diff options
Diffstat (limited to 'generic/tclCompCmds.c')
| -rw-r--r-- | generic/tclCompCmds.c | 641 |
1 files changed, 640 insertions, 1 deletions
diff --git a/generic/tclCompCmds.c b/generic/tclCompCmds.c index 2b59d5c..6183039 100644 --- a/generic/tclCompCmds.c +++ b/generic/tclCompCmds.c @@ -12,7 +12,7 @@ * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclCompCmds.c,v 1.159 2010/02/05 22:39:44 dkf Exp $ + * RCS: @(#) $Id: tclCompCmds.c,v 1.160 2010/02/09 20:51:54 dkf Exp $ */ #include "tclInt.h" @@ -182,6 +182,17 @@ static int CompileUnaryOpCmd(Tcl_Interp *interp, static void CompileReturnInternal(CompileEnv *envPtr, unsigned char op, int code, int level, Tcl_Obj *returnOpts); +static int IssueTryFinallyInstructions(Tcl_Interp *interp, + CompileEnv *envPtr, Tcl_Token *bodyToken, + int numHandlers, int *matchCodes, + Tcl_Obj **matchClauses, int *resultVarIndices, + int *optionVarIndices, Tcl_Token **handlerTokens, + Tcl_Token *finallyToken); +static int IssueTryInstructions(Tcl_Interp *interp, + CompileEnv *envPtr, Tcl_Token *bodyToken, + int numHandlers, int *matchCodes, + Tcl_Obj **matchClauses, int *resultVarIndices, + int *optionVarIndices, Tcl_Token **handlerTokens); #define PushVarNameWord(i,v,e,f,l,s,sc,word) \ PushVarName(i,v,e,f,l,s,sc, \ @@ -5064,6 +5075,634 @@ PrintJumptableInfo( /* *---------------------------------------------------------------------- * + * TclCompileTryCmd -- + * + * Procedure called to compile the "try" command. + * + * Results: + * Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer + * evaluation to runtime. + * + * Side effects: + * Instructions are added to envPtr to execute the "try" command at + * runtime. + * + *---------------------------------------------------------------------- + */ + +int +TclCompileTryCmd( + Tcl_Interp *interp, /* Used for error reporting. */ + Tcl_Parse *parsePtr, /* Points to a parse structure for the command + * created by Tcl_ParseCommand. */ + Command *cmdPtr, /* Points to defintion of command being + * compiled. */ + CompileEnv *envPtr) /* Holds resulting instructions. */ +{ + int numWords = parsePtr->numWords, numHandlers, result = TCL_ERROR; + Tcl_Token *bodyToken, *finallyToken, *tokenPtr; + Tcl_Token **handlerTokens = NULL; + Tcl_Obj **matchClauses = NULL; + int *matchCodes=NULL, *resultVarIndices=NULL, *optionVarIndices=NULL; + int i; + + if (numWords < 2) { + return TCL_ERROR; + } + + bodyToken = TokenAfter(parsePtr->tokenPtr); + + if (numWords == 2) { + /* + * No handlers or finally; do nothing beyond evaluating the body. + */ + + DefineLineInformation; /* TIP #280 */ + SetLineInformation(1); + CompileBody(envPtr, bodyToken, interp); + return TCL_OK; + } + + numWords -= 2; + tokenPtr = TokenAfter(bodyToken); + + /* + * Extract information about what handlers there are. + */ + + numHandlers = numWords >> 2; + numWords -= numHandlers * 4; + if (numHandlers > 0) { + handlerTokens = TclStackAlloc(interp, sizeof(Tcl_Token*)*numHandlers); + matchClauses = TclStackAlloc(interp, sizeof(Tcl_Obj *) * numHandlers); + memset(matchClauses, 0, sizeof(Tcl_Obj *) * numHandlers); + matchCodes = TclStackAlloc(interp, sizeof(int) * numHandlers); + resultVarIndices = TclStackAlloc(interp, sizeof(int) * numHandlers); + optionVarIndices = TclStackAlloc(interp, sizeof(int) * numHandlers); + + for (i=0 ; i<numHandlers ; i++) { + Tcl_Obj *tmpObj, **objv; + int objc; + + if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) { + goto failedToCompile; + } + if (tokenPtr[1].size == 4 + && !strncmp(tokenPtr[1].start, "trap", 4)) { + /* + * Parse the list of errorCode words to match against. + */ + + matchCodes[i] = TCL_ERROR; + tokenPtr = TokenAfter(tokenPtr); + TclNewObj(tmpObj); + Tcl_IncrRefCount(tmpObj); + if (!TclWordKnownAtCompileTime(tokenPtr, tmpObj) + || Tcl_ListObjLength(NULL, tmpObj, &objc) != TCL_OK + || (objc == 0)) { + TclDecrRefCount(tmpObj); + goto failedToCompile; + } + Tcl_ListObjReplace(NULL, tmpObj, 0, 0, 0, NULL); + matchClauses[i] = tmpObj; + } else if (tokenPtr[1].size == 2 + && !strncmp(tokenPtr[1].start, "on", 2)) { + int code; + static const char *codes[] = { + "ok", "error", "return", "break", "continue", NULL + }; + + /* + * Parse the result code to look for. + */ + + tokenPtr = TokenAfter(tokenPtr); + TclNewObj(tmpObj); + Tcl_IncrRefCount(tmpObj); + if (!TclWordKnownAtCompileTime(tokenPtr, tmpObj)) { + TclDecrRefCount(tmpObj); + goto failedToCompile; + } + if (Tcl_GetIntFromObj(NULL, tmpObj, &code) != TCL_OK + && Tcl_GetIndexFromObj(NULL, tmpObj, codes, "", + TCL_EXACT, &code) != TCL_OK) { + TclDecrRefCount(tmpObj); + goto failedToCompile; + } + matchCodes[i] = code; + TclDecrRefCount(tmpObj); + } else { + goto failedToCompile; + } + + /* + * Parse the variable binding. + */ + + tokenPtr = TokenAfter(tokenPtr); + TclNewObj(tmpObj); + Tcl_IncrRefCount(tmpObj); + if (!TclWordKnownAtCompileTime(tokenPtr, tmpObj)) { + TclDecrRefCount(tmpObj); + goto failedToCompile; + } + if (Tcl_ListObjGetElements(NULL, tmpObj, &objc, &objv) != TCL_OK + || (objc > 2)) { + TclDecrRefCount(tmpObj); + goto failedToCompile; + } + if (objc > 0) { + int len; + const char *varname = Tcl_GetStringFromObj(objv[0], &len); + + if (!TclIsLocalScalar(varname, len)) { + TclDecrRefCount(tmpObj); + goto failedToCompile; + } + resultVarIndices[i] = + TclFindCompiledLocal(varname, len, 1, envPtr); + } else { + resultVarIndices[i] = -1; + } + if (objc == 2) { + int len; + const char *varname = Tcl_GetStringFromObj(objv[1], &len); + + if (!TclIsLocalScalar(varname, len)) { + TclDecrRefCount(tmpObj); + goto failedToCompile; + } + optionVarIndices[i] = + TclFindCompiledLocal(varname, len, 1, envPtr); + } else { + optionVarIndices[i] = -1; + } + TclDecrRefCount(tmpObj); + + /* + * Extract the body for this handler. + */ + + tokenPtr = TokenAfter(tokenPtr); + if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) { + goto failedToCompile; + } + if (tokenPtr[1].size == 1 && tokenPtr[1].start[0] == '-') { + handlerTokens[i] = NULL; + } else { + handlerTokens[i] = tokenPtr; + } + + tokenPtr = TokenAfter(tokenPtr); + } + + if (handlerTokens[numHandlers-1] == NULL) { + goto failedToCompile; + } + } + + /* + * Parse the finally clause + */ + + if (numWords == 0) { + finallyToken = NULL; + } else if (numWords == 2) { + if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD || tokenPtr[1].size != 7 + || strncmp(tokenPtr[1].start, "finally", 7)) { + goto failedToCompile; + } + finallyToken = TokenAfter(tokenPtr); + } else { + goto failedToCompile; + } + + /* + * Issue the bytecode. + */ + + if (finallyToken) { + result = IssueTryFinallyInstructions(interp, envPtr, bodyToken, + numHandlers, matchCodes, matchClauses, resultVarIndices, + optionVarIndices, handlerTokens, finallyToken); + } else { + result = IssueTryInstructions(interp, envPtr, bodyToken, numHandlers, + matchCodes, matchClauses, resultVarIndices, optionVarIndices, + handlerTokens); + } + + /* + * Delete any temporary state and finish off. + */ + + failedToCompile: + if (numHandlers > 0) { + for (i=0 ; i<numHandlers ; i++) { + if (matchClauses[i]) { + TclDecrRefCount(matchClauses[i]); + } + } + TclStackFree(interp, optionVarIndices); + TclStackFree(interp, resultVarIndices); + TclStackFree(interp, matchCodes); + TclStackFree(interp, matchClauses); + TclStackFree(interp, handlerTokens); + } + return result; +} + +/* + *---------------------------------------------------------------------- + * + * IssueTryInstructions, IssueTryFinallyInstructions -- + * + * The code generators for [try]. Split from the parsing engine for + * reasons of developer sanity, and also split between no-finally and + * with-finally cases because so many of the details of generation vary + * between the two. + * + * The macros below make the instruction issuing easier to follow. + * + *---------------------------------------------------------------------- + */ + +#define OP(name) TclEmitOpcode(INST_##name, envPtr) +#define OP1(name,val) TclEmitInstInt1(INST_##name,(val),envPtr) +#define OP4(name,val) TclEmitInstInt4(INST_##name,(val),envPtr) +#define OP44(name,val1,val2) \ + TclEmitInstInt4(INST_##name,(val1),envPtr);TclEmitInt4((val2),envPtr) +#define BODY(token,index) \ + SetLineInformation((index));CompileBody(envPtr,(token),interp) +#define PUSH(str) \ + PushLiteral(envPtr,(str),strlen(str)) +#define JUMP(var,name) \ + (var) = CurrentOffset(envPtr);TclEmitInstInt4(INST_##name,0,envPtr) +#define FIXJUMP(var) \ + TclStoreInt4AtPtr(CurrentOffset(envPtr)-(var),envPtr->codeStart+(var)+1) + +static int +IssueTryInstructions( + Tcl_Interp *interp, + CompileEnv *envPtr, + Tcl_Token *bodyToken, + int numHandlers, + int *matchCodes, + Tcl_Obj **matchClauses, + int *resultVars, + int *optionVars, + Tcl_Token **handlerTokens) +{ + DefineLineInformation; /* TIP #280 */ + int range, resultVar, optionsVar; + int i, j, len, forwardsNeedFixing = 0; + int *addrsToFix, *forwardsToFix, notCodeJumpSource, notECJumpSource; + char buf[TCL_INTEGER_SPACE]; + + resultVar = TclFindCompiledLocal(NULL, 0, 1, envPtr); + optionsVar = TclFindCompiledLocal(NULL, 0, 1, envPtr); + if (resultVar < 0 || optionsVar < 0) { + return TCL_ERROR; + } + + /* + * Compile the body, trapping any error in it so that we can trap on it + * and/or run a finally clause. Note that there must be at least one + * on/trap clause; when none is present, this whole function is not called + * (and it's never called when there's a finally clause). + */ + + range = DeclareExceptionRange(envPtr, CATCH_EXCEPTION_RANGE); + OP4( BEGIN_CATCH4, range); + ExceptionRangeStarts(envPtr, range); + BODY( bodyToken, 1); + ExceptionRangeEnds(envPtr, range); + OP1( JUMP1, 3); + ExceptionRangeTarget(envPtr, range, catchOffset); + OP( PUSH_RESULT); + OP4( STORE_SCALAR4, resultVar); + OP( POP); + OP( PUSH_RETURN_OPTIONS); + OP4( STORE_SCALAR4, optionsVar); + OP( POP); + OP( PUSH_RETURN_CODE); + OP( END_CATCH); + + /* + * Now we handle all the registered 'on' and 'trap' handlers in order. + * For us to be here, there must be at least one handler. + * + * Slight overallocation, but reduces size of this function. + */ + + addrsToFix = TclStackAlloc(interp, sizeof(int)*numHandlers); + forwardsToFix = TclStackAlloc(interp, sizeof(int)*numHandlers); + + for (i=0 ; i<numHandlers ; i++) { + sprintf(buf, "%d", matchCodes[i]); + OP( DUP); + PUSH( buf); + OP( EQ); + JUMP(notCodeJumpSource, JUMP_FALSE4); + if (matchClauses[i]) { + Tcl_ListObjLength(NULL, matchClauses[i], &len); + + /* + * Match the errorcode according to try/trap rules. + */ + + OP4( LOAD_SCALAR4, optionsVar); + PUSH( "-errorcode"); + OP4( DICT_GET, 1); + OP44( LIST_RANGE_IMM, 0, len-1); + PUSH( TclGetString(matchClauses[i])); + OP( STR_EQ); + JUMP(notECJumpSource, JUMP_FALSE4); + } else { + notECJumpSource = -1; /* LINT */ + } + OP( POP); + + /* + * There is no finally clause, so we can avoid wrapping a catch + * context around the handler. That simplifies what instructions need + * to be issued a lot since we can let errors just fall through. + */ + + if (resultVars[i] >= 0) { + OP4( LOAD_SCALAR4, resultVar); + OP4( STORE_SCALAR4, resultVars[i]); + OP( POP); + if (optionVars[i] >= 0) { + OP4( LOAD_SCALAR4, optionsVar); + OP4( STORE_SCALAR4, optionVars[i]); + OP( POP); + } + } + if (!handlerTokens[i]) { + forwardsNeedFixing = 1; + JUMP(forwardsToFix[i], JUMP4); + } else { + forwardsToFix[i] = -1; + if (forwardsNeedFixing) { + forwardsNeedFixing = 0; + for (j=0 ; j<i ; j++) { + if (forwardsToFix[j] == -1) { + continue; + } + FIXJUMP(forwardsToFix[j]); + forwardsToFix[j] = -1; + } + } + BODY( handlerTokens[i], 5+i*4); + } + + JUMP(addrsToFix[i], JUMP4); + if (matchClauses[i]) { + FIXJUMP(notECJumpSource); + } + FIXJUMP(notCodeJumpSource); + } + + /* + * Drop the result code since it didn't match any clause, and reissue the + * exception. Note also that INST_RETURN_STK can proceed to the next + * instruction. + */ + + OP( POP); + OP4( LOAD_SCALAR4, optionsVar); + OP4( LOAD_SCALAR4, resultVar); + OP( RETURN_STK); + + /* + * Fix all the jumps from taken clauses to here (which is the end of the + * [try]). + */ + + for (i=0 ; i<numHandlers ; i++) { + FIXJUMP(addrsToFix[i]); + } + TclStackFree(interp, forwardsToFix); + TclStackFree(interp, addrsToFix); + return TCL_OK; +} + +static int +IssueTryFinallyInstructions( + Tcl_Interp *interp, + CompileEnv *envPtr, + Tcl_Token *bodyToken, + int numHandlers, + int *matchCodes, + Tcl_Obj **matchClauses, + int *resultVars, + int *optionVars, + Tcl_Token **handlerTokens, + Tcl_Token *finallyToken) /* Not NULL */ +{ + DefineLineInformation; /* TIP #280 */ + int savedStackDepth = envPtr->currStackDepth; + int range, resultVar, optionsVar, i, j, len, forwardsNeedFixing = 0; + int *addrsToFix, *forwardsToFix, notCodeJumpSource, notECJumpSource; + char buf[TCL_INTEGER_SPACE]; + + resultVar = TclFindCompiledLocal(NULL, 0, 1, envPtr); + optionsVar = TclFindCompiledLocal(NULL, 0, 1, envPtr); + if (resultVar < 0 || optionsVar < 0) { + return TCL_ERROR; + } + + /* + * Compile the body, trapping any error in it so that we can trap on it + * (if any trap matches) and run a finally clause. + */ + + range = DeclareExceptionRange(envPtr, CATCH_EXCEPTION_RANGE); + OP4( BEGIN_CATCH4, range); + ExceptionRangeStarts(envPtr, range); + BODY( bodyToken, 1); + ExceptionRangeEnds(envPtr, range); + OP1( JUMP1, 3); + ExceptionRangeTarget(envPtr, range, catchOffset); + OP( PUSH_RESULT); + OP4( STORE_SCALAR4, resultVar); + OP( POP); + OP( PUSH_RETURN_OPTIONS); + OP4( STORE_SCALAR4, optionsVar); + OP( POP); + OP( PUSH_RETURN_CODE); + OP( END_CATCH); + envPtr->currStackDepth = savedStackDepth + 1; + + /* + * Now we handle all the registered 'on' and 'trap' handlers in order. + */ + + if (numHandlers) { + /* + * Slight overallocation, but reduces size of this function. + */ + + addrsToFix = TclStackAlloc(interp, sizeof(int)*numHandlers); + forwardsToFix = TclStackAlloc(interp, sizeof(int)*numHandlers); + + for (i=0 ; i<numHandlers ; i++) { + sprintf(buf, "%d", matchCodes[i]); + OP( DUP); + PUSH( buf); + OP( EQ); + JUMP(notCodeJumpSource, JUMP_FALSE4); + if (matchClauses[i]) { + Tcl_ListObjLength(NULL, matchClauses[i], &len); + + /* + * Match the errorcode according to try/trap rules. + */ + + OP4( LOAD_SCALAR4, optionsVar); + PUSH( "-errorcode"); + OP4( DICT_GET, 1); + OP44( LIST_RANGE_IMM, 0, len-1); + PUSH( TclGetString(matchClauses[i])); + OP( STR_EQ); + JUMP(notECJumpSource, JUMP_FALSE4); + } else { + notECJumpSource = -1; /* LINT */ + } + + /* + * There is a finally clause, so we need a fairly complex sequence + * of instructions to deal with an on/trap handler because we must + * call the finally handler *and* we need to substitute the result + * from a failed trap for the result from the main script. + */ + + if (resultVars[i] >= 0 || handlerTokens[i]) { + range = DeclareExceptionRange(envPtr, CATCH_EXCEPTION_RANGE); + OP4( BEGIN_CATCH4, range); + ExceptionRangeStarts(envPtr, range); + } + if (resultVars[i] >= 0) { + OP4( LOAD_SCALAR4, resultVar); + OP4( STORE_SCALAR4, resultVars[i]); + OP( POP); + if (optionVars[i] >= 0) { + OP4( LOAD_SCALAR4, optionsVar); + OP4( STORE_SCALAR4, optionVars[i]); + OP( POP); + } + } + if (!handlerTokens[i]) { + /* + * No handler. Will not be the last handler (that condition is + * checked by the caller). Chain to the next one. + */ + + ExceptionRangeEnds(envPtr, range); + forwardsNeedFixing = 1; + JUMP(forwardsToFix[i], JUMP4); + if (resultVars[i] >= 0) { + goto finishTrapCatchHandling; + } + } else { + /* + * Got a handler. Make sure that any pending patch-up actions + * from previous unprocessed handlers are dealt with now that + * we know where they are to jump to. + */ + + if (forwardsNeedFixing) { + forwardsNeedFixing = 0; + OP1( JUMP1, 7); + for (j=0 ; j<i ; j++) { + if (forwardsToFix[j] == -1) { + continue; + } + FIXJUMP(forwardsToFix[j]); + forwardsToFix[j] = -1; + } + OP4( BEGIN_CATCH4, range); + } + BODY( handlerTokens[i], 5+i*4); + ExceptionRangeEnds(envPtr, range); + OP( POP); + OP1( JUMP1, 6); + forwardsToFix[i] = -1; + + /* + * Error in handler or setting of variables; replace the + * stored exception with the new one. Note that we only push + * this if we have either a body or some variable setting + * here. Otherwise this code is unreachable. + */ + + finishTrapCatchHandling: + ExceptionRangeTarget(envPtr, range, catchOffset); + OP( PUSH_RESULT); + OP4( STORE_SCALAR4, resultVar); + OP( POP); + OP( PUSH_RETURN_OPTIONS); + OP4( STORE_SCALAR4, optionsVar); + OP( POP); + OP( END_CATCH); + } + if (i+1 < numHandlers) { + JUMP(addrsToFix[i], JUMP4); + } + if (matchClauses[i]) { + FIXJUMP(notECJumpSource); + } + FIXJUMP(notCodeJumpSource); + } + + /* + * Fix all the jumps from taken clauses to here (the start of the + * finally clause). + */ + + for (i=0 ; i<numHandlers-1 ; i++) { + FIXJUMP(addrsToFix[i]); + } + TclStackFree(interp, forwardsToFix); + TclStackFree(interp, addrsToFix); + } + + /* + * Drop the result code. + */ + + OP( POP); + envPtr->currStackDepth = savedStackDepth; + + /* + * Process the finally clause (at last!) Note that we do not wrap this in + * error handlers because we would just rethrow immediately anyway. Then + * (on normal success) we reissue the exception. Note also that + * INST_RETURN_STK can proceed to the next instruction; that'll be the + * next command (or some inter-command manipulation). + */ + + BODY( finallyToken, 3 + 4*numHandlers); + OP( POP); + OP4( LOAD_SCALAR4, optionsVar); + OP4( LOAD_SCALAR4, resultVar); + OP( RETURN_STK); + + return TCL_OK; +} + +#undef OP +#undef OP1 +#undef OP4 +#undef OP44 +#undef BODY +#undef PUSH +#undef JUMP +#undef FIXJUMP + +/* + *---------------------------------------------------------------------- + * * TclCompileUnsetCmd -- * * Procedure called to compile the "unset" command. |