diff options
| -rw-r--r-- | clang/docs/ClangCommandLineReference.rst | 6 | ||||
| -rw-r--r-- | clang/docs/ReleaseNotes.rst | 6 | ||||
| -rw-r--r-- | clang/docs/UsersManual.rst | 6 | ||||
| -rw-r--r-- | clang/include/clang/Basic/LangOptions.def | 2 | ||||
| -rw-r--r-- | clang/include/clang/Driver/Options.td | 5 | ||||
| -rw-r--r-- | clang/include/clang/Frontend/CodeGenOptions.def | 4 | ||||
| -rw-r--r-- | clang/lib/CodeGen/ItaniumCXXABI.cpp | 14 | ||||
| -rw-r--r-- | clang/lib/Driver/ToolChains/Clang.cpp | 4 | ||||
| -rw-r--r-- | clang/lib/Frontend/CompilerInvocation.cpp | 4 | ||||
| -rw-r--r-- | clang/lib/Sema/SemaDeclCXX.cpp | 6 | ||||
| -rw-r--r-- | clang/test/CodeGenCXX/vtable-available-externally.cpp | 128 |
11 files changed, 182 insertions, 3 deletions
diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst index 264729dd0f1..513128119e2 100644 --- a/clang/docs/ClangCommandLineReference.rst +++ b/clang/docs/ClangCommandLineReference.rst @@ -1934,6 +1934,12 @@ Set the default symbol visibility for all global declarations Enables whole-program vtable optimization. Requires -flto +.. option:: -fforce-emit-vtables, -fno-force-emit-vtables + +In order to improve devirtualization, forces emitting of vtables even in +modules where it isn't necessary. It causes more inline virtual functions +to be emitted. + .. option:: -fwrapv, -fno-wrapv Treat signed integer overflow as two's complement diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 84145554647..15ae73e859e 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -112,6 +112,12 @@ New Compiler Flags 'no-strict' option, Clang attempts to match the overflowing behavior of the target's native float-to-int conversion instructions. +- :option: `-fforce-emit-vtables` and `-fno-force-emit-vtables`. + + In order to improve devirtualization, forces emitting of vtables even in + modules where it isn't necessary. It causes more inline virtual functions + to be emitted. + - ... Deprecated Compiler Flags diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst index 9778b1654de..b1c286193cf 100644 --- a/clang/docs/UsersManual.rst +++ b/clang/docs/UsersManual.rst @@ -1269,6 +1269,12 @@ are listed below. devirtualization and virtual constant propagation, for classes with :doc:`hidden LTO visibility <LTOVisibility>`. Requires ``-flto``. +.. option:: -fforce-emit-vtables + + In order to improve devirtualization, forces emitting of vtables even in + modules where it isn't necessary. It causes more inline virtual functions + to be emitted. + .. option:: -fno-assume-sane-operator-new Don't assume that the C++'s new operator is sane. diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def index 6bd8958e36d..f9246bd8935 100644 --- a/clang/include/clang/Basic/LangOptions.def +++ b/clang/include/clang/Basic/LangOptions.def @@ -293,6 +293,8 @@ LANGOPT(XRayAlwaysEmitTypedEvents, 1, 0, "controls whether to always emit intrinsic calls to " "__xray_typedevent(...) builtin.") +LANGOPT(ForceEmitVTables, 1, 0, "whether to emit all vtables") + BENIGN_LANGOPT(AllowEditorPlaceholders, 1, 0, "allow editor placeholders in source") diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index 4c04d33466d..cd02a5ab5bd 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -1688,6 +1688,11 @@ def fwhole_program_vtables : Flag<["-"], "fwhole-program-vtables">, Group<f_Grou HelpText<"Enables whole-program vtable optimization. Requires -flto">; def fno_whole_program_vtables : Flag<["-"], "fno-whole-program-vtables">, Group<f_Group>, Flags<[CoreOption]>; +def fforce_emit_vtables : Flag<["-"], "fforce-emit-vtables">, Group<f_Group>, + Flags<[CC1Option]>, + HelpText<"Emits more virtual tables to improve devirtualization">; +def fno_force_emit_vtables : Flag<["-"], "fno-force-emit-vtables">, Group<f_Group>, + Flags<[CoreOption]>; 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]>, diff --git a/clang/include/clang/Frontend/CodeGenOptions.def b/clang/include/clang/Frontend/CodeGenOptions.def index c2dd7e43588..019425d1946 100644 --- a/clang/include/clang/Frontend/CodeGenOptions.def +++ b/clang/include/clang/Frontend/CodeGenOptions.def @@ -332,6 +332,10 @@ CODEGENOPT(NoPLT, 1, 0) /// Whether to embed source in DWARF debug line section. CODEGENOPT(EmbedSource, 1, 0) +/// Whether to emit all vtables +CODEGENOPT(ForceEmitVTables, 1, 0) + + #undef CODEGENOPT #undef ENUM_CODEGENOPT #undef VALUE_CODEGENOPT diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp index d84a10c6ba2..6ac7d29752d 100644 --- a/clang/lib/CodeGen/ItaniumCXXABI.cpp +++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp @@ -1707,11 +1707,19 @@ bool ItaniumCXXABI::canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const { if (CGM.getLangOpts().AppleKext) return false; - // If we don't have any not emitted inline virtual function, and if vtable is - // not hidden, then we are safe to emit available_externally copy of vtable. + // If the vtable is hidden then it is not safe to emit an available_externally + // copy of vtable. + if (isVTableHidden(RD)) + return false; + + if (CGM.getCodeGenOpts().ForceEmitVTables) + return true; + + // If we don't have any not emitted inline virtual function then we are safe + // to emit an available_externally copy of vtable. // FIXME we can still emit a copy of the vtable if we // can emit definition of the inline functions. - return !hasAnyUnusedVirtualInlineFunction(RD) && !isVTableHidden(RD); + return !hasAnyUnusedVirtualInlineFunction(RD); } static llvm::Value *performTypeAdjustment(CodeGenFunction &CGF, Address InitialPtr, diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index 3eee463bb13..d392f68897c 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -3472,6 +3472,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA, options::OPT_fno_strict_vtable_pointers, false)) CmdArgs.push_back("-fstrict-vtable-pointers"); + if (Args.hasFlag(options::OPT_fforce_emit_vtables, + options::OPT_fno_force_emit_vtables, + false)) + CmdArgs.push_back("-fforce-emit-vtables"); if (!Args.hasFlag(options::OPT_foptimize_sibling_calls, options::OPT_fno_optimize_sibling_calls)) CmdArgs.push_back("-mdisable-tail-calls"); diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp index a959cdb2347..2aa74c38e2b 100644 --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -719,6 +719,7 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK, Opts.StrictEnums = Args.hasArg(OPT_fstrict_enums); Opts.StrictReturn = !Args.hasArg(OPT_fno_strict_return); Opts.StrictVTablePointers = Args.hasArg(OPT_fstrict_vtable_pointers); + Opts.ForceEmitVTables = Args.hasArg(OPT_fforce_emit_vtables); Opts.UnsafeFPMath = Args.hasArg(OPT_menable_unsafe_fp_math) || Args.hasArg(OPT_cl_unsafe_math_optimizations) || Args.hasArg(OPT_cl_fast_relaxed_math); @@ -2735,6 +2736,9 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK, Args.getAllArgValues(OPT_fxray_never_instrument); Opts.XRayAttrListFiles = Args.getAllArgValues(OPT_fxray_attr_list); + // -fforce-emit-vtables + Opts.ForceEmitVTables = Args.hasArg(OPT_fforce_emit_vtables); + // -fallow-editor-placeholders Opts.AllowEditorPlaceholders = Args.hasArg(OPT_fallow_editor_placeholders); diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index 55517fc3f66..f5e48210924 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -6125,6 +6125,12 @@ void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) { Record->setParamDestroyedInCallee(true); else if (Record->hasNonTrivialDestructor()) Record->setParamDestroyedInCallee(CanPass); + + if (getLangOpts().ForceEmitVTables) { + // If we want to emit all the vtables, we need to mark it as used. This + // is especially required for cases like vtable assumption loads. + MarkVTableUsed(Record->getInnerLocStart(), Record); + } } /// Look up the special member function that would be called by a special diff --git a/clang/test/CodeGenCXX/vtable-available-externally.cpp b/clang/test/CodeGenCXX/vtable-available-externally.cpp index 0e7e8b4a322..b52527d36c6 100644 --- a/clang/test/CodeGenCXX/vtable-available-externally.cpp +++ b/clang/test/CodeGenCXX/vtable-available-externally.cpp @@ -1,5 +1,6 @@ // RUN: %clang_cc1 %s -I%S -triple=x86_64-apple-darwin10 -std=c++98 -emit-llvm -o %t // RUN: %clang_cc1 %s -I%S -triple=x86_64-apple-darwin10 -std=c++98 -O2 -disable-llvm-passes -emit-llvm -o %t.opt +// RUN: %clang_cc1 %s -I%S -triple=x86_64-apple-darwin10 -std=c++98 -O2 -disable-llvm-passes -emit-llvm -o %t.vtable -fforce-emit-vtables -fstrict-vtable-pointers -mconstructor-aliases // RUN: FileCheck --check-prefix=CHECK-TEST1 %s < %t // RUN: FileCheck --check-prefix=CHECK-TEST2 %s < %t // RUN: FileCheck --check-prefix=CHECK-TEST5 %s < %t @@ -13,10 +14,13 @@ // RUN: FileCheck --check-prefix=CHECK-TEST15 %s < %t.opt // RUN: FileCheck --check-prefix=CHECK-TEST16 %s < %t.opt // RUN: FileCheck --check-prefix=CHECK-TEST17 %s < %t.opt +// RUN: FileCheck --check-prefix=CHECK-FORCE-EMIT %s < %t.vtable + #include <typeinfo> // CHECK-TEST1: @_ZTVN5Test11AE = external unnamed_addr constant +// CHECK-FORCE-EMIT-DAG: @_ZTVN5Test11AE = available_externally unnamed_addr constant namespace Test1 { struct A { @@ -213,6 +217,7 @@ namespace Test10 { // because A's key function is defined here, vtable is generated in this TU // CHECK-TEST10-DAG: @_ZTVN6Test101AE = unnamed_addr constant +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test101AE = unnamed_addr constant struct A { virtual void foo(); virtual void bar(); @@ -221,6 +226,7 @@ void A::foo() {} // Because key function is inline we will generate vtable as linkonce_odr. // CHECK-TEST10-DAG: @_ZTVN6Test101DE = linkonce_odr unnamed_addr constant +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test101DE = linkonce_odr unnamed_addr constant struct D : A { void bar(); }; @@ -237,6 +243,7 @@ struct B : A { // can't guarantee that we will be able to refer to bar from name // so (at the moment) we can't emit vtable available_externally. // CHECK-TEST10-DAG: @_ZTVN6Test101CE = external unnamed_addr constant +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test101CE = available_externally unnamed_addr constant struct C : A { void bar() {} // defined in body - not key function virtual inline void gar(); // inline in body - not key function @@ -245,6 +252,8 @@ struct C : A { // no key function, vtable will be generated everywhere it will be used // CHECK-TEST10-DAG: @_ZTVN6Test101EE = linkonce_odr unnamed_addr constant +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test101EE = linkonce_odr unnamed_addr constant + struct E : A {}; void g(A& a) { @@ -298,11 +307,13 @@ void g() { namespace Test12 { // CHECK-TEST12: @_ZTVN6Test121AE = external unnamed_addr constant +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test121AE = available_externally unnamed_addr constant struct A { virtual void foo(); virtual ~A() {} }; // CHECK-TEST12: @_ZTVN6Test121BE = external unnamed_addr constant +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test121BE = available_externally unnamed_addr constant struct B : A { void foo(); }; @@ -319,6 +330,9 @@ namespace Test13 { // CHECK-TEST13-DAG: @_ZTVN6Test131AE = available_externally unnamed_addr constant // CHECK-TEST13-DAG: @_ZTVN6Test131BE = external unnamed_addr constant +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test131AE = available_externally unnamed_addr constant +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test131BE = available_externally unnamed_addr constant + struct A { virtual ~A(); }; @@ -371,6 +385,8 @@ namespace Test16 { // generate available_externally vtable for it. // CHECK-TEST16-DAG: @_ZTVN6Test161SE = external unnamed_addr constant // CHECK-TEST16-DAG: @_ZTVN6Test162S2E = available_externally +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test161SE = external unnamed_addr constant +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test162S2E = available_externally struct S { __attribute__((visibility("hidden"))) virtual void doStuff(); @@ -395,6 +411,10 @@ namespace Test17 { // This test checks if we emit vtables opportunistically. // CHECK-TEST17-DAG: @_ZTVN6Test171AE = available_externally // CHECK-TEST17-DAG: @_ZTVN6Test171BE = external +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test171AE = available_externally +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test171BE = available_externally +// CHECK-FORCE-EMIT-DAG: define linkonce_odr void @_ZN6Test171BD2Ev( +// CHECK-FORCE-EMIT-DAG: define linkonce_odr void @_ZN6Test171BD0Ev( struct A { virtual void key(); @@ -418,3 +438,111 @@ void testcaseB() { } } // namespace Test17 + +namespace Test18 { +// Here vtable will be only emitted because it is referenced by assume-load +// after the Derived construction. +// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test187DerivedE = linkonce_odr unnamed_addr constant {{.*}} @_ZTIN6Test187DerivedE {{.*}} @_ZN6Test184Base3funEv {{.*}} @_ZN6Test184BaseD2Ev {{.*}} @_ZN6Test187DerivedD0Ev +// CHECK-FORCE-EMIT-DAG: define linkonce_odr void @_ZN6Test187DerivedD0Ev +// CHECK-FORCE-EMIT-DAG: define linkonce_odr void @_ZN6Test184BaseD2Ev +// CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN6Test184Base3funEv +// CHECK-FORCE-EMIT-DAG: @_ZTIN6Test187DerivedE = linkonce_odr constant + +struct Base { + virtual int fun() { return 42; } + virtual ~Base() { } +}; + +struct Derived : Base { + Derived(); +}; + +int foo() { + Derived *der = new Derived(); + return der->fun(); +} +} + +namespace TestTemplates { + +// CHECK-FORCE-EMIT-DAG: @_ZTVN13TestTemplates8TemplateIiEE = linkonce_odr unnamed_addr constant {{.*}} @_ZTIN13TestTemplates8TemplateIiEE {{.*}} @_ZN13TestTemplates8TemplateIiE3fooEi {{.*}}@_ZN13TestTemplates8TemplateIiE22thisShouldBeEmittedTooEi {{.*}}@_ZN13TestTemplates8TemplateIiED1Ev {{.*}}@_ZN13TestTemplates8TemplateIiED0Ev +// CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates8TemplateIiE22thisShouldBeEmittedTooEi + +template<class T> +struct Template { + Template(); + virtual T foo(T val); + // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates8TemplateIiE22thisShouldBeEmittedTooEi + virtual T thisShouldBeEmittedToo(T val) { return val; } + virtual ~Template(); +}; + + +struct NonTemplate { + typedef int T; + NonTemplate(); + virtual T foo(T val); + // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates11NonTemplate22thisShouldBeEmittedTooEi + virtual T thisShouldBeEmittedToo(T val) { return val; } + virtual ~NonTemplate(); +}; + +// CHECK-FORCE-EMIT-DAG: @_ZTVN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiEE = linkonce_odr {{.*}} @_ZTIN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiEE {{.*}} @_ZN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiE3fooEi {{.*}} @_ZN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiE22thisShouldBeEmittedTooEi {{.*}} @_ZN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiED1Ev {{.*}} @_ZN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiED0Ev + +struct OuterNonTemplate { + template<class T> + struct NestedTemplateInNonTemplate { + NestedTemplateInNonTemplate(); + virtual T foo(T val); + // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiE22thisShouldBeEmittedTooEi + virtual T thisShouldBeEmittedToo(T val) { return val; } + virtual ~NestedTemplateInNonTemplate(); + }; + + struct NestedNonTemplateInNonTemplate { + typedef int T; + NestedNonTemplateInNonTemplate(); + virtual T foo(T val); + // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates16OuterNonTemplate30NestedNonTemplateInNonTemplate22thisShouldBeEmittedTooEi + virtual T thisShouldBeEmittedToo(T val) { return val; } + virtual ~NestedNonTemplateInNonTemplate(); + }; +}; + +template<class> +struct OuterTemplate { + template<class T> + struct NestedTemplateInTemplate { + NestedTemplateInTemplate(); + virtual T foo(T val); + // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates13OuterTemplateIlE24NestedTemplateInTemplateIiE22thisShouldBeEmittedTooEi + virtual T thisShouldBeEmittedToo(T val) { return val; } + virtual ~NestedTemplateInTemplate(); + }; + + struct NestedNonTemplateInTemplate { + typedef int T; + NestedNonTemplateInTemplate(); + virtual T foo(T val); + // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates13OuterTemplateIlE27NestedNonTemplateInTemplate22thisShouldBeEmittedTooEi + virtual T thisShouldBeEmittedToo(T val) { return val; } + virtual ~NestedNonTemplateInTemplate(); + }; +}; + +template<class T> +int use() { + T *ptr = new T(); + return ptr->foo(42); +} + +void test() { + use<Template<int> >(); + use<OuterTemplate<long>::NestedTemplateInTemplate<int> >(); + use<OuterNonTemplate::NestedTemplateInNonTemplate<int> >(); + + use<NonTemplate>(); + use<OuterTemplate<long>::NestedNonTemplateInTemplate>(); + use<OuterNonTemplate::NestedNonTemplateInNonTemplate>(); +} +} |
