[lld] enable fixup chains by default for supported platforms

rmaz · rmaz · commit f6748d2b3e91 · 2024-01-30T15:11:34.000-08:00
This commit enables chained fixups by default for supported platforms.
This matches the logic used in ld64 907.
diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
@@ -49,6 +49,7 @@
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/TimeProfiler.h"
 #include "llvm/TargetParser/Host.h"
+#include "llvm/TextAPI/Architecture.h"
 #include "llvm/TextAPI/PackedVersion.h"
 
 #include <algorithm>
@@ -1042,41 +1043,44 @@ static bool shouldEmitChainedFixups(const InputArgList &args) {
   if (arg && arg->getOption().matches(OPT_no_fixup_chains))
     return false;
 
-  bool isRequested = arg != nullptr;
-
-  // Version numbers taken from the Xcode 13.3 release notes.
-  static const std::array<std::pair<PlatformType, VersionTuple>, 4> minVersion =
-      {{{PLATFORM_MACOS, VersionTuple(11, 0)},
-        {PLATFORM_IOS, VersionTuple(13, 4)},
-        {PLATFORM_TVOS, VersionTuple(14, 0)},
-        {PLATFORM_WATCHOS, VersionTuple(7, 0)}}};
-  PlatformType platform = removeSimulator(config->platformInfo.target.Platform);
-  auto it = llvm::find_if(minVersion,
-                          [&](const auto &p) { return p.first == platform; });
-  if (it != minVersion.end() &&
-      it->second > config->platformInfo.target.MinDeployment) {
-    if (!isRequested)
+  if (arg && arg->getOption().matches(OPT_fixup_chains)) {
+    if (!config->isPic) {
+      error("-fixup_chains is incompatible with -no_pie");
       return false;
+    }
 
-    warn("-fixup_chains requires " + getPlatformName(config->platform()) + " " +
-         it->second.getAsString() + ", which is newer than target minimum of " +
-         config->platformInfo.target.MinDeployment.getAsString());
+    return true;
   }
 
-  if (!is_contained({AK_x86_64, AK_x86_64h, AK_arm64}, config->arch())) {
-    if (isRequested)
-      error("-fixup_chains is only supported on x86_64 and arm64 targets");
+  // https://github.com/apple-oss-distributions/ld64/blob/main/src/ld/ld.hpp#L317-L318
+  static const std::array<std::pair<PlatformType, VersionTuple>, 7> minVersion =
+      {{
+          {PLATFORM_MACOS, VersionTuple(13, 0)},
+          {PLATFORM_IOSSIMULATOR, VersionTuple(16, 0)},
+          {PLATFORM_IOS, VersionTuple(13, 4)},
+          {PLATFORM_WATCHOSSIMULATOR, VersionTuple(8, 0)},
+          {PLATFORM_WATCHOS, VersionTuple(7, 0)},
+          {PLATFORM_TVOSSIMULATOR, VersionTuple(15, 0)},
+          {PLATFORM_TVOS, VersionTuple(14, 0)},
+      }};
+  PlatformType platform = config->platformInfo.target.Platform;
+  const auto *it = llvm::find_if(
+      minVersion, [&](const auto &p) { return p.first == platform; });
+
+  // We don't know the versions for other platforms, so default to disabled.
+  if (it == minVersion.end())
     return false;
-  }
 
-  if (!config->isPic) {
-    if (isRequested)
-      error("-fixup_chains is incompatible with -no_pie");
+  if (it->second > config->platformInfo.target.MinDeployment)
+    return false;
+
+  if (config->arch() == llvm::MachO::AK_i386)
     return false;
-  }
 
-  // TODO: Enable by default once stable.
-  return isRequested;
+  if (args.hasArg(OPT_preload))
+    return false;
+
+  return true;
 }
 
 void SymbolPatterns::clear() {
diff --git a/lld/test/MachO/arm64-32-stubs.s b/lld/test/MachO/arm64-32-stubs.s
@@ -10,7 +10,7 @@
 # RUN: llvm-mc -filetype=obj -triple=arm64_32-apple-watchos %t/test.s -o %t/test.o
 # RUN: %lld-watchos -dylib -install_name @executable_path/libfoo.dylib %t/foo.o -o %t/libfoo.dylib
 # RUN: %lld-watchos -dylib -install_name @executable_path/libbar.dylib %t/bar.o -o %t/libbar.dylib
-# RUN: %lld-watchos -lSystem %t/libfoo.dylib %t/libbar.dylib %t/test.o -o %t/test
+# RUN: %lld-watchos -lSystem %t/libfoo.dylib %t/libbar.dylib %t/test.o -o %t/test -no_fixup_chains
 
 # RUN: llvm-objdump --no-print-imm-hex --macho -d --no-show-raw-insn --section="__TEXT,__stubs" --section="__TEXT,__stub_helper" %t/test | FileCheck %s
 
diff --git a/lld/test/MachO/arm64-stubs.s b/lld/test/MachO/arm64-stubs.s
@@ -5,7 +5,7 @@
 # RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %t/test.s -o %t/test.o
 # RUN: %lld -arch arm64 -dylib -install_name @executable_path/libfoo.dylib %t/foo.o -o %t/libfoo.dylib
 # RUN: %lld -arch arm64 -dylib -install_name @executable_path/libbar.dylib %t/bar.o -o %t/libbar.dylib
-# RUN: %lld -arch arm64 -lSystem %t/libfoo.dylib %t/libbar.dylib %t/test.o -o %t/test
+# RUN: %lld -arch arm64 -lSystem %t/libfoo.dylib %t/libbar.dylib %t/test.o -o %t/test -no_fixup_chains
 
 # RUN: llvm-objdump --no-print-imm-hex --macho -d --no-show-raw-insn --section="__TEXT,__stubs" --section="__TEXT,__stub_helper" %t/test | FileCheck %s
 
diff --git a/lld/test/MachO/dyld-stub-binder.s b/lld/test/MachO/dyld-stub-binder.s
@@ -14,27 +14,27 @@
 # RUN: %lld -arch arm64 -lSystem -dylib %t/foo.o -o %t/libfoo.dylib
 # RUN: llvm-nm -m %t/libfoo.dylib | FileCheck --check-prefix=STUB %s
 
-
 ## Dylibs that do lazy dynamic calls do need dyld_stub_binder.
 # RUN: not %no-lsystem-lld -arch arm64 -dylib %t/bar.o %t/libfoo.dylib \
-# RUN:     -o %t/libbar.dylib 2>&1 | FileCheck --check-prefix=MISSINGSTUB %s
+# RUN:     -o %t/libbar.dylib -no_fixup_chains 2>&1 | \
+# RUN:     FileCheck --check-prefix=MISSINGSTUB %s
 # RUN: %lld -arch arm64 -lSystem -dylib %t/bar.o  %t/libfoo.dylib \
-# RUN:     -o %t/libbar.dylib
+# RUN:     -o %t/libbar.dylib -no_fixup_chains
 # RUN: llvm-nm -m %t/libbar.dylib | FileCheck --check-prefix=STUB %s
 
 ## As do executables.
 # RUN: not %no-lsystem-lld -arch arm64 %t/libfoo.dylib %t/libbar.dylib %t/test.o \
-# RUN:     -o %t/test 2>&1 | FileCheck --check-prefix=MISSINGSTUB %s
+# RUN:     -o %t/test -no_fixup_chains 2>&1 | FileCheck --check-prefix=MISSINGSTUB %s
 # RUN: %lld -arch arm64 -lSystem %t/libfoo.dylib %t/libbar.dylib %t/test.o \
-# RUN:     -o %t/test
+# RUN:     -o %t/test -no_fixup_chains
 # RUN: llvm-nm -m %t/test | FileCheck --check-prefix=STUB %s
 
 ## Test dynamic lookup of dyld_stub_binder.
 # RUN: %no-lsystem-lld -arch arm64 %t/libfoo.dylib %t/libbar.dylib %t/test.o \
-# RUN:     -o %t/test -undefined dynamic_lookup
+# RUN:     -o %t/test -undefined dynamic_lookup -no_fixup_chains
 # RUN: llvm-nm -m %t/test | FileCheck --check-prefix=DYNSTUB %s
 # RUN: %no-lsystem-lld -arch arm64 %t/libfoo.dylib %t/libbar.dylib %t/test.o \
-# RUN:     -o %t/test -U dyld_stub_binder
+# RUN:     -o %t/test -U dyld_stub_binder -no_fixup_chains
 # RUN: llvm-nm -m %t/test | FileCheck --check-prefix=DYNSTUB %s
 
 # MISSINGSTUB:      error: undefined symbol: dyld_stub_binder
diff --git a/lld/test/MachO/icf-safe.ll b/lld/test/MachO/icf-safe.ll
@@ -3,14 +3,14 @@
 ; RUN: rm -rf %t; mkdir %t
 
 ; RUN: llc -filetype=obj %s -O3 -o %t/icf-obj.o -enable-machine-outliner=never -mtriple arm64-apple-macos -addrsig
-; RUN: %lld -arch arm64 -lSystem --icf=safe -dylib -o %t/icf-safe.dylib %t/icf-obj.o
-; RUN: %lld -arch arm64 -lSystem --icf=all  -dylib -o %t/icf-all.dylib  %t/icf-obj.o
+; RUN: %lld -arch arm64 -lSystem --icf=safe -dylib -o %t/icf-safe.dylib %t/icf-obj.o -no_fixup_chains
+; RUN: %lld -arch arm64 -lSystem --icf=all  -dylib -o %t/icf-all.dylib  %t/icf-obj.o -no_fixup_chains
 ; RUN: llvm-objdump %t/icf-safe.dylib -d --macho | FileCheck %s --check-prefix=ICFSAFE
 ; RUN: llvm-objdump %t/icf-all.dylib  -d --macho | FileCheck %s --check-prefix=ICFALL
 
 ; RUN: llvm-as %s -o %t/icf-bitcode.o
-; RUN: %lld -arch arm64 -lSystem --icf=safe -dylib -o %t/icf-safe-bitcode.dylib %t/icf-bitcode.o
-; RUN: %lld -arch arm64 -lSystem --icf=all  -dylib -o %t/icf-all-bitcode.dylib %t/icf-bitcode.o
+; RUN: %lld -arch arm64 -lSystem --icf=safe -dylib -o %t/icf-safe-bitcode.dylib %t/icf-bitcode.o -no_fixup_chains
+; RUN: %lld -arch arm64 -lSystem --icf=all  -dylib -o %t/icf-all-bitcode.dylib %t/icf-bitcode.o -no_fixup_chains
 ; RUN: llvm-objdump %t/icf-safe-bitcode.dylib -d --macho | FileCheck %s --check-prefix=ICFSAFE
 ; RUN: llvm-objdump %t/icf-all-bitcode.dylib  -d --macho | FileCheck %s --check-prefix=ICFALL
 
diff --git a/lld/test/MachO/objc-selrefs.s b/lld/test/MachO/objc-selrefs.s
@@ -6,14 +6,14 @@
 # RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %t/implicit-selrefs.s -o %t/implicit-selrefs.o
 
 # RUN: %lld -dylib -arch arm64 -lSystem -o %t/explicit-only-no-icf \
-# RUN:   %t/explicit-selrefs-1.o %t/explicit-selrefs-2.o
+# RUN:   %t/explicit-selrefs-1.o %t/explicit-selrefs-2.o -no_fixup_chains
 # RUN: llvm-otool -vs __DATA __objc_selrefs %t/explicit-only-no-icf | \
 # RUN:   FileCheck %s --check-prefix=EXPLICIT-NO-ICF
 
 ## NOTE: ld64 always dedups the selrefs unconditionally, but we only do it when
 ## ICF is enabled.
 # RUN: %lld -dylib -arch arm64 -lSystem -o %t/explicit-only-with-icf \
-# RUN:   %t/explicit-selrefs-1.o %t/explicit-selrefs-2.o
+# RUN:   %t/explicit-selrefs-1.o %t/explicit-selrefs-2.o -no_fixup_chains
 # RUN: llvm-otool -vs __DATA __objc_selrefs %t/explicit-only-with-icf \
 # RUN:   | FileCheck %s --check-prefix=EXPLICIT-WITH-ICF
 
@@ -26,7 +26,8 @@
 
 ## We don't yet support dedup'ing implicitly-defined selrefs.
 # RUN: %lld -dylib -arch arm64 -lSystem --icf=all -o %t/explicit-and-implicit \
-# RUN:   %t/explicit-selrefs-1.o %t/explicit-selrefs-2.o %t/implicit-selrefs.o
+# RUN:   %t/explicit-selrefs-1.o %t/explicit-selrefs-2.o %t/implicit-selrefs.o \
+# RUN:   -no_fixup_chains
 # RUN: llvm-otool -vs __DATA __objc_selrefs %t/explicit-and-implicit \
 # RUN:   | FileCheck %s --check-prefix=EXPLICIT-AND-IMPLICIT
 
