From ff6d563b0455aea51775e6906f5e7f0dd67b7127 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Fri, 21 Jun 2019 17:49:54 -0400
Subject: [PATCH] fix implicit cast to optional to error union to return result
 loc

---
 src/analyze.cpp                |  2 ++
 src/ir.cpp                     |  9 ++++-----
 test/stage1/behavior/error.zig | 18 ++++++++++++++++++
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/src/analyze.cpp b/src/analyze.cpp
index d048dd977..85e390f2e 100644
--- a/src/analyze.cpp
+++ b/src/analyze.cpp
@@ -4512,6 +4512,8 @@ bool fn_eval_cacheable(Scope *scope, ZigType *return_type) {
             ScopeVarDecl *var_scope = (ScopeVarDecl *)scope;
             if (type_is_invalid(var_scope->var->var_type))
                 return false;
+            if (var_scope->var->const_value->special == ConstValSpecialUndef)
+                return false;
             if (can_mutate_comptime_var_state(var_scope->var->const_value))
                 return false;
         } else if (scope->id == ScopeIdFnDef) {
diff --git a/src/ir.cpp b/src/ir.cpp
index 425c22530..a6ec836a4 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -15092,7 +15092,9 @@ static IrInstruction *ir_resolve_result_raw(IrAnalyze *ira, IrInstruction *suspe
             ZigType *ptr_return_type = get_pointer_to_type(ira->codegen, ira->explicit_return_type, false);
             result_loc->written = true;
             result_loc->resolved_loc = ir_build_return_ptr(ira, result_loc->source_instruction, ptr_return_type);
-            set_up_result_loc_for_inferred_comptime(result_loc->resolved_loc);
+            if (ir_should_inline(ira->old_irb.exec, result_loc->source_instruction->scope)) {
+                set_up_result_loc_for_inferred_comptime(result_loc->resolved_loc);
+            }
             return result_loc->resolved_loc;
         }
         case ResultLocIdPeer: {
@@ -15207,9 +15209,6 @@ static IrInstruction *ir_resolve_result_raw(IrAnalyze *ira, IrInstruction *suspe
                     parent_ptr_type->data.pointer.is_const, parent_ptr_type->data.pointer.is_volatile, PtrLenSingle,
                     parent_ptr_align, 0, 0, parent_ptr_type->data.pointer.allow_zero);
 
-            if (value->value.special == ConstValSpecialRuntime) {
-                parent_result_loc->value.special = ConstValSpecialRuntime;
-            }
             result_loc->written = true;
             result_loc->resolved_loc = ir_analyze_ptr_cast(ira, suspend_source_instr, parent_result_loc,
                     ptr_type, result_bit_cast->base.source_instruction, false);
@@ -15388,7 +15387,7 @@ static bool ir_analyze_fn_call_inline_arg(IrAnalyze *ira, AstNode *fn_proto_node
         casted_arg = arg;
     }
 
-    ConstExprValue *arg_val = ir_resolve_const(ira, casted_arg, UndefBad);
+    ConstExprValue *arg_val = ir_resolve_const(ira, casted_arg, UndefOk);
     if (!arg_val)
         return false;
 
diff --git a/test/stage1/behavior/error.zig b/test/stage1/behavior/error.zig
index 82ddc72b7..264f140c9 100644
--- a/test/stage1/behavior/error.zig
+++ b/test/stage1/behavior/error.zig
@@ -357,3 +357,21 @@ test "nested catch" {
     S.entry();
     comptime S.entry();
 }
+
+test "implicit cast to optional to error union to return result loc" {
+    const S = struct {
+        fn entry() void {
+            if (func(undefined)) |opt| {
+                expect(opt != null);
+            } else |_| @panic("expected non error");
+        }
+        fn func(f: *Foo) anyerror!?*Foo {
+            return f;
+        }
+        const Foo = struct {
+            field: i32,
+        };
+    };
+    S.entry();
+    //comptime S.entry(); TODO
+}