From ecebb0d9afd6e14914f4bbcda989950ad9dbe1d1 Mon Sep 17 00:00:00 2001
From: ashbob999 <ashbob999@gmail.com>
Date: Sat, 26 Oct 2024 22:43:38 +0100
Subject: [PATCH] Make: Fixed the stringzillite still having dependencies dlls
 on windows

---
 CMakeLists.txt | 10 ----------
 c/lib.c        | 25 ++++++++++++++++++++++---
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 50c9312..780a893 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -361,16 +361,6 @@ if(${STRINGZILLA_BUILD_SHARED})
         "SZ_USE_ARM_NEON=1"
         "SZ_USE_ARM_SVE=$<IF:$<CXX_COMPILER_ID:MSVC>,0,1>")
     endif()
-
-    if (MSVC)
-      # Add dependencies for necessary runtime libraries in case of static linking
-      # This ensures that basic runtime functions are available:
-      # msvcrt.lib: Microsoft Visual C Runtime, required for basic C runtime functions on Windows.
-      # vcruntime.lib: Microsoft Visual C++ Runtime library for basic runtime functions.
-      # ucrt.lib: Universal C Runtime, necessary for linking basic C functions like I/O.
-      target_link_libraries(${target} PRIVATE msvcrt.lib vcruntime.lib ucrt.lib)
-    endif()
-
   endfunction()
 
   define_shared(stringzilla_shared)
diff --git a/c/lib.c b/c/lib.c
index c6b403e..2b45896 100644
--- a/c/lib.c
+++ b/c/lib.c
@@ -144,7 +144,7 @@ __attribute__((aligned(64))) static sz_implementations_t sz_dispatch_table;
  *  @brief  Initializes a global static "virtual table" of supported backends
  *          Run it just once to avoiding unnecessary `if`-s.
  */
-static void sz_dispatch_table_init(void) {
+SZ_DYNAMIC void sz_dispatch_table_init(void) {
     sz_implementations_t *impl = &sz_dispatch_table;
     sz_capability_t caps = sz_capabilities();
     sz_unused(caps); //< Unused when compiling on pre-SIMD machines.
@@ -232,9 +232,20 @@ static void sz_dispatch_table_init(void) {
 }
 
 #if defined(_MSC_VER)
-#pragma section(".CRT$XCU", read)
-__declspec(allocate(".CRT$XCU")) void (*_sz_dispatch_table_init)() = sz_dispatch_table_init;
 
+/*
+ * Makes sure the sz_dispatch_table_init function is called at startup, from either an executable or when loading a DLL.
+ * The section name must be no more than 8 characters long, and must be between .CRT$XCA and .CRT$XCZ alphabetically
+ * (exclusive).
+ * The Mircrosft C++ compiler puts C++ initialisation code in .CRT$XCU, so avoid that section.
+ *
+ * Reference: https://learn.microsoft.com/en-us/cpp/c-runtime-library/crt-initialization?view=msvc-170
+ */
+#pragma comment(linker, "/INCLUDE:_sz_dispatch_table_init")
+#pragma section(".CRT$XCS", read)
+__declspec(allocate(".CRT$XCS")) void (*_sz_dispatch_table_init)() = sz_dispatch_table_init;
+
+// Called either from CRT code or out own _DLLMainCRTStartup, when a DLL is loaded.
 BOOL WINAPI DllMain(HINSTANCE hints, DWORD forward_reason, LPVOID lp) {
     switch (forward_reason) {
     case DLL_PROCESS_ATTACH:
@@ -247,6 +258,14 @@ BOOL WINAPI DllMain(HINSTANCE hints, DWORD forward_reason, LPVOID lp) {
     return TRUE;
 }
 
+#if SZ_AVOID_LIBC
+// Called when the DLL is loaded, and ther is no CRT code.
+BOOL WINAPI _DllMainCRTStartup(HINSTANCE hints, DWORD forward_reason, LPVOID lp) {
+    DllMain(hints, forward_reason, lp);
+    return TRUE;
+}
+#endif
+
 #else
 __attribute__((constructor)) static void sz_dispatch_table_init_on_gcc_or_clang(void) { sz_dispatch_table_init(); }
 #endif