Commit 2d2a6ed1a4

@@ -1151,6 +1151,9 @@ pub const Scope = struct {
 
         is_comptime: bool,
 
+        /// when null, it is determined by build mode, changed by @setRuntimeSafety
+        want_safety: ?bool = null,
+
         /// This `Block` maps a block ZIR instruction to the corresponding
         /// AIR instruction for break instruction analysis.
         pub const Label = struct {
@@ -1195,12 +1198,12 @@ pub const Scope = struct {
                 .runtime_cond = parent.runtime_cond,
                 .runtime_loop = parent.runtime_loop,
                 .runtime_index = parent.runtime_index,
+                .want_safety = parent.want_safety,
             };
         }
 
         pub fn wantSafety(block: *const Block) bool {
-            // TODO take into account scope's safety overrides
-            return switch (block.sema.mod.optimizeMode()) {
+            return block.want_safety orelse switch (block.sema.mod.optimizeMode()) {
                 .Debug => true,
                 .ReleaseSafe => true,
                 .ReleaseFast => false,

@@ -2040,8 +2040,12 @@ fn zirSetFloatMode(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Index) Inner
 
 fn zirSetRuntimeSafety(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Index) InnerError!void {
     const inst_data = sema.code.instructions.items(.data)[inst].un_node;
-    const src: LazySrcLoc = inst_data.src();
-    return sema.mod.fail(&block.base, src, "TODO: implement Sema.zirSetRuntimeSafety", .{});
+    const operand_src: LazySrcLoc = .{ .node_offset_builtin_call_arg0 = inst_data.src_node };
+
+    const op = try sema.resolveInst(inst_data.operand);
+    const op_coerced = try sema.coerce(block, Type.initTag(.bool), op, operand_src);
+    const b = (try sema.resolveConstValue(block, operand_src, op_coerced)).toBool();
+    block.want_safety = b;
 }
 
 fn zirBreakpoint(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Index) InnerError!void {