Imported Upstream version 5.18.0.246

Former-commit-id: 0c7ce5b1a7851e13f22acfd379b7f9fb304e4833

external/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.h

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+//===-- llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.h --------*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Common functionality for different debug information format backends.
+// LLVM currently supports DWARF and CodeView.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGHANDLERBASE_H
+#define LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGHANDLERBASE_H
+
+#include "AsmPrinterHandler.h"
+#include "DbgValueHistoryCalculator.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/CodeGen/LexicalScopes.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/IR/DebugInfoMetadata.h"
+
+namespace llvm {
+
+class AsmPrinter;
+class MachineInstr;
+class MachineModuleInfo;
+
+/// Represents the location at which a variable is stored.
+struct DbgVariableLocation {
+  /// Base register.
+  unsigned Register;
+
+  /// Chain of offsetted loads necessary to load the value if it lives in
+  /// memory. Every load except for the last is pointer-sized.
+  SmallVector<int64_t, 1> LoadChain;
+
+  /// Present if the location is part of a larger variable.
+  llvm::Optional<llvm::DIExpression::FragmentInfo> FragmentInfo;
+
+  /// Extract a VariableLocation from a MachineInstr.
+  /// This will only work if Instruction is a debug value instruction
+  /// and the associated DIExpression is in one of the supported forms.
+  /// If these requirements are not met, the returned Optional will not
+  /// have a value.
+  static Optional<DbgVariableLocation>
+  extractFromMachineInstruction(const MachineInstr &Instruction);
+};
+
+/// Base class for debug information backends. Common functionality related to
+/// tracking which variables and scopes are alive at a given PC live here.
+class DebugHandlerBase : public AsmPrinterHandler {
+protected:
+  DebugHandlerBase(AsmPrinter *A);
+
+  /// Target of debug info emission.
+  AsmPrinter *Asm;
+
+  /// Collected machine module information.
+  MachineModuleInfo *MMI;
+
+  /// Previous instruction's location information. This is used to
+  /// determine label location to indicate scope boundaries in debug info.
+  /// We track the previous instruction's source location (if not line 0),
+  /// whether it was a label, and its parent BB.
+  DebugLoc PrevInstLoc;
+  MCSymbol *PrevLabel = nullptr;
+  const MachineBasicBlock *PrevInstBB = nullptr;
+
+  /// This location indicates end of function prologue and beginning of
+  /// function body.
+  DebugLoc PrologEndLoc;
+
+  /// If nonnull, stores the current machine instruction we're processing.
+  const MachineInstr *CurMI = nullptr;
+
+  LexicalScopes LScopes;
+
+  /// History of DBG_VALUE and clobber instructions for each user
+  /// variable.  Variables are listed in order of appearance.
+  DbgValueHistoryMap DbgValues;
+
+  /// Maps instruction with label emitted before instruction.
+  /// FIXME: Make this private from DwarfDebug, we have the necessary accessors
+  /// for it.
+  DenseMap<const MachineInstr *, MCSymbol *> LabelsBeforeInsn;
+
+  /// Maps instruction with label emitted after instruction.
+  DenseMap<const MachineInstr *, MCSymbol *> LabelsAfterInsn;
+
+  /// Indentify instructions that are marking the beginning of or
+  /// ending of a scope.
+  void identifyScopeMarkers();
+
+  /// Ensure that a label will be emitted before MI.
+  void requestLabelBeforeInsn(const MachineInstr *MI) {
+    LabelsBeforeInsn.insert(std::make_pair(MI, nullptr));
+  }
+
+  /// Ensure that a label will be emitted after MI.
+  void requestLabelAfterInsn(const MachineInstr *MI) {
+    LabelsAfterInsn.insert(std::make_pair(MI, nullptr));
+  }
+
+  virtual void beginFunctionImpl(const MachineFunction *MF) = 0;
+  virtual void endFunctionImpl(const MachineFunction *MF) = 0;
+  virtual void skippedNonDebugFunction() {}
+
+  // AsmPrinterHandler overrides.
+public:
+  void beginInstruction(const MachineInstr *MI) override;
+  void endInstruction() override;
+
+  void beginFunction(const MachineFunction *MF) override;
+  void endFunction(const MachineFunction *MF) override;
+
+  /// Return Label preceding the instruction.
+  MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
+
+  /// Return Label immediately following the instruction.
+  MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
+
+  /// Determine the relative position of the fragments described by P1 and P2.
+  /// Returns -1 if P1 is entirely before P2, 0 if P1 and P2 overlap, 1 if P1 is
+  /// entirely after P2.
+  static int fragmentCmp(const DIExpression *P1, const DIExpression *P2);
+
+  /// Determine whether two variable fragments overlap.
+  static bool fragmentsOverlap(const DIExpression *P1, const DIExpression *P2);
+
+  /// If this type is derived from a base type then return base type size.
+  static uint64_t getBaseTypeSize(const DITypeRef TyRef);
+};
+
+}
+
+#endif