Avoid sharing cmdName literals accross namespaces, and generalise usage of

the TclRegisterNewLiteral macro [Patch 1090905]

6 files changed, 74 insertions, 37 deletions

diff --git a/generic/tclCompile.c b/generic/tclCompile.c
index 243cc14..f732f36 100644
--- a/generic/tclCompile.c
+++ b/generic/tclCompile.c
@@ -11,7 +11,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclCompile.c,v 1.80 2004/12/20 18:27:18 msofer Exp $
+ * RCS: @(#) $Id: tclCompile.c,v 1.81 2004/12/24 18:06:56 msofer Exp $
  */
 
 #include "tclInt.h"
@@ -1146,10 +1146,11 @@ TclCompileScript(interp, script, numBytes, envPtr)
 			/*
 			 * No compile procedure so push the word. If the
 			 * command was found, push a CmdName object to
-			 * reduce runtime lookups.
+			 * reduce runtime lookups. Avoid sharing this literal
+			 * among different namespaces to reduce shimmering.
 			 */
 
-			objIndex = TclRegisterNewLiteral(envPtr,
+			objIndex = TclRegisterNewNSLiteral(envPtr,
 				tokenPtr[1].start, tokenPtr[1].size);
 			if (cmdPtr != NULL) {
 			    TclSetCmdNameObj(interp,
@@ -1318,9 +1319,9 @@ TclCompileTokens(interp, tokenPtr, count, envPtr)
 		if (Tcl_DStringLength(&textBuffer) > 0) {
 		    int literal;
 		    
-		    literal = TclRegisterLiteral(envPtr,
+		    literal = TclRegisterNewLiteral(envPtr,
 			    Tcl_DStringValue(&textBuffer),
-			    Tcl_DStringLength(&textBuffer), /*onHeap*/ 0);
+			    Tcl_DStringLength(&textBuffer));
 		    TclEmitPush(literal, envPtr);
 		    numObjsToConcat++;
 		    Tcl_DStringFree(&textBuffer);
@@ -1339,9 +1340,9 @@ TclCompileTokens(interp, tokenPtr, count, envPtr)
 		if (Tcl_DStringLength(&textBuffer) > 0) {
 		    int literal;
 		    
-		    literal = TclRegisterLiteral(envPtr,
+		    literal = TclRegisterNewLiteral(envPtr,
 			    Tcl_DStringValue(&textBuffer),
-			    Tcl_DStringLength(&textBuffer), /*onHeap*/ 0);
+			    Tcl_DStringLength(&textBuffer));
 		    TclEmitPush(literal, envPtr);
 		    numObjsToConcat++;
 		    Tcl_DStringFree(&textBuffer);
@@ -1433,8 +1434,8 @@ TclCompileTokens(interp, tokenPtr, count, envPtr)
     if (Tcl_DStringLength(&textBuffer) > 0) {
 	int literal;
 
-	literal = TclRegisterLiteral(envPtr, Tcl_DStringValue(&textBuffer),
-	        Tcl_DStringLength(&textBuffer), /*onHeap*/ 0);
+	literal = TclRegisterNewLiteral(envPtr, Tcl_DStringValue(&textBuffer),
+	        Tcl_DStringLength(&textBuffer));
 	TclEmitPush(literal, envPtr);
 	numObjsToConcat++;
     }
@@ -1456,7 +1457,7 @@ TclCompileTokens(interp, tokenPtr, count, envPtr)
      */
     
     if (envPtr->codeNext == entryCodeNext) {
-	TclEmitPush(TclRegisterLiteral(envPtr, "", 0, /*onHeap*/ 0),
+	TclEmitPush(TclRegisterNewLiteral(envPtr, "", 0),
 	        envPtr);
     }
     Tcl_DStringFree(&textBuffer);
@@ -1573,7 +1574,7 @@ TclCompileExprWords(interp, tokenPtr, numWords, envPtr)
     for (i = 0;  i < numWords;  i++) {
 	TclCompileTokens(interp, wordPtr+1, wordPtr->numComponents, envPtr);
 	if (i < (numWords - 1)) {
-	    TclEmitPush(TclRegisterLiteral(envPtr, " ", 1, /*onHeap*/ 0),
+	    TclEmitPush(TclRegisterNewLiteral(envPtr, " ", 1),
 	            envPtr);
 	}
 	wordPtr += (wordPtr->numComponents + 1);
diff --git a/generic/tclCompile.h b/generic/tclCompile.h
index a50409b..ae4c39c 100644
--- a/generic/tclCompile.h
+++ b/generic/tclCompile.h
@@ -8,7 +8,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclCompile.h,v 1.52 2004/12/10 13:09:14 msofer Exp $
+ * RCS: @(#) $Id: tclCompile.h,v 1.53 2004/12/24 18:06:58 msofer Exp $
  */
 
 #ifndef _TCLCOMPILATION
@@ -842,7 +842,7 @@ MODULE_SCOPE void	TclPrintSource _ANSI_ARGS_((FILE *outFile,
 			    CONST char *string, int maxChars));
 MODULE_SCOPE void	TclRegisterAuxDataType _ANSI_ARGS_((AuxDataType *typePtr));
 MODULE_SCOPE int	TclRegisterLiteral _ANSI_ARGS_((CompileEnv *envPtr,
-			    char *bytes, int length, int onHeap));
+			    char *bytes, int length, int flags));
 MODULE_SCOPE void	TclReleaseLiteral _ANSI_ARGS_((Tcl_Interp *interp,
 			    Tcl_Obj *objPtr));
 MODULE_SCOPE void	TclSetCmdNameObj _ANSI_ARGS_((Tcl_Interp *interp,
@@ -860,11 +860,13 @@ MODULE_SCOPE int	TclWordKnownAtCompileTime _ANSI_ARGS_((
 
 /*
  *----------------------------------------------------------------
- * Macros used by Tcl bytecode compilation and execution modules
- * inside the Tcl core but not used outside.
+ * Macros and flag values used by Tcl bytecode compilation and execution
+ * modules inside the Tcl core but not used outside.
  *----------------------------------------------------------------
  */
 
+#define LITERAL_ON_HEAP    0x01
+#define LITERAL_NS_SCOPE   0x02
 /*
  * Form of TclRegisterLiteral with onHeap == 0.
  * In that case, it is safe to cast away CONSTness, and it
@@ -872,7 +874,19 @@ MODULE_SCOPE int	TclWordKnownAtCompileTime _ANSI_ARGS_((
  */
 
 #define TclRegisterNewLiteral(envPtr, bytes, length) \
-	TclRegisterLiteral(envPtr, (char *)(bytes), length, /*onHeap*/ 0)
+	TclRegisterLiteral(envPtr, (char *)(bytes), length, \
+                /*flags*/ 0)
+
+/*
+ * Form of TclRegisterNSLiteral with onHeap == 0.
+ * In that case, it is safe to cast away CONSTness, and it
+ * is cleanest to do that here, all in one place.
+ */
+
+#define TclRegisterNewNSLiteral(envPtr, bytes, length) \
+	TclRegisterLiteral(envPtr, (char *)(bytes), length, \
+                /*flags*/ LITERAL_NS_SCOPE)
+
 
 /*
  * Macro used to manually adjust the stack requirements; used
diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index afbb4aa..a2b608c 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -11,7 +11,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclExecute.c,v 1.168 2004/12/15 20:44:36 msofer Exp $
+ * RCS: @(#) $Id: tclExecute.c,v 1.169 2004/12/24 18:06:58 msofer Exp $
  */
 
 #include "tclInt.h"
@@ -885,7 +885,7 @@ Tcl_ExprObj(interp, objPtr, resultPtrPtr)
 	 */
 	    
 	if (compEnv.codeNext == compEnv.codeStart) {
-	    TclEmitPush(TclRegisterLiteral(&compEnv, "0", 1, /*onHeap*/ 0),
+	    TclEmitPush(TclRegisterNewLiteral(&compEnv, "0", 1),
 		    &compEnv);
 	}
 
diff --git a/generic/tclInt.h b/generic/tclInt.h
index 5f10b46..0bd71f0 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -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: tclInt.h,v 1.208 2004/12/16 19:36:34 dkf Exp $
+ * RCS: @(#) $Id: tclInt.h,v 1.209 2004/12/24 18:07:00 msofer Exp $
  */
 
 #ifndef _TCLINT
@@ -973,6 +973,11 @@ typedef struct LiteralEntry {
 					 * entry can be freed when refCount
 					 * drops to 0. If in a local literal
 					 * table, -1. */
+    Namespace *nsPtr;                    /* Namespace in which this literal is
+					 * used. We try to avoid sharing
+					 * literal non-FQ command names among
+					 * different namespaces to reduce
+					 * shimmering.*/ 
 } LiteralEntry;
 
 typedef struct LiteralTable {
diff --git a/generic/tclLiteral.c b/generic/tclLiteral.c
index f5af52d..3f9f079 100644
--- a/generic/tclLiteral.c
+++ b/generic/tclLiteral.c
@@ -13,7 +13,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclLiteral.c,v 1.20 2004/08/02 15:33:36 dgp Exp $
+ * RCS: @(#) $Id: tclLiteral.c,v 1.21 2004/12/24 18:07:01 msofer Exp $
  */
 
 #include "tclInt.h"
@@ -238,17 +238,17 @@ TclDeleteLiteralTable(interp, tablePtr)
  *	in the global table. We then add a reference to the shared
  *	literal in the CompileEnv's literal array. 
  *
- *	If onHeap is 1, this procedure is given ownership of the string: if
- *	an object is created then its string representation is set directly
- *	from string, otherwise the string is freed. Typically, a caller sets
- *	onHeap 1 if "string" is an already heap-allocated buffer holding the
- *	result of backslash substitutions.
+ *	If LITERAL_ON_HEAP is set in flags, this procedure is given ownership
+ *	of the string: if an object is created then its string representation
+ *	is set directly from string, otherwise the string is freed. Typically,
+ *	a caller sets LITERAL_ON_HEAP if "string" is an already heap-allocated
+ *	buffer holding the result of backslash substitutions.
  *
  *----------------------------------------------------------------------
  */
 
 int
-TclRegisterLiteral(envPtr, bytes, length, onHeap)
+TclRegisterLiteral(envPtr, bytes, length, flags)
     CompileEnv *envPtr;		/* Points to the CompileEnv in whose object
 				 * array an object is found or created. */
     register char *bytes;	/* Points to string for which to find or
@@ -257,9 +257,11 @@ TclRegisterLiteral(envPtr, bytes, length, onHeap)
     int length;			/* Number of bytes in the string. If < 0,
 				 * the string consists of all bytes up to
 				 * the first null character. */
-    int onHeap;			/* If 1 then the caller already malloc'd
-				 * bytes and ownership is passed to this
-				 * procedure. */
+    int flags;			/* If LITERAL_ON_HEAP then the caller already
+				 * malloc'd bytes and ownership is passed to
+				 * this procedure. If LITERAL_NS_SCOPE then
+				 * the literal shouldnot be shared accross
+				 * namespaces. */
 {
     Interp *iPtr = envPtr->iPtr;
     LiteralTable *globalTablePtr = &(iPtr->literalTable);
@@ -270,6 +272,7 @@ TclRegisterLiteral(envPtr, bytes, length, onHeap)
     int localHash, globalHash, objIndex;
     long n;
     char buf[TCL_INTEGER_SPACE];
+    Namespace *nsPtr;
 
     if (length < 0) {
 	length = (bytes? strlen(bytes) : 0);
@@ -289,7 +292,7 @@ TclRegisterLiteral(envPtr, bytes, length, onHeap)
 		|| ((objPtr->bytes[0] == bytes[0])
 			&& (memcmp(objPtr->bytes, bytes, (unsigned) length)
 				== 0)))) {
-	    if (onHeap) {
+	    if (flags & LITERAL_ON_HEAP) {
 		ckfree(bytes);
 	    }
 	    objIndex = (localPtr - envPtr->literalArrayPtr);
@@ -302,15 +305,28 @@ TclRegisterLiteral(envPtr, bytes, length, onHeap)
     }
 
     /*
-     * The literal is new to this CompileEnv. Is it in the interpreter's
-     * global literal table?
+     * The literal is new to this CompileEnv. Should it be shared accross
+     * namespaces? If it is a fully qualified name, the namespace
+     * specification is not needed to avoid sharing.
+     */
+
+    if ((flags & LITERAL_NS_SCOPE) && iPtr->varFramePtr
+	    && ((length <2) || (bytes[0] != ':') || (bytes[1] != ':'))) {
+	nsPtr = iPtr->varFramePtr->nsPtr;
+    } else {
+	nsPtr = NULL;
+    }
+
+    /*
+     * Is it in the interpreter's global literal table?
      */
 
     globalHash = (hash & globalTablePtr->mask);
     for (globalPtr = globalTablePtr->buckets[globalHash];
 	 globalPtr != NULL;  globalPtr = globalPtr->nextPtr) {
 	objPtr = globalPtr->objPtr;
-	if ((objPtr->length == length) && ((length == 0)
+	if ((globalPtr->nsPtr == nsPtr)
+		&& (objPtr->length == length) && ((length == 0)
 		|| ((objPtr->bytes[0] == bytes[0])
 			&& (memcmp(objPtr->bytes, bytes, (unsigned) length)
 				== 0)))) {
@@ -319,7 +335,7 @@ TclRegisterLiteral(envPtr, bytes, length, onHeap)
 	     * local literal array.
 	     */
 	    
-	    if (onHeap) {
+	    if (flags & LITERAL_ON_HEAP) {
 		ckfree(bytes);
 	    }
 	    objIndex = AddLocalLiteralEntry(envPtr, globalPtr, localHash);
@@ -343,7 +359,7 @@ TclRegisterLiteral(envPtr, bytes, length, onHeap)
 
     TclNewObj(objPtr);
     Tcl_IncrRefCount(objPtr);
-    if (onHeap) {
+    if (flags & LITERAL_ON_HEAP) {
 	objPtr->bytes = bytes;
 	objPtr->length = length;
     } else {
@@ -373,6 +389,7 @@ TclRegisterLiteral(envPtr, bytes, length, onHeap)
     globalPtr = (LiteralEntry *) ckalloc((unsigned) sizeof(LiteralEntry));
     globalPtr->objPtr = objPtr;
     globalPtr->refCount = 0;
+    globalPtr->nsPtr = nsPtr;
     globalPtr->nextPtr = globalTablePtr->buckets[globalHash];
     globalTablePtr->buckets[globalHash] = globalPtr;
     globalTablePtr->numEntries++;
diff --git a/generic/tclProc.c b/generic/tclProc.c
index 89434b3..54e1572 100644
--- a/generic/tclProc.c
+++ b/generic/tclProc.c
@@ -10,7 +10,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclProc.c,v 1.71 2004/12/20 21:20:06 msofer Exp $
+ * RCS: @(#) $Id: tclProc.c,v 1.72 2004/12/24 18:07:01 msofer Exp $
  */
 
 #include "tclInt.h"
@@ -1837,6 +1837,6 @@ TclCompileNoOp(interp, parsePtr, envPtr)
 	} 
     }
     envPtr->currStackDepth = savedStackDepth;
-    TclEmitPush(TclRegisterLiteral(envPtr, "", 0, /*onHeap*/ 0), envPtr);
+    TclEmitPush(TclRegisterNewLiteral(envPtr, "", 0), envPtr);
     return TCL_OK;
 }