Revert "[clang] Enable sized deallocation by default in C++14 onwards (…

…llvm#83774)" (llvm#90299)

https://lab.llvm.org/buildbot/#/builders/168/builds/20063 (should be
fixed with llvm#90292)

More details in llvm#83774

This reverts commit cf5a8b4.

clang-tools-extra/clangd/unittests/FindTargetTests.cpp

@@ -839,9 +839,7 @@ TEST_F(TargetDeclTest, OverloadExpr) {
       [[delete]] x;
     }
   )cpp";
-  // Sized deallocation is enabled by default in C++14 onwards.
-  EXPECT_DECLS("CXXDeleteExpr",
-               "void operator delete(void *, unsigned long) noexcept");
+  EXPECT_DECLS("CXXDeleteExpr", "void operator delete(void *) noexcept");
 }
 
 TEST_F(TargetDeclTest, DependentExprs) {

clang-tools-extra/test/clang-tidy/checkers/misc/new-delete-overloads.cpp

@@ -12,6 +12,16 @@ struct S {
 // CHECK-MESSAGES: :[[@LINE+1]]:7: warning: declaration of 'operator new' has no matching declaration of 'operator delete' at the same scope
 void *operator new(size_t size) noexcept(false);
 
+struct T {
+  // Sized deallocations are not enabled by default, and so this new/delete pair
+  // does not match. However, we expect only one warning, for the new, because
+  // the operator delete is a placement delete and we do not warn on mismatching
+  // placement operations.
+  // CHECK-MESSAGES: :[[@LINE+1]]:9: warning: declaration of 'operator new' has no matching declaration of 'operator delete' at the same scope
+  void *operator new(size_t size) noexcept;
+  void operator delete(void *ptr, size_t) noexcept; // ok only if sized deallocation is enabled
+};
+
 struct U {
   void *operator new(size_t size) noexcept;
   void operator delete(void *ptr) noexcept;

clang/docs/ReleaseNotes.rst

@@ -90,11 +90,6 @@ C++ Language Changes
 --------------------
 - Implemented ``_BitInt`` literal suffixes ``__wb`` or ``__WB`` as a Clang extension with ``unsigned`` modifiers also allowed. (#GH85223).
 
-C++14 Feature Support
-^^^^^^^^^^^^^^^^^^^^^
-- Sized deallocation is enabled by default in C++14 onwards. The user may specify
-  ``-fno-sized-deallocation`` to disable it if there are some regressions.
-
 C++17 Feature Support
 ^^^^^^^^^^^^^^^^^^^^^
 - Clang now exposes ``__GCC_DESTRUCTIVE_SIZE`` and ``__GCC_CONSTRUCTIVE_SIZE``

clang/include/clang/Driver/Options.td

@@ -603,7 +603,6 @@ class MarshallingInfoVisibility<KeyPathAndMacro kpm, code default>
 // Key paths that are constant during parsing of options with the same key path prefix.
 defvar cplusplus = LangOpts<"CPlusPlus">;
 defvar cpp11 = LangOpts<"CPlusPlus11">;
-defvar cpp14 = LangOpts<"CPlusPlus14">;
 defvar cpp17 = LangOpts<"CPlusPlus17">;
 defvar cpp20 = LangOpts<"CPlusPlus20">;
 defvar c99 = LangOpts<"C99">;
@@ -3371,9 +3370,10 @@ defm relaxed_template_template_args : BoolFOption<"relaxed-template-template-arg
           "Enable C++17 relaxed template template argument matching">,
   NegFlag<SetFalse>>;
 defm sized_deallocation : BoolFOption<"sized-deallocation",
-  LangOpts<"SizedDeallocation">, Default<cpp14.KeyPath>,
-  PosFlag<SetTrue, [], [], "Enable C++14 sized global deallocation functions">,
-  NegFlag<SetFalse>, BothFlags<[], [ClangOption, CC1Option]>>;
+  LangOpts<"SizedDeallocation">, DefaultFalse,
+  PosFlag<SetTrue, [], [ClangOption, CC1Option],
+          "Enable C++14 sized global deallocation functions">,
+  NegFlag<SetFalse>>;
 defm aligned_allocation : BoolFOption<"aligned-allocation",
   LangOpts<"AlignedAllocation">, Default<cpp17.KeyPath>,
   PosFlag<SetTrue, [], [ClangOption], "Enable C++17 aligned allocation functions">,

clang/lib/Driver/ToolChains/Clang.cpp

@@ -7262,15 +7262,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   Args.addOptInFlag(CmdArgs, options::OPT_frelaxed_template_template_args,
                     options::OPT_fno_relaxed_template_template_args);
 
-  // -fsized-deallocation is on by default in C++14 onwards and otherwise off
-  // by default.
-  if (Arg *A = Args.getLastArg(options::OPT_fsized_deallocation,
-                               options::OPT_fno_sized_deallocation)) {
-    if (A->getOption().matches(options::OPT_fno_sized_deallocation))
-      CmdArgs.push_back("-fno-sized-deallocation");
-    else
-      CmdArgs.push_back("-fsized-deallocation");
-  }
+  // -fsized-deallocation is off by default, as it is an ABI-breaking change for
+  // most platforms.
+  Args.addOptInFlag(CmdArgs, options::OPT_fsized_deallocation,
+                    options::OPT_fno_sized_deallocation);
 
   // -faligned-allocation is on by default in C++17 onwards and otherwise off
   // by default.

clang/lib/Driver/ToolChains/Darwin.cpp

@@ -2912,68 +2912,16 @@ static bool sdkSupportsBuiltinModules(const Darwin::DarwinPlatformKind &TargetPl
   }
 }
 
-static inline llvm::VersionTuple
-sizedDeallocMinVersion(llvm::Triple::OSType OS) {
-  switch (OS) {
-  default:
-    break;
-  case llvm::Triple::Darwin:
-  case llvm::Triple::MacOSX: // Earliest supporting version is 10.12.
-    return llvm::VersionTuple(10U, 12U);
-  case llvm::Triple::IOS:
-  case llvm::Triple::TvOS: // Earliest supporting version is 10.0.0.
-    return llvm::VersionTuple(10U);
-  case llvm::Triple::WatchOS: // Earliest supporting version is 3.0.0.
-    return llvm::VersionTuple(3U);
-  }
-
-  llvm_unreachable("Unexpected OS");
-}
-
-bool Darwin::isSizedDeallocationUnavailable() const {
-  llvm::Triple::OSType OS;
-
-  if (isTargetMacCatalyst())
-    return TargetVersion < sizedDeallocMinVersion(llvm::Triple::MacOSX);
-  switch (TargetPlatform) {
-  case MacOS: // Earlier than 10.12.
-    OS = llvm::Triple::MacOSX;
-    break;
-  case IPhoneOS:
-    OS = llvm::Triple::IOS;
-    break;
-  case TvOS: // Earlier than 10.0.
-    OS = llvm::Triple::TvOS;
-    break;
-  case WatchOS: // Earlier than 3.0.
-    OS = llvm::Triple::WatchOS;
-    break;
-  case DriverKit:
-  case XROS:
-    // Always available.
-    return false;
-  }
-
-  return TargetVersion < sizedDeallocMinVersion(OS);
-}
-
-void Darwin::addClangTargetOptions(
-    const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args,
-    Action::OffloadKind DeviceOffloadKind) const {
+void Darwin::addClangTargetOptions(const llvm::opt::ArgList &DriverArgs,
+                                   llvm::opt::ArgStringList &CC1Args,
+                                   Action::OffloadKind DeviceOffloadKind) const {
   // Pass "-faligned-alloc-unavailable" only when the user hasn't manually
   // enabled or disabled aligned allocations.
   if (!DriverArgs.hasArgNoClaim(options::OPT_faligned_allocation,
                                 options::OPT_fno_aligned_allocation) &&
       isAlignedAllocationUnavailable())
     CC1Args.push_back("-faligned-alloc-unavailable");
 
-  // Pass "-fno-sized-deallocation" only when the user hasn't manually enabled
-  // or disabled sized deallocations.
-  if (!DriverArgs.hasArgNoClaim(options::OPT_fsized_deallocation,
-                                options::OPT_fno_sized_deallocation) &&
-      isSizedDeallocationUnavailable())
-    CC1Args.push_back("-fno-sized-deallocation");
-
   addClangCC1ASTargetOptions(DriverArgs, CC1Args);
 
   // Enable compatibility mode for NSItemProviderCompletionHandler in

clang/lib/Driver/ToolChains/Darwin.h

@@ -511,10 +511,6 @@ class LLVM_LIBRARY_VISIBILITY Darwin : public MachO {
   /// targeting.
   bool isAlignedAllocationUnavailable() const;
 
-  /// Return true if c++14 sized deallocation functions are not implemented in
-  /// the c++ standard library of the deployment target we are targeting.
-  bool isSizedDeallocationUnavailable() const;
-
   void addClangTargetOptions(const llvm::opt::ArgList &DriverArgs,
                              llvm::opt::ArgStringList &CC1Args,
                              Action::OffloadKind DeviceOffloadKind) const override;

clang/lib/Driver/ToolChains/ZOS.cpp

@@ -36,12 +36,6 @@ void ZOS::addClangTargetOptions(const ArgList &DriverArgs,
   if (!DriverArgs.hasArgNoClaim(options::OPT_faligned_allocation,
                                 options::OPT_fno_aligned_allocation))
     CC1Args.push_back("-faligned-alloc-unavailable");
-
-  // Pass "-fno-sized-deallocation" only when the user hasn't manually enabled
-  // or disabled sized deallocations.
-  if (!DriverArgs.hasArgNoClaim(options::OPT_fsized_deallocation,
-                                options::OPT_fno_sized_deallocation))
-    CC1Args.push_back("-fno-sized-deallocation");
 }
 
 void zos::Assembler::ConstructJob(Compilation &C, const JobAction &JA,

clang/test/AST/ast-dump-expr-json.cpp

@@ -2333,7 +2333,7 @@ void TestNonADLCall3() {
 // CHECK-NEXT:         "kind": "FunctionDecl",
 // CHECK-NEXT:         "name": "operator delete",
 // CHECK-NEXT:         "type": {
-// CHECK-NEXT:          "qualType": "void (void *, unsigned long) noexcept"
+// CHECK-NEXT:          "qualType": "void (void *) noexcept"
 // CHECK-NEXT:         }
 // CHECK-NEXT:        },
 // CHECK-NEXT:        "inner": [

clang/test/AST/ast-dump-expr.cpp

@@ -164,7 +164,7 @@ void UnaryExpressions(int *p) {
   // CHECK-NEXT: DeclRefExpr 0x{{[^ ]*}} <col:8> 'int *' lvalue ParmVar 0x{{[^ ]*}} 'p' 'int *'
 
   ::delete p;
-  // CHECK: CXXDeleteExpr 0x{{[^ ]*}} <line:[[@LINE-1]]:3, col:12> 'void' global Function 0x{{[^ ]*}} 'operator delete' 'void (void *, unsigned long) noexcept'
+  // CHECK: CXXDeleteExpr 0x{{[^ ]*}} <line:[[@LINE-1]]:3, col:12> 'void' global Function 0x{{[^ ]*}} 'operator delete' 'void (void *) noexcept'
   // CHECK-NEXT: ImplicitCastExpr
   // CHECK-NEXT: DeclRefExpr 0x{{[^ ]*}} <col:12> 'int *' lvalue ParmVar 0x{{[^ ]*}} 'p' 'int *'