From 4ffc2bbb5ec6993802a59f358c4316375615a27c Mon Sep 17 00:00:00 2001
From: kcbanner <kcbanner@gmail.com>
Date: Tue, 1 Nov 2022 23:11:52 -0400
Subject: [PATCH] cmake: handle llvm system libraries separately from the llvm
 libraries themselves, to fix path issues on windows

---
 build.zig            | 24 ++++++++++++++++++++++++
 cmake/Findllvm.cmake | 11 ++++++++---
 stage1/config.h.in   |  1 +
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/build.zig b/build.zig
index c11329dbf3..61b2a08b09 100644
--- a/build.zig
+++ b/build.zig
@@ -552,6 +552,7 @@ fn addCmakeCfgOptionsToExe(
     addCMakeLibraryList(exe, cfg.clang_libraries);
     addCMakeLibraryList(exe, cfg.lld_libraries);
     addCMakeLibraryList(exe, cfg.llvm_libraries);
+    addCMakeSystemLibraryList(exe, cfg.llvm_system_libraries);
 
     if (use_zig_libcxx) {
         exe.linkLibCpp();
@@ -679,6 +680,23 @@ fn addCMakeLibraryList(exe: *std.build.LibExeObjStep, list: []const u8) void {
     }
 }
 
+fn addCMakeSystemLibraryList(exe: *std.build.LibExeObjStep, list: []const u8) void {
+    var it = mem.tokenize(u8, list, ";");
+    while (it.next()) |lib| {
+        var start_offset: usize = 0;
+        var end_offset: usize = 0;
+        if (mem.startsWith(u8, lib, "-l")) {
+            start_offset = "-l".len;
+        }
+
+        if (exe.target.isWindows() and mem.endsWith(u8, lib, ".lib")) {
+            end_offset = ".lib".len;
+        }
+
+        exe.linkSystemLibrary(lib[start_offset..lib.len - end_offset]);
+    }
+}
+
 const CMakeConfig = struct {
     llvm_linkage: std.build.LibExeObjStep.Linkage,
     cmake_binary_dir: []const u8,
@@ -692,6 +710,7 @@ const CMakeConfig = struct {
     llvm_lib_dir: []const u8,
     llvm_include_dir: []const u8,
     llvm_libraries: []const u8,
+    llvm_system_libraries: []const u8,
     dia_guids_lib: []const u8,
 };
 
@@ -757,6 +776,7 @@ fn parseConfigH(b: *Builder, config_h_text: []const u8) ?CMakeConfig {
         .llvm_lib_dir = undefined,
         .llvm_include_dir = undefined,
         .llvm_libraries = undefined,
+        .llvm_system_libraries = undefined,
         .dia_guids_lib = undefined,
     };
 
@@ -797,6 +817,10 @@ fn parseConfigH(b: *Builder, config_h_text: []const u8) ?CMakeConfig {
             .prefix = "#define ZIG_LLVM_LIBRARIES ",
             .field = "llvm_libraries",
         },
+        .{
+            .prefix = "#define ZIG_LLVM_SYSTEM_LIBRARIES ",
+            .field = "llvm_system_libraries",
+        },
         .{
             .prefix = "#define ZIG_DIA_GUIDS_LIB ",
             .field = "dia_guids_lib",
diff --git a/cmake/Findllvm.cmake b/cmake/Findllvm.cmake
index 60a52056d8..87059f9f1d 100644
--- a/cmake/Findllvm.cmake
+++ b/cmake/Findllvm.cmake
@@ -5,6 +5,7 @@
 # LLVM_FOUND
 # LLVM_INCLUDE_DIRS
 # LLVM_LIBRARIES
+# LLVM_SYSTEM_LIBRARIES
 # LLVM_LIBDIRS
 # LLVM_LINK_MODE
 
@@ -172,9 +173,9 @@ if(ZIG_USE_LLVM_CONFIG)
         OUTPUT_STRIP_TRAILING_WHITESPACE)
     string(REPLACE " " ";" LLVM_STATIC_SYSTEM_LIBS "${LLVM_STATIC_SYSTEM_LIBS_SPACES}")
 
-    set(LLVM_LIBRARIES ${LLVM_LIBRARIES} ${LLVM_SYSTEM_LIBS} ${LLVM_STATIC_SYSTEM_LIBS})
+    set(LLVM_SYSTEM_LIBRARIES ${LLVM_SYSTEM_LIBS} ${LLVM_STATIC_SYSTEM_LIBS})
   else()
-    set(LLVM_LIBRARIES ${LLVM_LIBRARIES} ${LLVM_SYSTEM_LIBS})
+    set(LLVM_SYSTEM_LIBRARIES ${LLVM_SYSTEM_LIBS})
   endif()
 
   execute_process(
@@ -369,7 +370,11 @@ else()
   find_path(LLVM_INCLUDE_DIRS NAMES llvm/IR/IRBuilder.h)
 endif()
 
+if(NOT LLVM_SYSTEM_LIBRARIES)
+    set(LLVM_SYSTEM_LIBRARIES "")
+endif()
+
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(llvm DEFAULT_MSG LLVM_LIBRARIES LLVM_INCLUDE_DIRS)
 
-mark_as_advanced(LLVM_INCLUDE_DIRS LLVM_LIBRARIES LLVM_LIBDIRS)
+mark_as_advanced(LLVM_INCLUDE_DIRS LLVM_LIBRARIES LLVM_SYSTEM_LIBRARIES LLVM_LIBDIRS)
diff --git a/stage1/config.h.in b/stage1/config.h.in
index 0f1d902ef9..4ec1aa1fa6 100644
--- a/stage1/config.h.in
+++ b/stage1/config.h.in
@@ -28,5 +28,6 @@
 #define ZIG_LLVM_LIBRARIES "@LLVM_LIBRARIES@"
 #define ZIG_LLVM_LIB_PATH "@LLVM_LIBDIRS@"
 #define ZIG_LLVM_LINK_MODE "@LLVM_LINK_MODE@"
+#define ZIG_LLVM_SYSTEM_LIBRARIES "@LLVM_SYSTEM_LIBRARIES@"
 
 #endif