[codeview] Describe int local variables using .cv_def_range
Summary:
Refactor common value, scope, and label tracking logic out of DwarfDebug
into a common base class called DebugHandlerBase.
Update an old LLVM IR test case to avoid an assertion in LexicalScopes.
Reviewers: dblaikie, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16931
llvm-svn: 260432
diff --git a/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.h b/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.h
new file mode 100644
index 0000000..ce5f957
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.h
@@ -0,0 +1,105 @@
+//===-- 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/CodeGen/LexicalScopes.h"
+
+namespace llvm {
+
+class AsmPrinter;
+class MachineModuleInfo;
+
+/// Base class for debug information backends. Common functionality related to
+/// tracking which variables and scopes are alive at a given PC live here.
+class LLVM_LIBRARY_VISIBILITY 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 boundries in dwarf
+ /// debug info.
+ DebugLoc PrevInstLoc;
+ MCSymbol *PrevLabel = 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));
+ }
+
+ // 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 pieces 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 pieceCmp(const DIExpression *P1, const DIExpression *P2);
+
+ /// Determine whether two variable pieces overlap.
+ static bool piecesOverlap(const DIExpression *P1, const DIExpression *P2);
+};
+
+}
+
+#endif