[lld] 855d3cb - [lld-macho] Gate category checking behind --check-category-conflicts

[Jez Ng via llvm-commits]

Author: Jez Ng
Date: 2023-03-31T13:20:23-04:00
New Revision: 855d3cb8e3e831a48378865575bf950deda1ecf1

URL: https://github.com/llvm/llvm-project/commit/855d3cb8e3e831a48378865575bf950deda1ecf1
DIFF: https://github.com/llvm/llvm-project/commit/855d3cb8e3e831a48378865575bf950deda1ecf1.diff

LOG: [lld-macho] Gate category checking behind --check-category-conflicts

@oontvoo reports that the current implementation crashes on a bunch of
their builds. Let's leave it disabled by default for now.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D147341

Added: 
    

Modified: 
    lld/MachO/Driver.cpp
    lld/MachO/Options.td
    lld/test/MachO/objc-category-conflicts.s

Removed: 
    


################################################################################
diff  --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
index 9262fffda7d38..49f6651950167 100644
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -1921,7 +1921,8 @@ bool macho::link(ArrayRef<const char *> argsArr, llvm::raw_ostream &stdoutOS,
     if (config->deadStrip)
       markLive();
 
-    objc::checkCategories();
+    if (args.hasArg(OPT_check_category_conflicts))
+      objc::checkCategories();
 
     // ICF assumes that all literals have been folded already, so we must run
     // foldIdenticalLiterals before foldIdenticalSections.

diff  --git a/lld/MachO/Options.td b/lld/MachO/Options.td
index 408be46699770..ec747d0c9042b 100644
--- a/lld/MachO/Options.td
+++ b/lld/MachO/Options.td
@@ -121,6 +121,9 @@ def ignore_auto_link_option_eq : Joined<["--"], "ignore-auto-link-option=">,
 def strict_auto_link : Flag<["--"], "strict-auto-link">,
     HelpText<"Always warn for missing frameworks or libraries if they are loaded via LC_LINKER_OPTIONS">,
     Group<grp_lld>;
+def check_category_conflicts : Flag<["--"], "check-category-conflicts">,
+    HelpText<"Check for conflicts between category & class methods">,
+    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/objc-category-conflicts.s b/lld/test/MachO/objc-category-conflicts.s
index da1b0c6b38d77..59a9ed50eb055 100644
--- a/lld/test/MachO/objc-category-conflicts.s
+++ b/lld/test/MachO/objc-category-conflicts.s
@@ -9,21 +9,25 @@
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-macos11.0 -I %t %t/klass-with-no-rodata.s -o %t/klass-with-no-rodata.o
 # RUN: %lld -dylib -lobjc %t/klass.o -o %t/libklass.dylib
 
-# RUN: %no-fatal-warnings-lld -dylib -lobjc %t/klass.o %t/cat1.o %t/cat2.o -o \
+# RUN: %no-fatal-warnings-lld --check-category-conflicts -dylib -lobjc %t/klass.o %t/cat1.o %t/cat2.o -o \
 # RUN:   /dev/null 2>&1 | FileCheck %s --check-prefixes=CATCLS,CATCAT
-# RUN: %no-fatal-warnings-lld -dylib -lobjc %t/libklass.dylib %t/cat1.o \
+# RUN: %no-fatal-warnings-lld --check-category-conflicts -dylib -lobjc %t/libklass.dylib %t/cat1.o \
 # RUN:   %t/cat2.o -o /dev/null 2>&1 | FileCheck %s --check-prefix=CATCAT
 
 ## Check that we don't emit spurious warnings around the +load method while
 ## still emitting the other warnings. Note that we have made separate
 ## `*-with-load.s` files for ease of comparison with ld64; ld64 will not warn
 ## at all if multiple +load methods are present.
-# RUN: %no-fatal-warnings-lld -dylib -lobjc %t/klass-with-load.o \
+# RUN: %no-fatal-warnings-lld --check-category-conflicts -dylib -lobjc %t/klass-with-load.o \
 # RUN:   %t/cat1-with-load.o %t/cat2-with-load.o -o /dev/null 2>&1 | \
 # RUN:   FileCheck %s --check-prefixes=CATCLS,CATCAT --implicit-check-not '+load'
 
 ## Regression test: Check that we don't crash.
-# RUN: %no-fatal-warnings-lld -dylib -lobjc %t/klass-with-no-rodata.o -o /dev/null
+# RUN: %no-fatal-warnings-lld --check-category-conflicts -dylib -lobjc %t/klass-with-no-rodata.o -o /dev/null
+
+## Check that we don't emit any warnings without --check-category-conflicts.
+# RUN: %no-fatal-warnings-lld -dylib -lobjc %t/klass.o %t/cat1.o %t/cat2.o -o \
+# RUN:   /dev/null 2>&1 | FileCheck %s --implicit-check-not 'warning' --allow-empty
 
 # CATCLS:      warning: method '+s1' has conflicting definitions:
 # CATCLS-NEXT: >>> defined in category Cat1 from {{.*}}cat1{{.*}}.o