From b5642b361f4cd4352892c32172b1ed839d46328f Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sun, 31 Mar 2024 10:08:56 +0200
Subject: [PATCH 1/2] extern-so: give the version script a better name; show
 errors from failing to build the C lib

---
 .../{libcode.version => libtest.map}          |  2 ++
 src/tools/miri/tests/ui.rs                    | 20 +++++++++++--------
 2 files changed, 14 insertions(+), 8 deletions(-)
 rename src/tools/miri/tests/extern-so/{libcode.version => libtest.map} (72%)

diff --git a/src/tools/miri/tests/extern-so/libcode.version b/src/tools/miri/tests/extern-so/libtest.map
similarity index 72%
rename from src/tools/miri/tests/extern-so/libcode.version
rename to src/tools/miri/tests/extern-so/libtest.map
index 0f04b9aaebb3..a9887a79a798 100644
--- a/src/tools/miri/tests/extern-so/libcode.version
+++ b/src/tools/miri/tests/extern-so/libtest.map
@@ -1,9 +1,11 @@
 CODEABI_1.0 {
+    # Define which symbols to export.
     global: *add_one_int*; 
         *printer*; 
         *test_stack_spill*; 
         *get_unsigned_int*; 
         *add_int16*;
         *add_short_to_long*;
+    # The rest remains private.
     local: *;
 };
diff --git a/src/tools/miri/tests/ui.rs b/src/tools/miri/tests/ui.rs
index a75fa4cf986d..7e8d1401183b 100644
--- a/src/tools/miri/tests/ui.rs
+++ b/src/tools/miri/tests/ui.rs
@@ -1,9 +1,10 @@
-use colored::*;
-use regex::bytes::Regex;
 use std::ffi::OsString;
 use std::num::NonZeroUsize;
 use std::path::{Path, PathBuf};
 use std::{env, process::Command};
+
+use colored::*;
+use regex::bytes::Regex;
 use ui_test::color_eyre::eyre::{Context, Result};
 use ui_test::{
     status_emitter, CommandBuilder, Config, Format, Match, Mode, OutputConflictHandling,
@@ -44,12 +45,15 @@ fn build_so_for_c_ffi_tests() -> PathBuf {
             // This is to avoid automatically adding `malloc`, etc.
             // Source: https://anadoxin.org/blog/control-over-symbol-exports-in-gcc.html/
             "-fPIC",
-            "-Wl,--version-script=tests/extern-so/libcode.version",
+            "-Wl,--version-script=tests/extern-so/libtest.map",
         ])
         .output()
         .expect("failed to generate shared object file for testing external C function calls");
     if !cc_output.status.success() {
-        panic!("error in generating shared object file for testing external C function calls");
+        panic!(
+            "error in generating shared object file for testing external C function calls:\n{}",
+            String::from_utf8_lossy(&cc_output.stderr),
+        );
     }
     so_file_path
 }
@@ -120,10 +124,10 @@ fn run_tests(
     config.program.args.push("--target".into());
     config.program.args.push(target.into());
 
-    // If we're on linux, and we're testing the extern-so functionality,
-    // then build the shared object file for testing external C function calls
-    // and push the relevant compiler flag.
-    if cfg!(target_os = "linux") && path.starts_with("tests/extern-so/") {
+    // If we're testing the extern-so functionality, then build the shared object file for testing
+    // external C function calls and push the relevant compiler flag.
+    if path.starts_with("tests/extern-so/") {
+        assert!(cfg!(target_os = "linux"));
         let so_file_path = build_so_for_c_ffi_tests();
         let mut flag = std::ffi::OsString::from("-Zmiri-extern-so-file=");
         flag.push(so_file_path.into_os_string());

From 38780aa5a420c301b94345cfc372d8463ce46711 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sun, 31 Mar 2024 10:10:35 +0200
Subject: [PATCH 2/2] there is no need for these wildcards

---
 src/tools/miri/tests/extern-so/libtest.map | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/tools/miri/tests/extern-so/libtest.map b/src/tools/miri/tests/extern-so/libtest.map
index a9887a79a798..a57a4dc149fe 100644
--- a/src/tools/miri/tests/extern-so/libtest.map
+++ b/src/tools/miri/tests/extern-so/libtest.map
@@ -1,11 +1,12 @@
 CODEABI_1.0 {
     # Define which symbols to export.
-    global: *add_one_int*; 
-        *printer*; 
-        *test_stack_spill*; 
-        *get_unsigned_int*; 
-        *add_int16*;
-        *add_short_to_long*;
+    global:
+        add_one_int;
+        printer;
+        test_stack_spill;
+        get_unsigned_int;
+        add_int16;
+        add_short_to_long;
     # The rest remains private.
     local: *;
 };