
+ MCSection *
+ getSectionForExternalReference(const GlobalObject *GO,
+ const TargetMachine &TM) const override;
};
} // end namespace llvm
diff --git a/llvm/include/llvm/MC/MCObjectFileInfo.h b/llvm/include/llvm/MC/MCObjectFileInfo.h
index 2f7f5d64b466..18e77c4b3aff 100644
--- a/llvm/include/llvm/MC/MCObjectFileInfo.h
+++ b/llvm/include/llvm/MC/MCObjectFileInfo.h
@@ -216,6 +216,9 @@ class MCObjectFileInfo {
MCSection *GFIDsSection = nullptr;
MCSection *GLJMPSection = nullptr;
+ // XCOFF specific sections
+ MCSection *TOCBaseSection = nullptr;
+
public:
void InitMCObjectFileInfo(const Triple &TT, bool PIC, MCContext &ctx,
bool LargeCodeModel = false);
@@ -391,6 +394,9 @@ class MCObjectFileInfo {
MCSection *getGFIDsSection() const { return GFIDsSection; }
MCSection *getGLJMPSection() const { return GLJMPSection; }
+ // XCOFF specific sections
+ MCSection *getTOCBaseSection() const { return TOCBaseSection; }
+
MCSection *getEHFrameSection() {
return EHFrameSection;
}
diff --git a/llvm/include/llvm/Target/TargetLoweringObjectFile.h b/llvm/include/llvm/Target/TargetLoweringObjectFile.h
index d74341b23fb1..a13b09682a3a 100644
--- a/llvm/include/llvm/Target/TargetLoweringObjectFile.h
+++ b/llvm/include/llvm/Target/TargetLoweringObjectFile.h
@@ -212,6 +212,27 @@ class TargetLoweringObjectFile : public MCObjectFileInfo {
return nullptr;
}
+ /// On targets that use separate function descriptor symbols, return a section
+ /// for the descriptor given its symbol. Use only with defined functions.
+ virtual MCSection *getSectionForFunctionDescriptor(const MCSymbol *S) const {
+ return nullptr;
+ }
+
+ /// On targets that support TOC entries, return a section for the entry given
+ /// the symbol it refers to.
+ /// TODO: Implement this interface for existing ELF targets.
+ virtual MCSection *getSectionForTOCEntry(const MCSymbol *S) const {
+ return nullptr;
+ }
+
+ /// On targets that associate external references with a section, return such
+ /// a section for the given external global.
+ virtual MCSection *
+ getSectionForExternalReference(const GlobalObject *GO,
+ const TargetMachine &TM) const {
+ return nullptr;
+ }
+
protected:
virtual MCSection *SelectSectionForGlobal(const GlobalObject *GO,
SectionKind Kind,
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 8cb9814300d1..3b5c917c3d8c 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1832,6 +1832,22 @@ MCSection *TargetLoweringObjectFileXCOFF::getExplicitSectionGlobal(
report_fatal_error("XCOFF explicit sections not yet implemented.");
}
+MCSection *TargetLoweringObjectFileXCOFF::getSectionForExternalReference(
+ const GlobalObject *GO, const TargetMachine &TM) const {
+ assert(GO->isDeclaration() &&
+ "Tried to get ER section for a defined global.");
+
+ SmallString<128> Name;
+ getNameWithPrefix(Name, GO, TM);
+ XCOFF::StorageClass SC =
+ TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(GO);
+
+ // Externals go into a csect of type ER.
+ return getContext().getXCOFFSection(
+ Name, isa<Function>(GO) ? XCOFF::XMC_DS : XCOFF::XMC_UA, XCOFF::XTY_ER,
+ SC, SectionKind::getMetadata());
+}
+
MCSection *TargetLoweringObjectFileXCOFF::SelectSectionForGlobal(
const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
assert(!TM.getFunctionSections() && !TM.getDataSections() &&
@@ -1951,3 +1967,17 @@ XCOFF::StorageClass TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(
"Unhandled linkage when mapping linkage to StorageClass.");
}
}
+
+MCSection *TargetLoweringObjectFileXCOFF::getSectionForFunctionDescriptor(
+ const MCSymbol *FuncSym) const {
+ return getContext().getXCOFFSection(FuncSym->getName(), XCOFF::XMC_DS,
+ XCOFF::XTY_SD, XCOFF::C_HIDEXT,
+ SectionKind::getData());
+}
+
+MCSection *TargetLoweringObjectFileXCOFF::getSectionForTOCEntry(
+ const MCSymbol *Sym) const {
+ return getContext().getXCOFFSection(
+ cast<MCSymbolXCOFF>(Sym)->getUnqualifiedName(), XCOFF::XMC_TC,
+ XCOFF::XTY_SD, XCOFF::C_HIDEXT, SectionKind::getData());
+}
diff --git a/llvm/lib/MC/MCObjectFileInfo.cpp b/llvm/lib/MC/MCObjectFileInfo.cpp
index d567cc14a830..f339bcffcf68 100644
--- a/llvm/lib/MC/MCObjectFileInfo.cpp
+++ b/llvm/lib/MC/MCObjectFileInfo.cpp
@@ -795,6 +795,13 @@ void MCObjectFileInfo::initXCOFFMCObjectFileInfo(const Triple &T) {
ReadOnlySection = Ctx->getXCOFFSection(
".rodata", XCOFF::StorageMappingClass::XMC_RO, XCOFF::XTY_SD,
XCOFF::C_HIDEXT, SectionKind::getReadOnly());
+
+ TOCBaseSection = Ctx->getXCOFFSection(
+ "TOC", XCOFF::StorageMappingClass::XMC_TC0, XCOFF::XTY_SD,
+ XCOFF::C_HIDEXT, SectionKind::getData());
+
+ // The TOC-base always has 0 size, but 4 byte alignment.
+ TOCBaseSection->setAlignment(Align(4));
}
void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC,
diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index e1263e838fef..3e7fe81ed76f 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -1561,9 +1561,8 @@ void PPCAIXAsmPrinter::SetupMachineFunction(MachineFunction &MF) {
// Get the function descriptor symbol.
CurrentFnDescSym = getSymbol(&MF.getFunction());
// Set the containing csect.
- MCSectionXCOFF *FnDescSec = OutStreamer->getContext().getXCOFFSection(
- CurrentFnDescSym->getName(), XCOFF::XMC_DS, XCOFF::XTY_SD,
- XCOFF::C_HIDEXT, SectionKind::getData());
+ MCSectionXCOFF *FnDescSec = cast<MCSectionXCOFF>(
+ getObjFileLowering().getSectionForFunctionDescriptor(CurrentFnDescSym));
cast<MCSymbolXCOFF>(CurrentFnDescSym)->setContainingCsect(FnDescSec);
return AsmPrinter::SetupMachineFunction(MF);
@@ -1585,14 +1584,10 @@ const MCExpr *PPCAIXAsmPrinter::lowerConstant(const Constant *CV) {
if (const Function *F = dyn_cast<Function>(CV)) {
MCSymbolXCOFF *FSym = cast<MCSymbolXCOFF>(getSymbol(F));
if (!FSym->hasContainingCsect()) {
- const XCOFF::StorageClass SC =
+ MCSectionXCOFF *Csect = cast<MCSectionXCOFF>(
F->isDeclaration()
- ? TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(F)
- : XCOFF::C_HIDEXT;
- MCSectionXCOFF *Csect = OutStreamer->getContext().getXCOFFSection(
- FSym->getName(), XCOFF::XMC_DS,
- F->isDeclaration() ? XCOFF::XTY_ER : XCOFF::XTY_SD, SC,
- SectionKind::getData());
+ ? getObjFileLowering().getSectionForExternalReference(F, TM)
+ : getObjFileLowering().getSectionForFunctionDescriptor(FSym));
FSym->setContainingCsect(Csect);
}
return MCSymbolRefExpr::create(
@@ -1604,26 +1599,34 @@ const MCExpr *PPCAIXAsmPrinter::lowerConstant(const Constant *CV) {
void PPCAIXAsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
ValidateGV(GV);
- // External global variables are already handled.
- if (!GV->hasInitializer())
- return;
-
// Create the symbol, set its storage class.
MCSymbolXCOFF *GVSym = cast<MCSymbolXCOFF>(getSymbol(GV));
GVSym->setStorageClass(
TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(GV));
- SectionKind GVKind = getObjFileLowering().getKindForGlobal(GV, TM);
+ SectionKind GVKind;
+
+ // Create the containing csect and set it. We set it for externals as well,
+ // since this may not have been set elsewhere depending on how they are used.
+ MCSectionXCOFF *Csect = cast<MCSectionXCOFF>(
+ GV->isDeclaration()
+ ? getObjFileLowering().getSectionForExternalReference(GV, TM)
+ : getObjFileLowering().SectionForGlobal(
+ GV, GVKind = getObjFileLowering().getKindForGlobal(GV, TM),
+ TM));
+ GVSym->setContainingCsect(Csect);
+
+ // External global variables are already handled.
+ if (GV->isDeclaration())
+ return;
+
if ((!GVKind.isGlobalWriteableData() && !GVKind.isReadOnly()) ||
GVKind.isMergeable2ByteCString() || GVKind.isMergeable4ByteCString())
report_fatal_error("Encountered a global variable kind that is "
"not supported yet.");
- // Create the containing csect and switch to it.
- MCSectionXCOFF *Csect = cast<MCSectionXCOFF>(
- getObjFileLowering().SectionForGlobal(GV, GVKind, TM));
+ // Switch to the containing csect.
OutStreamer->SwitchSection(Csect);
- GVSym->setContainingCsect(Csect);
const DataLayout &DL = GV->getParent()->getDataLayout();
@@ -1661,10 +1664,9 @@ void PPCAIXAsmPrinter::EmitFunctionDescriptor() {
OutStreamer->EmitValue(MCSymbolRefExpr::create(CurrentFnSym, OutContext),
PointerSize);
// Emit TOC base address.
- const MCSectionXCOFF *TOCBaseSec = OutStreamer->getContext().getXCOFFSection(
- StringRef("TOC"), XCOFF::XMC_TC0, XCOFF::XTY_SD, XCOFF::C_HIDEXT,
- SectionKind::getData());
- const MCSymbol *TOCBaseSym = TOCBaseSec->getQualNameSymbol();
+ const MCSymbol *TOCBaseSym =
+ cast<MCSectionXCOFF>(getObjFileLowering().getTOCBaseSection())
+ ->getQualNameSymbol();
OutStreamer->EmitValue(MCSymbolRefExpr::create(TOCBaseSym, OutContext),
PointerSize);
// Emit a null environment pointer.
@@ -1679,23 +1681,16 @@ void PPCAIXAsmPrinter::EmitEndOfAsmFile(Module &M) {
if (M.empty())
return;
- // Emit TOC base.
- MCSectionXCOFF *TOCBaseSection = OutStreamer->getContext().getXCOFFSection(
- StringRef("TOC"), XCOFF::XMC_TC0, XCOFF::XTY_SD, XCOFF::C_HIDEXT,
- SectionKind::getData());
- // The TOC-base always has 0 size, but 4 byte alignment.
- TOCBaseSection->setAlignment(Align(4));
// Switch to section to emit TOC base.
- OutStreamer->SwitchSection(TOCBaseSection);
+ OutStreamer->SwitchSection(getObjFileLowering().getTOCBaseSection());
PPCTargetStreamer &TS =
static_cast<PPCTargetStreamer &>(*OutStreamer->getTargetStreamer());
for (auto &I : TOC) {
// Setup the csect for the current TC entry.
- MCSectionXCOFF *TCEntry = OutStreamer->getContext().getXCOFFSection(
- cast<MCSymbolXCOFF>(I.first)->getUnqualifiedName(), XCOFF::XMC_TC,
- XCOFF::XTY_SD, XCOFF::C_HIDEXT, SectionKind::getData());
+ MCSectionXCOFF *TCEntry = cast<MCSectionXCOFF>(
+ getObjFileLowering().getSectionForTOCEntry(I.first));
cast<MCSymbolXCOFF>(I.second)->setContainingCsect(TCEntry);
OutStreamer->SwitchSection(TCEntry);
@@ -1728,19 +1723,9 @@ PPCAIXAsmPrinter::getMCSymbolForTOCPseudoMO(const MachineOperand &MO) {
// Hence we may need to explictly create a MCSectionXCOFF for it so that we
// can return its symbol later.
if (GO->isDeclaration()) {
- if (!XSym->hasContainingCsect()) {
- // Make sure the storage class is set.
- const XCOFF::StorageClass SC =
- TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(GO);
- XSym->setStorageClass(SC);
-
- MCSectionXCOFF *Csect = OutStreamer->getContext().getXCOFFSection(
- XSym->getName(), isa<Function>(GO) ? XCOFF::XMC_DS : XCOFF::XMC_UA,
- XCOFF::XTY_ER, SC, SectionKind::getMetadata());
- XSym->setContainingCsect(Csect);
- }
-
- return XSym->getContainingCsect()->getQualNameSymbol();
+ return cast<MCSectionXCOFF>(
+ getObjFileLowering().getSectionForExternalReference(GO, TM))
+ ->getQualNameSymbol();
}
// Handle initialized global variables and defined functions.
@@ -1749,9 +1734,8 @@ PPCAIXAsmPrinter::getMCSymbolForTOCPseudoMO(const MachineOperand &MO) {
if (GOKind.isText()) {
// If the MO is a function, we want to make sure to refer to the function
// descriptor csect.
- return OutStreamer->getContext()
- .getXCOFFSection(XSym->getName(), XCOFF::XMC_DS, XCOFF::XTY_SD,
- XCOFF::C_HIDEXT, SectionKind::getData())
+ return cast<MCSectionXCOFF>(
+ getObjFileLowering().getSectionForFunctionDescriptor(XSym))
->getQualNameSymbol();
} else if (GOKind.isCommon() || GOKind.isBSSLocal()) {
// If the operand is a common then we should refer to the csect symbol.
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