[llvm] r244318 - [MC/Dwarf] Allow to specify custom parameters for linetable emission.
Frederic Riss via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 7 08:14:08 PDT 2015
Author: friss
Date: Fri Aug 7 10:14:08 2015
New Revision: 244318
URL: http://llvm.org/viewvc/llvm-project?rev=244318&view=rev
Log:
[MC/Dwarf] Allow to specify custom parameters for linetable emission.
NFC patch for current users, but llvm-dsymutil will use the new
functionality to adapt to the input linetable.
Based on a patch by Adrian Prantl.
Modified:
llvm/trunk/include/llvm/MC/MCAssembler.h
llvm/trunk/include/llvm/MC/MCDwarf.h
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
llvm/trunk/lib/MC/MCAssembler.cpp
llvm/trunk/lib/MC/MCDwarf.cpp
llvm/trunk/lib/MC/MCObjectStreamer.cpp
Modified: llvm/trunk/include/llvm/MC/MCAssembler.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCAssembler.h?rev=244318&r1=244317&r2=244318&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCAssembler.h (original)
+++ llvm/trunk/include/llvm/MC/MCAssembler.h Fri Aug 7 10:14:08 2015
@@ -18,6 +18,7 @@
#include "llvm/ADT/ilist_node.h"
#include "llvm/ADT/iterator.h"
#include "llvm/MC/MCDirectives.h"
+#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCFixup.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCLinkerOptimizationHint.h"
@@ -591,6 +592,8 @@ private:
/// List of declared file names
std::vector<std::string> FileNames;
+ MCDwarfLineTableParams LTParams;
+
/// The set of function symbols for which a .thumb_func directive has
/// been seen.
//
@@ -736,6 +739,9 @@ public:
MCObjectWriter &getWriter() const { return Writer; }
+ MCDwarfLineTableParams getDWARFLinetableParams() const { return LTParams; }
+ void setDWARFLinetableParams(MCDwarfLineTableParams P) { LTParams = P; }
+
/// Finish - Do final processing and write the object to the output stream.
/// \p Writer is used for custom object writer (as the MCJIT does),
/// if not specified it is automatically created from backend.
Modified: llvm/trunk/include/llvm/MC/MCDwarf.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCDwarf.h?rev=244318&r1=244317&r2=244318&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCDwarf.h (original)
+++ llvm/trunk/include/llvm/MC/MCDwarf.h Fri Aug 7 10:14:08 2015
@@ -182,6 +182,19 @@ public:
}
};
+struct MCDwarfLineTableParams {
+ /// First special line opcode - leave room for the standard opcodes.
+ /// Note: If you want to change this, you'll have to update the
+ /// "StandardOpcodeLengths" table that is emitted in
+ /// \c Emit().
+ unsigned char DWARF2LineOpcodeBase = 13;
+ /// Minimum line offset in a special line info. opcode. The value
+ /// -5 was chosen to give a reasonable range of values.
+ char DWARF2LineBase = -5;
+ /// Range of line offsets in a special line info. opcode.
+ unsigned char DWARF2LineRange = 14;
+};
+
struct MCDwarfLineTableHeader {
MCSymbol *Label;
SmallVector<std::string, 3> MCDwarfDirs;
@@ -192,9 +205,11 @@ struct MCDwarfLineTableHeader {
MCDwarfLineTableHeader() : Label(nullptr) {}
unsigned getFile(StringRef &Directory, StringRef &FileName,
unsigned FileNumber = 0);
- std::pair<MCSymbol *, MCSymbol *> Emit(MCStreamer *MCOS) const;
+ std::pair<MCSymbol *, MCSymbol *> Emit(MCStreamer *MCOS,
+ MCDwarfLineTableParams Params) const;
std::pair<MCSymbol *, MCSymbol *>
- Emit(MCStreamer *MCOS, ArrayRef<char> SpecialOpcodeLengths) const;
+ Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params,
+ ArrayRef<char> SpecialOpcodeLengths) const;
};
class MCDwarfDwoLineTable {
@@ -206,7 +221,7 @@ public:
unsigned getFile(StringRef Directory, StringRef FileName) {
return Header.getFile(Directory, FileName);
}
- void Emit(MCStreamer &MCOS) const;
+ void Emit(MCStreamer &MCOS, MCDwarfLineTableParams Params) const;
};
class MCDwarfLineTable {
@@ -215,10 +230,10 @@ class MCDwarfLineTable {
public:
// This emits the Dwarf file and the line tables for all Compile Units.
- static void Emit(MCObjectStreamer *MCOS);
+ static void Emit(MCObjectStreamer *MCOS, MCDwarfLineTableParams Params);
// This emits the Dwarf file and the line tables for a given Compile Unit.
- void EmitCU(MCObjectStreamer *MCOS) const;
+ void EmitCU(MCObjectStreamer *MCOS, MCDwarfLineTableParams Params) const;
unsigned getFile(StringRef &Directory, StringRef &FileName,
unsigned FileNumber = 0);
@@ -262,11 +277,12 @@ public:
class MCDwarfLineAddr {
public:
/// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
- static void Encode(MCContext &Context, int64_t LineDelta, uint64_t AddrDelta,
- raw_ostream &OS);
+ static void Encode(MCContext &Context, MCDwarfLineTableParams Params,
+ int64_t LineDelta, uint64_t AddrDelta, raw_ostream &OS);
/// Utility function to emit the encoding to a streamer.
- static void Emit(MCStreamer *MCOS, int64_t LineDelta, uint64_t AddrDelta);
+ static void Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params,
+ int64_t LineDelta, uint64_t AddrDelta);
};
class MCGenDwarfInfo {
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=244318&r1=244317&r2=244318&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Fri Aug 7 10:14:08 2015
@@ -33,6 +33,7 @@
#include "llvm/IR/Module.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
@@ -1894,7 +1895,7 @@ void DwarfDebug::emitDebugLineDWO() {
assert(useSplitDwarf() && "No split dwarf?");
Asm->OutStreamer->SwitchSection(
Asm->getObjFileLowering().getDwarfLineDWOSection());
- SplitTypeUnitFileTable.Emit(*Asm->OutStreamer);
+ SplitTypeUnitFileTable.Emit(*Asm->OutStreamer, MCDwarfLineTableParams());
}
// Emit the .debug_str.dwo section for separated dwarf. This contains the
Modified: llvm/trunk/lib/MC/MCAssembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCAssembler.cpp?rev=244318&r1=244317&r2=244318&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCAssembler.cpp (original)
+++ llvm/trunk/lib/MC/MCAssembler.cpp Fri Aug 7 10:14:08 2015
@@ -1026,7 +1026,8 @@ bool MCAssembler::relaxDwarfLineAddr(MCA
SmallString<8> &Data = DF.getContents();
Data.clear();
raw_svector_ostream OSE(Data);
- MCDwarfLineAddr::Encode(Context, LineDelta, AddrDelta, OSE);
+ MCDwarfLineAddr::Encode(Context, getDWARFLinetableParams(), LineDelta,
+ AddrDelta, OSE);
OSE.flush();
return OldSize != Data.size();
}
Modified: llvm/trunk/lib/MC/MCDwarf.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCDwarf.cpp?rev=244318&r1=244317&r2=244318&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCDwarf.cpp (original)
+++ llvm/trunk/lib/MC/MCDwarf.cpp Fri Aug 7 10:14:08 2015
@@ -29,25 +29,6 @@
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
-// Given a special op, return the address skip amount (in units of
-// DWARF2_LINE_MIN_INSN_LENGTH.
-#define SPECIAL_ADDR(op) (((op) - DWARF2_LINE_OPCODE_BASE)/DWARF2_LINE_RANGE)
-
-// The maximum address skip amount that can be encoded with a special op.
-#define MAX_SPECIAL_ADDR_DELTA SPECIAL_ADDR(255)
-
-// First special line opcode - leave room for the standard opcodes.
-// Note: If you want to change this, you'll have to update the
-// "standard_opcode_lengths" table that is emitted in DwarfFileTable::Emit().
-#define DWARF2_LINE_OPCODE_BASE 13
-
-// Minimum line offset in a special line info. opcode. This value
-// was chosen to give a reasonable range of values.
-#define DWARF2_LINE_BASE -5
-
-// Range of line offsets in a special line info. opcode.
-#define DWARF2_LINE_RANGE 14
-
static inline uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta) {
unsigned MinInsnLength = Context.getAsmInfo()->getMinInstAlignment();
if (MinInsnLength == 1)
@@ -197,7 +178,8 @@ EmitDwarfLineTable(MCObjectStreamer *MCO
//
// This emits the Dwarf file and the line tables.
//
-void MCDwarfLineTable::Emit(MCObjectStreamer *MCOS) {
+void MCDwarfLineTable::Emit(MCObjectStreamer *MCOS,
+ MCDwarfLineTableParams Params) {
MCContext &context = MCOS->getContext();
auto &LineTables = context.getMCDwarfLineTables();
@@ -212,14 +194,17 @@ void MCDwarfLineTable::Emit(MCObjectStre
// Handle the rest of the Compile Units.
for (const auto &CUIDTablePair : LineTables)
- CUIDTablePair.second.EmitCU(MCOS);
+ CUIDTablePair.second.EmitCU(MCOS, Params);
}
-void MCDwarfDwoLineTable::Emit(MCStreamer &MCOS) const {
- MCOS.EmitLabel(Header.Emit(&MCOS, None).second);
+void MCDwarfDwoLineTable::Emit(MCStreamer &MCOS,
+ MCDwarfLineTableParams Params) const {
+ MCOS.EmitLabel(Header.Emit(&MCOS, Params, None).second);
}
-std::pair<MCSymbol *, MCSymbol *> MCDwarfLineTableHeader::Emit(MCStreamer *MCOS) const {
+std::pair<MCSymbol *, MCSymbol *>
+MCDwarfLineTableHeader::Emit(MCStreamer *MCOS,
+ MCDwarfLineTableParams Params) const {
static const char StandardOpcodeLengths[] = {
0, // length of DW_LNS_copy
1, // length of DW_LNS_advance_pc
@@ -234,9 +219,10 @@ std::pair<MCSymbol *, MCSymbol *> MCDwar
0, // length of DW_LNS_set_epilogue_begin
1 // DW_LNS_set_isa
};
- assert(array_lengthof(StandardOpcodeLengths) ==
- (DWARF2_LINE_OPCODE_BASE - 1));
- return Emit(MCOS, StandardOpcodeLengths);
+ assert(array_lengthof(StandardOpcodeLengths) >=
+ (Params.DWARF2LineOpcodeBase - 1));
+ return Emit(MCOS, Params, ArrayRef<char>(StandardOpcodeLengths,
+ Params.DWARF2LineOpcodeBase - 1));
}
static const MCExpr *forceExpAbs(MCStreamer &OS, const MCExpr* Expr) {
@@ -256,7 +242,7 @@ static void emitAbsValue(MCStreamer &OS,
}
std::pair<MCSymbol *, MCSymbol *>
-MCDwarfLineTableHeader::Emit(MCStreamer *MCOS,
+MCDwarfLineTableHeader::Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params,
ArrayRef<char> StandardOpcodeLengths) const {
MCContext &context = MCOS->getContext();
@@ -293,8 +279,8 @@ MCDwarfLineTableHeader::Emit(MCStreamer
// Parameters of the state machine, are next.
MCOS->EmitIntValue(context.getAsmInfo()->getMinInstAlignment(), 1);
MCOS->EmitIntValue(DWARF2_LINE_DEFAULT_IS_STMT, 1);
- MCOS->EmitIntValue(DWARF2_LINE_BASE, 1);
- MCOS->EmitIntValue(DWARF2_LINE_RANGE, 1);
+ MCOS->EmitIntValue(Params.DWARF2LineBase, 1);
+ MCOS->EmitIntValue(Params.DWARF2LineRange, 1);
MCOS->EmitIntValue(StandardOpcodeLengths.size() + 1, 1);
// Standard opcode lengths
@@ -329,8 +315,9 @@ MCDwarfLineTableHeader::Emit(MCStreamer
return std::make_pair(LineStartSym, LineEndSym);
}
-void MCDwarfLineTable::EmitCU(MCObjectStreamer *MCOS) const {
- MCSymbol *LineEndSym = Header.Emit(MCOS).second;
+void MCDwarfLineTable::EmitCU(MCObjectStreamer *MCOS,
+ MCDwarfLineTableParams Params) const {
+ MCSymbol *LineEndSym = Header.Emit(MCOS, Params).second;
// Put out the line tables.
for (const auto &LineSec : MCLineSections.getMCLineEntries())
@@ -416,21 +403,31 @@ unsigned MCDwarfLineTableHeader::getFile
}
/// Utility function to emit the encoding to a streamer.
-void MCDwarfLineAddr::Emit(MCStreamer *MCOS, int64_t LineDelta,
- uint64_t AddrDelta) {
+void MCDwarfLineAddr::Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params,
+ int64_t LineDelta, uint64_t AddrDelta) {
MCContext &Context = MCOS->getContext();
SmallString<256> Tmp;
raw_svector_ostream OS(Tmp);
- MCDwarfLineAddr::Encode(Context, LineDelta, AddrDelta, OS);
+ MCDwarfLineAddr::Encode(Context, Params, LineDelta, AddrDelta, OS);
MCOS->EmitBytes(OS.str());
}
+/// Given a special op, return the address skip amount (in units of
+/// DWARF2_LINE_MIN_INSN_LENGTH).
+static uint64_t SpecialAddr(MCDwarfLineTableParams Params, uint64_t op) {
+ return (op - Params.DWARF2LineOpcodeBase) / Params.DWARF2LineRange;
+}
+
/// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
-void MCDwarfLineAddr::Encode(MCContext &Context, int64_t LineDelta,
- uint64_t AddrDelta, raw_ostream &OS) {
+void MCDwarfLineAddr::Encode(MCContext &Context, MCDwarfLineTableParams Params,
+ int64_t LineDelta, uint64_t AddrDelta,
+ raw_ostream &OS) {
uint64_t Temp, Opcode;
bool NeedCopy = false;
+ // The maximum address skip amount that can be encoded with a special op.
+ uint64_t MaxSpecialAddrDelta = SpecialAddr(Params, 255);
+
// Scale the address delta by the minimum instruction length.
AddrDelta = ScaleAddrDelta(Context, AddrDelta);
@@ -438,7 +435,7 @@ void MCDwarfLineAddr::Encode(MCContext &
// DW_LNE_end_sequence. We cannot use special opcodes here, since we want the
// end_sequence to emit the matrix entry.
if (LineDelta == INT64_MAX) {
- if (AddrDelta == MAX_SPECIAL_ADDR_DELTA)
+ if (AddrDelta == MaxSpecialAddrDelta)
OS << char(dwarf::DW_LNS_const_add_pc);
else if (AddrDelta) {
OS << char(dwarf::DW_LNS_advance_pc);
@@ -451,16 +448,16 @@ void MCDwarfLineAddr::Encode(MCContext &
}
// Bias the line delta by the base.
- Temp = LineDelta - DWARF2_LINE_BASE;
+ Temp = LineDelta - Params.DWARF2LineBase;
// If the line increment is out of range of a special opcode, we must encode
// it with DW_LNS_advance_line.
- if (Temp >= DWARF2_LINE_RANGE) {
+ if (Temp >= Params.DWARF2LineRange) {
OS << char(dwarf::DW_LNS_advance_line);
encodeSLEB128(LineDelta, OS);
LineDelta = 0;
- Temp = 0 - DWARF2_LINE_BASE;
+ Temp = 0 - Params.DWARF2LineBase;
NeedCopy = true;
}
@@ -471,19 +468,19 @@ void MCDwarfLineAddr::Encode(MCContext &
}
// Bias the opcode by the special opcode base.
- Temp += DWARF2_LINE_OPCODE_BASE;
+ Temp += Params.DWARF2LineOpcodeBase;
// Avoid overflow when addr_delta is large.
- if (AddrDelta < 256 + MAX_SPECIAL_ADDR_DELTA) {
+ if (AddrDelta < 256 + MaxSpecialAddrDelta) {
// Try using a special opcode.
- Opcode = Temp + AddrDelta * DWARF2_LINE_RANGE;
+ Opcode = Temp + AddrDelta * Params.DWARF2LineRange;
if (Opcode <= 255) {
OS << char(Opcode);
return;
}
// Try using DW_LNS_const_add_pc followed by special op.
- Opcode = Temp + (AddrDelta - MAX_SPECIAL_ADDR_DELTA) * DWARF2_LINE_RANGE;
+ Opcode = Temp + (AddrDelta - MaxSpecialAddrDelta) * Params.DWARF2LineRange;
if (Opcode <= 255) {
OS << char(dwarf::DW_LNS_const_add_pc);
OS << char(Opcode);
Modified: llvm/trunk/lib/MC/MCObjectStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCObjectStreamer.cpp?rev=244318&r1=244317&r2=244318&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCObjectStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCObjectStreamer.cpp Fri Aug 7 10:14:08 2015
@@ -321,8 +321,10 @@ static const MCExpr *buildSymbolDiff(MCO
return AddrDelta;
}
-static void emitDwarfSetLineAddr(MCObjectStreamer &OS, int64_t LineDelta,
- const MCSymbol *Label, int PointerSize) {
+static void emitDwarfSetLineAddr(MCObjectStreamer &OS,
+ MCDwarfLineTableParams Params,
+ int64_t LineDelta, const MCSymbol *Label,
+ int PointerSize) {
// emit the sequence to set the address
OS.EmitIntValue(dwarf::DW_LNS_extended_op, 1);
OS.EmitULEB128IntValue(PointerSize + 1);
@@ -330,7 +332,7 @@ static void emitDwarfSetLineAddr(MCObjec
OS.EmitSymbolValue(Label, PointerSize);
// emit the sequence for the LineDelta (from 1) and a zero address delta.
- MCDwarfLineAddr::Emit(&OS, LineDelta, 0);
+ MCDwarfLineAddr::Emit(&OS, Params, LineDelta, 0);
}
void MCObjectStreamer::EmitDwarfAdvanceLineAddr(int64_t LineDelta,
@@ -338,13 +340,15 @@ void MCObjectStreamer::EmitDwarfAdvanceL
const MCSymbol *Label,
unsigned PointerSize) {
if (!LastLabel) {
- emitDwarfSetLineAddr(*this, LineDelta, Label, PointerSize);
+ emitDwarfSetLineAddr(*this, Assembler->getDWARFLinetableParams(), LineDelta,
+ Label, PointerSize);
return;
}
const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel);
int64_t Res;
if (AddrDelta->evaluateAsAbsolute(Res, getAssembler())) {
- MCDwarfLineAddr::Emit(this, LineDelta, Res);
+ MCDwarfLineAddr::Emit(this, Assembler->getDWARFLinetableParams(), LineDelta,
+ Res);
return;
}
insert(new MCDwarfLineAddrFragment(LineDelta, *AddrDelta));
@@ -451,7 +455,7 @@ void MCObjectStreamer::FinishImpl() {
MCGenDwarfInfo::Emit(this);
// Dump out the dwarf file & directory tables and line tables.
- MCDwarfLineTable::Emit(this);
+ MCDwarfLineTable::Emit(this, getAssembler().getDWARFLinetableParams());
flushPendingLabels(nullptr);
getAssembler().Finish();
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