harec

commit fa2b3a43dd98f64d34ec4024aab48dad84798a14
parent cf8f62f69138171d5983ab35ddf2bd6dda989fa9
Author: Eyal Sawady <ecs@d2evs.net>
Date:   Sun, 31 Jan 2021 17:58:51 -0500

Implement static assertions

Diffstat:
M
src/check.c
 | 
23
+++++++++++++++++++++++
M
src/gen.c
 | 
3
+++
M
src/parse.c
 | 
9
++-------

3 files changed, 28 insertions(+), 7 deletions(-)
diff --git a/src/check.c b/src/check.c
@@ -211,6 +211,7 @@ check_expr_assert(struct context *ctx,
 	trace(TR_CHECK, "assert");
 	expr->type = EXPR_ASSERT;
 	expr->result = &builtin_type_void;
+	expr->assert.is_static = aexpr->assert.is_static;
 
 	if (aexpr->assert.cond != NULL) {
 		expr->assert.cond = xcalloc(1, sizeof(struct expression));
@@ -242,6 +243,28 @@ check_expr_assert(struct context *ctx,
 		expr->assert.message->constant.string.value = s;
 		expr->assert.message->constant.string.len = n;
 	}
+
+	if (expr->assert.is_static) {
+		bool cond;
+		if (expr->assert.cond != NULL) {
+			struct expression out = {0};
+			enum eval_result r =
+				eval_expr(ctx, expr->assert.cond, &out);
+			expect(&aexpr->assert.cond->loc, r == EVAL_OK,
+				"Unable to evaluate static assertion at compile time");
+			assert(out.result->storage == TYPE_STORAGE_BOOL);
+			cond = out.constant.bval;
+		} else {
+			cond = false; 
+		}
+		if (aexpr->assert.message != NULL) {
+			expect(&aexpr->assert.cond->loc, cond,
+				"Static assertion failed: %s",
+				expr->assert.message->constant.string.value);
+		} else {
+			expect(&aexpr->loc, cond, "Static assertion failed");
+		}
+	}
 }
 
 static void
diff --git a/src/gen.c b/src/gen.c
@@ -644,6 +644,9 @@ gen_expr_assert(struct gen_context *ctx,
 	const struct qbe_value *out)
 {
 	assert(expr->assert.message); // Invariant
+	if (expr->assert.is_static) {
+		return;
+	}
 
 	struct qbe_statement failedl = {0}, passedl = {0};
 	struct qbe_value bfailed = {0}, bpassed = {0};
diff --git a/src/parse.c b/src/parse.c
@@ -983,7 +983,7 @@ parse_plain_expression(struct lexer *lexer)
 static struct ast_expression *
 parse_assertion_expression(struct lexer *lexer, bool is_static)
 {
-	trace(TR_PARSE, "assertion");
+	trace(TR_PARSE, is_static ? "static assertion" : "assertion");
 
 	struct ast_expression *exp = mkexpr(&lexer->loc);
 	exp->type = EXPR_ASSERT;
@@ -991,16 +991,11 @@ parse_assertion_expression(struct lexer *lexer, bool is_static)
 
 	struct token tok;
 	switch (lex(lexer, &tok)) {
-	case T_STATIC:
-		// XXX: The caller should deal with this for us
-		exp->assert.is_static = true;
-		lex(lexer, &tok);
-		break;
 	case T_ASSERT:
 	case T_ABORT:
 		break;
 	default:
-		synassert(false, &tok, T_STATIC, T_ASSERT, T_ABORT, T_EOF);
+		synassert(false, &tok, T_ASSERT, T_ABORT, T_EOF);
 	}
 
 	switch (tok.token) {