From 76a259799d5bac3effabd1df44c0dec9e4fa16d4 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Thu, 13 May 2021 11:52:58 -0700
Subject: [PATCH] stage2: only build and link libunwind when linking libc++

---
 src/Compilation.zig |  1 +
 src/link/Elf.zig    | 10 +++-------
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/src/Compilation.zig b/src/Compilation.zig
index b14e598f71..0f04f02b7d 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -3023,6 +3023,7 @@ fn wantBuildLibUnwindFromSource(comp: *Compilation) bool {
         .Exe => true,
     };
     return comp.bin_file.options.link_libc and is_exe_or_dyn_lib and
+        comp.bin_file.options.link_libcpp and
         target_util.libcNeedsLibUnwind(comp.getTarget());
 }
 
diff --git a/src/link/Elf.zig b/src/link/Elf.zig
index fbbe40022a..b94e562eb7 100644
--- a/src/link/Elf.zig
+++ b/src/link/Elf.zig
@@ -1643,20 +1643,19 @@ fn linkWithLLD(self: *Elf, comp: *Compilation) !void {
             if (self.base.options.link_libcpp) {
                 try argv.append(comp.libcxxabi_static_lib.?.full_object_path);
                 try argv.append(comp.libcxx_static_lib.?.full_object_path);
+                if (target_util.libcNeedsLibUnwind(target)) {
+                    try argv.append(comp.libunwind_static_lib.?.full_object_path);
+                }
             }
 
             // libc dep
             if (self.base.options.link_libc) {
                 if (self.base.options.libc_installation != null) {
-                    if (target_util.libcNeedsLibUnwind(target)) {
-                        try argv.append(comp.libunwind_static_lib.?.full_object_path);
-                    }
                     const needs_grouping = self.base.options.link_mode == .Static;
                     if (needs_grouping) try argv.append("--start-group");
                     try argv.appendSlice(target_util.libcFullLinkFlags(target));
                     if (needs_grouping) try argv.append("--end-group");
                 } else if (target.isGnuLibC()) {
-                    try argv.append(comp.libunwind_static_lib.?.full_object_path);
                     for (glibc.libs) |lib| {
                         const lib_path = try std.fmt.allocPrint(arena, "{s}{c}lib{s}.so.{d}", .{
                             comp.glibc_so_files.?.dir_path, fs.path.sep, lib.name, lib.sover,
@@ -1665,13 +1664,10 @@ fn linkWithLLD(self: *Elf, comp: *Compilation) !void {
                     }
                     try argv.append(try comp.get_libc_crt_file(arena, "libc_nonshared.a"));
                 } else if (target.isMusl()) {
-                    try argv.append(comp.libunwind_static_lib.?.full_object_path);
                     try argv.append(try comp.get_libc_crt_file(arena, switch (self.base.options.link_mode) {
                         .Static => "libc.a",
                         .Dynamic => "libc.so",
                     }));
-                } else if (self.base.options.link_libcpp) {
-                    try argv.append(comp.libunwind_static_lib.?.full_object_path);
                 } else {
                     unreachable; // Compiler was supposed to emit an error for not being able to provide libc.
                 }