diff options
Diffstat (limited to 'generic/tclCompCmds.c')
-rw-r--r-- | generic/tclCompCmds.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/generic/tclCompCmds.c b/generic/tclCompCmds.c index 79b2709..5c21a2f 100644 --- a/generic/tclCompCmds.c +++ b/generic/tclCompCmds.c @@ -2514,6 +2514,225 @@ PrintForeachInfo( * * TclCompileGlobalCmd -- * + * Procedure called to compile the "format" 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 "format" command at + * runtime. + * + *---------------------------------------------------------------------- + */ + +int +TclCompileFormatCmd( + 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. */ +{ + DefineLineInformation; /* TIP #280 */ + Tcl_Token *tokenPtr = parsePtr->tokenPtr; + Tcl_Obj **objv, *formatObj, *tmpObj; + char *bytes, *start; + int i, j, len; + + /* + * Don't handle any guaranteed-error cases. + */ + + if (parsePtr->numWords < 2) { + return TCL_ERROR; + } + + /* + * Check if the argument words are all compile-time-known literals; that's + * a case we can handle by compiling to a constant. + */ + + formatObj = Tcl_NewObj(); + Tcl_IncrRefCount(formatObj); + tokenPtr = TokenAfter(tokenPtr); + if (!TclWordKnownAtCompileTime(tokenPtr, formatObj)) { + Tcl_DecrRefCount(formatObj); + return TCL_ERROR; + } + + objv = ckalloc((parsePtr->numWords-2) * sizeof(Tcl_Obj *)); + for (i=0 ; i+2 < parsePtr->numWords ; i++) { + tokenPtr = TokenAfter(tokenPtr); + objv[i] = Tcl_NewObj(); + Tcl_IncrRefCount(objv[i]); + if (!TclWordKnownAtCompileTime(tokenPtr, objv[i])) { + goto checkForStringConcatCase; + } + } + + /* + * Everything is a literal, so the result is constant too (or an error if + * the format is broken). Do the format now. + */ + + tmpObj = Tcl_Format(interp, Tcl_GetString(formatObj), + parsePtr->numWords-2, objv); + for (; --i>=0 ;) { + Tcl_DecrRefCount(objv[i]); + } + ckfree(objv); + Tcl_DecrRefCount(formatObj); + if (tmpObj == NULL) { + return TCL_ERROR; + } + + /* + * Not an error, always a constant result, so just push the result as a + * literal. Job done. + */ + + bytes = Tcl_GetStringFromObj(tmpObj, &len); + PushLiteral(envPtr, bytes, len); + Tcl_DecrRefCount(tmpObj); + return TCL_OK; + + checkForStringConcatCase: + /* + * See if we can generate a sequence of things to concatenate. This + * requires that all the % sequences be %s or %%, as everything else is + * sufficiently complex that we don't bother. + * + * First, get the state of the system relatively sensible (cleaning up + * after our attempt to spot a literal). + */ + + for (; --i>=0 ;) { + Tcl_DecrRefCount(objv[i]); + } + ckfree(objv); + tokenPtr = TokenAfter(parsePtr->tokenPtr); + tokenPtr = TokenAfter(tokenPtr); + i = 0; + + /* + * Now scan through and check for non-%s and non-%% substitutions. + */ + + for (bytes = Tcl_GetString(formatObj) ; *bytes ; bytes++) { + if (*bytes == '%') { + bytes++; + if (*bytes == 's') { + i++; + continue; + } else if (*bytes == '%') { + continue; + } + Tcl_DecrRefCount(formatObj); + return TCL_ERROR; + } + } + + /* + * Check if the number of things to concatenate will fit in a byte. + */ + + if (i+2 != parsePtr->numWords || i > 125) { + Tcl_DecrRefCount(formatObj); + return TCL_ERROR; + } + + /* + * Generate the pushes of the things to concatenate, a sequence of + * literals and compiled tokens (of which at least one is non-literal or + * we'd have the case in the first half of this function) which we will + * concatenate. + */ + + i = 0; /* The count of things to concat. */ + j = 2; /* The index into the argument tokens, for + * TIP#280 handling. */ + start = Tcl_GetString(formatObj); + /* The start of the currently-scanned literal + * in the format string. */ + tmpObj = Tcl_NewObj(); /* The buffer used to accumulate the literal + * being built. */ + for (bytes = start ; *bytes ; bytes++) { + if (*bytes == '%') { + Tcl_AppendToObj(tmpObj, start, bytes - start); + if (*++bytes == '%') { + Tcl_AppendToObj(tmpObj, "%", 1); + } else { + char *b = Tcl_GetStringFromObj(tmpObj, &len); + + /* + * If there is a non-empty literal from the format string, + * push it and reset. + */ + + if (len > 0) { + PushLiteral(envPtr, b, len); + Tcl_DecrRefCount(tmpObj); + tmpObj = Tcl_NewObj(); + i++; + } + + /* + * Push the code to produce the string that would be + * substituted with %s, except we'll be concatenating + * directly. + */ + + CompileWord(envPtr, tokenPtr, interp, j); + tokenPtr = TokenAfter(tokenPtr); + j++; + i++; + } + start = bytes + 1; + } + } + + /* + * Handle the case of a trailing literal. + */ + + Tcl_AppendToObj(tmpObj, start, bytes - start); + bytes = Tcl_GetStringFromObj(tmpObj, &len); + if (len > 0) { + PushLiteral(envPtr, bytes, len); + i++; + } + Tcl_DecrRefCount(tmpObj); + Tcl_DecrRefCount(formatObj); + + if (i > 1) { + /* + * Do the concatenation, which produces the result. + */ + + TclEmitInstInt1(INST_CONCAT1, i, envPtr); + } else { + /* + * EVIL HACK! Force there to be a string representation in the case + * where there's just a "%s" in the format; case covered by the test + * format-20.1 (and it is horrible...) + */ + + TclEmitOpcode(INST_DUP, envPtr); + PushLiteral(envPtr, "", 0); + TclEmitOpcode(INST_STR_EQ, envPtr); + TclEmitOpcode(INST_POP, envPtr); + } + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * TclCompileGlobalCmd -- + * * Procedure called to compile the "global" command. * * Results: |