macos: better SDK version detection

SDK version detection:
- read SDKSettings.json before inferral from SDK path
- vendored libc: add SDKSettings.json for SDK version info

resolveLibSystem:
- adjust search order to { search_dirs, { sysroot or vendored }}
- previous search order was { sysroot, search_dirs, vendored }

1 files changed, 7 insertions, 0 deletions

diff --git a/src/Compilation.zig b/src/Compilation.zig
index 7cbb64e6c0..e9f6be89fd 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -1554,6 +1554,7 @@ pub fn create(gpa: Allocator, options: InitOptions) !*Compilation {
             .use_lld = use_lld,
             .use_llvm = use_llvm,
             .use_lib_llvm = use_lib_llvm,
+            .libc_provider = libc_dirs.provider,
             .link_libc = link_libc,
             .link_libcpp = link_libcpp,
             .link_libunwind = link_libunwind,
@@ -5654,6 +5655,7 @@ const LibCDirs = struct {
     libc_installation: ?*const LibCInstallation,
     libc_framework_dir_list: []const []const u8,
     sysroot: ?[]const u8,
+    provider: link.LibCProvider,
 };
 
 fn getZigShippedLibCIncludeDirsDarwin(arena: Allocator, zig_lib_dir: []const u8) !LibCDirs {
@@ -5669,6 +5671,7 @@ fn getZigShippedLibCIncludeDirsDarwin(arena: Allocator, zig_lib_dir: []const u8)
         .libc_installation = null,
         .libc_framework_dir_list = &.{},
         .sysroot = null,
+        .provider = .vendored,
     };
 }
 
@@ -5686,6 +5689,7 @@ pub fn detectLibCIncludeDirs(
             .libc_installation = null,
             .libc_framework_dir_list = &.{},
             .sysroot = null,
+            .provider = .none,
         };
     }
 
@@ -5743,6 +5747,7 @@ pub fn detectLibCIncludeDirs(
         .libc_installation = null,
         .libc_framework_dir_list = &.{},
         .sysroot = null,
+        .provider = .none,
     };
 }
 
@@ -5797,6 +5802,7 @@ fn detectLibCFromLibCInstallation(arena: Allocator, target: Target, lci: *const
         .libc_installation = lci,
         .libc_framework_dir_list = framework_list.items,
         .sysroot = sysroot,
+        .provider = if (sysroot == null) .installation else .sysroot,
     };
 }
 
@@ -5858,6 +5864,7 @@ fn detectLibCFromBuilding(
         .libc_installation = null,
         .libc_framework_dir_list = &.{},
         .sysroot = null,
+        .provider = .vendored,
     };
 }