From df9462690f9ca28e1b0fc3185f319c335cc3a32c Mon Sep 17 00:00:00 2001
From: Jakub Konka <kubkon@jakubkonka.com>
Date: Fri, 6 Oct 2023 12:42:58 +0200
Subject: [PATCH] std: fix memory bug in getExternalExecutor

Until now, we would pass `candidate: NativeTargetInfo` which creates
a copy of the `NativeTargetInfo.DynamicLinker` buffer. We would then
return this buffer in `bad_dl: []const u8` which would goes out-of-scope
the moment we leave this function frame yielding garbage. To fix this,
we just need to remember to pass by const-pointer
`candidate: *const NativeTargetInfo`.
---
 lib/std/Build/Step/Run.zig              | 2 +-
 lib/std/zig/system/NativeTargetInfo.zig | 2 +-
 src/main.zig                            | 6 +++---
 test/src/Cases.zig                      | 2 +-
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/std/Build/Step/Run.zig b/lib/std/Build/Step/Run.zig
index 66e9224fe5..9d8f26559c 100644
--- a/lib/std/Build/Step/Run.zig
+++ b/lib/std/Build/Step/Run.zig
@@ -679,7 +679,7 @@ fn runCommand(
             }
 
             const need_cross_glibc = exe.target.isGnuLibC() and exe.is_linking_libc;
-            switch (b.host.getExternalExecutor(exe.target_info, .{
+            switch (b.host.getExternalExecutor(&exe.target_info, .{
                 .qemu_fixes_dl = need_cross_glibc and b.glibc_runtimes_dir != null,
                 .link_libc = exe.is_linking_libc,
             })) {
diff --git a/lib/std/zig/system/NativeTargetInfo.zig b/lib/std/zig/system/NativeTargetInfo.zig
index 6691e0f3cb..bcb60d968e 100644
--- a/lib/std/zig/system/NativeTargetInfo.zig
+++ b/lib/std/zig/system/NativeTargetInfo.zig
@@ -1002,7 +1002,7 @@ pub const GetExternalExecutorOptions = struct {
 /// of the other target.
 pub fn getExternalExecutor(
     host: NativeTargetInfo,
-    candidate: NativeTargetInfo,
+    candidate: *const NativeTargetInfo,
     options: GetExternalExecutorOptions,
 ) Executor {
     const os_match = host.target.os.tag == candidate.target.os.tag;
diff --git a/src/main.zig b/src/main.zig
index f7f3da1b99..247669440d 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -3667,7 +3667,7 @@ fn buildOutputType(
             test_exec_args.items,
             self_exe_path.?,
             arg_mode,
-            target_info,
+            &target_info,
             &comp_destroyed,
             all_args,
             runtime_args_start,
@@ -3995,7 +3995,7 @@ fn runOrTest(
     test_exec_args: []const ?[]const u8,
     self_exe_path: []const u8,
     arg_mode: ArgMode,
-    target_info: std.zig.system.NativeTargetInfo,
+    target_info: *const std.zig.system.NativeTargetInfo,
     comp_destroyed: *bool,
     all_args: []const []const u8,
     runtime_args_start: ?usize,
@@ -6256,7 +6256,7 @@ fn parseIntSuffix(arg: []const u8, prefix_len: usize) u64 {
 fn warnAboutForeignBinaries(
     arena: Allocator,
     arg_mode: ArgMode,
-    target_info: std.zig.system.NativeTargetInfo,
+    target_info: *const std.zig.system.NativeTargetInfo,
     link_libc: bool,
 ) !void {
     const host_cross_target: std.zig.CrossTarget = .{};
diff --git a/test/src/Cases.zig b/test/src/Cases.zig
index 1252da0e95..fe1fb6fe34 100644
--- a/test/src/Cases.zig
+++ b/test/src/Cases.zig
@@ -590,7 +590,7 @@ pub fn lowerToBuildSteps(
                 const run = if (case.target.ofmt == .c) run_step: {
                     const target_info = std.zig.system.NativeTargetInfo.detect(case.target) catch |err|
                         std.debug.panic("unable to detect notive host: {s}\n", .{@errorName(err)});
-                    if (host.getExternalExecutor(target_info, .{ .link_libc = true }) != .native) {
+                    if (host.getExternalExecutor(&target_info, .{ .link_libc = true }) != .native) {
                         // We wouldn't be able to run the compiled C code.
                         break :no_exec;
                     }