diff options
Diffstat (limited to 'lib/CodeGen/AsmPrinter/DwarfExpression.h')
-rw-r--r-- | lib/CodeGen/AsmPrinter/DwarfExpression.h | 95 |
1 files changed, 84 insertions, 11 deletions
diff --git a/lib/CodeGen/AsmPrinter/DwarfExpression.h b/lib/CodeGen/AsmPrinter/DwarfExpression.h index ec2ef6e575f7..1ad46669f9b2 100644 --- a/lib/CodeGen/AsmPrinter/DwarfExpression.h +++ b/lib/CodeGen/AsmPrinter/DwarfExpression.h @@ -13,6 +13,7 @@ #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFEXPRESSION_H #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFEXPRESSION_H +#include "ByteStreamer.h" #include "llvm/ADT/ArrayRef.h" #include "llvm/ADT/None.h" #include "llvm/ADT/Optional.h" @@ -26,7 +27,6 @@ namespace llvm { class AsmPrinter; class APInt; -class ByteStreamer; class DwarfCompileUnit; class DIELoc; class TargetRegisterInfo; @@ -95,6 +95,13 @@ public: /// Base class containing the logic for constructing DWARF expressions /// independently of whether they are emitted into a DIE or into a .debug_loc /// entry. +/// +/// Some DWARF operations, e.g. DW_OP_entry_value, need to calculate the size +/// of a succeeding DWARF block before the latter is emitted to the output. +/// To handle such cases, data can conditionally be emitted to a temporary +/// buffer, which can later on be committed to the main output. The size of the +/// temporary buffer is queryable, allowing for the size of the data to be +/// emitted before the data is committed. class DwarfExpression { protected: /// Holds information about all subregisters comprising a register location. @@ -104,6 +111,9 @@ protected: const char *Comment; }; + /// Whether we are currently emitting an entry value operation. + bool IsEmittingEntryValue = false; + DwarfCompileUnit &CU; /// The register location, if any. @@ -120,7 +130,7 @@ protected: enum { Unknown = 0, Register, Memory, Implicit }; /// The flags of location description being produced. - enum { EntryValue = 1 }; + enum { EntryValue = 1, CallSiteParamValue }; unsigned LocationKind : 3; unsigned LocationFlags : 2; @@ -147,6 +157,10 @@ public: return LocationFlags & EntryValue; } + bool isParameterValue() { + return LocationFlags & CallSiteParamValue; + } + Optional<uint8_t> TagOffset; protected: @@ -174,6 +188,22 @@ protected: virtual void emitBaseTypeRef(uint64_t Idx) = 0; + /// Start emitting data to the temporary buffer. The data stored in the + /// temporary buffer can be committed to the main output using + /// commitTemporaryBuffer(). + virtual void enableTemporaryBuffer() = 0; + + /// Disable emission to the temporary buffer. This does not commit data + /// in the temporary buffer to the main output. + virtual void disableTemporaryBuffer() = 0; + + /// Return the emitted size, in number of bytes, for the data stored in the + /// temporary buffer. + virtual unsigned getTemporaryBufferSize() = 0; + + /// Commit the data stored in the temporary buffer to the main output. + virtual void commitTemporaryBuffer() = 0; + /// Emit a normalized unsigned constant. void emitConstu(uint64_t Value); @@ -233,6 +263,10 @@ protected: /// expression. See PR21176 for more details. void addStackValue(); + /// Finalize an entry value by emitting its size operand, and committing the + /// DWARF block which has been emitted to the temporary buffer. + void finalizeEntryValue(); + ~DwarfExpression() = default; public: @@ -264,6 +298,11 @@ public: LocationFlags |= EntryValue; } + /// Lock this down to become a call site parameter location. + void setCallSiteParamValueFlag() { + LocationFlags |= CallSiteParamValue; + } + /// Emit a machine register location. As an optimization this may also consume /// the prefix of a DwarfExpression if a more efficient representation for /// combining the register location and the first operation exists. @@ -278,8 +317,11 @@ public: DIExpressionCursor &Expr, unsigned MachineReg, unsigned FragmentOffsetInBits = 0); - /// Emit entry value dwarf operation. - void addEntryValueExpression(DIExpressionCursor &ExprCursor); + /// Begin emission of an entry value dwarf operation. The entry value's + /// first operand is the size of the DWARF block (its second operand), + /// which needs to be calculated at time of emission, so we don't emit + /// any operands here. + void beginEntryValueExpression(DIExpressionCursor &ExprCursor); /// Emit all remaining operations in the DIExpressionCursor. /// @@ -299,31 +341,62 @@ public: /// DwarfExpression implementation for .debug_loc entries. class DebugLocDwarfExpression final : public DwarfExpression { - ByteStreamer &BS; + + struct TempBuffer { + SmallString<32> Bytes; + std::vector<std::string> Comments; + BufferByteStreamer BS; + + TempBuffer(bool GenerateComments) : BS(Bytes, Comments, GenerateComments) {} + }; + + std::unique_ptr<TempBuffer> TmpBuf; + BufferByteStreamer &OutBS; + bool IsBuffering = false; + + /// Return the byte streamer that currently is being emitted to. + ByteStreamer &getActiveStreamer() { return IsBuffering ? TmpBuf->BS : OutBS; } void emitOp(uint8_t Op, const char *Comment = nullptr) override; void emitSigned(int64_t Value) override; void emitUnsigned(uint64_t Value) override; void emitData1(uint8_t Value) override; void emitBaseTypeRef(uint64_t Idx) override; + + void enableTemporaryBuffer() override; + void disableTemporaryBuffer() override; + unsigned getTemporaryBufferSize() override; + void commitTemporaryBuffer() override; + bool isFrameRegister(const TargetRegisterInfo &TRI, unsigned MachineReg) override; - public: - DebugLocDwarfExpression(unsigned DwarfVersion, ByteStreamer &BS, DwarfCompileUnit &CU) - : DwarfExpression(DwarfVersion, CU), BS(BS) {} + DebugLocDwarfExpression(unsigned DwarfVersion, BufferByteStreamer &BS, + DwarfCompileUnit &CU) + : DwarfExpression(DwarfVersion, CU), OutBS(BS) {} }; /// DwarfExpression implementation for singular DW_AT_location. class DIEDwarfExpression final : public DwarfExpression { -const AsmPrinter &AP; - DIELoc &DIE; + const AsmPrinter &AP; + DIELoc &OutDIE; + DIELoc TmpDIE; + bool IsBuffering = false; + + /// Return the DIE that currently is being emitted to. + DIELoc &getActiveDIE() { return IsBuffering ? TmpDIE : OutDIE; } void emitOp(uint8_t Op, const char *Comment = nullptr) override; void emitSigned(int64_t Value) override; void emitUnsigned(uint64_t Value) override; void emitData1(uint8_t Value) override; void emitBaseTypeRef(uint64_t Idx) override; + + void enableTemporaryBuffer() override; + void disableTemporaryBuffer() override; + unsigned getTemporaryBufferSize() override; + void commitTemporaryBuffer() override; + bool isFrameRegister(const TargetRegisterInfo &TRI, unsigned MachineReg) override; public: @@ -331,7 +404,7 @@ public: DIELoc *finalize() { DwarfExpression::finalize(); - return &DIE; + return &OutDIE; } }; |