3 files changed, 22 insertions, 1 deletions
diff --git a/src/all_types.hpp b/src/all_types.hpp
index 7378e4d6e4..e7e925f42f 100644
--- a/src/all_types.hpp
+++ b/src/all_types.hpp
@@ -1033,6 +1033,7 @@ enum BuiltinFnId {
     BuiltinFnIdCDefine,
     BuiltinFnIdCUndef,
     BuiltinFnIdCompileVar,
+    BuiltinFnIdConstEval,
 };
 
 struct BuiltinFnEntry {
diff --git a/src/analyze.cpp b/src/analyze.cpp
index d6485d0312..2b8119ed48 100644
--- a/src/analyze.cpp
+++ b/src/analyze.cpp
@@ -4127,8 +4127,26 @@ static TypeTableEntry *analyze_builtin_fn_call_expr(CodeGen *g, ImportTableEntry
                         buf_sprintf("unrecognized compile variable: '%s'", buf_ptr(&var_name)));
                     return g->builtin_types.entry_invalid;
                 }
+            }
+        case BuiltinFnIdConstEval:
+            {
+                AstNode **expr_node = node->data.fn_call_expr.params.at(0)->parent_field;
+                TypeTableEntry *resolved_type = analyze_expression(g, import, context, expected_type, *expr_node);
+                if (resolved_type->id == TypeTableEntryIdInvalid) {
+                    return resolved_type;
+                }
 
-                break;
+                ConstExprValue *const_expr_val = &get_resolved_expr(*expr_node)->const_val;
+
+                if (!const_expr_val->ok) {
+                    add_node_error(g, *expr_node, buf_sprintf("unable to evaluate constant expression"));
+                    return resolved_type;
+                }
+
+                ConstExprValue *const_val = &get_resolved_expr(node)->const_val;
+                *const_val = *const_expr_val;
+
+                return resolved_type;
             }
 
     }
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 6ef2a92158..43e78ce194 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -310,6 +310,7 @@ static LLVMValueRef gen_builtin_fn_call_expr(CodeGen *g, AstNode *node) {
         case BuiltinFnIdMaxValue:
         case BuiltinFnIdMemberCount:
         case BuiltinFnIdCompileVar:
+        case BuiltinFnIdConstEval:
             // caught by constant expression eval codegen
             zig_unreachable();
     }
@@ -3513,6 +3514,7 @@ static void define_builtin_fns(CodeGen *g) {
     create_builtin_fn_with_arg_count(g, BuiltinFnIdCDefine, "c_define", 2);
     create_builtin_fn_with_arg_count(g, BuiltinFnIdCUndef, "c_undef", 1);
     create_builtin_fn_with_arg_count(g, BuiltinFnIdCompileVar, "compile_var", 1);
+    create_builtin_fn_with_arg_count(g, BuiltinFnIdConstEval, "const_eval", 1);
 }