From 47f9722c32be4b05a7b958a945d86d408607092d Mon Sep 17 00:00:00 2001
From: Keith Smiley <keithbsmiley@gmail.com>
Date: Sat, 8 Oct 2022 21:28:02 -0700
Subject: [PATCH] [lld-macho] Add --ignore-auto-link-option

This provides a workaround for a small difference in ld64 behavior where
ld64 ignores invalid LC_LINKER_OPTIONS unless the link fails. Instead of
fully adopting that behavior, this provides an escape hatch by allowing
users to specify `--ignore-auto-link-option` passing the invalid library
or framework name

Fixes https://github.com/llvm/llvm-project/issues/56939

Differential Revision: https://reviews.llvm.org/D135530
---
 lld/MachO/Config.h                 | 5 +++++
 lld/MachO/Driver.cpp               | 6 ++++++
 lld/MachO/Options.td               | 6 ++++++
 lld/test/MachO/lc-linker-option.ll | 2 ++
 4 files changed, 19 insertions(+)

diff --git a/lld/MachO/Config.h b/lld/MachO/Config.h
index 3d5f4cb..fff740e 100644
--- a/lld/MachO/Config.h
+++ b/lld/MachO/Config.h
@@ -169,6 +169,11 @@ struct Configuration {
   bool deadStrip = false;
   bool errorForArchMismatch = false;
   bool ignoreAutoLink = false;
+  // ld64 allows invalid auto link options as long as the link succeeds. LLD
+  // does not, but there are cases in the wild where the invalid linker options
+  // exist. This allows users to ignore the specific invalid options in the case
+  // they can't easily fix them.
+  llvm::StringSet<> ignoreAutoLinkOptions;
   PlatformInfo platformInfo;
   llvm::Optional<PlatformInfo> secondaryPlatformInfo;
   NamespaceKind namespaceKind = NamespaceKind::twolevel;
diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
index 29472f2..8ef2a36 100644
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -478,11 +478,15 @@ void macho::parseLCLinkerOption(InputFile *f, unsigned argc, StringRef data) {
   unsigned i = 0;
   StringRef arg = argv[i];
   if (arg.consume_front("-l")) {
+    if (config->ignoreAutoLinkOptions.contains(arg))
+      return;
     addLibrary(arg, /*isNeeded=*/false, /*isWeak=*/false,
                /*isReexport=*/false, /*isHidden=*/false, /*isExplicit=*/false,
                LoadType::LCLinkerOption);
   } else if (arg == "-framework") {
     StringRef name = argv[++i];
+    if (config->ignoreAutoLinkOptions.contains(name))
+      return;
     addFramework(name, /*isNeeded=*/false, /*isWeak=*/false,
                  /*isReexport=*/false, /*isExplicit=*/false,
                  LoadType::LCLinkerOption);
@@ -1543,6 +1547,8 @@ bool macho::link(ArrayRef<const char *> argsArr, llvm::raw_ostream &stdoutOS,
       getenv("LD_DYLIB_CPU_SUBTYPES_MUST_MATCH");
   config->objcStubsMode = getObjCStubsMode(args);
   config->ignoreAutoLink = args.hasArg(OPT_ignore_auto_link);
+  for (const Arg *arg : args.filtered(OPT_ignore_auto_link_option))
+    config->ignoreAutoLinkOptions.insert(arg->getValue());
 
   for (const Arg *arg : args.filtered(OPT_alias)) {
     config->aliasedSymbols.push_back(
diff --git a/lld/MachO/Options.td b/lld/MachO/Options.td
index fda7ae3..2871091 100644
--- a/lld/MachO/Options.td
+++ b/lld/MachO/Options.td
@@ -95,6 +95,12 @@ def no_call_graph_profile_sort : Flag<["--"], "no-call-graph-profile-sort">,
 def print_symbol_order_eq: Joined<["--"], "print-symbol-order=">,
     HelpText<"Print a symbol order specified by --call-graph-profile-sort into the specified file">,
     Group<grp_lld>;
+def ignore_auto_link_option : Separate<["--"], "ignore-auto-link-option">,
+    Group<grp_lld>;
+def ignore_auto_link_option_eq : Joined<["--"], "ignore-auto-link-option=">,
+    Alias<!cast<Separate>(ignore_auto_link_option)>,
+    HelpText<"Ignore a single auto-linked library or framework. Useful to ignore invalid options that ld64 ignores">,
+    Group<grp_lld>;
 
 // This is a complete Options.td compiled from Apple's ld(1) manpage
 // dated 2018-03-07 and cross checked with ld64 source code in repo
diff --git a/lld/test/MachO/lc-linker-option.ll b/lld/test/MachO/lc-linker-option.ll
index 48dd5b9..f7060e0 100644
--- a/lld/test/MachO/lc-linker-option.ll
+++ b/lld/test/MachO/lc-linker-option.ll
@@ -13,6 +13,8 @@
 ; FRAME-NEXT:    name /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation
 
 ; RUN: not %lld %t/framework.o -o %t/frame_no_autolink -ignore_auto_link 2>&1 | FileCheck --check-prefix=NO_AUTOLINK %s
+; RUN: not %lld %t/framework.o -o %t/frame_no_autolink --ignore-auto-link-option CoreFoundation 2>&1 | FileCheck --check-prefix=NO_AUTOLINK %s
+; RUN: not %lld %t/framework.o -o %t/frame_no_autolink --ignore-auto-link-option=CoreFoundation 2>&1 | FileCheck --check-prefix=NO_AUTOLINK %s
 ; NO_AUTOLINK: error: undefined symbol: __CFBigNumGetInt128
 
 ; RUN: llvm-as %t/l.ll -o %t/l.o
-- 
2.7.4