cmake: fix handling of transitive zstd dependency

- Remove ZIG_ENABLE_ZSTD in favour of allowing ZIG_STATIC_ZSTD to be toggled off explicitly when ZIG_STATIC is on
- Remove ZIG_ENABLE_LIBCPP (now unused)

Author: kcbanner

CMakeLists.txt

@@ -89,11 +89,9 @@ endif()
 
 set(ZIG_STATIC off CACHE BOOL "Attempt to build a static zig executable (not compatible with glibc)")
 set(ZIG_SHARED_LLVM off CACHE BOOL "Prefer linking against shared LLVM libraries")
-set(ZIG_STATIC_LLVM off CACHE BOOL "Prefer linking against static LLVM libraries")
-set(ZIG_STATIC_ZLIB off CACHE BOOL "Prefer linking against static zlib")
-set(ZIG_ENABLE_ZSTD on CACHE BOOL "Enable linking zstd")
-set(ZIG_ENABLE_LIBCPP on CACHE BOOL "Enable linking libcpp")
-set(ZIG_STATIC_ZSTD off CACHE BOOL "Prefer linking against static zstd")
+set(ZIG_STATIC_LLVM ${ZIG_STATIC} CACHE BOOL "Prefer linking against static LLVM libraries")
+set(ZIG_STATIC_ZLIB ${ZIG_STATIC} CACHE BOOL "Prefer linking against static zlib")
+set(ZIG_STATIC_ZSTD ${ZIG_STATIC} CACHE BOOL "Prefer linking against static zstd")
 set(ZIG_USE_CCACHE off CACHE BOOL "Use ccache")
 
 if(ZIG_USE_CCACHE)
@@ -105,12 +103,6 @@ if(ZIG_USE_CCACHE)
     endif()
 endif()
 
-if(ZIG_STATIC)
-    set(ZIG_STATIC_LLVM ON)
-    set(ZIG_STATIC_ZLIB ON)
-    set(ZIG_STATIC_ZSTD ON)
-endif()
-
 if (ZIG_SHARED_LLVM AND ZIG_STATIC_LLVM)
     message(SEND_ERROR "-DZIG_SHARED_LLVM and -DZIG_STATIC_LLVM cannot both be enabled simultaneously")
 endif()
@@ -150,8 +142,13 @@ if(ZIG_STATIC_ZLIB)
     list(APPEND LLVM_LIBRARIES "${ZLIB}")
 endif()
 
-if(ZIG_STATIC_ZSTD AND ZIG_ENABLE_ZSTD)
-    list(REMOVE_ITEM LLVM_SYSTEM_LIBRARIES "-lzstd")
+if(ZIG_STATIC_ZSTD)
+    if (MSVC)
+        list(REMOVE_ITEM LLVM_SYSTEM_LIBRARIES "zstd.lib")
+    else()
+        list(REMOVE_ITEM LLVM_SYSTEM_LIBRARIES "-lzstd")
+    endif()
+
     find_library(ZSTD NAMES libzstd.a libzstdstatic.a zstd NAMES_PER_DIR)
     list(APPEND LLVM_LIBRARIES "${ZSTD}")
 endif()