Rework bytecode intialization to serve different callers better.

5 files changed, 72 insertions, 54 deletions

diff --git a/generic/tclAssembly.c b/generic/tclAssembly.c
index 7db5d69..4ad31d2 100644
--- a/generic/tclAssembly.c
+++ b/generic/tclAssembly.c
@@ -891,15 +891,13 @@ CompileAssembleObj(
      */
 
     TclEmitOpcode(INST_DONE, &compEnv);
-    TclInitByteCodeObj(objPtr, &compEnv);
-    objPtr->typePtr = &assembleCodeType;
+    codePtr = TclInitByteCodeObj(objPtr, &assembleCodeType, &compEnv);
     TclFreeCompileEnv(&compEnv);
 
     /*
      * Record the local variable context to which the bytecode pertains
      */
 
-    codePtr = objPtr->internalRep.twoPtrValue.ptr1;
     if (iPtr->varFramePtr->localCachePtr) {
 	codePtr->localCachePtr = iPtr->varFramePtr->localCachePtr;
 	codePtr->localCachePtr->refCount++;
diff --git a/generic/tclCompExpr.c b/generic/tclCompExpr.c
index 4390282..654666a 100644
--- a/generic/tclCompExpr.c
+++ b/generic/tclCompExpr.c
@@ -2181,7 +2181,6 @@ ExecConstantExprTree(
     CompileEnv *envPtr;
     ByteCode *byteCodePtr;
     int code;
-    Tcl_Obj *byteCodeObj = Tcl_NewObj();
     NRE_callback *rootPtr = TOP_CB(interp);
 
     /*
@@ -2195,14 +2194,12 @@ ExecConstantExprTree(
     CompileExprTree(interp, nodes, index, litObjvPtr, NULL, NULL, envPtr,
 	    0 /* optimize */);
     TclEmitOpcode(INST_DONE, envPtr);
-    Tcl_IncrRefCount(byteCodeObj);
-    TclInitByteCodeObj(byteCodeObj, envPtr);
+    byteCodePtr = TclInitByteCode(envPtr);
     TclFreeCompileEnv(envPtr);
     TclStackFree(interp, envPtr);
-    byteCodePtr = byteCodeObj->internalRep.twoPtrValue.ptr1;
     TclNRExecuteByteCode(interp, byteCodePtr);
     code = TclNRRunCallbacks(interp, TCL_OK, rootPtr);
-    Tcl_DecrRefCount(byteCodeObj);
+    TclReleaseByteCode(byteCodePtr);
     return code;
 }
 
diff --git a/generic/tclCompile.c b/generic/tclCompile.c
index 002b551..96b418c 100644
--- a/generic/tclCompile.c
+++ b/generic/tclCompile.c
@@ -677,6 +677,7 @@ static void		FreeSubstCodeInternalRep(Tcl_Obj *objPtr);
 static int		GetCmdLocEncodingSize(CompileEnv *envPtr);
 static int		IsCompactibleCompileEnv(Tcl_Interp *interp,
 			    CompileEnv *envPtr);
+static void		PreventCycle(Tcl_Obj *objPtr, CompileEnv *envPtr);
 #ifdef TCL_COMPILE_STATS
 static void		RecordByteCodeStats(ByteCode *codePtr);
 #endif /* TCL_COMPILE_STATS */
@@ -867,7 +868,7 @@ TclSetByteCodeFromAny(
 #endif /*TCL_COMPILE_DEBUG*/
 
     if (result == TCL_OK) {
-	TclInitByteCodeObj(objPtr, &compEnv);
+	(void) TclInitByteCodeObj(objPtr, &tclByteCodeType, &compEnv);
 #ifdef TCL_COMPILE_DEBUG
 	if (tclTraceCompile >= 2) {
 	    TclPrintByteCodeObj(interp, objPtr);
@@ -1321,11 +1322,9 @@ CompileSubstObj(
 	TclSubstCompile(interp, bytes, numBytes, flags, 1, &compEnv);
 
 	TclEmitOpcode(INST_DONE, &compEnv);
-	TclInitByteCodeObj(objPtr, &compEnv);
-	objPtr->typePtr = &substCodeType;
+	codePtr = TclInitByteCodeObj(objPtr, &substCodeType, &compEnv);
 	TclFreeCompileEnv(&compEnv);
 
-	codePtr = objPtr->internalRep.twoPtrValue.ptr1;
 	objPtr->internalRep.twoPtrValue.ptr1 = codePtr;
 	objPtr->internalRep.twoPtrValue.ptr2 = INT2PTR(flags);
 	if (iPtr->varFramePtr->localCachePtr) {
@@ -2709,11 +2708,40 @@ TclCompileNoOp(
  *----------------------------------------------------------------------
  */
 
-void
-TclInitByteCodeObj(
-    Tcl_Obj *objPtr,		/* Points object that should be initialized,
-				 * and whose string rep contains the source
-				 * code. */
+static void
+PreventCycle(
+    Tcl_Obj *objPtr,
+    CompileEnv *envPtr)
+{
+    int i;
+
+    for (i = 0;  i < envPtr->literalArrayNext; i++) {
+	if (objPtr == TclFetchLiteral(envPtr, i)) {
+	    /*
+	     * Prevent circular reference where the bytecode intrep of
+	     * a value contains a literal which is that same value.
+	     * If this is allowed to happen, refcount decrements may not
+	     * reach zero, and memory may leak.  Bugs 467523, 3357771
+	     *
+	     * NOTE:  [Bugs 3392070, 3389764] We make a copy based completely
+	     * on the string value, and do not call Tcl_DuplicateObj() so we
+             * can be sure we do not have any lingering cycles hiding in
+	     * the intrep.
+	     */
+	    int numBytes;
+	    const char *bytes = Tcl_GetStringFromObj(objPtr, &numBytes);
+	    Tcl_Obj *copyPtr = Tcl_NewStringObj(bytes, numBytes);
+
+	    Tcl_IncrRefCount(copyPtr);
+	    TclReleaseLiteral((Tcl_Interp *)envPtr->iPtr, objPtr);
+
+	    envPtr->literalArrayPtr[i].objPtr = copyPtr;
+	}
+    }
+}
+
+ByteCode *
+TclInitByteCode(
     register CompileEnv *envPtr)/* Points to the CompileEnv structure from
 				 * which to create a ByteCode structure. */
 {
@@ -2791,29 +2819,7 @@ TclInitByteCodeObj(
     p += TCL_ALIGN(codeBytes);		/* align object array */
     codePtr->objArrayPtr = (Tcl_Obj **) p;
     for (i = 0;  i < numLitObjects;  i++) {
-	Tcl_Obj *fetched = TclFetchLiteral(envPtr, i);
-
-	if (objPtr == fetched) {
-	    /*
-	     * Prevent circular reference where the bytecode intrep of
-	     * a value contains a literal which is that same value.
-	     * If this is allowed to happen, refcount decrements may not
-	     * reach zero, and memory may leak.  Bugs 467523, 3357771
-	     *
-	     * NOTE:  [Bugs 3392070, 3389764] We make a copy based completely
-	     * on the string value, and do not call Tcl_DuplicateObj() so we
-             * can be sure we do not have any lingering cycles hiding in
-	     * the intrep.
-	     */
-	    int numBytes;
-	    const char *bytes = Tcl_GetStringFromObj(objPtr, &numBytes);
-
-	    codePtr->objArrayPtr[i] = Tcl_NewStringObj(bytes, numBytes);
-	    Tcl_IncrRefCount(codePtr->objArrayPtr[i]);
-	    TclReleaseLiteral((Tcl_Interp *)iPtr, objPtr);
-	} else {
-	    codePtr->objArrayPtr[i] = fetched;
-	}
+	codePtr->objArrayPtr[i] = TclFetchLiteral(envPtr, i);
     }
 
     p += TCL_ALIGN(objArrayBytes);	/* align exception range array */
@@ -2856,15 +2862,6 @@ TclInitByteCodeObj(
 #endif /* TCL_COMPILE_STATS */
 
     /*
-     * Free the old internal rep then convert the object to a bytecode object
-     * by making its internal rep point to the just compiled ByteCode.
-     */
-
-    TclFreeIntRep(objPtr);
-    objPtr->internalRep.twoPtrValue.ptr1 = codePtr;
-    objPtr->typePtr = &tclByteCodeType;
-
-    /*
      * TIP #280. Associate the extended per-word line information with the
      * byte code object (internal rep), for use with the bc compiler.
      */
@@ -2877,6 +2874,33 @@ TclInitByteCodeObj(
     envPtr->iPtr = NULL;
 
     codePtr->localCachePtr = NULL;
+    return codePtr;
+}
+
+ByteCode *
+TclInitByteCodeObj(
+    Tcl_Obj *objPtr,		/* Points object that should be initialized,
+				 * and whose string rep contains the source
+				 * code. */
+    const Tcl_ObjType *typePtr,
+    register CompileEnv *envPtr)/* Points to the CompileEnv structure from
+				 * which to create a ByteCode structure. */
+{
+    ByteCode *codePtr;
+
+    PreventCycle(objPtr, envPtr);
+
+    codePtr = TclInitByteCode(envPtr);
+
+    /*
+     * Free the old internal rep then convert the object to a bytecode object
+     * by making its internal rep point to the just compiled ByteCode.
+     */
+
+    TclFreeIntRep(objPtr);
+    objPtr->internalRep.twoPtrValue.ptr1 = codePtr;
+    objPtr->typePtr = typePtr;
+    return codePtr;
 }
 
 /*
diff --git a/generic/tclCompile.h b/generic/tclCompile.h
index 86a9db0..f99c07c 100644
--- a/generic/tclCompile.h
+++ b/generic/tclCompile.h
@@ -1118,8 +1118,9 @@ MODULE_SCOPE int	TclFixupForwardJump(CompileEnv *envPtr,
 			    int distThreshold);
 MODULE_SCOPE void	TclFreeCompileEnv(CompileEnv *envPtr);
 MODULE_SCOPE void	TclFreeJumpFixupArray(JumpFixupArray *fixupArrayPtr);
-MODULE_SCOPE void	TclInitByteCodeObj(Tcl_Obj *objPtr,
-			    CompileEnv *envPtr);
+MODULE_SCOPE ByteCode *	TclInitByteCode(CompileEnv *envPtr);
+MODULE_SCOPE ByteCode *	TclInitByteCodeObj(Tcl_Obj *objPtr,
+			    const Tcl_ObjType *typePtr, CompileEnv *envPtr);
 MODULE_SCOPE void	TclInitCompileEnv(Tcl_Interp *interp,
 			    CompileEnv *envPtr, const char *string,
 			    int numBytes, const CmdFrame *invoker, int word);
diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index 2a2b951..cd28a92 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -1565,10 +1565,8 @@ CompileExprObj(
 	 */
 
 	TclEmitOpcode(INST_DONE, &compEnv);
-	TclInitByteCodeObj(objPtr, &compEnv);
-	objPtr->typePtr = &exprCodeType;
+	codePtr = TclInitByteCodeObj(objPtr, &exprCodeType, &compEnv);
 	TclFreeCompileEnv(&compEnv);
-	codePtr = objPtr->internalRep.twoPtrValue.ptr1;
 	if (iPtr->varFramePtr->localCachePtr) {
 	    codePtr->localCachePtr = iPtr->varFramePtr->localCachePtr;
 	    codePtr->localCachePtr->refCount++;