Revert r267784, r267824 and r267830.

It makes compiler-rt tests fail if the gold plugin is enabled.

Revert "Rework interface for bitset-using features to use a notion of LTO visibility."
Revert "Driver: only produce CFI -fvisibility= error when compiling."
Revert "clang/test/CodeGenCXX/cfi-blacklist.cpp: Exclude ms targets. They would be non-cfi."

llvm-svn: 267871

Author: d0k

clang/docs/ControlFlowIntegrity.rst

@@ -25,25 +25,13 @@ As currently implemented, all schemes rely on link-time optimization (LTO);
 so it is required to specify ``-flto``, and the linker used must support LTO,
 for example via the `gold plugin`_.
 
-To allow the checks to be implemented efficiently, the program must
-be structured such that certain object files are compiled with CFI
+To allow the checks to be implemented efficiently, the program must be
+structured such that certain object files are compiled with CFI
 enabled, and are statically linked into the program. This may preclude
-the use of shared libraries in some cases.
-
-The compiler will only produce CFI checks for a class if it can infer hidden
-LTO visibility for that class. LTO visibility is a property of a class that
-is inferred from flags and attributes. For more details, see the documentation
-for :doc:`LTO visibility <LTOVisibility>`.
-
-The ``-fsanitize=cfi-{vcall,nvcall,derived-cast,unrelated-cast}`` flags
-require that a ``-fvisibility=`` flag also be specified. This is because the
-default visibility setting is ``-fvisibility=default``, which would disable
-CFI checks for classes without visibility attributes. Most users will want
-to specify ``-fvisibility=hidden``, which enables CFI checks for such classes.
-
-Experimental support for :ref:`cross-DSO control flow integrity
-<cfi-cross-dso>` exists that does not require classes to have hidden LTO
-visibility. This cross-DSO support has unstable ABI at this time.
+the use of shared libraries in some cases. Experimental support for
+:ref:`cross-DSO control flow integrity <cfi-cross-dso>` exists that
+does not have these requirements. This cross-DSO support has unstable
+ABI at this time.
 
 .. _gold plugin: http://llvm.org/docs/GoldPlugin.html
 
@@ -245,6 +233,11 @@ A :doc:`SanitizerSpecialCaseList` can be used to relax CFI checks for certain
 source files, functions and types using the ``src``, ``fun`` and ``type``
 entity types.
 
+In addition, if a type has a ``uuid`` attribute and the blacklist contains
+the type entry ``attr:uuid``, CFI checks are suppressed for that type. This
+allows all COM types to be easily blacklisted, which is useful as COM types
+are typically defined outside of the linked program.
+
 .. code-block:: bash
 
     # Suppress checking for code in a file.
@@ -254,6 +247,8 @@ entity types.
     fun:*MyFooBar*
     # Ignore all types in the standard library.
     type:std::*
+    # Ignore all types with a uuid attribute.
+    type:attr:uuid
 
 .. _cfi-cross-dso:
 
@@ -265,11 +260,6 @@ flow integrity mode, which allows all CFI schemes listed above to
 apply across DSO boundaries. As in the regular CFI, each DSO must be
 built with ``-flto``.
 
-Normally, CFI checks will only be performed for classes that have hidden LTO
-visibility. With this flag enabled, the compiler will emit cross-DSO CFI
-checks for all classes, except for those which appear in the CFI blacklist
-or which use a ``no_sanitize`` attribute.
-
 Design
 ======
 

clang/docs/LTOVisibility.rst

@@ -1056,8 +1056,17 @@ are listed below.
 .. option:: -fwhole-program-vtables
 
    Enable whole-program vtable optimizations, such as single-implementation
-   devirtualization and virtual constant propagation, for classes with
-   :doc:`hidden LTO visibility <LTOVisibility>`. Requires ``-flto``.
+   devirtualization and virtual constant propagation. Requires ``-flto``.
+
+   By default, the compiler will assume that all type hierarchies are
+   closed except those in the ``std`` namespace, the ``stdext`` namespace
+   and classes with the ``__declspec(uuid())`` attribute.
+
+.. option:: -fwhole-program-vtables-blacklist=path
+
+   Allows the user to specify the path to a list of additional classes to
+   blacklist from whole-program vtable optimizations. This list is in the
+   :ref:`CFI blacklist <cfi-blacklist>` format.
 
 .. option:: -fno-assume-sane-operator-new
 

clang/docs/UsersManual.rst

@@ -31,7 +31,6 @@ Using Clang as a Compiler
    SanitizerStats
    SanitizerSpecialCaseList
    ControlFlowIntegrity
-   LTOVisibility
    SafeStack
    Modules
    MSVCCompatibility

clang/docs/index.rst

@@ -1611,12 +1611,6 @@ def WeakRef : InheritableAttr {
   let Documentation = [Undocumented];
 }
 
-def LTOVisibilityPublic : InheritableAttr {
-  let Spellings = [CXX11<"clang", "lto_visibility_public">];
-  let Subjects = SubjectList<[Record]>;
-  let Documentation = [LTOVisibilityDocs];
-}
-
 def AnyX86Interrupt : InheritableAttr, TargetSpecificAttr<TargetAnyX86> {
   // NOTE: If you add any additional spellings, ARMInterrupt's,
   // MSP430Interrupt's and MipsInterrupt's spellings must match.

clang/include/clang/Basic/Attr.td

@@ -2380,10 +2380,3 @@ The ``ifunc`` attribute may only be used on a function declaration.  A function
 Not all targets support this attribute.  ELF targets support this attribute when using binutils v2.20.1 or higher and glibc v2.11.1 or higher.  Non-ELF targets currently do not support this attribute.
   }];
 }
-
-def LTOVisibilityDocs : Documentation {
-  let Category = DocCatType;
-  let Content = [{
-See :doc:`LTOVisibility`.
-  }];
-}

clang/include/clang/Basic/AttrDocs.td

@@ -282,9 +282,6 @@ def fprofile_instrument_path_EQ : Joined<["-"], "fprofile-instrument-path=">,
 def fprofile_instrument_use_path_EQ :
     Joined<["-"], "fprofile-instrument-use-path=">,
     HelpText<"Specify the profile path in PGO use compilation">;
-def flto_visibility_public_std:
-    Flag<["-"], "flto-visibility-public-std">,
-    HelpText<"Use public LTO visibility for classes in std and stdext namespaces">;
 
 //===----------------------------------------------------------------------===//
 // Dependency Output Options

clang/include/clang/Driver/CC1Options.td

@@ -1152,6 +1152,9 @@ def fwhole_program_vtables : Flag<["-"], "fwhole-program-vtables">, Group<f_Grou
   Flags<[CC1Option]>,
   HelpText<"Enables whole-program vtable optimization. Requires -flto">;
 def fno_whole_program_vtables : Flag<["-"], "fno-whole-program-vtables">, Group<f_Group>;
+def fwhole_program_vtables_blacklist_EQ : Joined<["-"], "fwhole-program-vtables-blacklist=">,
+  Group<f_Group>, Flags<[CC1Option]>,
+  HelpText<"Path to a blacklist file for whole-program vtable optimization">;
 def fwrapv : Flag<["-"], "fwrapv">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Treat signed integer overflow as two's complement">;
 def fwritable_strings : Flag<["-"], "fwritable-strings">, Group<f_Group>, Flags<[CC1Option]>,

clang/include/clang/Driver/Options.td

@@ -187,10 +187,6 @@ CODEGENOPT(EmitLLVMUseLists, 1, 0) ///< Control whether to serialize use-lists.
 CODEGENOPT(WholeProgramVTables, 1, 0) ///< Whether to apply whole-program
                                       ///  vtable optimization.
 
-/// Whether to use public LTO visibility for entities in std and stdext
-/// namespaces. This is enabled by clang-cl's /MT and /MTd flags.
-CODEGENOPT(LTOVisibilityPublicStd, 1, 0)
-
 /// The user specified number of registers to be used for integral arguments,
 /// or 0 if unspecified.
 VALUE_CODEGENOPT(NumRegisterParameters, 32, 0)

clang/include/clang/Frontend/CodeGenOptions.def

@@ -199,6 +199,9 @@ class CodeGenOptions : public CodeGenOptionsBase {
   /// \brief A list of all -fno-builtin-* function names (e.g., memset).
   std::vector<std::string> NoBuiltinFuncs;
 
+  /// List of blacklist files for the whole-program vtable optimization feature.
+  std::vector<std::string> WholeProgramVTablesBlacklistFiles;
+
 public:
   // Define accessors/mutators for code generation options of enumeration type.
 #define CODEGENOPT(Name, Bits, Default)