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The Debugger convinced me to make probeAddr() safe for any 1/2/4-byte read

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This commit is contained in:
Jeff Parsons 2015-11-06 14:00:49 -08:00
commit ef282eee47
2 changed files with 69 additions and 33 deletions
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53
modules/pcjs/lib/debugger.js
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@ -2060,10 +2060,7 @@ if (DEBUGGER) {
*/
Debugger.prototype.getWord = function(dbgAddr, fAdvance)
{
if (!dbgAddr.fData32) {
return this.getShort(dbgAddr, fAdvance? 2 : 0);
}
return this.getLong(dbgAddr, fAdvance? 4 : 0);
return dbgAddr.fData32? this.getLong(dbgAddr, fAdvance? 4 : 0) : this.getShort(dbgAddr, fAdvance? 2 : 0);
};
/**
@ -2107,6 +2104,9 @@ if (DEBUGGER) {
/**
* setByte(dbgAddr, b, inc)
*
* WARNING: Be careful with the editing commands that use function, because we don't have a safe
* counterpart to cpu.probeAddr().
*
* @this {Debugger}
* @param {DbgAddr} dbgAddr
* @param {number} b
@ -2125,6 +2125,9 @@ if (DEBUGGER) {
/**
* setShort(dbgAddr, w, inc)
*
* WARNING: Be careful with the editing commands that use function, because we don't have a safe
* counterpart to cpu.probeAddr().
*
* @this {Debugger}
* @param {DbgAddr} dbgAddr
* @param {number} w
@ -3360,7 +3363,7 @@ if (DEBUGGER) {
i += sReplace.length;
continue;
}
$i++;
i++;
}
/*
* Replace every ^XXXX:XXXX, where XXXX:XXXX is a segmented address, with the FCB filename stored at that address.
@ -3856,7 +3859,13 @@ if (DEBUGGER) {
sStopped += " (";
if (this.checksEnabled()) {
sStopped += this.cOpcodes + " opcodes, ";
this.cOpcodes = this.cOpcodesStart = 0;
/*
* $ops displays progress by calculating cOpcodes - cOpcodesStart, so before
* zeroing cOpcodes, we should subtract cOpcodes from cOpcodesStart (since we're
* effectively subtracting cOpcodes from cOpcodes as well).
*/
this.cOpcodesStart -= this.cOpcodes;
this.cOpcodes = 0;
}
sStopped += this.nCycles + " cycles, " + msTotal + " ms, " + nCyclesPerSecond + " hz)";
if (MAXDEBUG && this.chipset) {
@ -6300,7 +6309,7 @@ if (DEBUGGER) {
* Displays information about the given software interrupt (assuming that said interrupt is in progress).
*
* These messages also reset the system variable $ops (by updating cOpcodesStart), to make it easier to see
* how many opcodes were executed since the interrupt "started".
* how many opcodes were executed since these interrupts "started".
*
* @this {Debugger}
* @param {string|undefined} sInt
@ -7151,6 +7160,9 @@ if (DEBUGGER) {
/**
* getCall(dbgAddr, fFar)
*
* Given a possible return address (typically from the stack), look for a matching CALL (or INT) that
* immediately precedes that address.
*
* @this {Debugger}
* @param {DbgAddr} dbgAddr
* @param {boolean} [fFar]
@ -7167,8 +7179,18 @@ if (DEBUGGER) {
dbgAddr.addr = null;
var s = this.getInstruction(dbgAddr);
if (s.indexOf("CALL") > 0 || fFar && s.indexOf("INT") > 0) {
sCall = s;
break;
/*
* Verify that the length of this CALL (or INT), when added to the address of the CALL (or INT),
* matches the original return address. We do this by getting the string index of the opcode bytes,
* subtracting that from the string index of the next space, and dividing that difference by two,
* to yield the length of the CALL (or INT) instruction, in bytes.
*/
var i = s.indexOf(' ');
var j = s.indexOf(' ', i+1);
if (off + (j - i - 1)/2 == offOrig) {
sCall = s;
break;
}
}
}
off--;
@ -7202,7 +7224,7 @@ if (DEBUGGER) {
this.println("stack trace for " + this.toHexAddr(dbgAddrStack));
while (cFrames < nFrames) {
var sCall = null, cTests = 256;
var sCall = null, sCallPrev = null, cTests = 256;
while ((dbgAddrStack.off >>> 0) < (this.cpu.regLSPLimit >>> 0)) {
dbgAddrCall.off = this.getWord(dbgAddrStack, true);
/*
@ -7225,14 +7247,21 @@ if (DEBUGGER) {
break;
}
}
if (!sCall) break;
/*
* The sCallPrev check eliminates duplicate sequential calls, which are usually (but not always)
* indicative of a false positive, in which case the previous call is probably bogus as well, but
* at least we won't duplicate that mistake. Of course, there are always exceptions, recursion
* being one of them, but it's rare that we're debugging recursive code.
*/
if (!sCall || sCall == sCallPrev) break;
var sSymbol = null;
if (sCmd == "ks") {
var a = sCall.match(/[0-9A-F]+$/);
if (a) sSymbol = this.doList(a[0]);
}
sCall = str.pad(sCall, 50) + " ;" + (sSymbol || "stack=" + this.toHexAddr(dbgAddrStack) + " return=" + this.toHexAddr(dbgAddrCall));
sCall = str.pad(sCall, 50) + " ;" + (sSymbol || "stack=" + this.toHexAddr(dbgAddrStack)); // + " return=" + this.toHexAddr(dbgAddrCall));
this.println(sCall);
sCallPrev = sCall;
cFrames++;
}
if (!cFrames) this.println("no return addresses found");