[TargetInfo] Set 'UseSignedCharForObjCBool' to false by default

[arphaman]

Summary

The target-specific flag 'UseSignedCharForObjCBool' is used to determine the type for the Objective-C BOOL type. We should set it to false by default so that new targets can avoid setting it to true.

[arphaman]

Ping.

[arphaman]

Ping.

[aaron.ballman]

lib/Basic/Targets.cpp

4340–4341 ↗

(On Diff #87818)

Rather than using an if statement, why not assign directly? UseSignedCharForObjCBool = !T.isWatchOS();

4772–4773 ↗

(On Diff #87818)

Same here.

[arphaman]

Sorry, missed the comments last year. Updated.

[arphaman]

Only make the change for the Darwin platforms to avoid ObjC ABI breakage for non-Darwin platforms.

[aaron.ballman]

lib/Basic/Targets/PPC.h

349

Do you need to specify this? Isn't it handled by the TargetInfo constructor?

364

Likewise.

lib/Basic/TargetInfo.cpp

TargetInfo::TargetInfo(const llvm::Triple &T) : TargetOpts(), Triple(T) {
   IntPtrType = SignedLong;
   WCharType = SignedInt;
   WIntType = SignedInt;
   Char16Type = UnsignedShort;
   Char32Type = UnsignedInt;
   Int64Type = SignedLongLong;
   SigAtomicType = SignedInt;
   ProcessIDType = SignedInt;
-  UseSignedCharForObjCBool = true;
+  // New Darwin platforms use the true bool type.
+  UseSignedCharForObjCBool = !Triple.isOSDarwin();
   UseBitFieldTypeAlignment = true;
   UseZeroLengthBitfieldAlignment = false;
   UseExplicitBitFieldAlignment = true;
   ZeroLengthBitfieldBoundary = 0;
   HalfFormat = &llvm::APFloat::IEEEhalf();
   FloatFormat = &llvm::APFloat::IEEEsingle();
   DoubleFormat = &llvm::APFloat::IEEEdouble();
   LongDoubleFormat = &llvm::APFloat::IEEEdouble();

lib/Basic/Targets/AArch64.cpp

MinGWARM64TargetInfo::MinGWARM64TargetInfo(const llvm::Triple &Triple,
     : WindowsARM64TargetInfo(Triple, Opts) {
   TheCXXABI.set(TargetCXXABI::GenericAArch64);
 }
 
 DarwinAArch64TargetInfo::DarwinAArch64TargetInfo(const llvm::Triple &Triple,
                                                  const TargetOptions &Opts)
     : DarwinTargetInfo<AArch64leTargetInfo>(Triple, Opts) {
   Int64Type = SignedLongLong;
-  UseSignedCharForObjCBool = false;
 
   LongDoubleWidth = LongDoubleAlign = SuitableAlign = 64;
   LongDoubleFormat = &llvm::APFloat::IEEEdouble();
 
   TheCXXABI.set(TargetCXXABI::iOS64);
 }
 
 void DarwinAArch64TargetInfo::getOSDefines(const LangOptions &Opts,

lib/Basic/Targets/ARM.cpp

DarwinARMTargetInfo::DarwinARMTargetInfo(const llvm::Triple &Triple,
   // iOS always has 64-bit atomic instructions.
   // FIXME: This should be based off of the target features in
   // ARMleTargetInfo.
   MaxAtomicInlineWidth = 64;
 
   if (Triple.isWatchABI()) {
     // Darwin on iOS uses a variant of the ARM C++ ABI.
     TheCXXABI.set(TargetCXXABI::WatchOS);
-
-    // BOOL should be a real boolean on the new ABI
-    UseSignedCharForObjCBool = false;
-  } else
+  } else {
     TheCXXABI.set(TargetCXXABI::iOS);
+    // BOOL should be a character on the iOS ABI.
+    UseSignedCharForObjCBool = true;
+  }
 }
 
 void DarwinARMTargetInfo::getOSDefines(const LangOptions &Opts,
                                        const llvm::Triple &Triple,
                                        MacroBuilder &Builder) const {
   getDarwinDefines(Builder, Opts, Triple, PlatformName, PlatformMinVersion);
 }
 

lib/Basic/Targets/PPC.h

class LLVM_LIBRARY_VISIBILITY DarwinPPC32TargetInfo
     : public DarwinTargetInfo<PPC32TargetInfo> {
 public:
   DarwinPPC32TargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : DarwinTargetInfo<PPC32TargetInfo>(Triple, Opts) {
     HasAlignMac68kSupport = true;
     BoolWidth = BoolAlign = 32; // XXX support -mone-byte-bool?
     PtrDiffType = SignedInt; // for http://llvm.org/bugs/show_bug.cgi?id=15726
     LongLongAlign = 32;
+    UseSignedCharForObjCBool = true;
     resetDataLayout("E-m:o-p:32:32-f64:32:64-n32");
   }
 
   BuiltinVaListKind getBuiltinVaListKind() const override {
     return TargetInfo::CharPtrBuiltinVaList;
   }
 };
 
 class LLVM_LIBRARY_VISIBILITY DarwinPPC64TargetInfo
     : public DarwinTargetInfo<PPC64TargetInfo> {
 public:
   DarwinPPC64TargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : DarwinTargetInfo<PPC64TargetInfo>(Triple, Opts) {
     HasAlignMac68kSupport = true;
+    UseSignedCharForObjCBool = true;
     resetDataLayout("E-m:o-i64:64-n32:64");
   }
 };
 
 } // namespace targets
 } // namespace clang
 #endif // LLVM_CLANG_LIB_BASIC_TARGETS_PPC_H

lib/Basic/Targets/X86.h

public:
   DarwinI386TargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : DarwinTargetInfo<X86_32TargetInfo>(Triple, Opts) {
     LongDoubleWidth = 128;
     LongDoubleAlign = 128;
     SuitableAlign = 128;
     MaxVectorAlign = 256;
     // The watchOS simulator uses the builtin bool type for Objective-C.
     llvm::Triple T = llvm::Triple(Triple);
-    if (T.isWatchOS())
-      UseSignedCharForObjCBool = false;
+    UseSignedCharForObjCBool = !T.isWatchOS();
     SizeType = UnsignedLong;
     IntPtrType = SignedLong;
     resetDataLayout("e-m:o-p:32:32-f64:32:64-f80:128-n8:16:32-S128");
     HasAlignMac68kSupport = true;
   }
 
   bool handleTargetFeatures(std::vector<std::string> &Features,
                             DiagnosticsEngine &Diags) override {

 class LLVM_LIBRARY_VISIBILITY DarwinX86_64TargetInfo
     : public DarwinTargetInfo<X86_64TargetInfo> {
 public:
   DarwinX86_64TargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : DarwinTargetInfo<X86_64TargetInfo>(Triple, Opts) {
     Int64Type = SignedLongLong;
     // The 64-bit iOS simulator uses the builtin bool type for Objective-C.
     llvm::Triple T = llvm::Triple(Triple);
-    if (T.isiOS())
-      UseSignedCharForObjCBool = false;
+    UseSignedCharForObjCBool = !T.isiOS();
     resetDataLayout("e-m:o-i64:64-f80:128-n8:16:32:64-S128");
   }
 
   bool handleTargetFeatures(std::vector<std::string> &Features,
                             DiagnosticsEngine &Diags) override {
     if (!DarwinTargetInfo<X86_64TargetInfo>::handleTargetFeatures(Features,
                                                                   Diags))
       return false;

test/Frontend/objc-bool-is-bool.m

 // RUN: %clang_cc1 -fsyntax-only -E -dM -triple=armv7k-apple-watchos %s | FileCheck --check-prefix=BOOL %s
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=armv7-apple-watchos %s | FileCheck --check-prefix=CHAR %s
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=armv7-apple-ios %s | FileCheck --check-prefix=CHAR %s
+
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=arm64-apple-ios %s | FileCheck --check-prefix=BOOL %s
+
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=i686-apple-darwin16 %s | FileCheck --check-prefix=CHAR %s
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=i686-apple-ios %s | FileCheck --check-prefix=CHAR %s
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=i686-apple-tvos %s | FileCheck --check-prefix=CHAR %s
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=i686-apple-watchos %s | FileCheck --check-prefix=BOOL %s
+
 // RUN: %clang_cc1 -fsyntax-only -E -dM -triple=x86_64-apple-darwin16 %s | FileCheck --check-prefix=CHAR %s
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=x86_64-apple-ios %s | FileCheck --check-prefix=BOOL %s
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=x86_64-apple-tvos %s | FileCheck --check-prefix=BOOL %s
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=x86_64-apple-watchos %s | FileCheck --check-prefix=CHAR %s
+
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=ppc32-apple-darwin16 %s | FileCheck --check-prefix=CHAR %s
+// RUN: %clang_cc1 -fsyntax-only -E -dM -triple=ppc64-apple-darwin16 %s | FileCheck --check-prefix=CHAR %s
+
 // RUN: %clang_cc1 -x c -fsyntax-only -E -dM -triple=x86_64-apple-darwin16 %s | FileCheck --check-prefix=CHAR %s
 // RUN: %clang_cc1 -x objective-c++ -fsyntax-only -E -dM -triple=x86_64-apple-darwin16 %s | FileCheck --check-prefix=CHAR %s
 // RUN: %clang_cc1 -x c++ -fsyntax-only -E -dM -triple=x86_64-apple-darwin16 %s | FileCheck --check-prefix=CHAR %s
 
 // rdar://21170440
 
 // BOOL: #define __OBJC_BOOL_IS_BOOL 1
 // BOOL-NOT: #define __OBJC_BOOL_IS_BOOL 0
 
 // CHAR: #define __OBJC_BOOL_IS_BOOL 0
 // CHAR-NOT: #define __OBJC_BOOL_IS_BOOL 1