From 2859532759626d4782896f4c151bf58a668da85b Mon Sep 17 00:00:00 2001
From: dkf <donal.k.fellows@manchester.ac.uk>
Date: Thu, 20 Jun 2013 11:05:20 +0000
Subject: Properly encode more operand types to reduce the number of special
cases in the disassembler.
---
generic/tclCompile.c | 18 +++---
generic/tclCompile.h | 8 ++-
generic/tclDisassemble.c | 164 ++++++++++++++++++++++++++---------------------
3 files changed, 106 insertions(+), 84 deletions(-)
diff --git a/generic/tclCompile.c b/generic/tclCompile.c
index 65fc218..aee711c 100644
--- a/generic/tclCompile.c
+++ b/generic/tclCompile.c
@@ -55,9 +55,9 @@ InstructionDesc const tclInstructionTable[] = {
/* Name Bytes stackEffect #Opnds Operand types */
{"done", 1, -1, 0, {OPERAND_NONE}},
/* Finish ByteCode execution and return stktop (top stack item) */
- {"push1", 2, +1, 1, {OPERAND_UINT1}},
+ {"push1", 2, +1, 1, {OPERAND_LIT1}},
/* Push object at ByteCode objArray[op1] */
- {"push4", 5, +1, 1, {OPERAND_UINT4}},
+ {"push4", 5, +1, 1, {OPERAND_LIT4}},
/* Push object at ByteCode objArray[op4] */
{"pop", 1, -1, 0, {OPERAND_NONE}},
/* Pop the topmost stack object */
@@ -125,17 +125,17 @@ InstructionDesc const tclInstructionTable[] = {
{"incrStkImm", 2, 0, 1, {OPERAND_INT1}},
/* Incr general variable; unparsed name is top, amount is op1 */
- {"jump1", 2, 0, 1, {OPERAND_INT1}},
+ {"jump1", 2, 0, 1, {OPERAND_OFFSET1}},
/* Jump relative to (pc + op1) */
- {"jump4", 5, 0, 1, {OPERAND_INT4}},
+ {"jump4", 5, 0, 1, {OPERAND_OFFSET4}},
/* Jump relative to (pc + op4) */
- {"jumpTrue1", 2, -1, 1, {OPERAND_INT1}},
+ {"jumpTrue1", 2, -1, 1, {OPERAND_OFFSET1}},
/* Jump relative to (pc + op1) if stktop expr object is true */
- {"jumpTrue4", 5, -1, 1, {OPERAND_INT4}},
+ {"jumpTrue4", 5, -1, 1, {OPERAND_OFFSET4}},
/* Jump relative to (pc + op4) if stktop expr object is true */
- {"jumpFalse1", 2, -1, 1, {OPERAND_INT1}},
+ {"jumpFalse1", 2, -1, 1, {OPERAND_OFFSET1}},
/* Jump relative to (pc + op1) if stktop expr object is false */
- {"jumpFalse4", 5, -1, 1, {OPERAND_INT4}},
+ {"jumpFalse4", 5, -1, 1, {OPERAND_OFFSET4}},
/* Jump relative to (pc + op4) if stktop expr object is false */
{"lor", 1, -1, 0, {OPERAND_NONE}},
@@ -298,7 +298,7 @@ InstructionDesc const tclInstructionTable[] = {
/* List Index: push (lindex stktop op4) */
{"listRangeImm", 9, 0, 2, {OPERAND_IDX4, OPERAND_IDX4}},
/* List Range: push (lrange stktop op4 op4) */
- {"startCommand", 9, 0, 2, {OPERAND_INT4,OPERAND_UINT4}},
+ {"startCommand", 9, 0, 2, {OPERAND_OFFSET4, OPERAND_UINT4}},
/* Start of bytecoded command: op is the length of the cmd's code, op2
* is number of commands here */
diff --git a/generic/tclCompile.h b/generic/tclCompile.h
index cf7b563..1f42b05 100644
--- a/generic/tclCompile.h
+++ b/generic/tclCompile.h
@@ -822,8 +822,14 @@ typedef enum InstOperandType {
* variable table. */
OPERAND_LVT4, /* Four byte unsigned index into the local
* variable table. */
- OPERAND_AUX4 /* Four byte unsigned index into the aux data
+ OPERAND_AUX4, /* Four byte unsigned index into the aux data
* table. */
+ OPERAND_OFFSET1, /* One byte signed jump offset. */
+ OPERAND_OFFSET4, /* Four byte signed jump offset. */
+ OPERAND_LIT1, /* One byte unsigned index into table of
+ * literals. */
+ OPERAND_LIT4 /* Four byte unsigned index into table of
+ * literals. */
} InstOperandType;
typedef struct InstructionDesc {
diff --git a/generic/tclDisassemble.c b/generic/tclDisassemble.c
index 7f0b11a..c7072ee 100644
--- a/generic/tclDisassemble.c
+++ b/generic/tclDisassemble.c
@@ -482,42 +482,52 @@ FormatInstruction(
switch (instDesc->opTypes[i]) {
case OPERAND_INT1:
opnd = TclGetInt1AtPtr(pc+numBytes); numBytes++;
- if (opCode == INST_JUMP1 || opCode == INST_JUMP_TRUE1
- || opCode == INST_JUMP_FALSE1) {
- sprintf(suffixBuffer, "pc %u", pcOffset+opnd);
- }
Tcl_AppendPrintfToObj(bufferObj, "%+d ", opnd);
break;
case OPERAND_INT4:
opnd = TclGetInt4AtPtr(pc+numBytes); numBytes += 4;
- if (opCode == INST_JUMP4 || opCode == INST_JUMP_TRUE4
- || opCode == INST_JUMP_FALSE4) {
- sprintf(suffixBuffer, "pc %u", pcOffset+opnd);
- } else if (opCode == INST_START_CMD) {
- sprintf(suffixBuffer, "next cmd at pc %u", pcOffset+opnd);
- }
Tcl_AppendPrintfToObj(bufferObj, "%+d ", opnd);
break;
case OPERAND_UINT1:
opnd = TclGetUInt1AtPtr(pc+numBytes); numBytes++;
- if (opCode == INST_PUSH1) {
- suffixObj = codePtr->objArrayPtr[opnd];
- }
Tcl_AppendPrintfToObj(bufferObj, "%u ", (unsigned) opnd);
break;
- case OPERAND_AUX4:
case OPERAND_UINT4:
opnd = TclGetUInt4AtPtr(pc+numBytes); numBytes += 4;
- if (opCode == INST_PUSH4) {
- suffixObj = codePtr->objArrayPtr[opnd];
- } else if (opCode == INST_START_CMD && opnd != 1) {
+ if (opCode == INST_START_CMD) {
sprintf(suffixBuffer+strlen(suffixBuffer),
", %u cmds start here", opnd);
}
Tcl_AppendPrintfToObj(bufferObj, "%u ", (unsigned) opnd);
- if (instDesc->opTypes[i] == OPERAND_AUX4) {
- auxPtr = &codePtr->auxDataArrayPtr[opnd];
+ break;
+ case OPERAND_OFFSET1:
+ opnd = TclGetInt1AtPtr(pc+numBytes); numBytes++;
+ sprintf(suffixBuffer, "pc %u", pcOffset+opnd);
+ Tcl_AppendPrintfToObj(bufferObj, "%+d ", opnd);
+ break;
+ case OPERAND_OFFSET4:
+ opnd = TclGetInt4AtPtr(pc+numBytes); numBytes += 4;
+ if (opCode == INST_START_CMD) {
+ sprintf(suffixBuffer, "next cmd at pc %u", pcOffset+opnd);
+ } else {
+ sprintf(suffixBuffer, "pc %u", pcOffset+opnd);
}
+ Tcl_AppendPrintfToObj(bufferObj, "%+d ", opnd);
+ break;
+ case OPERAND_LIT1:
+ opnd = TclGetUInt1AtPtr(pc+numBytes); numBytes++;
+ suffixObj = codePtr->objArrayPtr[opnd];
+ Tcl_AppendPrintfToObj(bufferObj, "%u ", (unsigned) opnd);
+ break;
+ case OPERAND_LIT4:
+ opnd = TclGetUInt4AtPtr(pc+numBytes); numBytes += 4;
+ suffixObj = codePtr->objArrayPtr[opnd];
+ Tcl_AppendPrintfToObj(bufferObj, "%u ", (unsigned) opnd);
+ break;
+ case OPERAND_AUX4:
+ opnd = TclGetUInt4AtPtr(pc+numBytes); numBytes += 4;
+ Tcl_AppendPrintfToObj(bufferObj, "%u ", (unsigned) opnd);
+ auxPtr = &codePtr->auxDataArrayPtr[opnd];
break;
case OPERAND_IDX4:
opnd = TclGetInt4AtPtr(pc+numBytes); numBytes += 4;
@@ -896,54 +906,67 @@ DisassembleByteCodeAsDicts(
instructions = Tcl_NewObj();
for (pc=codePtr->codeStart; pc<codePtr->codeStart+codePtr->numCodeBytes;){
const InstructionDesc *instDesc = &tclInstructionTable[*pc];
+ int address = pc - codePtr->codeStart;
inst = Tcl_NewObj();
- Tcl_ListObjAppendElement(NULL, inst,
- Tcl_NewStringObj(instDesc->name, -1));
+ Tcl_ListObjAppendElement(NULL, inst, Tcl_NewStringObj(
+ instDesc->name, -1));
opnd = pc + 1;
for (i=0 ; i<instDesc->numOperands ; i++) {
switch (instDesc->opTypes[i]) {
case OPERAND_INT1:
val = TclGetInt1AtPtr(opnd);
opnd += 1;
- if (*pc == INST_JUMP1 || *pc == INST_JUMP_TRUE1
- || *pc == INST_JUMP_FALSE1) {
- Tcl_ListObjAppendElement(NULL, inst, Tcl_ObjPrintf(
- "pc %d", pc+val-codePtr->codeStart));
- } else {
- Tcl_ListObjAppendElement(NULL, inst, Tcl_NewIntObj(val));
- }
- break;
+ goto formatNumber;
+ case OPERAND_UINT1:
+ val = TclGetUInt1AtPtr(opnd);
+ opnd += 1;
+ goto formatNumber;
case OPERAND_INT4:
val = TclGetInt4AtPtr(opnd);
opnd += 4;
- if (*pc == INST_JUMP4 || *pc == INST_JUMP_TRUE4
- || *pc == INST_JUMP_FALSE4 || *pc == INST_START_CMD) {
- Tcl_ListObjAppendElement(NULL, inst, Tcl_ObjPrintf(
- "pc %d", pc+val-codePtr->codeStart));
- } else {
- Tcl_ListObjAppendElement(NULL, inst, Tcl_NewIntObj(val));
- }
+ goto formatNumber;
+ case OPERAND_UINT4:
+ val = TclGetUInt4AtPtr(opnd);
+ opnd += 4;
+ formatNumber:
+ Tcl_ListObjAppendElement(NULL, inst, Tcl_NewIntObj(val));
break;
- case OPERAND_UINT1:
+
+ case OPERAND_OFFSET1:
+ val = TclGetInt1AtPtr(opnd);
+ opnd += 1;
+ goto formatAddress;
+ case OPERAND_OFFSET4:
+ val = TclGetInt4AtPtr(opnd);
+ opnd += 4;
+ formatAddress:
+ Tcl_ListObjAppendElement(NULL, inst, Tcl_ObjPrintf(
+ "pc %d", address + val));
+ break;
+
+ case OPERAND_LIT1:
val = TclGetUInt1AtPtr(opnd);
opnd += 1;
- if (*pc == INST_PUSH1) {
- Tcl_ListObjAppendElement(NULL, inst, Tcl_ObjPrintf(
- "@%d", val));
- } else {
- Tcl_ListObjAppendElement(NULL, inst, Tcl_NewIntObj(val));
- }
+ goto formatLiteral;
+ case OPERAND_LIT4:
+ val = TclGetUInt4AtPtr(opnd);
+ opnd += 4;
+ formatLiteral:
+ Tcl_ListObjAppendElement(NULL, inst, Tcl_ObjPrintf(
+ "@%d", val));
break;
- case OPERAND_UINT4:
+
+ case OPERAND_LVT1:
+ val = TclGetUInt1AtPtr(opnd);
+ opnd += 1;
+ goto formatVariable;
+ case OPERAND_LVT4:
val = TclGetUInt4AtPtr(opnd);
opnd += 4;
- if (*pc == INST_PUSH4) {
- Tcl_ListObjAppendElement(NULL, inst, Tcl_ObjPrintf(
- "@%d", val));
- } else {
- Tcl_ListObjAppendElement(NULL, inst, Tcl_NewIntObj(val));
- }
+ formatVariable:
+ Tcl_ListObjAppendElement(NULL, inst, Tcl_ObjPrintf(
+ "%%%d", val));
break;
case OPERAND_IDX4:
val = TclGetInt4AtPtr(opnd);
@@ -952,37 +975,24 @@ DisassembleByteCodeAsDicts(
Tcl_ListObjAppendElement(NULL, inst, Tcl_ObjPrintf(
".%d", val));
} else if (val == -2) {
- Tcl_ListObjAppendElement(NULL, inst,
- Tcl_NewStringObj(".end", -1));
+ Tcl_ListObjAppendElement(NULL, inst, Tcl_NewStringObj(
+ ".end", -1));
} else {
- Tcl_ListObjAppendElement(NULL, inst,
- Tcl_ObjPrintf(".end-%d", -2-val));
+ Tcl_ListObjAppendElement(NULL, inst, Tcl_ObjPrintf(
+ ".end-%d", -2-val));
}
break;
- case OPERAND_LVT1:
- val = TclGetUInt1AtPtr(opnd);
- opnd += 1;
- Tcl_ListObjAppendElement(NULL, inst,
- Tcl_ObjPrintf("%%%d", val));
- break;
- case OPERAND_LVT4:
- val = TclGetUInt4AtPtr(opnd);
- opnd += 4;
- Tcl_ListObjAppendElement(NULL, inst,
- Tcl_ObjPrintf("%%%d", val));
- break;
case OPERAND_AUX4:
val = TclGetInt4AtPtr(opnd);
opnd += 4;
- Tcl_ListObjAppendElement(NULL, inst,
- Tcl_ObjPrintf("?%d", val));
+ Tcl_ListObjAppendElement(NULL, inst, Tcl_ObjPrintf(
+ "?%d", val));
break;
case OPERAND_NONE:
Tcl_Panic("opcode %d with more than zero 'no' operands", *pc);
}
}
- Tcl_DictObjPut(NULL, instructions,
- Tcl_NewIntObj(pc - codePtr->codeStart), inst);
+ Tcl_DictObjPut(NULL, instructions, Tcl_NewIntObj(address), inst);
pc += instDesc->numBytes;
}
@@ -1039,18 +1049,23 @@ DisassembleByteCodeAsDicts(
/*
* Get the command information from the bytecode.
+ *
+ * The way these are encoded in the bytecode is non-trivial; the Decode
+ * macro (which updates its argument and returns the next decoded value)
+ * handles this so that the rest of the code does not.
*/
+#define Decode(ptr) \
+ ((TclGetUInt1AtPtr(ptr) == 0xFF) \
+ ? ((ptr)+=5 , TclGetInt4AtPtr((ptr)-4)) \
+ : ((ptr)+=1 , TclGetInt1AtPtr((ptr)-1)))
+
commands = Tcl_NewObj();
codeOffPtr = codePtr->codeDeltaStart;
codeLenPtr = codePtr->codeLengthStart;
srcOffPtr = codePtr->srcDeltaStart;
srcLenPtr = codePtr->srcLengthStart;
codeOffset = sourceOffset = 0;
-#define Decode(ptr) \
- ((TclGetUInt1AtPtr(ptr) == 0xFF) \
- ? ((ptr)+=5,TclGetInt4AtPtr((ptr)-4)) \
- : ((ptr)+=1,TclGetInt1AtPtr((ptr)-1)))
for (i=0 ; i<codePtr->numCommands ; i++) {
Tcl_Obj *cmd;
@@ -1077,6 +1092,7 @@ DisassembleByteCodeAsDicts(
Tcl_NewStringObj(codePtr->source+sourceOffset, sourceLength));
Tcl_ListObjAppendElement(NULL, commands, cmd);
}
+
#undef Decode
/*
--
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