From eb45e104be216adb76eaacfeea78935ee5165e0b Mon Sep 17 00:00:00 2001
From: ketmar <ketmar@ketmar.no-ip.org>
Date: Thu, 23 Jul 2020 07:29:42 +0000
Subject: [PATCH] urasm: added "XBRANCH" forth word flag; it will use
 `USE_REL_BRANCH` EQU label to choose branch type

FossilOrigin-Name: 9dfecbff2d2700e11aeb65b32831f611c4619d8a0ef984d0bb56e23748e09deb
---
 src/urasm.c | 35 +++++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/src/urasm.c b/src/urasm.c
index 5bfde7f..a46f0cf 100644
--- a/src/urasm.c
+++ b/src/urasm.c
@@ -3558,7 +3558,7 @@ typedef struct ForthWordT {
   char *name; // uppercased
   uint16_t nfa;
   uint16_t cfa;
-  int isbranch; // <0: wants relative addr; >0: wants absolute addr
+  int isbranch; // -1: wants relative addr; 1: wants absolute addr; -666: check `USE_REL_BRANCH`
   struct ForthWordT *next;
 } ForthWord;
 
@@ -3722,6 +3722,17 @@ static int piForthUser (void) {
 }
 
 
+static void forthParseBranchFlag (ForthWord *nw) {
+  const char *wname = forthGetWord();
+  if (wname) {
+         if (strcasecmp(wname, "RBRANCH") == 0) nw->isbranch = -1;
+    else if (strcasecmp(wname, "ABRANCH") == 0) nw->isbranch = 1;
+    else if (strcasecmp(wname, "XBRANCH") == 0) nw->isbranch = -666;
+    else fatal("end of line expected");
+  }
+}
+
+
 static int piForthCodeWord (void) {
   if (asmMode != AMODE_NORMAL) fatal("invalid forth define");
   asmMode = AMODE_FCODE;
@@ -3730,12 +3741,7 @@ static int piForthCodeWord (void) {
   ForthWord *nw = forthWordHead(wname, 0);
   // cfa
   emitWord((disp+2)&0xffffU);
-  wname = forthGetWord();
-  if (wname) {
-         if (strcasecmp(wname, "RBRANCH") == 0) nw->isbranch = -1;
-    else if (strcasecmp(wname, "ABRANCH") == 0) nw->isbranch = 1;
-    else fatal("end of line expected");
-  }
+  forthParseBranchFlag(nw);
   checkOperatorEnd();
   //fprintf(stderr, "FORTH CODE WORD: '%s'\n", nw->name);
   forthCurrWord = nw->name;
@@ -3770,12 +3776,7 @@ static int piForthWord (void) {
   free(fwn);
   // cfa
   forthEmitLabel("_doforth");
-  wname = forthGetWord();
-  if (wname) {
-         if (strcasecmp(wname, "RBRANCH") == 0) nw->isbranch = -1;
-    else if (strcasecmp(wname, "ABRANCH") == 0) nw->isbranch = 1;
-    else fatal("end of line expected");
-  }
+  forthParseBranchFlag(nw);
   checkOperatorEnd();
   //fprintf(stderr, "FORTH WORD: '%s'\n", nw->name);
   forthCurrWord = nw->name;
@@ -4101,7 +4102,13 @@ static void processForthWordLine (void) {
         if (!lbl) fatal("unknown label in forth code: '%s'", wname);
         if (!lbl->known) fatal("undefined label '%s'", lbl->name);
         if (lbl->value < 0 || lbl->value > 65535) fatal("invalid jump label in forth code: '%s' (%d)", wname, lbl->value);
-        if (fw->isbranch < 0) {
+        int brt = fw->isbranch;
+        if (brt == -666) {
+          UrLabelInfo *brtl = urFindLabel("USE_REL_BRANCH");
+          if (!brtl || !brtl->known || brtl->type < 0) fatal("forth XBRANCH requires defined `USE_REL_BRANCH`");
+          brt = (brtl->value ? -1 : 1);
+        }
+        if (brt < 0) {
           // relative
           int v = lbl->value-(int)disp;
           if (v < -32767 || v > 32767) fatal("forth jump too far");
-- 
2.11.4.GIT