[file_sys/system_archive] remove uneeded ctor/dtor initializations for std::map<> when creating system archives for nx_tzdb generated files (#3919)

sounds like word salad but let me say:

- std::map<> created a static ctor for EVERY SINGLE ZONEINFO
- fuck that, instead lets just use a raw array and construct things statically
- works the same except with less baggage carried around (+ less heap allocations!!!)

this should help reduce codesize due to the aforementioned global ctor/dtor

Signed-off-by: lizzie <lizzie@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3919
Reviewed-by: crueter <crueter@eden-emu.dev>

2 files changed, 24 insertions, 9 deletions

diff --git a/externals/nx_tzdb/NxTzdbCreateHeader.cmake b/externals/nx_tzdb/NxTzdbCreateHeader.cmake
index 95606d8629..229c8aa43d 100644
--- a/externals/nx_tzdb/NxTzdbCreateHeader.cmake
+++ b/externals/nx_tzdb/NxTzdbCreateHeader.cmake
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+# SPDX-License-Identifier: GPL-3.0-or-later
+
 # SPDX-FileCopyrightText: 2023 yuzu Emulator Project
 # SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -16,15 +19,24 @@ if (NOT FILE_LIST)
 endif()
 
 set(DIRECTORY_NAME ${HEADER_NAME})
-
 set(FILE_DATA "")
+
+string(APPEND FILE_DATA "[[nodiscard]] static inline std::vector<FileSys::VirtualFile> CollectFiles_${DIRECTORY_NAME}() {\n")
+string(APPEND FILE_DATA [[
+    std::vector<FileSys::VirtualFile> vfs_files;
+    auto const fn = [&](std::string_view name, std::span<const u8> data) {
+        vfs_files.push_back(std::make_shared<FileSys::VectorVfsFile>(
+            std::vector<u8>(data.begin(), data.end()),
+            std::string{name}
+        ));
+    };
+]])
 foreach(ZONE_FILE ${FILE_LIST})
     if (ZONE_FILE STREQUAL "\n")
         continue()
     endif()
-
-    string(APPEND FILE_DATA "{\"${ZONE_FILE}\",\n{")
-
+    string(APPEND FILE_DATA "  {\n")
+    string(APPEND FILE_DATA "    constexpr uint8_t tzdb_data[] = {\n")
     file(READ ${ZONE_PATH}/${ZONE_FILE} ZONE_DATA HEX)
     string(LENGTH "${ZONE_DATA}" ZONE_DATA_LEN)
     foreach(I RANGE 0 ${ZONE_DATA_LEN} 2)
@@ -42,9 +54,12 @@ foreach(ZONE_FILE ${FILE_LIST})
             string(APPEND FILE_DATA " ")
         endif()
     endforeach()
-
-    string(APPEND FILE_DATA "}},\n")
+    string(APPEND FILE_DATA "    };\n")
+    string(APPEND FILE_DATA "    fn(\"${ZONE_FILE}\", tzdb_data);\n")
+    string(APPEND FILE_DATA "  }\n")
 endforeach()
+string(APPEND FILE_DATA "  return vfs_files;\n")
+string(APPEND FILE_DATA "}\n")
 
 file(READ ${NX_TZDB_SOURCE_DIR}/tzdb_template.h.in NX_TZDB_TEMPLATE_H_IN)
 file(CONFIGURE OUTPUT ${NX_TZDB_INCLUDE_DIR}/nx_tzdb/${HEADER_NAME}.h CONTENT "${NX_TZDB_TEMPLATE_H_IN}")
diff --git a/externals/nx_tzdb/tzdb_template.h.in b/externals/nx_tzdb/tzdb_template.h.in
index 289d002ea8..d7907b846d 100644
--- a/externals/nx_tzdb/tzdb_template.h.in
+++ b/externals/nx_tzdb/tzdb_template.h.in
@@ -9,10 +9,10 @@
 
 namespace NxTzdb {
 
+// @DIRECTORY_NAME@
+
 // clang-format off
-const static std::map<const char*, const std::vector<uint8_t>> @DIRECTORY_NAME@ = 
-{
-@FILE_DATA@};
+@FILE_DATA@
 // clang-format on
 
 } // namespace NxTzdb