From eb1bd725b710c9098e8ec7fb5254ce49da9f5e27 Mon Sep 17 00:00:00 2001
From: Gleb Mazovetskiy <glex.spb@gmail.com>
Date: Tue, 12 Sep 2023 08:02:24 +0100
Subject: [PATCH] Add an option to avoid wchar APIs on Windows

With this, fmt can be used on Windows 98 and the Original Xbox with:

    set(FMT_OS OFF)

It is not exposed as a CMake option but one can define it manually
in the fmt subproject, e.g.:

    target_compile_definitions(fmt PUBLIC FMT_WINDOWS_NO_WCHAR)

Fixes #3631
---
 include/fmt/core.h       | 2 +-
 include/fmt/format-inl.h | 4 ++--
 test/format-impl-test.cc | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/fmt/core.h b/include/fmt/core.h
index f9e3b7d6dc163..d5b7fbd03ab9c 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -2675,7 +2675,7 @@ void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
                 typename vformat_args<Char>::type args, locale_ref loc = {});
 
 FMT_API void vprint_mojibake(std::FILE*, string_view, format_args);
-#ifndef _WIN32
+#if !defined(_WIN32) || defined(FMT_WINDOWS_NO_WCHAR)
 inline void vprint_mojibake(std::FILE*, string_view, format_args) {}
 #endif
 }  // namespace detail
diff --git a/include/fmt/format-inl.h b/include/fmt/format-inl.h
index 553e7ce88d4b8..f4763bd7ac2e0 100644
--- a/include/fmt/format-inl.h
+++ b/include/fmt/format-inl.h
@@ -18,7 +18,7 @@
 #  include <locale>
 #endif
 
-#ifdef _WIN32
+#if defined(_WIN32) && !defined(FMT_WINDOWS_NO_WCHAR)
 #  include <io.h>  // _isatty
 #endif
 
@@ -1426,7 +1426,7 @@ FMT_FUNC std::string vformat(string_view fmt, format_args args) {
 }
 
 namespace detail {
-#ifndef _WIN32
+#if !defined(_WIN32) || defined(FMT_WINDOWS_NO_WCHAR)
 FMT_FUNC bool write_console(std::FILE*, string_view) { return false; }
 #else
 using dword = conditional_t<sizeof(long) == 4, unsigned long, unsigned>;
diff --git a/test/format-impl-test.cc b/test/format-impl-test.cc
index 1c468b4388aa9..4d6198b68d9f8 100644
--- a/test/format-impl-test.cc
+++ b/test/format-impl-test.cc
@@ -351,7 +351,7 @@ TEST(format_impl_test, write_dragon_even) {
   if (!FMT_MSC_VERSION) EXPECT_EQ(s, "33554450");
 }
 
-#ifdef _WIN32
+#if defined(_WIN32) && !defined(FMT_WINDOWS_NO_WCHAR)
 #  include <windows.h>
 
 TEST(format_impl_test, write_console_signature) {