Debugger step-over can fail (#1194, PR #1203)

. QoL cleanup (show RTS address) for step-over failure cases
. Add source code for repro test 1 and 2
This commit is contained in:
Michael "Code Poet" Pohoreski
2023-03-31 01:45:54 -07:00
committed by GitHub
parent 4e8006456f
commit a3c6156508
3 changed files with 154 additions and 46 deletions
+90 -24
View File
@@ -2294,7 +2294,8 @@ Update_t CmdStepOver (int nArgs)
while (nDebugSteps -- > 0)
{
int nOpcode = *(mem + regs.pc); // g_nDisasmCurAddress
int nOpcode = *(mem + regs.pc);
WORD nExpectedAddr = (regs.pc + 3) & _6502_MEM_END; // Wrap around 64K edge case when PC = $FFFD..$FFFF: 20 xx xx
// int eMode = g_aOpcodes[ nOpcode ].addrmode;
// int nByte = g_aOpmodes[eMode]._nBytes;
// if ((eMode == AM_A) &&
@@ -2302,10 +2303,80 @@ Update_t CmdStepOver (int nArgs)
CmdTrace(0);
if (nOpcode == OPCODE_JSR)
{
/*
Repro #2 Test when SP <= 0x01 before JSR and _6502_GetStackReturnAddress() fetch return address
300:BA 86 FF A2 01 9A 20 0D 03 A6 FF 9A 60 A9 FF 20 A8 FC 60
BPX 306
MD1 100
MD2 1E0
ORG $300
TSX ; 300
STX $FF ; 301
LDX #1 ; 303
TXS ; 305
JSR DelayFF ; 306
LDX $FF ; 309
TXS ; 30B
RTS ; 30C
DelayFF LDA #$FF ; 30D
JSR $FCA8 ; 30F
RTS ; 312
*/
CmdStepOut(0);
g_nDebugSteps = 0xFFFF;
int nMaxSteps = 0xFFFFF; // GH #1194
g_nDebugSteps = nMaxSteps;
while (g_nDebugSteps != 0)
{
DebugContinueStepping(true);
}
// If the PC isn't at the expected address after the JSR print a diagnostic so the user knows the stack may be buggered up
if (regs.pc != nExpectedAddr)
{
WORD nActualAddr = _6502_GetStackReturnAddress();
bool bValidAddr = (nActualAddr == nExpectedAddr);
int nStackOffset = _6502_FindStackReturnAddress( nExpectedAddr ); // Trace stack to seee if our expected address is on it
/*
ORG $300
Main JSR HugeWait
RTS
HugeWait LDY #$FF
Loop JSR Delay
DEY
BNE Loop
RTS
Delay LDA #$FF
JSR $FCA8
RTS
Repro #1
1. MSVC: Revert line to repro: int nMaxSteps = 0xFFFF;
2. MSVC: Set BP on line above: (regs.pc != nExpectedAddr)
3. AppleWin:
F7
300:A0 FF 20 09 03 88 D0 FA 60 A9 FF 20 A8 FC 60
BPX 30B
F7
CALL 768
<Ctrl>-<Space>
4. MSVC:Change regs.sp to one of 3 cases:
Case Addr On Stack Top of Stack Diagnostic nStackOffset R SP Continue in emulator
0 No No ERROR -1 regs.sp = 0x1F3
1 Yes Yes INFO O regs.sp = 0x1F2 R PC FCB3
2 Yes No WARN +1 regs.sp = 0x1F1 R S F1
*/
/**/ if (nStackOffset < 0) ConsolePrintFormat( CHC_ERROR "ERROR" CHC_ARG_SEP ":" CHC_ERROR " Didn't step over JSR! " CHC_ARG_SEP "(" CHC_DEFAULT "RTS " CHC_ARG_SEP "$" CHC_ADDRESS "%04X" CHC_DEFAULT " not found!" CHC_ARG_SEP ")", nExpectedAddr ); // Case 0
else if (nStackOffset == 0) ConsolePrintFormat( CHC_INFO "INFO" CHC_ARG_SEP ":" CHC_INFO " Didn't step over JSR! " CHC_ARG_SEP "(" CHC_DEFAULT "RTS " CHC_ARG_SEP "$" CHC_ADDRESS "%04X" CHC_DEFAULT " on top of stack." CHC_ARG_SEP ")", nExpectedAddr ); // Case 1
else /* */ ConsolePrintFormat( CHC_WARNING "WARN" CHC_ARG_SEP ":" CHC_WARNING " Didn't step over JSR! " CHC_ARG_SEP "(" CHC_DEFAULT "Stack has RTS " CHC_ARG_SEP "$" CHC_ADDRESS "%04X" CHC_DEFAULT " but needs fixup: " CHC_ARG_SEP "$" CHC_NUM_HEX "%02X" CHC_DEFAULT " bytes" CHC_ARG_SEP ")", nExpectedAddr, nStackOffset & 0xFF ); // Case 2
ConsolePrintFormat( CHC_DEFAULT " Please report '" CHC_SYMBOL "nMaxSteps" CHC_ARG_SEP " = " CHC_DEFAULT "0x" CHC_NUM_HEX "%04X" CHC_DEFAULT "' to:", nMaxSteps );
ConsolePrintFormat( CHC_PATH " https://github.com/AppleWin/AppleWin/issues/1194" );
ConsoleUpdate();
}
}
}
@@ -2317,13 +2388,11 @@ Update_t CmdStepOut (int nArgs)
{
// TODO: "RET" should probably pop the Call stack
// Also see: CmdCursorJumpRetAddr
WORD nAddress;
if (_6502_GetStackReturnAddress( nAddress ))
{
nArgs = _Arg_1( nAddress );
g_aArgs[1].sArg[0] = 0;
CmdGo( 1, true );
}
WORD nAddress = _6502_GetStackReturnAddress();
nArgs = _Arg_1( nAddress );
g_aArgs[1].sArg[0] = 0;
CmdGo( 1, true );
return UPDATE_ALL;
}
@@ -3296,22 +3365,19 @@ Update_t CmdCursorJumpPC (int nArgs)
//===========================================================================
Update_t CmdCursorJumpRetAddr (int nArgs)
{
WORD nAddress = 0;
if (_6502_GetStackReturnAddress( nAddress ))
{
g_nDisasmCurAddress = nAddress;
WORD nAddress = _6502_GetStackReturnAddress();
g_nDisasmCurAddress = nAddress;
if (CURSOR_ALIGN_CENTER == nArgs)
{
WindowUpdateDisasmSize();
}
else
if (CURSOR_ALIGN_TOP == nArgs)
{
g_nDisasmCurLine = 0;
}
DisasmCalcTopBotAddress();
if (CURSOR_ALIGN_CENTER == nArgs)
{
WindowUpdateDisasmSize();
}
else
if (CURSOR_ALIGN_TOP == nArgs)
{
g_nDisasmCurLine = 0;
}
DisasmCalcTopBotAddress();
return UPDATE_ALL;
}
@@ -8609,7 +8675,7 @@ void DebugContinueStepping (const bool bCallerWillUpdateDisplay/*=false*/)
bool skipStopReason = false;
if (regs.pc == g_nDebugStepUntil)
stopReason = "PC matches 'Go until' address";
stopReason = StrFormat( CHC_DEFAULT "Register " CHC_REGS "PC" CHC_DEFAULT " matches '" CHC_INFO "Go until" CHC_DEFAULT "' address $" CHC_ADDRESS "%04X", g_nDebugStepUntil);
else if (g_bDebugBreakpointHit & BP_HIT_INVALID)
stopReason = "Invalid opcode";
else if (g_bDebugBreakpointHit & BP_HIT_OPCODE)