From cdd7e2a99c25c7b41e950e619fd98ed2250c91be Mon Sep 17 00:00:00 2001
From: Augusto Gunsch <augustogunsch@tutanota.com>
Date: Sat, 14 Nov 2020 12:31:57 -0300
Subject: [PATCH] Add branching commands

---
 templates.h  | 28 ++++++++++++++++++++++--
 translator.c | 60 ++++++++++++++++++++++++++++++++++++++++++++--------
 translator.h |  1 +
 3 files changed, 78 insertions(+), 11 deletions(-)

diff --git a/templates.h b/templates.h
index 5c9aa26..391f443 100644
--- a/templates.h
+++ b/templates.h
@@ -105,10 +105,9 @@ char* tnot[TNOTN] = {
 	"M=!M",
 };
 
-#define TCOMPN 15
+#define TCOMPN 14
 char* tcomp[TCOMPN] = {
 	"",
-	"M=D",
 	"@SP",
 	"M=M-1",
 	"A=M",
@@ -123,4 +122,29 @@ char* tcomp[TCOMPN] = {
 	"M=0",
 	""
 };
+
+#define TLABELN 2
+char* tlabel[TLABELN] = {
+	"",
+	""
+};
+
+#define TGOTON 3
+char* tgoto[TGOTON] = {
+	"",
+	"",
+	"0;JMP"
+};
+
+#define TIFGOTON 7
+char* tifgoto[TIFGOTON] = {
+	"",
+	"@SP",
+	"M=M-1",
+	"A=M",
+	"D=M",
+	"",
+	"D;JNE"
+};
+
 #endif
diff --git a/translator.c b/translator.c
index aba4569..f64f2a5 100644
--- a/translator.c
+++ b/translator.c
@@ -4,7 +4,7 @@
 #include <ctype.h>
 #include "translator.h"
 #include "templates.h"
-#define CMPLIMIT 1000
+#define CMPLIMIT 9999
 #define CMPLEN 4
 
 void pushtoclean(struct Translator* t, char* topush) {
@@ -113,9 +113,9 @@ char* mkcmplab(struct Translator* t, struct line* ln) {
 		fprintf(stderr, "Reached comparison limit (%i); line %i\n", CMPLIMIT, ln->truen);
 		exit(1);
 	}
-	int newsz = (CMPLEN+13)*sizeof(char);
+	int newsz = (t->fnamelen + CMPLEN + 6) * sizeof(char);
 	char* label = (char*)malloc(newsz);
-	snprintf(label, newsz, "COMPARISON-%i", t->compcount);
+	snprintf(label, newsz, "%s-CMP-%i", t->fname, t->compcount);
 	pushtoclean(t, label);
 	return label;
 }
@@ -147,8 +147,7 @@ char* mklab(struct Translator* t, char* label, int labellen) {
 
 char* mkstatind(struct Translator* t, struct line* ln, int indlen) {
 	checkind(ln, indlen);
-	int fnamelen = strlen(t->fname);
-	int newsz = sizeof(char) * (fnamelen + indlen + 3);
+	int newsz = sizeof(char) * (t->fnamelen + indlen + 3);
 	char* newind = (char*)malloc(newsz);
 	snprintf(newind, newsz, "@%s.%s", t->fname, ln->tokens[2]);
 	pushtoclean(t, newind);
@@ -327,14 +326,50 @@ void comp(struct Translator* t, struct line* ln, char* op) {
 	char* trueop = (char*)malloc(opsz);
 	snprintf(trueop, opsz, "D;J%s", op);
 	tcomp[TCOMPN-5] = trueop;
+	pushtoclean(t, trueop);
 
 	// (label)
 	tcomp[TCOMPN-1] = mklab(t, label, labellen);
-	free(label);
 
 	addasmlns(t, ln, tcomp, TCOMPN);
 };
 
+void label(struct Translator* t, struct line* ln) {
+	if(ln->tokenscount < 2) {
+		fprintf(stderr, "Expected label; line %i", ln->truen);
+		exit(1);
+	}
+	
+	// (label)
+	tlabel[TLABELN-1] = mklab(t, ln->tokens[1], strlen(ln->tokens[1]));
+
+	addasmlns(t, ln, tlabel, TLABELN);
+}
+
+void mygoto(struct Translator* t, struct line* ln) {
+	if(ln->tokenscount < 2) {
+		fprintf(stderr, "Expected label; line %i", ln->truen);
+		exit(1);
+	}
+
+	// @label
+	tgoto[TGOTON-2] = atlab(t, ln->tokens[1], strlen(ln->tokens[1]));
+
+	addasmlns(t, ln, tgoto, TGOTON);
+}
+
+void ifgoto(struct Translator* t, struct line* ln) {
+	if(ln->tokenscount < 2) {
+		fprintf(stderr, "Expected label; line %i", ln->truen);
+		exit(1);
+	}
+	
+	// @label
+	tifgoto[TIFGOTON-2] = atlab(t, ln->tokens[1], strlen(ln->tokens[1]));
+
+	addasmlns(t, ln, tifgoto, TIFGOTON);
+}
+
 void switchpush(struct Translator* t, struct line* ln) {
 	checkopamnt(3, ln);
 	char* seg = ln->tokens[1];
@@ -375,7 +410,7 @@ void switchop(struct Translator* t, struct line* ln) {
 	else if(!strcmp(op, "pop"))
 		switchpop(t, ln);
 	else if(!strcmp(op, "add"))
-		arith(t, ln, "M=M+D");
+		arith(t, ln, "M=D+M");
 	else if(!strcmp(op, "sub"))
 		arith(t, ln, "M=M-D");
 	else if(!strcmp(op, "neg"))
@@ -387,11 +422,17 @@ void switchop(struct Translator* t, struct line* ln) {
 	else if(!strcmp(op, "lt"))
 		comp(t, ln, "GT");
 	else if(!strcmp(op, "and"))
-		arith(t, ln, "M=M&D");
+		arith(t, ln, "M=D&M");
 	else if(!strcmp(op, "or"))
-		arith(t, ln, "M=M|D");
+		arith(t, ln, "M=D|M");
 	else if(!strcmp(op, "not"))
 		addasmlns(t, ln, tnot, TNOTN);
+	else if(!strcmp(op, "label"))
+		label(t, ln);
+	else if(!strcmp(op, "goto"))
+		mygoto(t, ln);
+	else if(!strcmp(op, "if-goto"))
+		ifgoto(t, ln);
 	else {
 		fprintf(stderr, "Unrecognized operation '%s'; line %i\n", op, ln->truen);
 		exit(1);
@@ -416,6 +457,7 @@ struct Translator* mktranslator(struct lnarray* lns, char* fname) {
 
 	t->lns = lns;
 	t->fname = fname;
+	t->fnamelen = strlen(fname);
 
 	return t;
 }
diff --git a/translator.h b/translator.h
index ea4de6b..7e8e587 100644
--- a/translator.h
+++ b/translator.h
@@ -16,6 +16,7 @@ struct Translator {
 	int tocleanind;
 	struct lnarray* lns;
 	char* fname;
+	int fnamelen;
 	int compcount;
 };