compiler

commit 2343dad778541f4119e9277ddf1f1a7271ba56d2
parent 2215c34db5349131d5855bbd4bc69dcf4d6b64cc
Author: Brian Swetland <swetland@frotz.net>
Date:   Wed,  8 Dec 2021 08:08:59 -0800

compiler2: cleanup

- no more AST_LABEL, just generate an assignment if needed
- start sketching some generalized assignment handling

Diffstat:
M
src/codegen-risc5-simple.c
 | 
40
++++++++++++++++++++++++++++++----------
M
src/compiler2.c
 | 
27
++++++++++++---------------

2 files changed, 42 insertions(+), 25 deletions(-)
diff --git a/src/codegen-risc5-simple.c b/src/codegen-risc5-simple.c
@@ -282,11 +282,37 @@ u32 gen_assign_expr(Ast expr, Symbol sym) {
 	}
 }
 
+#if 0
+u32 gen_assign_loc(Ast lhs) {
+	if (lhs->kind == AST_NAME) {
+		u32 base;
+		i32 offset;
+		sym_get_loc(lhs->sym, &base, &offset);
+		r = get_reg_tmp();
+		if (lhs->sym->flags & SYM_IS_REFERNCE) {
+		gen_opi(ADD, r, base, offset);
+
+		return r;
+	} else if (lhs->kind == AST_INDEX) {
+		u32 ar = gen_assign_loc(lhs->c0);
+		u32 r = gen_expr(lhs->c1);
+
+		u32 lbase;
+		i32 loffset;
+		u32 kind = gen_assign_loc(lhs->c0, &lbase, &loffset);
+
+	} else if (lhs->kind == AST_DEREF) {
+	} else {
+		err_ast = lhs;
+		error("invalid lhs expr %s", ast_kind[lhs->kind]);
+	}
+}
+#endif
+
 u32 gen_assign(Ast lhs, Ast expr) {
 	gen_trace("gen_assign()");
 
-	if ((lhs->kind == AST_LOCAL) ||
-	    (lhs->kind == AST_NAME)) {
+	if (lhs->kind == AST_NAME) {
 		u32 base;
 		i32 offset;
 		sym_get_loc(lhs->sym, &base, &offset);
@@ -296,6 +322,8 @@ u32 gen_assign(Ast lhs, Ast expr) {
 		return r;
 	} else if (lhs->kind == AST_INDEX) {
 		error("wip");
+	} else if (lhs->kind == AST_DEREF) {
+
 	} else {
 		err_ast = lhs;
 		error("illegal on lhs (%s)", ast_kind[lhs->kind]);
@@ -503,9 +531,6 @@ u32 gen_expr(Ast node) {
 	} else if (node->kind == AST_BINOP) {
 		u32 op = node->ival;
 		if (op == tASSIGN) {
-			if (node->c0->kind != AST_NAME) {
-				error("unhandled complex assignment");
-			}
 			return gen_assign(node->c0, node->c1);
 		} else if ((op & tcMASK) == tcRELOP) {
 			return gen_relop(node, rel_op_to_cc_tab[op - tEQ]);
@@ -637,11 +662,6 @@ void gen_stmt(Ast node) {
 	if (kind == AST_EXPR) {
 		u32 r = gen_expr(node->c0);
 		put_reg(r);
-	} else if (kind == AST_LOCAL) {
-		if (node->c0) {
-			u32 r = gen_assign(node, node->c0);
-			put_reg(r);
-		}
 	} else if (kind == AST_IF) {
 		gen_if_else(node);
 	} else if (kind == AST_WHILE) {
diff --git a/src/compiler2.c b/src/compiler2.c
@@ -88,7 +88,6 @@ enum {
 	AST_ENUMDEF,  // c2=FIELD*
 	AST_FUNC,     // c0=BLOCK
 	AST_GLOBAL,   // c0=EXPR
-	AST_LOCAL,    // c0=NAME c1=EXPR?
 	AST_FIELD,
 };
 
@@ -97,7 +96,7 @@ str ast_kind[AST_FIELD + 1] = {
 	"BLOCK", "EXPR", "CALL", "WHILE", "IF",
 	"RETURN", "BREAK", "CONTINUE", "IFELSE",
 	"PROGRAM", "TYPEDEF", "ENUMDEF", "FUNCDEF",
-	"GLOBAL", "LOCAL", "FIELD",
+	"GLOBAL", "FIELD",
 };
 
 struct AstRec {
@@ -323,8 +322,8 @@ Ast ast_make_const(ast_t kind, u32 x, Type type) {
 	return ast_make(kind, x, nil, nil, type);
 }
 
-Ast ast_make_name(String name) {
-	return ast_make(AST_NAME, 0, name, nil, nil);
+Ast ast_make_name(String name, Symbol sym) {
+	return ast_make(AST_NAME, 0, name, sym, sym->type);
 }
 
 // ================================================================
@@ -1127,9 +1126,7 @@ Ast parse_operand() {
 		if (sym == nil) {
 			error("undefined identifier '%s'", ctx.ident->text);
 		}
-		node = ast_make_name(ctx.ident);
-		node->sym = sym;
-		node->type = sym->type;
+		node = ast_make_name(ctx.ident, sym);
 	} else {
 		error("invalid expression");
 	}
@@ -1510,14 +1507,11 @@ Ast parse_local_var() {
 		ctx.local_stack = ctx.alloc_stack;
 	}
 
-	Ast node = ast_make_simple(AST_LOCAL, 0);
-	node->name = name;
-	node->type = type;
-	node->sym = sym;
-
+	Ast node = nil;
 	if (ctx.tok == tASSIGN) {
 		next();
-		node->c0 = parse_expr();
+		node = ast_make_simple(AST_EXPR, 0);
+		node->c0 = ast_make_binop(tASSIGN, ast_make_name(name, sym), parse_expr());
 	}
 	require(tSEMI);
 
@@ -1644,8 +1638,11 @@ Ast parse_block() {
 		}
 
 		// append to block's list of statements
-		last->c2 = node;
-		last = node;
+		// some of these don't always return a node (like local var)
+		if (node != nil) {
+			last->c2 = node;
+			last = node;
+		}
 	}
 	return block;
 }