Commit 1d6c804b29fed146aafda0f56cae7a4853b6abf9 | zig

author	Isaac Freund <mail@isaacfreund.com> 2021-05-18 23:09:28+02:00
committer	Andrew Kelley <andrew@ziglang.org> 2021-05-19 01:22:36-04:00
log	1d6c804b29fed146aafda0f56cae7a4853b6abf9
tree	14bd343538920798222de899203147826957d207
parent	8861ee18f7fe9559a02389f07c4e5cdc5a8ffbde

stage2: only default to linking system libc if linking system libs

We do need to link the system libc if linking system libraries as
they may potentially be compiled against e.g. a newer glibc version
than zig can provide. However if not linking system libraries, using
the zig provided libc is more reliable as it does not depend on any
quirks of the host system or being able to invoke the system cc to
find include dirs.

1 files changed, 15 insertions(+), 1 deletions(-)

src
- Compilation.zig

src/Compilation.zig+15-1

 @@ -951,6 +951,7 @@ pub fn create(gpa: *Allocator, options: InitOptions) !*Compilation {
             options.target,
             options.is_native_abi,
             link_libc,
+            options.system_libs.len != 0,
             options.libc_installation,
         );
 @@ -3129,6 +3130,7 @@ fn detectLibCIncludeDirs(
     target: Target,
     is_native_abi: bool,
     link_libc: bool,
+    link_system_libs: bool,
     libc_installation: ?*const LibCInstallation,
 ) !LibCDirs {
     if (!link_libc) {
 @@ -3142,12 +3144,16 @@ fn detectLibCIncludeDirs(
         return detectLibCFromLibCInstallation(arena, target, lci);
     }
-    if (is_native_abi) {
+    // If linking system libraries and targeting the native abi, default to
+    // using the system libc installation.
+    if (link_system_libs and is_native_abi) {
         const libc = try arena.create(LibCInstallation);
         libc.* = try LibCInstallation.findNative(.{ .allocator = arena, .verbose = true });
         return detectLibCFromLibCInstallation(arena, target, libc);
     }
+    // If not linking system libraries, build and provide our own libc by
+    // default if possible.
     if (target_util.canBuildLibC(target)) {
         const generic_name = target_util.libCGenericName(target);
         // Some architectures are handled by the same set of headers.
 @@ -3198,6 +3204,14 @@ fn detectLibCIncludeDirs(
         };
     }
+    // If zig can't build the libc for the target and we are targeting the
+    // native abi, fall back to using the system libc installation.
+    if (is_native_abi) {
+        const libc = try arena.create(LibCInstallation);
+        libc.* = try LibCInstallation.findNative(.{ .allocator = arena, .verbose = true });
+        return detectLibCFromLibCInstallation(arena, target, libc);
+    }
     return LibCDirs{
         .libc_include_dir_list = &[0][]u8{},
         .libc_installation = null,