RFC re alternative approach to #370

calma/CalmaRdpt.c

@@ -58,7 +58,7 @@ extern int CalmaPathCount;
 extern HashTable calmaDefInitHash;
 
 extern void calmaLayerError(char *mesg, int layer, int dt);
-bool calmaReadPath(CIFPath **pathheadpp, int iscale);
+CIFPath *calmaReadPath(int iscale);
 
 /*
  * ----------------------------------------------------------------------------
@@ -237,7 +237,8 @@ calmaElementBoundary(void)
 	plane = cifCurReadPlanes[ciftype];
 
     /* Read the path itself, building up a path structure */
-    if (!calmaReadPath(&pathheadp, (plane == NULL) ? 0 : 1))
+    pathheadp = calmaReadPath((plane == NULL) ? 0 : 1);
+    if (pathheadp == NULL)
     {
 	if (plane != NULL)
 	    CalmaReadError("Error while reading path for boundary/box; ignored.\n");
@@ -595,7 +596,8 @@ calmaElementPath(void)
 
     /* Read the points in the path */
     savescale = calmaReadScale1;
-    if (!calmaReadPath(&pathheadp, 2))
+    pathheadp = calmaReadPath(2);
+    if (pathheadp == NULL)
     {
 	CalmaReadError("Improper path; ignored.\n");
 	return;
@@ -1098,26 +1100,24 @@ calmaElementText(void)
  * centerline, to avoid roundoff errors.
  *
  * Results:
- *	TRUE is returned if the path was parsed successfully,
- *	FALSE otherwise.
+ *	non-NULL CIFPath* the caller takes ownership of
+ *	if the path was parsed successfully, otherwise NULL.
  *
  * Side effects:
- *	Modifies the parameter pathheadpp to point to the path
- *	that is constructed.
+ *	None
  *
  * ----------------------------------------------------------------------------
  */
 
-bool
+CIFPath *
 calmaReadPath(
-    CIFPath **pathheadpp,
     int iscale)
 {
-    CIFPath path, *pathtailp, *newpathp;
+    CIFPath path, *pathheadp, *pathtailp, *newpathp;
     int nbytes, rtype, npoints, savescale;
     bool nonManhattan = FALSE;
 
-    *pathheadpp = (CIFPath *) NULL;
+    pathheadp = (CIFPath *) NULL;
     pathtailp = (CIFPath *) NULL;
     path.cifp_next = (CIFPath *) NULL;
 
@@ -1126,12 +1126,12 @@ calmaReadPath(
     if (nbytes < 0)
     {
 	CalmaReadError("EOF when reading path.\n");
-	return (FALSE);
+	return (NULL);
     }
     if (rtype != CALMA_XY)
     {
 	calmaUnexpected(CALMA_XY, rtype);
-	return (FALSE);
+	return (NULL);
     }
 
     /* Read this many points (pairs of four-byte integers) */
@@ -1142,7 +1142,7 @@ calmaReadPath(
 	calmaReadPoint(&path.cifp_point, iscale);
 	if (savescale != calmaReadScale1)
 	{
-	    CIFPath *phead = *pathheadpp;
+	    CIFPath *phead = pathheadp;
 	    int newscale = calmaReadScale1 / savescale;
 	    while (phead != NULL)
 	    {
@@ -1157,16 +1157,16 @@ calmaReadPath(
 	}
 	if (FEOF(calmaInputFile))
 	{
-	    CIFFreePath(*pathheadpp);
-	    return (FALSE);
+	    CIFFreePath(pathheadp);
+	    return (NULL);
 	}
 
 	if (iscale != 0)
 	{
 	    newpathp = (CIFPath *) mallocMagic((unsigned) (sizeof (CIFPath)));
 	    *newpathp = path;
 
-	    if (*pathheadpp)
+	    if (pathheadp)
 	    {
 		/*
 		 * Check that this segment is Manhattan.  If not, remember the
@@ -1187,11 +1187,11 @@ calmaReadPath(
 		}
 		pathtailp->cifp_next = newpathp;
 	    }
-	    else *pathheadpp = newpathp;
+	    else pathheadp = newpathp;
 	    pathtailp = newpathp;
 	}
     }
-    return (*pathheadpp != NULL);
+    return (pathheadp);
 }
 
 /*

cif/CIFrdpt.c

@@ -687,7 +687,8 @@ CIFParseWire(void)
 
     width /= cifReadScale2;
     savescale = cifReadScale1;
-    if (!CIFParsePath(&pathheadp, 2))
+    pathheadp = CIFParsePath(2);
+    if (pathheadp == NULL)
     {
 	CIFReadError("wire, but improper path; ignored.\n");
 	CIFSkipToSemi();
@@ -797,7 +798,8 @@ CIFParsePoly(void)
 	CIFSkipToSemi();
 	return FALSE;
     }
-    if (!CIFParsePath(&pathheadp, 1))
+    pathheadp = CIFParsePath(1);
+    if (pathheadp == NULL)
     {
 	CIFReadError("polygon, but improper path; ignored.\n");
 	CIFSkipToSemi();

cif/CIFrdutils.c

@@ -649,12 +649,11 @@ CIFParsePoint(
  *	one or more points.
  *
  * Results:
- *	TRUE is returned if the path was parsed successfully,
- *	FALSE otherwise.
+ *	non-NULL CIFPath* the caller takes ownership of
+ *	if the path was parsed successfully, otherwise NULL.
  *
  * Side effects:
- *	Modifies the parameter pathheadpp to point to the path
- *	that is constructed.
+ *	None
  *
  * Corrections:
  *	CIF coordinates are multiplied by 2 to cover the case where
@@ -666,17 +665,16 @@ CIFParsePoint(
  * ----------------------------------------------------------------------------
  */
 
-bool
+CIFPath *
 CIFParsePath(
-    CIFPath **pathheadpp,
     int iscale)
 {
-    CIFPath *pathtailp, *newpathp;
+    CIFPath *pathheadp, *pathtailp, *newpathp;
     bool nonManhattan = FALSE;		/* diagnostic only */
     CIFPath path;
     int savescale;
 
-    *pathheadpp = NULL;
+    pathheadp = NULL;
     pathtailp = NULL;
     path.cifp_next = NULL;
     while (TRUE)
@@ -688,12 +686,12 @@ CIFParsePath(
 	savescale = cifReadScale1;
 	if (!CIFParsePoint(&path.cifp_point, iscale))
 	{
-	    CIFFreePath(*pathheadpp);
-	    return FALSE;
+	    CIFFreePath(pathheadp);
+	    return NULL;
 	}
 	if (savescale != cifReadScale1)
 	{
-	    CIFPath *phead = *pathheadpp;
+	    CIFPath *phead = pathheadp;
 	    int newscale = cifReadScale1 / savescale;
 	    while (phead != NULL)
 	    {
@@ -704,7 +702,7 @@ CIFParsePath(
 	}
 	newpathp = (CIFPath *) mallocMagic((unsigned) (sizeof (CIFPath)));
 	*newpathp = path;
-	if (*pathheadpp)
+	if (pathheadp)
 	{
 	    /*
 	     * Check that this segment is Manhattan.  If not, remember the
@@ -721,10 +719,10 @@ CIFParsePath(
 	    }
 	    pathtailp->cifp_next = newpathp;
 	}
-	else *pathheadpp = newpathp;
+	else pathheadp = newpathp;
 	pathtailp = newpathp;
     }
-    return (*pathheadpp != NULL);
+    return pathheadp;
 }
 
 /*

cif/CIFread.h

@@ -166,7 +166,7 @@ extern bool CIFParseUser(void);
 extern bool CIFParseCall(void);
 extern bool CIFParseTransform(Transform *transformp);
 extern bool CIFParseInteger(int *valuep);
-extern bool CIFParsePath(CIFPath **pathheadpp, int iscale);
+extern CIFPath *CIFParsePath(int iscale);
 extern bool CIFParsePoint(Point *pointp, int iscale);
 extern bool CIFParseSInteger(int *valuep);
 extern void CIFSkipToSemi(void);