diff options
| -rw-r--r-- | generic/tclAssembly.c | 9 | ||||
| -rw-r--r-- | generic/tclCompCmdsGR.c | 116 | ||||
| -rw-r--r-- | generic/tclCompCmdsSZ.c | 43 | ||||
| -rw-r--r-- | generic/tclCompile.h | 4 |
4 files changed, 99 insertions, 73 deletions
diff --git a/generic/tclAssembly.c b/generic/tclAssembly.c index 02c64bd..a3fac8f 100644 --- a/generic/tclAssembly.c +++ b/generic/tclAssembly.c @@ -2258,8 +2258,13 @@ GetListIndexOperand( Tcl_DecrRefCount(value); /* Convert to an integer, advance to the next token and return. */ - status = TclGetIndexFromToken(tokenPtr, result, TCL_INDEX_OUT_OF_RANGE, - TCL_INDEX_OUT_OF_RANGE); + /* + * NOTE: Indexing a list with an index before it yields the + * same result as indexing after it, and might be more easily portable + * when list size limits grow. + */ + status = TclGetIndexFromToken(tokenPtr, result, TCL_INDEX_BEFORE, + TCL_INDEX_BEFORE); *tokenPtrPtr = TokenAfter(tokenPtr); if (status == TCL_ERROR && interp) { Tcl_SetObjResult(interp, Tcl_ObjPrintf("bad index \"%.*s\"", diff --git a/generic/tclCompCmdsGR.c b/generic/tclCompCmdsGR.c index 8585bce..501c7a4 100644 --- a/generic/tclCompCmdsGR.c +++ b/generic/tclCompCmdsGR.c @@ -42,18 +42,21 @@ static int IndexTailVarIfKnown(Tcl_Interp *interp, * arithmetic expressions that can be fully computed at compile * time. The absolute index values that can be directly meaningful * as an index into either a list or a string are those integer - * values >= 0 and < INT_MAX. The largest string supported in Tcl 8 - * has bytelength INT_MAX. This means the largest character supported - * length is also INT_MAX, and the index of the last character in a - * string of length INT_MAX is INT_MAX-1. + * values >= TCL_INDEX_START (0) and < TCL_INDEX_AFTER (INT_MAX). + * The largest string supported in Tcl 8 has bytelength INT_MAX. + * This means the largest character supported length is also INT_MAX, + * and the index of the last character in a string of length INT_MAX + * is INT_MAX-1. * * Any absolute index value parsed outside that range is encoded * using the minBoundary and maxBounday values passed in by the * caller as the encoding to use for indices that are either - * less than or greater than the usable index range. INT_MAX + * less than or greater than the usable index range. TCL_INDEX_AFTER * is available as a good choice for most callers to use for - * maxBoundary. Likewise, the value -1 is good for most callers - * to use for minBoundary. + * maxBoundary. Likewise, the value TCL_INDEX_BEFORE is good for + * most callers to use for minBoundary. Other values are possible + * when the caller knows it is helpful in producing its own behavior + * for indices before and after the indexed item. * * A token can also be parsed as an end-relative index expression. * All end-relative expressions that indicate an index larger @@ -101,7 +104,7 @@ TclGetIndexFromToken( if (result == TCL_OK) { /* We parsed a value in the range INT_MIN...INT_MAX */ integerEncode: - if (idx < 0) { + if (idx < TCL_INDEX_START) { /* All negative absolute indices are "before the beginning" */ idx = minBoundary; } else if (idx == INT_MAX) { @@ -123,7 +126,7 @@ TclGetIndexFromToken( */ idx = maxBoundary; } else if (idx < INT_MIN - TCL_INDEX_END) { - /* These indices alwasy indicate "before the beginning */ + /* These indices always indicate "before the beginning */ idx = minBoundary; } else { /* Encoded end-positive (or end+negative) are offset */ @@ -214,7 +217,7 @@ TclCompileGlobalCmd( return TCL_ERROR; } - /* TODO: Consider what value can pass throug the + /* TODO: Consider what value can pass through the * IndexTailVarIfKnown() screen. Full CompileWord() * likely does not apply here. Push known value instead. */ CompileWord(envPtr, varTokenPtr, interp, i); @@ -1174,15 +1177,14 @@ TclCompileLindexCmd( } idxTokenPtr = TokenAfter(valTokenPtr); - if (TclGetIndexFromToken(idxTokenPtr, &idx, - TCL_INDEX_OUT_OF_RANGE, TCL_INDEX_OUT_OF_RANGE) == TCL_OK) { + if (TclGetIndexFromToken(idxTokenPtr, &idx, TCL_INDEX_BEFORE, + TCL_INDEX_BEFORE) == TCL_OK) { /* - * All checks have been completed, and we have exactly one of these - * constructs: - * lindex <arbitraryValue> <posInt> - * lindex <arbitraryValue> end-<posInt> - * This is best compiled as a push of the arbitrary value followed by - * an "immediate lindex" which is the most efficient variety. + * The idxTokenPtr parsed as a valid index value and was + * encoded as expected by INST_LIST_INDEX_IMM. + * + * NOTE: that we rely on indexing before a list producing the + * same result as indexing after a list. */ CompileWord(envPtr, valTokenPtr, interp, 1); @@ -1403,24 +1405,25 @@ TclCompileLrangeCmd( } listTokenPtr = TokenAfter(parsePtr->tokenPtr); - /* - * Parse the indices. Will only compile if both are constants and not an - * _integer_ less than zero (since we reserve negative indices here for - * end-relative indexing) or an end-based index greater than 'end' itself. - */ - tokenPtr = TokenAfter(listTokenPtr); - if (TclGetIndexFromToken(tokenPtr, &idx1, -1, INT_MAX) != TCL_OK) { + if (TclGetIndexFromToken(tokenPtr, &idx1, TCL_INDEX_START, + TCL_INDEX_AFTER) != TCL_OK) { return TCL_ERROR; } + /* + * Token was an index value, and we treat all "first" indices + * before the list same as the start of the list. + */ tokenPtr = TokenAfter(tokenPtr); - if (TclGetIndexFromToken(tokenPtr, &idx2, -1, INT_MAX) != TCL_OK) { + if (TclGetIndexFromToken(tokenPtr, &idx2, TCL_INDEX_BEFORE, + TCL_INDEX_END) != TCL_OK) { return TCL_ERROR; } - if (idx1 == INT_MAX && idx2 == INT_MAX) { - idx2 = TCL_INDEX_OUT_OF_RANGE; - } + /* + * Token was an index value, and we treat all "last" indices + * after the list same as the end of the list. + */ /* * Issue instructions. It's not safe to skip doing the LIST_RANGE, as @@ -1470,7 +1473,16 @@ TclCompileLinsertCmd( */ tokenPtr = TokenAfter(listTokenPtr); - if (TclGetIndexFromToken(tokenPtr, &idx, 0, INT_MAX) != TCL_OK) { + + /* + * NOTE: This command treats all inserts at indices before the list + * the same as inserts at the start of the list, and all inserts + * after the list the same as inserts at the end of the list. We + * make that transformation here so we can use the optimized bytecode + * as much as possible. + */ + if (TclGetIndexFromToken(tokenPtr, &idx, TCL_INDEX_START, + TCL_INDEX_END) != TCL_OK) { return TCL_ERROR; } @@ -1494,10 +1506,10 @@ TclCompileLinsertCmd( } TclEmitInstInt4( INST_LIST, i-3, envPtr); - if (idx == 0 /*start*/) { + if (idx == TCL_INDEX_START) { TclEmitInstInt4( INST_REVERSE, 2, envPtr); TclEmitOpcode( INST_LIST_CONCAT, envPtr); - } else if (idx == TCL_INDEX_END /*end*/) { + } else if (idx == TCL_INDEX_END) { TclEmitOpcode( INST_LIST_CONCAT, envPtr); } else { /* @@ -1558,42 +1570,42 @@ TclCompileLreplaceCmd( } listTokenPtr = TokenAfter(parsePtr->tokenPtr); - /* - * Parse the indices. Will only compile if both are constants and not an - * _integer_ less than zero (since we reserve negative indices here for - * end-relative indexing) or an end-based index greater than 'end' itself. - */ - tokenPtr = TokenAfter(listTokenPtr); - if (TclGetIndexFromToken(tokenPtr, &idx1, -1, INT_MAX) != TCL_OK) { + if (TclGetIndexFromToken(tokenPtr, &idx1, TCL_INDEX_START, + TCL_INDEX_AFTER) != TCL_OK) { return TCL_ERROR; } tokenPtr = TokenAfter(tokenPtr); - if (TclGetIndexFromToken(tokenPtr, &idx2, -1, TCL_INDEX_END) != TCL_OK) { + if (TclGetIndexFromToken(tokenPtr, &idx2, TCL_INDEX_BEFORE, + TCL_INDEX_END) != TCL_OK) { return TCL_ERROR; } /* - * idx1, idx2 are now in canonical form: - * - * - integer: [0,len+1] - * - end index: TCL_INDEX_END - * - -ive offset: TCL_INDEX_END-[len-1,0] + * idx1, idx2 are the conventional encoded forms of the tokens parsed + * as all forms of index values. Values of idx1 that come before the + * list are treated the same as if they were the start of the list. + * Values of idx2 that come after the list are treated the same as if + * they were the end of the list. */ + if (idx1 == TCL_INDEX_AFTER) { + /* + * [lreplace] treats idx1 value end+1 differently from end+2, etc. + * The operand encoding cannot distinguish them, so we must bail + * out to direct evaluation. + */ + return TCL_ERROR; + } + +/* TODO: ...... */ /* * Compilation fails when one index is end-based but the other isn't. * Fixing this will require more bytecodes, but this is a workaround for * now. [Bug 47ac84309b] */ - if (idx1 == INT_MAX) { - /* consider special handling for too large first index - * "list doesn't contain element ...", so still not compiled */ - return TCL_ERROR; - } - if ((idx1 <= TCL_INDEX_END) != (idx2 <= TCL_INDEX_END)) { /* @@ -3049,7 +3061,7 @@ TclCompileVariableCmd( return TCL_ERROR; } - /* TODO: Consider what value can pass throug the + /* TODO: Consider what value can pass through the * IndexTailVarIfKnown() screen. Full CompileWord() * likely does not apply here. Push known value instead. */ CompileWord(envPtr, varTokenPtr, interp, i); diff --git a/generic/tclCompCmdsSZ.c b/generic/tclCompCmdsSZ.c index bf8c482..d10d1c1 100644 --- a/generic/tclCompCmdsSZ.c +++ b/generic/tclCompCmdsSZ.c @@ -934,15 +934,22 @@ TclCompileStringRangeCmd( * Parse the two indices. */ - if (TclGetIndexFromToken(fromTokenPtr, &idx1, -1, INT_MAX) != TCL_OK) { + if (TclGetIndexFromToken(fromTokenPtr, &idx1, TCL_INDEX_START, + TCL_INDEX_AFTER) != TCL_OK) { goto nonConstantIndices; } - if (TclGetIndexFromToken(toTokenPtr, &idx2, -1, INT_MAX) != TCL_OK) { + /* + * Token parsed as an index expression. We treat all indices before + * the string the same as the start of the string. + */ + if (TclGetIndexFromToken(toTokenPtr, &idx2, TCL_INDEX_BEFORE, + TCL_INDEX_END) != TCL_OK) { goto nonConstantIndices; } - if (idx1 == INT_MAX && idx2 == INT_MAX) { - idx2 = TCL_INDEX_OUT_OF_RANGE; - } + /* + * Token parsed as an index expression. We treat all indices after + * the string the same as the end of the string. + */ /* * Push the operand onto the stack and then the substring operation. @@ -987,27 +994,27 @@ TclCompileStringReplaceCmd( replacementTokenPtr = TokenAfter(tokenPtr); } - /* - * Parse the indices. Will only compile special cases if both are - * constants and not an _integer_ less than zero (since we reserve - * negative indices here for end-relative indexing) or an end-based index - * greater than 'end' itself. - */ - tokenPtr = TokenAfter(valueTokenPtr); - if (TclGetIndexFromToken(tokenPtr, &idx1, -1, INT_MAX) != TCL_OK) { + if (TclGetIndexFromToken(tokenPtr, &idx1, TCL_INDEX_START, + TCL_INDEX_AFTER) != TCL_OK) { goto genericReplace; } + /* + * Token parsed as an index value. Indices before the string are + * treated as index of start of string. + */ tokenPtr = TokenAfter(tokenPtr); - if (TclGetIndexFromToken(tokenPtr, &idx2, -1, INT_MAX) != TCL_OK) { - goto genericReplace; - } - if (idx1 == INT_MAX && idx2 == INT_MAX) { - /* avoid replacement of last char in large string (just don't compile). */ + if (TclGetIndexFromToken(tokenPtr, &idx2, TCL_INDEX_BEFORE, + TCL_INDEX_END) != TCL_OK) { goto genericReplace; } + /* + * Token parsed as an index value. Indices after the string are + * treated as index of end of string. + */ +/* TODO...... */ /* * We handle these replacements specially: first character (where * idx1=idx2=0) and last character (where idx1=idx2=TCL_INDEX_END). Anything diff --git a/generic/tclCompile.h b/generic/tclCompile.h index 2f23b90..9501d93 100644 --- a/generic/tclCompile.h +++ b/generic/tclCompile.h @@ -1690,7 +1690,9 @@ MODULE_SCOPE int TclPushProcCallFrame(ClientData clientData, */ #define TCL_INDEX_END (-2) -#define TCL_INDEX_OUT_OF_RANGE (-1) +#define TCL_INDEX_BEFORE (-1) +#define TCL_INDEX_START (0) +#define TCL_INDEX_AFTER (INT_MAX) /* * DTrace probe macros (NOPs if DTrace support is not enabled). |