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Tweak stack unwinding when inside prologue and epilogue.

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ccrause 2023-12-10 22:00:57 +02:00 committed by Martin
parent 3a85791bb6
commit 3dcb41cdbd
1 changed files with 18 additions and 18 deletions
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36
components/fpdebug/fpdbgdisasavr.pp
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@ -419,7 +419,6 @@ var
opcode, frameOffset: word;
d, k: byte;
stackState: TPrologueState;
instr: TAVRInstruction;
begin
{ AVR function entry example
3e: df 93 push r29
@ -461,7 +460,6 @@ begin
// Loop until prologue buffer is empty, or stepped inside stack frame
while (ADataLen > 1) and AnIsOutsideFrame do
begin
//FDecoder.Disassemble(AData, instr);
opcode := AData[0] or (AData[1] shl 8);
inc(AData, 2);
dec(ADataLen, 2);
@ -477,7 +475,7 @@ begin
OpCodeSetSPL: stackState := psWriteSPL;
OpCodeZeroR1, OpCodeZeroR16: ;
else
// Push a register onto stack
// Push stack
if (opcode and OpCodePushMask) = OpCodePushMask then
begin
if (stackState <= psPush) or (stackState = psLoadSreg) then
@ -583,9 +581,7 @@ begin
cc: 08 95 ret
}
// Also read previous instruction, for simple procs/interrupts it may not be easy to spot the start of epilogue
// so the previous instruction could tie break
ADataLen := Min(MaxEpilogueSize, AEndPC - AnAddress + 2);
ADataLen := Min(MaxEpilogueSize, AEndPC - AnAddress);
Result := ReadCodeAt(AEndPC - ADataLen, ADataLen);
if not Result then
exit;
@ -613,7 +609,7 @@ begin
OpCodeSetSPL: stackState := esWriteSPL;
OpCodeRet, OpCodeReti: stackState := esRet;
else
// Push a register onto stack
// Pop stack
if (opcode and OpCodePopMask) = OpCodePopMask then
begin
if (stackState <= esPop) or (stackState = esWriteSreg) then
@ -1508,7 +1504,6 @@ var
NextIdx: LongInt;
LastFrameBase: TDBGPtr;
OutSideFrame: Boolean;
StackPtr: TDBGPtr;
startPC, endPC: TDBGPtr;
returnAddrStackOffset: word;
b: byte;
@ -1527,10 +1522,10 @@ begin
// Get start/end PC of proc from debug info
if not Self.Process.FindProcStartEndPC(CodePointer, startPC, endPC) then
begin
// Give up for now, it is complicated to locate prologue/epilogue in general without proc limits
// ToDo: Perhaps interpret .debug_frame info if available,
// or scan forward from address until an epilogue is found.
exit;
{ Assume we are at beginning of proc. GetFunctionFrameReturnAddress should then
assume we are outside the stack frame (or no stack frame exists).
}
endPC := CodePointer;
end;
if not TAvrAsmDecoder(Process.Disassembler).GetFunctionFrameReturnAddress(CodePointer, startPC, endPC, returnAddrStackOffset, OutSideFrame) then
@ -1541,24 +1536,29 @@ begin
if OutSideFrame then begin
// Before adjustment of frame pointer, or after restoration of frame pointer,
// return PC should be located by offset from SP
if not Process.ReadData(DataOffset or (StackPtr + returnAddrStackOffset), Size, CodePointer) or (CodePointer = 0) then exit;
if not Process.ReadData(DataOffset or (StackPointer + returnAddrStackOffset), Size, CodePointer) or
(CodePointer = 0) then
exit;
{$PUSH}{$R-}{$Q-}
StackPointer := StackPointer + returnAddrStackOffset + 1;
FrameBasePointer := StackPointer; // After popping return-addr from "StackPtr"
{$POP}
end
else begin
// Inside stack frame, return PC should be located by offset from FP
if not Process.ReadData(DataOffset or (FrameBasePointer + returnAddrStackOffset), Size, CodePointer) or (CodePointer = 0) then exit;
{$PUSH}{$R-}{$Q-}
FrameBasePointer := StackPointer + returnAddrStackOffset + Size - 1; // After popping return-addr from stack
{$POP}
end;
// Convert return address from BE to LE, shl 1 to get byte address
CodePointer := BEtoN(word(CodePointer)) shl 1;
{$PUSH}{$R-}{$Q-}
StackPtr := FrameBasePointer + returnAddrStackOffset + Size - 1; // After popping return-addr from "StackPtr"
FrameBasePointer := StackPtr; // Estimate of previous FP
{$POP}
FLastFrameBaseIncreased := (FrameBasePointer <> 0) and (FrameBasePointer > LastFrameBase);
ANewFrame:= TDbgCallstackEntry.create(Thread, NextIdx, FrameBasePointer, CodePointer);
ANewFrame.RegisterValueList.DbgRegisterAutoCreate[nPC].SetValue(CodePointer, IntToStr(CodePointer),Size, PCindex);
ANewFrame.RegisterValueList.DbgRegisterAutoCreate[nSP].SetValue(StackPtr, IntToStr(StackPtr),Size, SPindex);
ANewFrame.RegisterValueList.DbgRegisterAutoCreate[nSP].SetValue(StackPointer, IntToStr(StackPointer),Size, SPindex);
ANewFrame.RegisterValueList.DbgRegisterAutoCreate['r28'].SetValue(byte(FrameBasePointer), IntToStr(b),Size, 28);
ANewFrame.RegisterValueList.DbgRegisterAutoCreate['r29'].SetValue((FrameBasePointer and $FF00) shr 8, IntToStr(b),Size, 29);