implement VAR += .. feature, contributed by Pieter Hijma

commands/make/h.h

@@ -277,6 +277,7 @@ _PROTOTYPE(void input, (FILE *fd ));
 _PROTOTYPE(struct macro *getmp, (char *name ));
 _PROTOTYPE(char *getmacro, (char *name ));
 _PROTOTYPE(struct macro *setmacro, (char *name, char *val ));
+_PROTOTYPE(struct macro *addmacro, (char *name, char *val ));
 _PROTOTYPE(void setDFmacro, (char *name, char *val ));
 _PROTOTYPE(void doexp, (struct str *to, char *from ));
 _PROTOTYPE(void expand, (struct str *strs ));

commands/make/input.c

@@ -308,6 +308,36 @@ FILE *fd;
 	while (isspace(*p))  p++;	/*  Find first target  */
 
 
+	while (((q = strchr(p, '+')) != (char *)0) &&
+	    (q[1] == '=') && (p != q) && (q[-1] == '\\'))	/*  Find value */
+	{
+		a = q - 1;	/*  Del \ chr; move rest back  */
+		p = q;
+		while(*a++ = *q++)
+			;
+	}
+
+	if (q != (char *)0 && q[1] == '=') {
+
+		*q++ = '\0';		/*  Separate name and val  */
+		*q++ = '\0';		/*  Separate name and val  */
+		while (isspace(*q))
+			q++;
+		if (p = strrchr(q, '\n'))
+			*p = '\0';
+
+		p = str1;
+		if ((a = gettok(&p)) == (char *)0)
+			error("No macro name",(char *)0);
+
+		addmacro(a, q);
+
+		if (getline(&str1s, fd))
+			return;
+		continue;
+	}
+
+
 	while (((q = strchr(p, '=')) != (char *)0) &&
 	    (p != q) && (q[-1] == '\\'))	/*  Find value */
 	{

commands/make/macro.c

@@ -47,6 +47,41 @@ char *name;
 }
 
 
+struct macro *addmacro(name, val)
+char *name;
+char *val;
+{
+  register struct macro *rp;
+  register char         *cp;
+  int len_old_value;
+
+
+		/*  Replace macro definition if it exists  */
+  for (rp = macrohead; rp; rp = rp->m_next)
+	if (strcmp(name, rp->m_name) == 0) {
+		if(rp->m_flag & M_OVERRIDE) return rp;	/* mustn't change */
+		break;
+		}
+
+	if (!rp)		/*  If not defined, allocate space for new  */
+	{
+			fatal("Cannot add to a non-existing macro",(char *)0,0);
+	}
+
+	len_old_value = strlen(rp->m_val);
+	if ((cp = (char *) malloc(len_old_value+1+strlen(val)+1)) == (char *)0)
+		fatal("No memory for macro",(char *)0,0);
+	strcpy(cp, rp->m_val);		/*  Copy in old value  */
+	cp[len_old_value] = ' ';
+	strcpy(cp+len_old_value+1, val);		/*  Copy in new value  */
+	free(rp->m_val);
+	rp->m_val = cp;
+
+  return rp;
+}
+
+
+
 struct macro *setmacro(name, val)
 char *name;
 char *val;