Move DwarfCompileUnit from DwarfUnit.h to its own header (DwarfCompileUnit.h)
In preparation for sinking all the subprogram emission code down from
DwarfDebug into DwarfCompileUnit, this will avoid bloating
DwarfUnit.h/cpp greatly and make concerns a bit more clear/isolated.
(sinking this handling down is part of the work to handle emitting
minimal subprograms for -gmlt-like data into the skeleton CU under
fission)
llvm-svn: 219057
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
new file mode 100644
index 0000000..b7a56e3
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -0,0 +1,277 @@
+#include "DwarfCompileUnit.h"
+
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+
+namespace llvm {
+
+DwarfCompileUnit::DwarfCompileUnit(unsigned UID, DICompileUnit Node,
+ AsmPrinter *A, DwarfDebug *DW,
+ DwarfFile *DWU)
+ : DwarfUnit(UID, dwarf::DW_TAG_compile_unit, Node, A, DW, DWU) {
+ insertDIE(Node, &getUnitDie());
+}
+
+/// addLabelAddress - Add a dwarf label attribute data and value using
+/// DW_FORM_addr or DW_FORM_GNU_addr_index.
+///
+void DwarfCompileUnit::addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
+ const MCSymbol *Label) {
+
+ // Don't use the address pool in non-fission or in the skeleton unit itself.
+ // FIXME: Once GDB supports this, it's probably worthwhile using the address
+ // pool from the skeleton - maybe even in non-fission (possibly fewer
+ // relocations by sharing them in the pool, but we have other ideas about how
+ // to reduce the number of relocations as well/instead).
+ if (!DD->useSplitDwarf() || !Skeleton)
+ return addLocalLabelAddress(Die, Attribute, Label);
+
+ if (Label)
+ DD->addArangeLabel(SymbolCU(this, Label));
+
+ unsigned idx = DD->getAddressPool().getIndex(Label);
+ DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
+ Die.addValue(Attribute, dwarf::DW_FORM_GNU_addr_index, Value);
+}
+
+void DwarfCompileUnit::addLocalLabelAddress(DIE &Die,
+ dwarf::Attribute Attribute,
+ const MCSymbol *Label) {
+ if (Label)
+ DD->addArangeLabel(SymbolCU(this, Label));
+
+ Die.addValue(Attribute, dwarf::DW_FORM_addr,
+ Label ? (DIEValue *)new (DIEValueAllocator) DIELabel(Label)
+ : new (DIEValueAllocator) DIEInteger(0));
+}
+
+unsigned DwarfCompileUnit::getOrCreateSourceID(StringRef FileName, StringRef DirName) {
+ // If we print assembly, we can't separate .file entries according to
+ // compile units. Thus all files will belong to the default compile unit.
+
+ // FIXME: add a better feature test than hasRawTextSupport. Even better,
+ // extend .file to support this.
+ return Asm->OutStreamer.EmitDwarfFileDirective(
+ 0, DirName, FileName,
+ Asm->OutStreamer.hasRawTextSupport() ? 0 : getUniqueID());
+}
+
+// Return const expression if value is a GEP to access merged global
+// constant. e.g.
+// i8* getelementptr ({ i8, i8, i8, i8 }* @_MergedGlobals, i32 0, i32 0)
+static const ConstantExpr *getMergedGlobalExpr(const Value *V) {
+ const ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(V);
+ if (!CE || CE->getNumOperands() != 3 ||
+ CE->getOpcode() != Instruction::GetElementPtr)
+ return nullptr;
+
+ // First operand points to a global struct.
+ Value *Ptr = CE->getOperand(0);
+ if (!isa<GlobalValue>(Ptr) ||
+ !isa<StructType>(cast<PointerType>(Ptr->getType())->getElementType()))
+ return nullptr;
+
+ // Second operand is zero.
+ const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CE->getOperand(1));
+ if (!CI || !CI->isZero())
+ return nullptr;
+
+ // Third operand is offset.
+ if (!isa<ConstantInt>(CE->getOperand(2)))
+ return nullptr;
+
+ return CE;
+}
+
+/// getOrCreateGlobalVariableDIE - get or create global variable DIE.
+DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(DIGlobalVariable GV) {
+ // Check for pre-existence.
+ if (DIE *Die = getDIE(GV))
+ return Die;
+
+ assert(GV.isGlobalVariable());
+
+ DIScope GVContext = GV.getContext();
+ DIType GTy = DD->resolve(GV.getType());
+
+ // If this is a static data member definition, some attributes belong
+ // to the declaration DIE.
+ DIE *VariableDIE = nullptr;
+ bool IsStaticMember = false;
+ DIDerivedType SDMDecl = GV.getStaticDataMemberDeclaration();
+ if (SDMDecl.Verify()) {
+ assert(SDMDecl.isStaticMember() && "Expected static member decl");
+ // We need the declaration DIE that is in the static member's class.
+ VariableDIE = getOrCreateStaticMemberDIE(SDMDecl);
+ IsStaticMember = true;
+ }
+
+ // If this is not a static data member definition, create the variable
+ // DIE and add the initial set of attributes to it.
+ if (!VariableDIE) {
+ // Construct the context before querying for the existence of the DIE in
+ // case such construction creates the DIE.
+ DIE *ContextDIE = getOrCreateContextDIE(GVContext);
+
+ // Add to map.
+ VariableDIE = &createAndAddDIE(GV.getTag(), *ContextDIE, GV);
+
+ // Add name and type.
+ addString(*VariableDIE, dwarf::DW_AT_name, GV.getDisplayName());
+ addType(*VariableDIE, GTy);
+
+ // Add scoping info.
+ if (!GV.isLocalToUnit())
+ addFlag(*VariableDIE, dwarf::DW_AT_external);
+
+ // Add line number info.
+ addSourceLine(*VariableDIE, GV);
+ }
+
+ // Add location.
+ bool addToAccelTable = false;
+ DIE *VariableSpecDIE = nullptr;
+ bool isGlobalVariable = GV.getGlobal() != nullptr;
+ if (isGlobalVariable) {
+ addToAccelTable = true;
+ DIELoc *Loc = new (DIEValueAllocator) DIELoc();
+ const MCSymbol *Sym = Asm->getSymbol(GV.getGlobal());
+ if (GV.getGlobal()->isThreadLocal()) {
+ // FIXME: Make this work with -gsplit-dwarf.
+ unsigned PointerSize = Asm->getDataLayout().getPointerSize();
+ assert((PointerSize == 4 || PointerSize == 8) &&
+ "Add support for other sizes if necessary");
+ // Based on GCC's support for TLS:
+ if (!DD->useSplitDwarf()) {
+ // 1) Start with a constNu of the appropriate pointer size
+ addUInt(*Loc, dwarf::DW_FORM_data1,
+ PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
+ // 2) containing the (relocated) offset of the TLS variable
+ // within the module's TLS block.
+ addExpr(*Loc, dwarf::DW_FORM_udata,
+ Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
+ } else {
+ addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
+ addUInt(*Loc, dwarf::DW_FORM_udata,
+ DD->getAddressPool().getIndex(Sym, /* TLS */ true));
+ }
+ // 3) followed by a custom OP to make the debugger do a TLS lookup.
+ addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_push_tls_address);
+ } else {
+ DD->addArangeLabel(SymbolCU(this, Sym));
+ addOpAddress(*Loc, Sym);
+ }
+ // A static member's declaration is already flagged as such.
+ if (!SDMDecl.Verify() && !GV.isDefinition())
+ addFlag(*VariableDIE, dwarf::DW_AT_declaration);
+ // Do not create specification DIE if context is either compile unit
+ // or a subprogram.
+ if (GVContext && GV.isDefinition() && !GVContext.isCompileUnit() &&
+ !GVContext.isFile() && !DD->isSubprogramContext(GVContext)) {
+ // Create specification DIE.
+ VariableSpecDIE = &createAndAddDIE(dwarf::DW_TAG_variable, UnitDie);
+ addDIEEntry(*VariableSpecDIE, dwarf::DW_AT_specification, *VariableDIE);
+ addBlock(*VariableSpecDIE, dwarf::DW_AT_location, Loc);
+ // A static member's declaration is already flagged as such.
+ if (!SDMDecl.Verify())
+ addFlag(*VariableDIE, dwarf::DW_AT_declaration);
+ } else {
+ addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
+ }
+ // Add the linkage name.
+ StringRef LinkageName = GV.getLinkageName();
+ if (!LinkageName.empty())
+ // From DWARF4: DIEs to which DW_AT_linkage_name may apply include:
+ // TAG_common_block, TAG_constant, TAG_entry_point, TAG_subprogram and
+ // TAG_variable.
+ addString(IsStaticMember && VariableSpecDIE ? *VariableSpecDIE
+ : *VariableDIE,
+ DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
+ : dwarf::DW_AT_MIPS_linkage_name,
+ GlobalValue::getRealLinkageName(LinkageName));
+ } else if (const ConstantInt *CI =
+ dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
+ // AT_const_value was added when the static member was created. To avoid
+ // emitting AT_const_value multiple times, we only add AT_const_value when
+ // it is not a static member.
+ if (!IsStaticMember)
+ addConstantValue(*VariableDIE, CI, GTy);
+ } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV.getConstant())) {
+ addToAccelTable = true;
+ // GV is a merged global.
+ DIELoc *Loc = new (DIEValueAllocator) DIELoc();
+ Value *Ptr = CE->getOperand(0);
+ MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
+ DD->addArangeLabel(SymbolCU(this, Sym));
+ addOpAddress(*Loc, Sym);
+ addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
+ SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
+ addUInt(*Loc, dwarf::DW_FORM_udata,
+ Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
+ addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
+ addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
+ }
+
+ DIE *ResultDIE = VariableSpecDIE ? VariableSpecDIE : VariableDIE;
+
+ if (addToAccelTable) {
+ DD->addAccelName(GV.getName(), *ResultDIE);
+
+ // If the linkage name is different than the name, go ahead and output
+ // that as well into the name table.
+ if (GV.getLinkageName() != "" && GV.getName() != GV.getLinkageName())
+ DD->addAccelName(GV.getLinkageName(), *ResultDIE);
+ }
+
+ addGlobalName(GV.getName(), *ResultDIE, GV.getContext());
+ return ResultDIE;
+}
+
+void DwarfCompileUnit::addRange(RangeSpan Range) {
+ bool SameAsPrevCU = this == DD->getPrevCU();
+ DD->setPrevCU(this);
+ // If we have no current ranges just add the range and return, otherwise,
+ // check the current section and CU against the previous section and CU we
+ // emitted into and the subprogram was contained within. If these are the
+ // same then extend our current range, otherwise add this as a new range.
+ if (CURanges.empty() || !SameAsPrevCU ||
+ (&CURanges.back().getEnd()->getSection() !=
+ &Range.getEnd()->getSection())) {
+ CURanges.push_back(Range);
+ return;
+ }
+
+ CURanges.back().setEnd(Range.getEnd());
+}
+
+void DwarfCompileUnit::initStmtList(MCSymbol *DwarfLineSectionSym) {
+ // Define start line table label for each Compile Unit.
+ MCSymbol *LineTableStartSym =
+ Asm->OutStreamer.getDwarfLineTableSymbol(getUniqueID());
+
+ stmtListIndex = UnitDie.getValues().size();
+
+ // DW_AT_stmt_list is a offset of line number information for this
+ // compile unit in debug_line section. For split dwarf this is
+ // left in the skeleton CU and so not included.
+ // The line table entries are not always emitted in assembly, so it
+ // is not okay to use line_table_start here.
+ if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
+ addSectionLabel(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym);
+ else
+ addSectionDelta(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym,
+ DwarfLineSectionSym);
+}
+
+void DwarfCompileUnit::applyStmtList(DIE &D) {
+ D.addValue(dwarf::DW_AT_stmt_list,
+ UnitDie.getAbbrev().getData()[stmtListIndex].getForm(),
+ UnitDie.getValues()[stmtListIndex]);
+}
+
+} // end llvm namespace