hare

commit aba521506ff6c227f02483bcca47bca1f8646b1a
parent d5a5d2e1f205aaa313f2d74bb43279be935e80f2
Author: Drew DeVault <sir@cmpwn.com>
Date:   Mon, 23 Aug 2021 13:04:07 +0200

cmd/harec: basic gen_expr_const implementation

I'm not going to finish this until we simplify lex::value. The basic
idea is to also introduce:

	type ast::value = lex::value;
	type unit::value = ast::value;

Then I also want to merge bool, null, and void, into lex::value.

Signed-off-by: Drew DeVault <sir@cmpwn.com>

Diffstat:
M
cmd/harec/gen.ha
 | 
23
+++++++++++++++++++++--
M
cmd/harec/qbe.ha
 | 
3
++-

2 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/cmd/harec/gen.ha b/cmd/harec/gen.ha
@@ -1,6 +1,7 @@
 use bufio;
 use fmt;
 use hare::ast;
+use hare::lex;
 use hare::module;
 use hare::types;
 use hare::unit;
@@ -63,12 +64,30 @@ fn gen_func(ctx: *context, decl: *unit::decl) void = {
 
 	fmt::fprintln(ctx.out, mklabel(ctx, "body"))!;
 	gen_expr(ctx, fndecl.body: *unit::expr);
+	emit(ctx, void, qinstr::RET); // TODO
 
 	io::write(os::stdout, bufio::buffer(ctx.out))!;
 	fmt::println("}\n")!;
 };
 
 fn gen_expr(ctx: *context, expr: *unit::expr) value = {
-	emit(ctx, void, qinstr::RET); // TODO
-	return vvoid;
+	match (expr.expr) {
+		unit::constant_expr => return gen_expr_const(ctx, expr),
+		* => abort(), // TODO
+	};
+	abort(); // Unreachable
+};
+
+fn gen_expr_const(ctx: *context, expr: *unit::expr) value = {
+	const constexpr = expr.expr as unit::constant_expr;
+	const val: qval = match (constexpr) {
+		void => return vvoid,
+		b: bool => (if (b) 1u32 else 0u32): constant,
+		unit::_null => 0u64, // XXX: Arch
+		v: lex::value => abort(), // TODO
+	};
+	return value {
+		value = val,
+		_type = expr.result,
+	};
 };
diff --git a/cmd/harec/qbe.ha b/cmd/harec/qbe.ha
@@ -4,9 +4,10 @@ type global = str;
 type temporary = str;
 type qvoid = void;
 type constant = (u32 | u64 | f32 | f64 | str | qvoid);
+type qval = (global | temporary | constant);
 
 type value = struct {
-	value: (global | temporary | constant),
+	value: qval,
 	_type: const *types::_type,
 };