harec

commit 934349a5b9b12e914f422b23af207bb6c70a88c2
parent 3f6c4d6ec990739d04b2ccd04151087869c39581
Author: Drew DeVault <sir@cmpwn.com>
Date:   Fri, 13 Aug 2021 14:52:56 +0200

gen: abort when reaching supposedly unreachable code

This can be expanded

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

Diffstat:
M
include/gen.h
 | 
1
+
M
rt/abort.ha
 | 
1
+
M
src/gen.c
 | 
16
++++++++++++++++

3 files changed, 18 insertions(+), 0 deletions(-)
diff --git a/include/gen.h b/include/gen.h
@@ -11,6 +11,7 @@ enum fixed_aborts {
 	ABORT_TYPE_ASSERTION = 1,
 	ABORT_ALLOC_FAILURE = 2,
 	ABORT_STATIC_EXCEEDED = 3,
+	ABORT_UNREACHABLE = 4,
 };
 
 struct gen_arch {
diff --git a/rt/abort.ha b/rt/abort.ha
@@ -11,6 +11,7 @@ const reasons: [_]str = [
 	"slice or array access out of bounds",	// 0
 	"type assertion failed",		// 1
 	"out of memory",			// 2
+	"unreachable code",			// 3
 ];
 
 export @noreturn fn abort_fixed(loc: str, i: int) void = {
diff --git a/src/gen.c b/src/gen.c
@@ -2107,8 +2107,16 @@ next:
 	if (_default) {
 		bval = gen_expr_with(ctx, _default->value, out);
 		branch_copyresult(ctx, bval, gvout, out);
+		if (!_default->value->terminates) {
+			pushi(ctx->current, NULL, Q_JMP, &bout, NULL);
+		}
 	}
 
+	struct qbe_statement labort;
+	mklabel(ctx, &labort, ".%d");
+	push(&ctx->current->body, &labort);
+	gen_fixed_abort(ctx, expr->loc, ABORT_UNREACHABLE);
+
 	push(&ctx->current->body, &lout);
 	return gvout;
 }
@@ -2294,8 +2302,16 @@ gen_expr_switch_with(struct gen_context *ctx,
 	if (_default) {
 		bval = gen_expr_with(ctx, _default->value, out);
 		branch_copyresult(ctx, bval, gvout, out);
+		if (!_default->value->terminates) {
+			pushi(ctx->current, NULL, Q_JMP, &bout, NULL);
+		}
 	}
 
+	struct qbe_statement labort;
+	mklabel(ctx, &labort, ".%d");
+	push(&ctx->current->body, &labort);
+	gen_fixed_abort(ctx, expr->loc, ABORT_UNREACHABLE);
+
 	push(&ctx->current->body, &lout);
 	return gvout;
 }