jdoerfert updated this revision to Diff 311070. jdoerfert added a comment. Remove accidental test change and ensure users create `KnownAssumptionString` objects
Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D91979/new/ https://reviews.llvm.org/D91979 Files: clang/docs/LanguageExtensions.rst clang/include/clang/Basic/Attr.td clang/include/clang/Basic/AttrDocs.td clang/include/clang/Basic/DiagnosticGroups.td clang/include/clang/Basic/DiagnosticSemaKinds.td clang/include/clang/Sema/Sema.h clang/lib/CodeGen/CGCall.cpp clang/lib/Sema/CMakeLists.txt clang/lib/Sema/SemaDeclAttr.cpp clang/test/CodeGen/assume_attr.c clang/test/CodeGenCXX/assume_attr.cpp clang/test/Misc/pragma-attribute-supported-attributes-list.test clang/test/Sema/attr-assume.c llvm/include/llvm/IR/Assumptions.h llvm/lib/IR/Assumptions.cpp llvm/lib/IR/CMakeLists.txt
Index: llvm/lib/IR/CMakeLists.txt =================================================================== --- llvm/lib/IR/CMakeLists.txt +++ llvm/lib/IR/CMakeLists.txt @@ -1,6 +1,7 @@ add_llvm_component_library(LLVMCore AbstractCallSite.cpp AsmWriter.cpp + Assumptions.cpp Attributes.cpp AutoUpgrade.cpp BasicBlock.cpp Index: llvm/lib/IR/Assumptions.cpp =================================================================== --- /dev/null +++ llvm/lib/IR/Assumptions.cpp @@ -0,0 +1,36 @@ +//===- Assumptions.cpp ------ Collection of helpers for assumptions -------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +//===----------------------------------------------------------------------===// + +#include "llvm/IR/Assumptions.h" +#include "llvm/IR/Attributes.h" +#include "llvm/IR/Function.h" + +using namespace llvm; + +bool llvm::hasAssumption(Function &F, + const KnownAssumptionString &AssumptionStr) { + const Attribute &A = F.getFnAttribute(AssumptionAttrKey); + if (!A.isValid()) + return false; + assert(A.isStringAttribute() && "Expected a string attribute!"); + + SmallVector<StringRef, 8> Strings; + A.getValueAsString().split(Strings, ","); + + return llvm::any_of(Strings, [=](StringRef Assumption) { + return Assumption == AssumptionStr; + }); +} + +StringSet<> llvm::KnownAssumptionStrings({ + "omp_no_openmp", // OpenMP 5.1 + "omp_no_openmp_routines", // OpenMP 5.1 + "omp_no_parallelism", // OpenMP 5.1 +}); Index: llvm/include/llvm/IR/Assumptions.h =================================================================== --- /dev/null +++ llvm/include/llvm/IR/Assumptions.h @@ -0,0 +1,50 @@ +//===--- Assumptions.h - Assumption handling and organization ---*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// String assumptions that are known to optimization passes should be placed in +// the KnownAssumptionStrings set. This can be done in various ways, i.a., +// via a static KnownAssumptionString object. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_ASSUMPTIONS_H +#define LLVM_ASSUMPTIONS_H + +#include "llvm/ADT/StringRef.h" +#include "llvm/ADT/StringSet.h" + +namespace llvm { + +class Function; + +/// The key we use for assumption attributes. +constexpr StringRef AssumptionAttrKey = "llvm.assume"; + +/// A set of known assumption strings that are accepted without warning and +/// which can be recommended as typo correction. +extern StringSet<> KnownAssumptionStrings; + +/// Helper that allows to insert a new assumption string in the known assumption +/// set by creating a (static) object. +struct KnownAssumptionString { + KnownAssumptionString(StringRef AssumptionStr) + : AssumptionStr(AssumptionStr) { + KnownAssumptionStrings.insert(AssumptionStr); + } + operator StringRef() const { return AssumptionStr; } + +private: + StringRef AssumptionStr; +}; + +/// Return true if \p F has the assumption \p AssumptionStr attached. +bool hasAssumption(Function &F, const KnownAssumptionString &AssumptionStr); + +} // namespace llvm + +#endif Index: clang/test/Sema/attr-assume.c =================================================================== --- /dev/null +++ clang/test/Sema/attr-assume.c @@ -0,0 +1,14 @@ +// RUN: %clang_cc1 -triple i386-apple-darwin9 -fsyntax-only -verify %s + +void f1() __attribute__((assume(3))); // expected-error {{'assume' attribute requires a string}} +void f2() __attribute__((assume(int))); // expected-error {{expected expression}} +void f3() __attribute__((assume(for))); // expected-error {{expected expression}} +void f4() __attribute__((assume("QQQQ"))); // expected-warning {{the assumption string 'QQQQ' is not known and might be misspelled}} +void f5() __attribute__((assume("omp_no_openmp"))); +void f6() __attribute__((assume("omp_noopenmp"))); // expected-warning {{the assumption string 'omp_noopenmp' is not known and might be misspelled; did you mean 'omp_no_openmp'?}} +void f7() __attribute__((assume("omp_no_openmp_routine"))); // expected-warning {{the assumption string 'omp_no_openmp_routine' is not known and might be misspelled; did you mean 'omp_no_openmp_routines'?}} +void f8() __attribute__((assume("omp_no_openmp1"))); // expected-warning {{the assumption string 'omp_no_openmp1' is not known and might be misspelled; did you mean 'omp_no_openmp'?}} +void f9() __attribute__((assume("omp_no_openmp", "omp_no_openmp"))); // expected-error {{'assume' attribute takes one argument}} + +int g1 __attribute__((assume(0))); // expected-warning {{'assume' attribute only applies to functions}} +int g2 __attribute__((assume("omp_no_openmp"))); // expected-warning {{'assume' attribute only applies to functions}} Index: clang/test/Misc/pragma-attribute-supported-attributes-list.test =================================================================== --- clang/test/Misc/pragma-attribute-supported-attributes-list.test +++ clang/test/Misc/pragma-attribute-supported-attributes-list.test @@ -20,6 +20,7 @@ // CHECK-NEXT: ArcWeakrefUnavailable (SubjectMatchRule_objc_interface) // CHECK-NEXT: ArmBuiltinAlias (SubjectMatchRule_function) // CHECK-NEXT: AssumeAligned (SubjectMatchRule_objc_method, SubjectMatchRule_function) +// CHECK-NEXT: Assumption (SubjectMatchRule_function) // CHECK-NEXT: Availability ((SubjectMatchRule_record, SubjectMatchRule_enum, SubjectMatchRule_enum_constant, SubjectMatchRule_field, SubjectMatchRule_function, SubjectMatchRule_namespace, SubjectMatchRule_objc_category, SubjectMatchRule_objc_implementation, SubjectMatchRule_objc_interface, SubjectMatchRule_objc_method, SubjectMatchRule_objc_property, SubjectMatchRule_objc_protocol, SubjectMatchRule_record, SubjectMatchRule_type_alias, SubjectMatchRule_variable)) // CHECK-NEXT: BPFPreserveAccessIndex (SubjectMatchRule_record) // CHECK-NEXT: CFAuditedTransfer (SubjectMatchRule_function) Index: clang/test/CodeGenCXX/assume_attr.cpp =================================================================== --- /dev/null +++ clang/test/CodeGenCXX/assume_attr.cpp @@ -0,0 +1,120 @@ +// RUN: %clang_cc1 -emit-llvm -triple i386-linux-gnu %s -o - | FileCheck %s +// RUN: %clang_cc1 -x c++ -emit-pch -triple i386-linux-gnu -o %t %s +// RUN: %clang_cc1 -include-pch %t %s -triple i386-linux-gnu -emit-llvm -o - | FileCheck %s +// expected-no-diagnostics + +#ifndef HEADER +#define HEADER + +/// foo: declarations only + +__attribute__((assume("foo:before1"))) void foo(); + +__attribute__((assume("foo:before2"))) +__attribute__((assume("foo:before3"))) void +foo(); + +/// baz: static function declarations and a definition + +__attribute__((assume("baz:before1"))) static void baz(); + +__attribute__((assume("baz:before2"))) +__attribute__((assume("baz:before3"))) static void +baz(); + +// Definition +__attribute__((assume("baz:def1,baz:def2"))) static void baz() { foo(); } + +__attribute__((assume("baz:after"))) static void baz(); + +/// bar: external function declarations and a definition + +__attribute__((assume("bar:before1"))) void bar(); + +__attribute__((assume("bar:before2"))) +__attribute__((assume("bar:before3"))) void +bar(); + +// Definition +__attribute__((assume("bar:def1,bar:def2"))) void bar() { baz(); } + +__attribute__((assume("bar:after"))) void bar(); + +/// back to foo + +__attribute__((assume("foo:after"))) void foo(); + +/// class tests +class C { + __attribute__((assume("C:private_method"))) void private_method(); + __attribute__((assume("C:private_static"))) static void private_static(); + +public: + __attribute__((assume("C:public_method1"))) void public_method(); + __attribute__((assume("C:public_static1"))) static void public_static(); +}; + +__attribute__((assume("C:public_method2"))) void C::public_method() { + private_method(); +} + +__attribute__((assume("C:public_static2"))) void C::public_static() { + private_static(); +} + +/// template tests +template <typename T> +__attribute__((assume("template_func<T>"))) void template_func() {} + +template <> +__attribute__((assume("template_func<float>"))) void template_func<float>() {} + +template <> +void template_func<int>() {} + +template <typename T> +struct S { + __attribute__((assume("S<T>::method"))) void method(); +}; + +template <> +__attribute__((assume("S<float>::method"))) void S<float>::method() {} + +template <> +void S<int>::method() {} + +// CHECK: define{{.*}} void @_Z3barv() #0 +// CHECK: define{{.*}} void @_ZL3bazv() #1 +// CHECK: define{{.*}} void @_ZN1C13public_methodEv({{.*}}) #2 +// CHECK: declare{{.*}} void @_ZN1C14private_methodEv({{.*}}) #3 +// CHECK: define{{.*}} void @_ZN1C13public_staticEv() #4 +// CHECK: declare{{.*}} void @_ZN1C14private_staticEv() #5 +// CHECK: define{{.*}} void @_Z13template_funcIfEvv() #6 +// CHECK: define{{.*}} void @_Z13template_funcIiEvv() #7 +// CHECK: define{{.*}} void @_ZN1SIfE6methodEv({{.*}}) #8 +// CHECK: define{{.*}} void @_ZN1SIiE6methodEv({{.*}}) #9 +// CHECK: declare{{.*}} void @_Z3foov() #10 +// CHECK: attributes #0 +// CHECK-SAME: "llvm.assume"="bar:before1,bar:before2,bar:before3,bar:def1,bar:def2" +// CHECK: attributes #1 +// CHECK-SAME: "llvm.assume"="baz:before1,baz:before2,baz:before3,baz:def1,baz:def2,baz:after" +// CHECK: attributes #2 +// CHECK-SAME: "llvm.assume"="C:public_method1,C:public_method2" +// CHECK: attributes #3 +// CHECK-SAME: "llvm.assume"="C:private_method" +// CHECK: attributes #4 +// CHECK-SAME: "llvm.assume"="C:public_static1,C:public_static2" +// CHECK: attributes #5 +// CHECK-SAME: "llvm.assume"="C:private_static" +// CHECK: attributes #6 +// CHECK-SAME: "llvm.assume"="template_func<T>,template_func<float>" +// CHECK: attributes #7 +// CHECK-SAME: "llvm.assume"="template_func<T>" +// CHECK: attributes #8 +// CHECK-SAME: "llvm.assume"="S<T>::method,S<float>::method" +// CHECK: attributes #9 +// CHECK-SAME: "llvm.assume"="S<T>::method" +// CHECK: attributes #10 +// CHECK-SAME: "llvm.assume"="foo:before1,foo:before2,foo:before3" + +#endif Index: clang/test/CodeGen/assume_attr.c =================================================================== --- /dev/null +++ clang/test/CodeGen/assume_attr.c @@ -0,0 +1,58 @@ +// RUN: %clang_cc1 -emit-llvm -triple i386-linux-gnu %s -o - | FileCheck %s +// RUN: %clang_cc1 -x c -emit-pch -o %t %s +// RUN: %clang_cc1 -include-pch %t %s -emit-llvm -o - | FileCheck %s + +// TODO: for "foo" and "bar", "after" is not added as it appears "after" the first use or definition respectively. There might be a way to allow that. + +// CHECK: define{{.*}} void @bar() #0 +// CHECK: define{{.*}} void @baz() #1 +// CHECK: declare{{.*}} void @foo() #2 +// CHECK: attributes #0 +// CHECK-SAME: "llvm.assume"="bar:before1,bar:before2,bar:before3,bar:def1,bar:def2" +// CHECK: attributes #1 +// CHECK-SAME: "llvm.assume"="baz:before1,baz:before2,baz:before3,baz:def1,baz:def2,baz:after" +// CHECK: attributes #2 +// CHECK-SAME: "llvm.assume"="foo:before1,foo:before2,foo:before3" + +#ifndef HEADER +#define HEADER + +/// foo: declarations only + +__attribute__((assume("foo:before1"))) void foo(void); + +__attribute__((assume("foo:before2"))) +__attribute__((assume("foo:before3"))) void +foo(void); + +/// baz: static function declarations and a definition + +__attribute__((assume("baz:before1"))) static void baz(void); + +__attribute__((assume("baz:before2"))) +__attribute__((assume("baz:before3"))) static void +baz(void); + +// Definition +__attribute__((assume("baz:def1,baz:def2"))) static void baz(void) { foo(); } + +__attribute__((assume("baz:after"))) static void baz(void); + +/// bar: external function declarations and a definition + +__attribute__((assume("bar:before1"))) void bar(void); + +__attribute__((assume("bar:before2"))) +__attribute__((assume("bar:before3"))) void +bar(void); + +// Definition +__attribute__((assume("bar:def1,bar:def2"))) void bar(void) { baz(); } + +__attribute__((assume("bar:after"))) void bar(void); + +/// back to foo + +__attribute__((assume("foo:after"))) void foo(void); + +#endif Index: clang/lib/Sema/SemaDeclAttr.cpp =================================================================== --- clang/lib/Sema/SemaDeclAttr.cpp +++ clang/lib/Sema/SemaDeclAttr.cpp @@ -23,6 +23,7 @@ #include "clang/AST/RecursiveASTVisitor.h" #include "clang/AST/Type.h" #include "clang/Basic/CharInfo.h" +#include "clang/Basic/SourceLocation.h" #include "clang/Basic/SourceManager.h" #include "clang/Basic/TargetBuiltins.h" #include "clang/Basic/TargetInfo.h" @@ -38,6 +39,7 @@ #include "llvm/ADT/Optional.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/StringExtras.h" +#include "llvm/IR/Assumptions.h" #include "llvm/Support/MathExtras.h" #include "llvm/Support/raw_ostream.h" @@ -1675,6 +1677,40 @@ D->addAttr(::new (Context) AllocAlignAttr(Context, CI, Idx)); } +static void handleAssumumptionAttr(Sema &S, Decl *D, const ParsedAttr &AL) { + // Handle the case where the attribute has a text message. + StringRef Str; + SourceLocation AttrStrLoc; + if (!S.checkStringLiteralArgumentAttr(AL, 0, Str, &AttrStrLoc)) + return; + + S.CheckAssumptionAttr(AttrStrLoc, Str); + + D->addAttr(::new (S.Context) AssumptionAttr(S.Context, AL, Str)); +} + +void Sema::CheckAssumptionAttr(SourceLocation Loc, StringRef AssumptionStr) { + if (llvm::KnownAssumptionStrings.count(AssumptionStr)) + return; + + unsigned BestEditDistance = 3; + StringRef Suggestion; + for (const auto &KnownAssumptionIt : llvm::KnownAssumptionStrings) { + unsigned EditDistance = + AssumptionStr.edit_distance(KnownAssumptionIt.getKey()); + if (EditDistance < BestEditDistance) { + Suggestion = KnownAssumptionIt.getKey(); + BestEditDistance = EditDistance; + } + } + + if (!Suggestion.empty()) + Diag(Loc, diag::warn_assume_attribute_string_unknown_suggested) + << AssumptionStr << Suggestion; + else + Diag(Loc, diag::warn_assume_attribute_string_unknown) << AssumptionStr; +} + /// Normalize the attribute, __foo__ becomes foo. /// Returns true if normalization was applied. static bool normalizeName(StringRef &AttrName) { @@ -7722,6 +7758,9 @@ case ParsedAttr::AT_Unavailable: handleAttrWithMessage<UnavailableAttr>(S, D, AL); break; + case ParsedAttr::AT_Assumption: + handleAssumumptionAttr(S, D, AL); + break; case ParsedAttr::AT_ObjCDirect: handleObjCDirectAttr(S, D, AL); break; Index: clang/lib/Sema/CMakeLists.txt =================================================================== --- clang/lib/Sema/CMakeLists.txt +++ clang/lib/Sema/CMakeLists.txt @@ -1,5 +1,6 @@ set(LLVM_LINK_COMPONENTS FrontendOpenMP + Core Support ) Index: clang/lib/CodeGen/CGCall.cpp =================================================================== --- clang/lib/CodeGen/CGCall.cpp +++ clang/lib/CodeGen/CGCall.cpp @@ -31,6 +31,7 @@ #include "clang/CodeGen/SwiftCallingConv.h" #include "llvm/ADT/StringExtras.h" #include "llvm/Analysis/ValueTracking.h" +#include "llvm/IR/Assumptions.h" #include "llvm/IR/Attributes.h" #include "llvm/IR/CallingConv.h" #include "llvm/IR/DataLayout.h" @@ -2016,6 +2017,18 @@ llvm::toStringRef(CodeGenOpts.UniformWGSize)); } } + + std::string AssumptionValueStr; + for (AssumptionAttr *AssumptionA : + TargetDecl->specific_attrs<AssumptionAttr>()) { + std::string AS = AssumptionA->getAssumption().str(); + if (!AS.empty() && !AssumptionValueStr.empty()) + AssumptionValueStr += ","; + AssumptionValueStr += AS; + } + + if (!AssumptionValueStr.empty()) + FuncAttrs.addAttribute(llvm::AssumptionAttrKey, AssumptionValueStr); } // Attach "no-builtins" attributes to: Index: clang/include/clang/Sema/Sema.h =================================================================== --- clang/include/clang/Sema/Sema.h +++ clang/include/clang/Sema/Sema.h @@ -58,8 +58,8 @@ #include "llvm/ADT/Optional.h" #include "llvm/ADT/SetVector.h" #include "llvm/ADT/SmallBitVector.h" -#include "llvm/ADT/SmallSet.h" #include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallSet.h" #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/TinyPtrVector.h" #include "llvm/Frontend/OpenMP/OMPConstants.h" @@ -9998,6 +9998,9 @@ void AddAnnotationAttr(Decl *D, const AttributeCommonInfo &CI, StringRef Annot, MutableArrayRef<Expr *> Args); + /// Check if \p AssumptionStr is a known assumption and warn if not. + void CheckAssumptionAttr(SourceLocation Loc, StringRef AssumptionStr); + /// AddLaunchBoundsAttr - Adds a launch_bounds attribute to a particular /// declaration. void AddLaunchBoundsAttr(Decl *D, const AttributeCommonInfo &CI, Index: clang/include/clang/Basic/DiagnosticSemaKinds.td =================================================================== --- clang/include/clang/Basic/DiagnosticSemaKinds.td +++ clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -740,6 +740,13 @@ def warn_assume_side_effects : Warning< "the argument to %0 has side effects that will be discarded">, InGroup<DiagGroup<"assume">>; +def warn_assume_attribute_string_unknown : Warning< + "the assumption string '%0' is not known and might be misspelled">, + InGroup<Assumption>; +def warn_assume_attribute_string_unknown_suggested : Warning< + "the assumption string '%0' is not known and might be misspelled; " + "did you mean '%1'?">, + InGroup<Assumption>; def warn_builtin_chk_overflow : Warning< "'%0' will always overflow; destination buffer has size %1," Index: clang/include/clang/Basic/DiagnosticGroups.td =================================================================== --- clang/include/clang/Basic/DiagnosticGroups.td +++ clang/include/clang/Basic/DiagnosticGroups.td @@ -19,6 +19,7 @@ def ODR : DiagGroup<"odr">; def : DiagGroup<"abi">; def AbsoluteValue : DiagGroup<"absolute-value">; +def Assumption : DiagGroup<"assumption">; def AddressOfTemporary : DiagGroup<"address-of-temporary">; def : DiagGroup<"aggregate-return">; def GNUAlignofExpression : DiagGroup<"gnu-alignof-expression">; Index: clang/include/clang/Basic/AttrDocs.td =================================================================== --- clang/include/clang/Basic/AttrDocs.td +++ clang/include/clang/Basic/AttrDocs.td @@ -3919,6 +3919,41 @@ }]; } +def AssumptionDocs : Documentation { + let Category = DocCatFunction; + let Heading = "assume"; + let Content = [{ +Clang supports the ``__attribute__((assume("assumption")))`` attribute to +provide additional information to the optimizer. The string-literal, here +"assumption", will be attached to the function declaration such that later +analysis and optimization passes can assume the "assumption" to hold. +This is similar to :ref:`__builtin_assume <langext-__builtin_assume>` but +instead of an expression that can be assumed to be non-zero, the assumption is +expressed as a string and it holds for the entire function. + +A function can have multiple assume attributes and they propagate from prior +declarations to later definitions. Multiple assumptions are aggregated into a +single comma separated string. Thus, one can provide multiple assumptions via +a comma separated string, i.a., +``__attribute__((assume("assumption1,assumption2")))``. + +While LLVM plugins might provide more assumption strings, the default LLVM +optimization passes are aware of the following assumptions: + + .. code-block:: none + + "omp_no_openmp" + "omp_no_openmp_routines" + "omp_no_parallelism" + +The OpenMP standard defines the meaning of OpenMP assumptions ("omp_XYZ" is +spelled "XYZ" in the `OpenMP 5.1 Standard`_). + +.. _`OpenMP 5.1 Standard`: https://www.openmp.org/spec-html/5.1/openmpsu37.html#x56-560002.5.2 + +}]; +} + def NoStackProtectorDocs : Documentation { let Category = DocCatFunction; let Content = [{ Index: clang/include/clang/Basic/Attr.td =================================================================== --- clang/include/clang/Basic/Attr.td +++ clang/include/clang/Basic/Attr.td @@ -3477,6 +3477,14 @@ }]; } +def Assumption : InheritableAttr { + let Spellings = [Clang<"assume">]; + let Subjects = SubjectList<[Function, ObjCMethod]>; + let InheritEvenIfAlreadyPresent = 1; + let Documentation = [AssumptionDocs]; + let Args = [StringArgument<"Assumption">]; +} + def InternalLinkage : InheritableAttr { let Spellings = [Clang<"internal_linkage">]; let Subjects = SubjectList<[Var, Function, CXXRecord]>; Index: clang/docs/LanguageExtensions.rst =================================================================== --- clang/docs/LanguageExtensions.rst +++ clang/docs/LanguageExtensions.rst @@ -1740,6 +1740,8 @@ <langext-vectors>` instead of builtins, in order to reduce the number of builtins that we need to implement. +.. _langext-__builtin_assume: + ``__builtin_assume`` ------------------------------
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