CLI: resolve system libs into static libraries

using the provided -L directories before checking if we need to integrate
with system library paths. This prevents false positive of invoking
system cc to find native paths when in fact all dependencies are
satisfied by -L (or --search-prefix to zig build).

build.zig

@@ -502,9 +502,7 @@ fn addCmakeCfgOptionsToExe(
     }
 }
 
-fn addStaticLlvmOptionsToExe(
-    exe: *std.build.LibExeObjStep,
-) !void {
+fn addStaticLlvmOptionsToExe(exe: *std.build.LibExeObjStep) !void {
     // Adds the Zig C++ sources which both stage1 and stage2 need.
     //
     // We need this because otherwise zig_clang_cc1_main.cpp ends up pulling

ci/zinc/linux_test.sh

@@ -48,7 +48,7 @@ cd $WORKSPACE
 $ZIG fmt --check .
 
 # Build stage2 standalone so that we can test stage2 against stage2 compiler-rt.
-$ZIG build -p stage2 -Denable-llvm -Dstatic-llvm -Duse-zig-libcxx
+$ZIG build -p stage2 -Dstatic-llvm -Duse-zig-libcxx
 
 stage2/bin/zig test test/behavior.zig -I test -fLLVM
 stage2/bin/zig test test/behavior.zig -I test
@@ -94,7 +94,6 @@ tidy --drop-empty-elements no -qe zig-cache/langref.html
 $ZIG build
   --prefix "RELEASE_STAGING" \
   --search-prefix "$DEPS_LOCAL" \
-  -Denable-llvm \
   -Dstatic-llvm \
   -Drelease \
   -Dstrip \

src/main.zig

@@ -2008,28 +2008,34 @@ fn buildOutputType(
     // are part of libc or libc++. We remove them from the list and communicate their
     // existence via flags instead.
     {
+        // Similarly, if any libs in this list are statically provided, we remove
+        // them from this list and populate the link_objects array instead.
+        const sep = fs.path.sep_str;
+        var test_path = std.ArrayList(u8).init(gpa);
+        defer test_path.deinit();
+
         var i: usize = 0;
-        while (i < system_libs.count()) {
+        syslib: while (i < system_libs.count()) {
             const lib_name = system_libs.keys()[i];
 
             if (target_util.is_libc_lib_name(target_info.target, lib_name)) {
                 link_libc = true;
-                _ = system_libs.orderedRemove(lib_name);
+                system_libs.orderedRemoveAt(i);
                 continue;
             }
             if (target_util.is_libcpp_lib_name(target_info.target, lib_name)) {
                 link_libcpp = true;
-                _ = system_libs.orderedRemove(lib_name);
+                system_libs.orderedRemoveAt(i);
                 continue;
             }
             if (mem.eql(u8, lib_name, "unwind")) {
                 link_libunwind = true;
-                _ = system_libs.orderedRemove(lib_name);
+                system_libs.orderedRemoveAt(i);
                 continue;
             }
             if (target_util.is_compiler_rt_lib_name(target_info.target, lib_name)) {
                 std.log.warn("ignoring superfluous library '{s}': this dependency is fulfilled instead by compiler-rt which zig unconditionally provides", .{lib_name});
-                _ = system_libs.orderedRemove(lib_name);
+                system_libs.orderedRemoveAt(i);
                 continue;
             }
             if (std.fs.path.isAbsolute(lib_name)) {
@@ -2038,10 +2044,30 @@ fn buildOutputType(
             if (target_info.target.os.tag == .wasi) {
                 if (wasi_libc.getEmulatedLibCRTFile(lib_name)) |crt_file| {
                     try wasi_emulated_libs.append(crt_file);
-                    _ = system_libs.orderedRemove(lib_name);
+                    system_libs.orderedRemoveAt(i);
                     continue;
                 }
             }
+
+            for (lib_dirs.items) |lib_dir_path| {
+                test_path.clearRetainingCapacity();
+                try test_path.writer().print("{s}" ++ sep ++ "{s}{s}{s}", .{
+                    lib_dir_path,
+                    target_info.target.libPrefix(),
+                    lib_name,
+                    target_info.target.staticLibSuffix(),
+                });
+                fs.cwd().access(test_path.items, .{}) catch |err| switch (err) {
+                    error.FileNotFound => continue,
+                    else => |e| fatal("unable to search for static library '{s}': {s}", .{
+                        test_path.items, @errorName(e),
+                    }),
+                };
+                try link_objects.append(.{ .path = try arena.dupe(u8, test_path.items) });
+                system_libs.orderedRemoveAt(i);
+                continue :syslib;
+            }
+
             i += 1;
         }
     }
@@ -2068,7 +2094,9 @@ fn buildOutputType(
             want_native_include_dirs = true;
     }
 
-    if (sysroot == null and cross_target.isNativeOs() and (system_libs.count() != 0 or want_native_include_dirs)) {
+    if (sysroot == null and cross_target.isNativeOs() and
+        (system_libs.count() != 0 or want_native_include_dirs))
+    {
         const paths = std.zig.system.NativePaths.detect(arena, target_info) catch |err| {
             fatal("unable to detect native system paths: {s}", .{@errorName(err)});
         };