1 files changed, 132 insertions, 0 deletions
diff --git a/sem3/osc/miniproject/cnasm/codegen.c b/sem3/osc/miniproject/cnasm/codegen.c
new file mode 100644
index 0000000..c995df9
--- /dev/null
+++ b/sem3/osc/miniproject/cnasm/codegen.c
@@ -0,0 +1,132 @@
+#include "codegen.h"
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include "ast.h"
+
+static void gencondjmp(FILE *f, cond_t *c, bool neg) {
+	uint8_t cmp = neg ? c->cmp^0x80 : c->cmp;
+	fprintf(f, "cmp %s %s\n", c->a, c->b);
+	switch(cmp) {
+		case CEQ:
+			fprintf(f, "je ");
+			break;
+		case CNEQ:
+			fprintf(f, "jne ");
+			break;
+		case CGT:
+			fprintf(f, "jg ");
+			break;
+		case CLT:
+			fprintf(f, "jl ");
+			break;
+		case CLEQ:
+			fprintf(f, "jle ");
+			break;
+		case CGEQ:
+			fprintf(f, "jge ");
+			break;
+		default:
+			fprintf(stderr, "Invalid cmp type %x", cmp);
+			fprintf(f, "jmp ");
+	}
+}
+
+static void genif(FILE *f, struct genctx *ctx, ast_node_t *n) {
+	bool doElse = n->flowctrl.iffalse;
+	// Create conditional jump
+	gencondjmp(f, n->flowctrl.condition, true);
+	if( doElse ) {
+		fprintf(f, "else_%d\n", ctx->nested);
+	} else {
+		fprintf(f, "end_%d\n", ctx->nested);
+	}
+
+	struct genctx octx = { ctx->nested+1 };
+	// Paste code
+	gentree(f, &octx, n->flowctrl.iftrue);
+	
+	// Do else
+	if( doElse ) {
+		fprintf(f, "jmp end_%d\n", ctx->nested);
+		fprintf(f, "else_%d:\n", ctx->nested);
+		gentree(f, &octx, n->flowctrl.iffalse);
+	}
+
+	// End block
+	fprintf(f, "end_%d:\n", ctx->nested);
+}
+
+static void genwhile(FILE *f, struct genctx *ctx, ast_node_t *n) {
+	// Create loop label
+	fprintf(f, "loop_%d:\n", ctx->nested);
+
+	// Create conditional jump
+	gencondjmp(f, n->flowctrl.condition, true);
+	fprintf(f, "end_%d\n", ctx->nested);
+
+	struct genctx octx = { ctx->nested+1 };
+	// Paste code
+	gentree(f, &octx, n->flowctrl.iftrue);
+
+	// Jump to start
+	fprintf(f, "jmp loop_%d\n", ctx->nested);
+	
+	// End block
+	fprintf(f, "end_%d:\n", ctx->nested);
+}
+
+static void genfor(FILE *f, struct genctx *ctx, ast_node_t *n) {
+	// Do pre stuff
+	fprintf(f, "%s\n", n->forloop.pre);
+
+	// Create loop label
+	fprintf(f, "loop_%d:\n", ctx->nested);
+
+	// Create conditional jump
+	gencondjmp(f, n->flowctrl.condition, true);
+	fprintf(f, "end_%d\n", ctx->nested);
+
+	struct genctx octx = { ctx->nested+1 };
+	// Paste code
+	gentree(f, &octx, n->forloop.stuff);
+
+	// Do inc stuff
+	fprintf(f, "%s\n", n->forloop.inc);
+	// Jump to start
+	fprintf(f, "jmp loop_%d\n", ctx->nested);
+	
+	// End block
+	fprintf(f, "end_%d:\n", ctx->nested);
+}
+
+void gentree(FILE *f, struct genctx *ctx, ast_node_t *n) {
+	if( !n ) {
+		return;
+	}
+	if( ctx == NULL ) {
+		ctx = malloc(sizeof(struct genctx));
+		ctx->nested = 0;
+	}
+	switch(n->t) {
+		case TSTM_LIST: 
+			gentree(f, ctx, n->list.children[0]);
+			gentree(f, ctx, n->list.children[1]);
+			break;
+		case TIF:
+			genif(f, ctx, n);
+			break;
+		case TIDENT:
+			fprintf(f, "%s\n", n->ident);
+			break;
+		case TFOR:
+			genfor(f, ctx, n);
+			break;
+		case TWHILE:
+			genwhile(f, ctx, n);
+			break;
+		default:
+			return;
+	}
+}