introduce OUTerrorf() and IFerrorf()

a varargs variant of the older variants OUTerror() and IFerror()

src/frontend/outitf.c

@@ -1285,6 +1285,31 @@ OUTerror(int flags, char *format, IFuid *names)
     fflush(cp_err);
 }
 
+
+void
+OUTerrorf(int flags, const char *format, ...)
+{
+    struct mesg *m;
+    va_list args;
+
+    if ((flags == ERR_INFO) && cp_getvar("printinfo", CP_BOOL, NULL))
+        return;
+
+    for (m = msgs; m->flag; m++)
+        if (flags & m->flag)
+            fprintf(cp_err, "%s: ", m->string);
+
+    va_start (args, format);
+
+    vfprintf(cp_err, format, args);
+    fputc('\n', cp_err);
+
+    fflush(cp_err);
+
+    va_end(args);
+}
+
+
 static int
 InterpFileAdd(runDesc *run, IFvalue *refValue, IFvalue *valuePtr)
 {

src/frontend/outitf.h

@@ -63,6 +63,7 @@ int OUTendDomain(runDesc *plotPtr);
 int OUTattributes(runDesc *plotPtr, IFuid varName, int param, IFvalue *value);
 int OUTstopnow(void);
 void OUTerror(int flags, char *format, IFuid *names);
+void OUTerrorf(int, const char *fmt, ...)  __attribute__ ((format (__printf__, 2, 3)));
 
 
 #endif

src/include/ngspice/ifsim.h

@@ -437,7 +437,13 @@ struct IFfrontEnd {
                             /* should we stop now? */
     double (*IFseconds) (void);
                             /* what time is it? */
-    int (*IFerror) (int, char *, IFuid *);
+    void (*IFerror) (int, char *, IFuid *);
+                            /* output an error or warning message */
+#ifdef __GNUC__
+    void (*IFerrorf) (int, const char *fmt, ...) __attribute__ ((format (__printf__, 2, 3)));
+#else
+    void (*IFerrorf) (int, const char *fmt, ...);
+#endif
                             /* output an error or warning message */
     int (*OUTpBeginPlot) (CKTcircuit *, JOB *,
                           IFuid,

src/main.c

@@ -204,7 +204,9 @@ extern int OUTwBeginPlot(CKTcircuit *,JOB *,IFuid,IFuid,int,int,IFuid *,int,runD
 extern int OUTwReference(runDesc *,IFvalue *,void **);
 extern int OUTwData(runDesc *,int,IFvalue *,void *), OUTwEnd(runDesc *), OUTendPlot(runDesc *);
 extern int OUTbeginDomain(runDesc *,IFuid,int,IFvalue *);
-extern int OUTendDomain(runDesc *), OUTstopnow(void), OUTerror(int,char *,IFuid *);
+extern int OUTendDomain(runDesc *), OUTstopnow(void);
+extern void OUTerror(int,char *,IFuid *);
+extern void OUTerrorf(int, const char *fmt, ...)  __attribute__ ((format (__printf__, 2, 3)));
 extern int OUTattributes(runDesc *,IFuid,int,IFvalue *);
 
 extern void initw(void);
@@ -215,6 +217,7 @@ IFfrontEnd nutmeginfo = {
     OUTstopnow,
     seconds,
     OUTerror,
+    OUTerrorf,
     OUTpBeginPlot,
     OUTpData,
     OUTwBeginPlot,