[lld] [lldb] [compiler-rt] [libcxx] [llvm] [lld-macho] Find objects in library search path (PR #78628)

[via llvm-commits]

https://github.com/OldWorldOrdr updated https://github.com/llvm/llvm-project/pull/78628

>From e73fc2d0263e9e601f2964a90cfe347e8d2bb87c Mon Sep 17 00:00:00 2001
From: OldWorldOrdr <joey.t.reinhart at gmail.com>
Date: Thu, 18 Jan 2024 16:20:52 -0500
Subject: [PATCH 1/4] [lld-macho] Find objects in library search path

---
 lld/MachO/Driver.cpp | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
index 401459a054394e..f04165f5c02615 100644
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -95,11 +95,16 @@ static std::optional<StringRef> findLibrary(StringRef name) {
               findPathCombination("lib" + name, config->librarySearchPaths,
                                   {".tbd", ".dylib", ".so"}))
         return path;
-      return findPathCombination("lib" + name, config->librarySearchPaths,
-                                 {".a"});
+      else if (std::optional<StringRef> path = findPathCombination(
+                   "lib" + name, config->librarySearchPaths, {".a"}))
+        return path;
+      return findPathCombination(name, config->librarySearchPaths, {""});
     }
-    return findPathCombination("lib" + name, config->librarySearchPaths,
-                               {".tbd", ".dylib", ".so", ".a"});
+    if (std::optional<StringRef> path =
+            findPathCombination("lib" + name, config->librarySearchPaths,
+                                {".tbd", ".dylib", ".so", ".a"}))
+      return path;
+    return findPathCombination(name, config->librarySearchPaths, {""});
   };
 
   std::optional<StringRef> path = doFind();

>From 5b29c5da6770982fb2f36edcd3a367893b18a19d Mon Sep 17 00:00:00 2001
From: OldWorldOrdr <joey.t.reinhart at gmail.com>
Date: Thu, 18 Jan 2024 21:16:57 -0500
Subject: [PATCH 2/4] [lld-macho] find objects in library search path version 2

---
 lld/MachO/Driver.cpp | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
index f04165f5c02615..f8b01da5255c6d 100644
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -90,21 +90,19 @@ static std::optional<StringRef> findLibrary(StringRef name) {
     return entry->second;
 
   auto doFind = [&] {
+    // Special case for Csu support files.
+    if (name.ends_with(".o"))
+      return findPathCombination(name, config->librarySearchPaths, {""});
     if (config->searchDylibsFirst) {
       if (std::optional<StringRef> path =
               findPathCombination("lib" + name, config->librarySearchPaths,
                                   {".tbd", ".dylib", ".so"}))
         return path;
-      else if (std::optional<StringRef> path = findPathCombination(
-                   "lib" + name, config->librarySearchPaths, {".a"}))
-        return path;
-      return findPathCombination(name, config->librarySearchPaths, {""});
+      return findPathCombination("lib" + name, config->librarySearchPaths,
+                                 {".a"});
     }
-    if (std::optional<StringRef> path =
-            findPathCombination("lib" + name, config->librarySearchPaths,
-                                {".tbd", ".dylib", ".so", ".a"}))
-      return path;
-    return findPathCombination(name, config->librarySearchPaths, {""});
+    return findPathCombination("lib" + name, config->librarySearchPaths,
+                               {".tbd", ".dylib", ".so", ".a"});
   };
 
   std::optional<StringRef> path = doFind();

>From 5aab87e5c580ca1dba654fb00cf9571c7e3c7999 Mon Sep 17 00:00:00 2001
From: OldWorldOrdr <joey.t.reinhart at gmail.com>
Date: Fri, 19 Jan 2024 01:32:20 -0500
Subject: [PATCH 3/4] add test case

---
 lld/test/MachO/link-csu-obj.s | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 lld/test/MachO/link-csu-obj.s

diff --git a/lld/test/MachO/link-csu-obj.s b/lld/test/MachO/link-csu-obj.s
new file mode 100644
index 00000000000000..00cb26bb260743
--- /dev/null
+++ b/lld/test/MachO/link-csu-obj.s
@@ -0,0 +1,10 @@
+# REQUIRES: x86
+# RUN: mkdir -p %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %p/Inputs/libhello.s -o %t/hello.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t/main.o
+# RUN: %lld -L %t %t/main.o %t/hello.o -o %t/a.out
+
+.globl _main
+_main:
+    call _print_hello
+    ret

>From 6e8b321b1ed74665f26e5ee6dd0a04ec7b4dbb89 Mon Sep 17 00:00:00 2001
From: OldWorldOrdr <joey.t.reinhart at gmail.com>
Date: Fri, 19 Jan 2024 11:38:25 -0500
Subject: [PATCH 4/4] Improve comment

---
 lld/MachO/Driver.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
index f8b01da5255c6d..7ac3f51cec103f 100644
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -90,7 +90,8 @@ static std::optional<StringRef> findLibrary(StringRef name) {
     return entry->second;
 
   auto doFind = [&] {
-    // Special case for Csu support files.
+    // Special case for Csu support files required for Mac OS X 10.7 and older
+    // (crt1.o)
     if (name.ends_with(".o"))
       return findPathCombination(name, config->librarySearchPaths, {""});
     if (config->searchDylibsFirst) {