- Assert on optional-returning-function in a comma expression. #2722

releasenotes.md

@@ -52,6 +52,7 @@
 - `io::read_fully` now handles unbounded streams properly.
 - Crash when doing a type property lookup for const inline enums in some cases #2717.
 - Incorrect alignment on typedef and local variable debug info.
+- Assert on optional-returning-function in a comma expression. #2722
 
 ### Stdlib changes
 - Add `ThreadPool` join function to wait for all threads to finish in the pool without destroying the threads.

src/compiler/llvm_codegen_stmt.c

@@ -197,8 +197,7 @@ static void llvm_emit_cond(GenContext *c, BEValue *be_value, Expr *expr, bool bo
 	ByteSize last_index = size - 1;
 	for (ByteSize i = 0; i < last_index; i++)
 	{
-		BEValue value;
+		llvm_emit_ignored_expr(c, expr->cond_expr[i]);
-		llvm_emit_expr(c, &value, expr->cond_expr[i]);
 	}
 
 	// Emit the last element.

src/compiler/llvm_codegen_value.c

@@ -129,6 +129,10 @@ void llvm_value_rvalue(GenContext *c, BEValue *value)
 
 void llvm_emit_jump_to_optional_exit(GenContext *c, LLVMValueRef opt_value)
 {
+	if (!c->catch.block)
+	{
+		puts("foekf");
+	}
 	ASSERT_AT(c->last_emitted_loc, c->catch.block && "unexpected emit");
 	bool is_constant_opt = llvm_is_const(opt_value);
 

src/compiler/sema_stmts.c

@@ -1121,7 +1121,9 @@ static inline bool sema_analyse_cond_list(SemaContext *context, Expr *expr, Cond
 	// 2. Walk through each of our declarations / expressions as if they were regular expressions.
 	for (unsigned i = 0; i < entries - 1; i++)
 	{
-		if (!sema_analyse_expr_rvalue(context, dexprs[i])) return false;
+		Expr *dexpr = dexprs[i];
+		if (!sema_analyse_expr_rvalue(context, dexpr)) return false;
+		if (!sema_expr_check_discard(context, dexpr)) return false;
 	}
 
 	if (!sema_analyse_last_cond(context, dexprs[entries - 1], cond_type, result)) return false;

test/test_suite/errors/discard_in_cond_valid.c3t

@@ -0,0 +1,8 @@
+module main;
+
+fn int? may_fault() @maydiscard => 2;
+
+fn void main()
+{
+    if (may_fault(), true);
+}

test/test_suite/errors/optional_discard_in_cond.c3

@@ -0,0 +1,8 @@
+module main;
+
+fn int? may_fault() => 2;
+
+fn void main()
+{
+    if (may_fault(), true); // #error: You can either assign it to a variable
+}

test/test_suite/errors/try_with_chained_unwrap_errors.c3

@@ -59,7 +59,7 @@ fn void test8()
 {
     int? a;
     int e;
-    if (e == 0, try c = a && try d = a && e > 0) {}
+    if (e = 3, try c = a && try d = a && e > 0) {}
     if (try b = a && try c = a && e > 0) {}
     if (try c = a && try d = a) { c++; }
 }