add if statements

1 files changed, 83 insertions, 6 deletions

diff --git a/main.c b/main.c
index e39c00b..6da1bf2 100644
--- a/main.c
+++ b/main.c
@@ -12,7 +12,7 @@
 #include "strio.h"
 #include "ir.h"
 
-int no_opt = 0;
+int no_opt = 1;
 
 typedef struct {
 	DYNARR(Proc) procs;
@@ -35,7 +35,9 @@ Node *parse_expr(Lexer *l, Proc *p);
 
 void parse_return(Lexer *l, Proc *p) {
 	lex_next(l);
-	p->stop = node_new(p, N_RETURN, p->start, parse_expr(l, p));
+	Node *n = node_new(p, N_RETURN, p->ctrl, parse_expr(l, p));
+	node_add(p, n, p->stop);
+	p->ctrl = n;
 }
 
 void parse_let(Lexer *l, Proc *p) {
@@ -57,13 +59,16 @@ recurse:
 void parse_stmt(Lexer *l, Proc *p);
 
 /* TODO: return node from this! */
-void parse_block(Lexer *l, Proc *p) {
+void parse_block(Lexer *l, Proc *p, ScopeNameList *nl) {
 	lex_next(l);
 	scope_push(&p->scope, p);
 	while (l->tok != TOK_RBRACE) {
 		lex_expected_not(l, TM_EOF);
 		parse_stmt(l, p);
 	}
+	if (nl) {
+		scope_collect(&p->scope, p, nl, &p->arena);
+	}
 	scope_pop(&p->scope, p);
 	lex_expected(l, TM_RBRACE);
 	lex_next(l);
@@ -80,6 +85,76 @@ void parse_assign(Lexer *l, Proc *p) {
 	}
 }
 
+void merge_scope(Proc *p, ScopeNameList *na, ScopeNameList *nb) {
+	for (ScopeFrame *f = p->scope.tail; f; f = f->prev) {
+		for (NameBinding *b = f->latest; b; b = b->prev) {
+			int i, j;
+			for (i = 0; i < na->len && !str_eql(na->data[i].name, b->name); i++);
+			for (j = 0; j < nb->len && !str_eql(nb->data[j].name, b->name); j++);
+			if (i >= na->len && j >= nb->len) continue; /* no change */
+			Node *phi;
+			if (i >= na->len) {
+				phi = node_new(p, N_PHI, p->ctrl, b->node, nb->data[j].node);
+			} else if (j >= na->len) {
+				phi = node_new(p, N_PHI, p->ctrl, na->data[i].node, b->node);
+			} else {
+				phi = node_new(p, N_PHI, p->ctrl, na->data[i].node, nb->data[j].node);
+			}
+			node_add(p, phi, p->keepalive);
+			node_remove(p, b->node, p->keepalive);
+			b->node = phi;
+		}
+	}
+
+	for (int i = 0; i < na->len; i++) node_remove(p, na->data[i].node, p->keepalive);
+	for (int i = 0; i < nb->len; i++) node_remove(p, nb->data[i].node, p->keepalive);
+}
+
+void parse_if(Lexer *l, Proc *p) {
+	lex_next(l);
+	Node *cond = parse_expr(l, p);
+	Node *ctrl_if = NULL, *ctrl_else = NULL;
+	Node *if_node = node_new(p, N_IF_ELSE, p->ctrl, cond);
+	if_node->val = (Value) {
+		.type = { T_TOP, T_TUPLE, NULL },
+		.tuple = {
+			.len = 2,
+			.cap = 0,
+			.data = (Value[2]) {
+				{ .type = { T_CTRL, T_NONE, NULL } },
+				{ .type = { T_CTRL, T_NONE, NULL } },
+			}
+		}
+	};
+	Node *if_true = node_new(p, N_PROJ, if_node);
+	Node *if_false = node_new(p, N_PROJ, if_node);
+	ScopeNameList scope_before = { 0 }, scope_true = { 0 }, scope_false = { 0 };
+	if_true->val.i = 0;
+	if_false->val.i = 1;
+	scope_collect(&p->scope, p, &scope_before, &p->arena);
+	NODE_KEEP(p, cond, {
+		p->ctrl = if_true;
+		lex_expected(l, TM_LBRACE);
+		parse_block(l, p, &scope_true);
+		ctrl_if = p->ctrl;
+		if (l->tok == TOK_ELSE) {
+			NODE_KEEP(p, ctrl_if, {
+				p->ctrl = if_false;
+				lex_expect(l, TM_LBRACE);
+				parse_block(l, p, &scope_false);
+				ctrl_else = p->ctrl;
+			});
+		}
+	});
+	if (ctrl_else) {
+		p->ctrl = node_new(p, N_REGION, ctrl_if, ctrl_else);
+		merge_scope(p, &scope_true, &scope_false);
+	} else {
+		p->ctrl = node_new(p, N_REGION, ctrl_if, if_false);
+		merge_scope(p, &scope_before, &scope_true);
+	}
+}
+
 void parse_stmt(Lexer *l, Proc *p) {
 	/* TODO */
 	(void)l;
@@ -91,18 +166,20 @@ void parse_stmt(Lexer *l, Proc *p) {
 		parse_let(l, p);
 		break;
 	case TOK_LBRACE:
-		parse_block(l, p);
+		parse_block(l, p, NULL);
 		break;
 	case TOK_IDENT:
 		parse_assign(l, p);
 		break;
+	case TOK_IF:
+		parse_if(l, p);
+		break;
 	default:
 		lex_expected(l, TM_RBRACE);
 		break;
 	}
 }
 
-
 Type parse_type(Lexer *l, Proc *proc) {
 	(void)proc;
 	Type t = { .lvl = T_BOT };
@@ -137,7 +214,7 @@ void parse_args_list(Lexer *l, Proc *proc) {
 		lex_expect(l, TM_IDENT | TM_COMMA);
 		if (l->tok == TOK_COMMA) continue;
 		Value v = (Value) { .type = parse_type(l, proc) };
-		ZDA_PUSH(&start->val.tuple, v, &proc->arena);
+		ZDA_PUSH(&proc->arena, &start->val.tuple, v);
 		lex_expected(l, TM_RPAREN | TM_COMMA);
 		for (int j = 0; j < id; j++) {
 			Node *proj = node_new(proc, N_PROJ, proc->start);