1 files changed, 89 insertions, 2 deletions
diff --git a/generic/tclCompCmds.c b/generic/tclCompCmds.c
index 3d5bfe0..d1d7a80 100644
--- a/generic/tclCompCmds.c
+++ b/generic/tclCompCmds.c
@@ -690,6 +690,93 @@ TclCompileCatchCmd(
 /*
  *----------------------------------------------------------------------
  *
+ * TclCompileConcatCmd --
+ *
+ *	Procedure called to compile the "concat" 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 "concat" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileConcatCmd(
+    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_Obj *objPtr, *listObj;
+    Tcl_Token *tokenPtr;
+    int i;
+
+    /* TODO: Consider compiling expansion case. */
+    if (parsePtr->numWords == 1) {
+	/*
+	 * [concat] without arguments just pushes an empty object.
+	 */
+
+	PushStringLiteral(envPtr, "");
+	return TCL_OK;
+    }
+
+    /*
+     * Test if all arguments are compile-time known. If they are, we can
+     * implement with a simple push.
+     */
+
+    listObj = Tcl_NewObj();
+    for (i = 1, tokenPtr = parsePtr->tokenPtr; i < parsePtr->numWords; i++) {
+	tokenPtr = TokenAfter(tokenPtr);
+	objPtr = Tcl_NewObj();
+	if (!TclWordKnownAtCompileTime(tokenPtr, objPtr)) {
+	    Tcl_DecrRefCount(objPtr);
+	    Tcl_DecrRefCount(listObj);
+	    listObj = NULL;
+	    break;
+	}
+	(void) Tcl_ListObjAppendElement(NULL, listObj, objPtr);
+    }
+    if (listObj != NULL) {
+	Tcl_Obj **objs;
+	const char *bytes;
+	int len;
+
+	Tcl_ListObjGetElements(NULL, listObj, &len, &objs);
+	objPtr = Tcl_ConcatObj(len, objs);
+	Tcl_DecrRefCount(listObj);
+	bytes = Tcl_GetStringFromObj(objPtr, &len);
+	PushLiteral(envPtr, bytes, len);
+	Tcl_DecrRefCount(objPtr);
+	return TCL_OK;
+    }
+
+    /*
+     * General case: runtime concat.
+     */
+
+    for (i = 1, tokenPtr = parsePtr->tokenPtr; i < parsePtr->numWords; i++) {
+	tokenPtr = TokenAfter(tokenPtr);
+	CompileWord(envPtr, tokenPtr, interp, i);
+    }
+
+    TclEmitInstInt4(	INST_CONCAT_STK, i-1,		envPtr);
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
  * TclCompileContinueCmd --
  *
  *	Procedure called to compile the "continue" command.
@@ -1678,7 +1765,7 @@ TclCompileDictAppendCmd(
 	tokenPtr = TokenAfter(tokenPtr);
     }
     if (parsePtr->numWords > 4) {
-	TclEmitInstInt1(INST_CONCAT1, parsePtr->numWords-3, envPtr);
+	TclEmitInstInt1(INST_STR_CONCAT1, parsePtr->numWords-3, envPtr);
     }
 
     /*
@@ -3011,7 +3098,7 @@ TclCompileFormatCmd(
 	 * Do the concatenation, which produces the result.
 	 */
 
-	TclEmitInstInt1(INST_CONCAT1, i, envPtr);
+	TclEmitInstInt1(INST_STR_CONCAT1, i, envPtr);
     } else {
 	/*
 	 * EVIL HACK! Force there to be a string representation in the case