From e251dd2937f9caaf882a32adb4d40f787a7e00d3 Mon Sep 17 00:00:00 2001 From: Miguel Sofer Date: Wed, 30 Jul 2008 17:54:21 +0000 Subject: * generic/tclBasic.c (TclNREvalObjEx): new comments and code reorg to clarify what is happening. --- ChangeLog | 3 + generic/tclBasic.c | 166 ++++++++++++++++++++++++++++------------------------- 2 files changed, 92 insertions(+), 77 deletions(-) diff --git a/ChangeLog b/ChangeLog index 511aef8..9c277fa 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,8 @@ 2008-07-30 Miguel Sofer + * generic/tclBasic.c (TclNREvalObjEx): new comments and code reorg + to clarify what is happening. + * generic/tclBasic.c: guard against the value of iPtr->evalFlags changing between the times where TEOV and TEOV_exception run. Thanks dgp for catching this. diff --git a/generic/tclBasic.c b/generic/tclBasic.c index 028fb1e..fd93641 100644 --- a/generic/tclBasic.c +++ b/generic/tclBasic.c @@ -16,7 +16,7 @@ * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclBasic.c,v 1.337 2008/07/30 17:34:52 msofer Exp $ + * RCS: @(#) $Id: tclBasic.c,v 1.338 2008/07/30 17:54:23 msofer Exp $ */ #include "tclInt.h" @@ -5657,15 +5657,16 @@ TclNREvalObjEx( const CmdFrame *invoker, /* Frame of the command doing the eval. */ int word) /* Index of the word which is in objPtr. */ { - register Interp *iPtr = (Interp *) interp; - char *script; - int numSrcBytes; + Interp *iPtr = (Interp *) interp; int result; - int allowExceptions = (iPtr->evalFlags & TCL_ALLOW_EXCEPTIONS); List *listRepPtr = objPtr->internalRep.twoPtrValue.ptr1; - Tcl_IncrRefCount(objPtr); - + /* + * This function consists of three independent blocks for: direct + * evaluation of canonical lists, compileation and bytecode execution and + * finally direct evaluation. Precisely one of these blocks will be run. + */ + if ((objPtr->typePtr == &tclListType) && /* is a list... */ ((objPtr->bytes == NULL || /* ...without a string rep */ listRepPtr->canonicalFlag))) { /* ...or that is canonical */ @@ -5727,11 +5728,13 @@ TclNREvalObjEx( /* * Shimmer protection! Always pass an unshared obj. The caller could * incr the refCount of objPtr AFTER calling us! To be completely safe - * we always make a copy. + * we always make a copy. The callback takes care od the refCounts for + * both listPtr and objPtr. * * FIXME OPT: preserve just the internal rep? */ + Tcl_IncrRefCount(objPtr); listPtr = TclListObjCopy(interp, objPtr); Tcl_IncrRefCount(listPtr); TclNRAddCallback(interp, TEOEx_ListCallback, objPtr, eoFramePtr, @@ -5749,6 +5752,7 @@ TclNREvalObjEx( * We transfer this to the byte code compiler. */ + int allowExceptions = (iPtr->evalFlags & TCL_ALLOW_EXCEPTIONS); ByteCode *codePtr; CallFrame *savedVarFramePtr = NULL; /* Saves old copy of * iPtr->varFramePtr in case @@ -5758,6 +5762,7 @@ TclNREvalObjEx( savedVarFramePtr = iPtr->varFramePtr; iPtr->varFramePtr = iPtr->rootFramePtr; } + Tcl_IncrRefCount(objPtr); codePtr = TclCompileObj(interp, objPtr, invoker, word); TclNRAddCallback(interp, TEOEx_ByteCodeCallback, savedVarFramePtr, @@ -5766,91 +5771,98 @@ TclNREvalObjEx( return TCL_OK; } - /* - * We're not supposed to use the compiler or byte-code interpreter. Let - * Tcl_EvalEx evaluate the command directly (and probably more slowly). - * - * TIP #280. Propagate context as much as we can. Especially if the script - * to evaluate is a single literal it makes sense to look if our context - * is one with absolute line numbers we can then track into the literal - * itself too. - * - * See also tclCompile.c, TclInitCompileEnv, for the equivalent code in - * the bytecode compiler. - */ - - if (invoker == NULL) { - /* - * No context, force opening of our own. - */ - - script = Tcl_GetStringFromObj(objPtr, &numSrcBytes); - result = Tcl_EvalEx(interp, script, numSrcBytes, flags); - } else { + { /* - * We have an invoker, describing the command asking for the - * evaluation of a subordinate script. This script may originate in a - * literal word, or from a variable, etc. Using the line array we now - * check if we have good line information for the relevant word. The - * type of context is relevant as well. In a non-'source' context we - * don't have to try tracking lines. + * We're not supposed to use the compiler or byte-code + * interpreter. Let Tcl_EvalEx evaluate the command directly (and + * probably more slowly). + * + * TIP #280. Propagate context as much as we can. Especially if the + * script to evaluate is a single literal it makes sense to look if + * our context is one with absolute line numbers we can then track + * into the literal itself too. * - * First see if the word exists and is a literal. If not we go through - * the easy dynamic branch. No need to perform more complex - * invokations. + * See also tclCompile.c, TclInitCompileEnv, for the equivalent code + * in the bytecode compiler. */ - int pc = 0; - CmdFrame *ctxPtr = (CmdFrame *) - TclStackAlloc(interp, sizeof(CmdFrame)); - - *ctxPtr = *invoker; - if (invoker->type == TCL_LOCATION_BC) { - /* - * Note: Type BC => ctxPtr->data.eval.path is not used. - * ctxPtr->data.tebc.codePtr is used instead. - */ - - TclGetSrcInfoForPc(ctxPtr); - pc = 1; - } - - script = Tcl_GetStringFromObj(objPtr, &numSrcBytes); - - if ((invoker->nline <= word) || - (invoker->line[word] < 0) || - (ctxPtr->type != TCL_LOCATION_SOURCE)) { + char *script; + int numSrcBytes; + + Tcl_IncrRefCount(objPtr); + if (invoker == NULL) { /* - * Dynamic script, or dynamic context, force our own context. + * No context, force opening of our own. */ - + + script = Tcl_GetStringFromObj(objPtr, &numSrcBytes); result = Tcl_EvalEx(interp, script, numSrcBytes, flags); - } else { /* - * Absolute context to reuse. + * We have an invoker, describing the command asking for the + * evaluation of a subordinate script. This script may originate in a + * literal word, or from a variable, etc. Using the line array we now + * check if we have good line information for the relevant word. The + * type of context is relevant as well. In a non-'source' context we + * don't have to try tracking lines. + * + * First see if the word exists and is a literal. If not we go through + * the easy dynamic branch. No need to perform more complex + * invokations. */ - - iPtr->invokeCmdFramePtr = ctxPtr; - iPtr->evalFlags |= TCL_EVAL_CTX; - - result = TclEvalEx(interp, script, numSrcBytes, flags, - ctxPtr->line[word]); - - if (pc) { + + int pc = 0; + CmdFrame *ctxPtr = (CmdFrame *) + TclStackAlloc(interp, sizeof(CmdFrame)); + + *ctxPtr = *invoker; + if (invoker->type == TCL_LOCATION_BC) { /* - * Death of SrcInfo reference. + * Note: Type BC => ctxPtr->data.eval.path is not used. + * ctxPtr->data.tebc.codePtr is used instead. */ - - Tcl_DecrRefCount(ctxPtr->data.eval.path); + + TclGetSrcInfoForPc(ctxPtr); + pc = 1; } + + script = Tcl_GetStringFromObj(objPtr, &numSrcBytes); + + if ((invoker->nline <= word) || + (invoker->line[word] < 0) || + (ctxPtr->type != TCL_LOCATION_SOURCE)) { + /* + * Dynamic script, or dynamic context, force our own context. + */ + + result = Tcl_EvalEx(interp, script, numSrcBytes, flags); + + } else { + /* + * Absolute context to reuse. + */ + + iPtr->invokeCmdFramePtr = ctxPtr; + iPtr->evalFlags |= TCL_EVAL_CTX; + + result = TclEvalEx(interp, script, numSrcBytes, flags, + ctxPtr->line[word]); + + if (pc) { + /* + * Death of SrcInfo reference. + */ + + Tcl_DecrRefCount(ctxPtr->data.eval.path); + } + } + TclStackFree(interp, ctxPtr); } - TclStackFree(interp, ctxPtr); + TclDecrRefCount(objPtr); + return result; } - TclDecrRefCount(objPtr); - return result; } - + static int TEOEx_ByteCodeCallback( ClientData data[], -- cgit v0.12