Skip to content
This repository has been archived by the owner on Oct 12, 2022. It is now read-only.

Commit

Permalink
Reset lastAddress to 0 on sequence end + use first file:line found fo…
Browse files Browse the repository at this point in the history 
…r address
  • Loading branch information
@yazd
yazd committed Sep 3, 2015
1 parent 068be2e commit 2f5ff93
Showing 1 changed file with 53 additions and 25 deletions.
78 changes: 53 additions & 25 deletions src/rt/backtrace/dwarf.d
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,8 @@ import rt.backtrace.elf;

import core.stdc.string : strlen, memchr;

//debug = DwarfDebugMachine;

struct Location
{
const(char)[] file = null; // file is missing directory, but DMD emits directory directly into file
Expand Down Expand Up @@ -94,11 +96,14 @@ private:
// the lifetime of the Location data is the lifetime of the mmapped ElfSection
void resolveAddresses(ElfSection* debugLineSection, Location[] locations) @nogc nothrow
{
debug(DwarfDebugMachine) import core.stdc.stdio;

size_t numberOfLocationsFound = 0;

const(ubyte)[] dbg = debugLineSection.get();
while (dbg.length > 0)
{
debug(DwarfDebugMachine) printf("new debug program\n");
const(LPHeader)* lph = cast(const(LPHeader)*) dbg.ptr;

if (lph.unitLength == 0xffff_ffff) // is 64-bit dwarf?
Expand Down Expand Up @@ -137,6 +142,7 @@ void resolveAddresses(ElfSection* debugLineSection, Location[] locations) @nogc
while (pathData[0] != 0)
{
directories[currentDirectoryIndex] = cast(const(char)[]) pathData[0 .. strlen(cast(char*) (pathData.ptr))];
debug(DwarfDebugMachine) printf("dir: %s\n", pathData.ptr);
pathData = pathData[directories[currentDirectoryIndex].length + 1 .. $];
currentDirectoryIndex++;
}
Expand Down Expand Up @@ -165,6 +171,7 @@ void resolveAddresses(ElfSection* debugLineSection, Location[] locations) @nogc
while (pathData[0] != 0)
{
filenames[currentFileIndex] = cast(const(char)[]) pathData[0 .. strlen(cast(char*) (pathData.ptr))];
debug(DwarfDebugMachine) printf("file: %s\n", pathData.ptr);
pathData = pathData[filenames[currentFileIndex].length + 1 .. $];

auto dirIndex = pathData.readULEB128(); // unused
Expand All @@ -177,27 +184,46 @@ void resolveAddresses(ElfSection* debugLineSection, Location[] locations) @nogc
LocationInfo lastLoc = LocationInfo(-1, -1);
size_t lastAddress = 0x0;

debug(DwarfDebugMachine) printf("program:\n");
runStateMachine(lph, program, standardOpcodeLengths,
(size_t address, LocationInfo locInfo)
(size_t address, LocationInfo locInfo, bool isEndSequence)
{
foreach (ref loc; locations)
// If loc.line != -1, then it has been set previously.
// Some implementations (eg. dmd) write an address to
// the debug data multiple times, but so far I have found
// that the first occurrence to be the correct one.
foreach (ref loc; locations) if (loc.line == -1)
{
if (loc.address == address)
{
debug(DwarfDebugMachine) printf("-- found for [0x%x]:\n", loc.address);
debug(DwarfDebugMachine) printf("-- file: %.*s\n", filenames[locInfo.file - 1].length, filenames[locInfo.file - 1].ptr);
debug(DwarfDebugMachine) printf("-- line: %d\n", locInfo.line);
loc.file = filenames[locInfo.file - 1];
loc.line = locInfo.line;
numberOfLocationsFound++;
}
else if (loc.address < address && lastAddress < loc.address && lastAddress != 0)
{
debug(DwarfDebugMachine) printf("-- found for [0x%x]:\n", loc.address);
debug(DwarfDebugMachine) printf("-- file: %.*s\n", filenames[lastLoc.file - 1].length, filenames[lastLoc.file - 1].ptr);
debug(DwarfDebugMachine) printf("-- line: %d\n", lastLoc.line);
loc.file = filenames[lastLoc.file - 1];
loc.line = lastLoc.line;
numberOfLocationsFound++;
}
}

lastAddress = address;
lastLoc = locInfo;
if (isEndSequence)
{
lastAddress = 0;
}
else
{
lastAddress = address;
lastLoc = locInfo;
}

return numberOfLocationsFound < locations.length;
}
);
Expand All @@ -207,9 +233,11 @@ void resolveAddresses(ElfSection* debugLineSection, Location[] locations) @nogc
}
}

alias RunStateMachineCallback = bool delegate(size_t, LocationInfo) @nogc nothrow;
alias RunStateMachineCallback = bool delegate(size_t, LocationInfo, bool) @nogc nothrow;
bool runStateMachine(const(LPHeader)* lpHeader, const(ubyte)[] program, const(ubyte)[] standardOpcodeLengths, scope RunStateMachineCallback callback) @nogc nothrow
{
debug(DwarfDebugMachine) import core.stdc.stdio;

StateMachine machine;
machine.isStatement = lpHeader.defaultIsStatement;

Expand All @@ -228,98 +256,98 @@ bool runStateMachine(const(LPHeader)* lpHeader, const(ubyte)[] program, const(ub
{
case endSequence:
machine.isEndSequence = true;
// trace("endSequence ", "0x%x".format(m.address));
if (!callback(machine.address, LocationInfo(machine.fileIndex, machine.line))) return true;
debug(DwarfDebugMachine) printf("endSequence 0x%x\n", machine.address);
if (!callback(machine.address, LocationInfo(machine.fileIndex, machine.line), true)) return true;
machine = StateMachine.init;
machine.isStatement = lpHeader.defaultIsStatement;
break;

case setAddress:
size_t address = program.read!size_t();
// trace("setAddress ", "0x%x".format(address));
debug(DwarfDebugMachine) printf("setAddress 0x%x\n", address);
machine.address = address;
break;

case defineFile: // TODO: add proper implementation
// trace("defineFile");
debug(DwarfDebugMachine) printf("defineFile\n");
program = program[len - 1 .. $];
break;

default:
// unknown opcode
// trace("unknown extended opcode ", eopcode);
debug(DwarfDebugMachine) printf("unknown extended opcode %d\n", cast(int) eopcode);
program = program[len - 1 .. $];
break;
}

break;

case copy:
// trace("copy");
if (!callback(machine.address, LocationInfo(machine.fileIndex, machine.line))) return true;
debug(DwarfDebugMachine) printf("copy 0x%x\n", machine.address);
if (!callback(machine.address, LocationInfo(machine.fileIndex, machine.line), false)) return true;
machine.isBasicBlock = false;
machine.isPrologueEnd = false;
machine.isEpilogueBegin = false;
break;

case advancePC:
ulong op = readULEB128(program);
// trace("advancePC ", op * lpHeader.minimumInstructionLength);
machine.address += op * lpHeader.minimumInstructionLength;
debug(DwarfDebugMachine) printf("advancePC %d to 0x%x\n", cast(int) (op * lpHeader.minimumInstructionLength), machine.address);
break;

case advanceLine:
long ad = readSLEB128(program);
// trace("advanceLine ", ad);
machine.line += ad;
debug(DwarfDebugMachine) printf("advanceLine %d to %d\n", cast(int) ad, cast(int) machine.line);
break;

case setFile:
uint index = cast(uint) readULEB128(program);
// trace("setFile to ", index);
debug(DwarfDebugMachine) printf("setFile to %d\n", cast(int) index);
machine.fileIndex = index;
break;

case setColumn:
uint col = cast(uint) readULEB128(program);
// trace("setColumn ", col);
debug(DwarfDebugMachine) printf("setColumn %d\n", cast(int) col);
machine.column = col;
break;

case negateStatement:
// trace("negateStatement");
debug(DwarfDebugMachine) printf("negateStatement\n");
machine.isStatement = !machine.isStatement;
break;

case setBasicBlock:
// trace("setBasicBlock");
debug(DwarfDebugMachine) printf("setBasicBlock\n");
machine.isBasicBlock = true;
break;

case constAddPC:
machine.address += (255 - lpHeader.opcodeBase) / lpHeader.lineRange * lpHeader.minimumInstructionLength;
// trace("constAddPC ", "0x%x".format(machine.address));
debug(DwarfDebugMachine) printf("constAddPC 0x%x\n", machine.address);
break;

case fixedAdvancePC:
uint add = program.read!uint();
// trace("fixedAdvancePC ", add);
machine.address += add;
debug(DwarfDebugMachine) printf("fixedAdvancePC %d to 0x%x\n", cast(int) add, machine.address);
break;

case setPrologueEnd:
machine.isPrologueEnd = true;
// trace("setPrologueEnd");
debug(DwarfDebugMachine) printf("setPrologueEnd\n");
break;

case setEpilogueBegin:
machine.isEpilogueBegin = true;
// trace("setEpilogueBegin");
debug(DwarfDebugMachine) printf("setEpilogueBegin\n");
break;

case setISA:
machine.isa = cast(uint) readULEB128(program);
// trace("setISA ", m.isa);
debug(DwarfDebugMachine) printf("setISA %d\n", cast(int) machine.isa);
break;

default:
Expand All @@ -335,8 +363,8 @@ bool runStateMachine(const(LPHeader)* lpHeader, const(ubyte)[] program, const(ub
auto linc = lpHeader.lineBase + (opcode % lpHeader.lineRange);
machine.line += linc;

// trace("special ", ainc, " ", linc);
if (!callback(machine.address, LocationInfo(machine.fileIndex, machine.line))) return true;
debug(DwarfDebugMachine) printf("special %d %d to 0x%x line %d\n", cast(int) ainc, cast(int) linc, machine.address, cast(int) machine.line);
if (!callback(machine.address, LocationInfo(machine.fileIndex, machine.line), false)) return true;
}
}

Expand Down

0 comments on commit 2f5ff93

Please sign in to comment.