From 462446fd9a5d85458f1c61de353ce679ff5dbf9b Mon Sep 17 00:00:00 2001 From: Roman Lebedev Date: Fri, 22 Mar 2019 19:46:25 +0000 Subject: [PATCH] [clang-tidy] openmp-exception-escape - a new check Summary: Finally, we are here! Analyzes OpenMP Structured Blocks and checks that no exception escapes out of the Structured Block it was thrown in. As per the OpenMP specification, structured block is an executable statement, possibly compound, with a single entry at the top and a single exit at the bottom. Which means, ``throw`` may not be used to to 'exit' out of the structured block. If an exception is not caught in the same structured block it was thrown in, the behaviour is undefined / implementation defined, the program will likely terminate. Reviewers: JonasToth, aaron.ballman, baloghadamsoftware, gribozavr Reviewed By: aaron.ballman, gribozavr Subscribers: mgorny, xazax.hun, rnkovacs, guansong, jdoerfert, cfe-commits, ABataev Tags: #clang-tools-extra, #openmp, #clang Differential Revision: https://reviews.llvm.org/D59466 llvm-svn: 356802 --- clang-tools-extra/clang-tidy/openmp/CMakeLists.txt | 2 + .../clang-tidy/openmp/ExceptionEscapeCheck.cpp | 84 +++++++++++++ .../clang-tidy/openmp/ExceptionEscapeCheck.h | 41 +++++++ .../clang-tidy/openmp/OpenMPTidyModule.cpp | 3 + .../clang-tidy/utils/ExceptionAnalyzer.cpp | 11 ++ .../clang-tidy/utils/ExceptionAnalyzer.h | 2 + clang-tools-extra/docs/ReleaseNotes.rst | 6 + clang-tools-extra/docs/clang-tidy/checks/list.rst | 1 + .../clang-tidy/checks/openmp-exception-escape.rst | 25 ++++ .../bugprone-exception-escape-openmp.cpp | 29 +++++ .../test/clang-tidy/openmp-exception-escape.cpp | 132 +++++++++++++++++++++ 11 files changed, 336 insertions(+) create mode 100644 clang-tools-extra/clang-tidy/openmp/ExceptionEscapeCheck.cpp create mode 100644 clang-tools-extra/clang-tidy/openmp/ExceptionEscapeCheck.h create mode 100644 clang-tools-extra/docs/clang-tidy/checks/openmp-exception-escape.rst create mode 100644 clang-tools-extra/test/clang-tidy/bugprone-exception-escape-openmp.cpp create mode 100644 clang-tools-extra/test/clang-tidy/openmp-exception-escape.cpp diff --git a/clang-tools-extra/clang-tidy/openmp/CMakeLists.txt b/clang-tools-extra/clang-tidy/openmp/CMakeLists.txt index 7522be3..bbd65f2 100644 --- a/clang-tools-extra/clang-tidy/openmp/CMakeLists.txt +++ b/clang-tools-extra/clang-tidy/openmp/CMakeLists.txt @@ -1,6 +1,7 @@ set(LLVM_LINK_COMPONENTS support) add_clang_library(clangTidyOpenMPModule + ExceptionEscapeCheck.cpp OpenMPTidyModule.cpp UseDefaultNoneCheck.cpp @@ -9,4 +10,5 @@ add_clang_library(clangTidyOpenMPModule clangASTMatchers clangBasic clangTidy + clangTidyUtils ) diff --git a/clang-tools-extra/clang-tidy/openmp/ExceptionEscapeCheck.cpp b/clang-tools-extra/clang-tidy/openmp/ExceptionEscapeCheck.cpp new file mode 100644 index 0000000..218437a --- /dev/null +++ b/clang-tools-extra/clang-tidy/openmp/ExceptionEscapeCheck.cpp @@ -0,0 +1,84 @@ +//===--- ExceptionEscapeCheck.cpp - clang-tidy ----------------------------===// +// +// 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 "ExceptionEscapeCheck.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/OpenMPClause.h" +#include "clang/AST/Stmt.h" +#include "clang/AST/StmtOpenMP.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/ASTMatchers/ASTMatchers.h" +#include "clang/ASTMatchers/ASTMatchersMacros.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace tidy { +namespace openmp { + +ExceptionEscapeCheck::ExceptionEscapeCheck(StringRef Name, + ClangTidyContext *Context) + : ClangTidyCheck(Name, Context), + RawIgnoredExceptions(Options.get("IgnoredExceptions", "")) { + llvm::SmallVector FunctionsThatShouldNotThrowVec, + IgnoredExceptionsVec; + + llvm::StringSet<> IgnoredExceptions; + StringRef(RawIgnoredExceptions).split(IgnoredExceptionsVec, ",", -1, false); + llvm::transform(IgnoredExceptionsVec, IgnoredExceptionsVec.begin(), + [](StringRef S) { return S.trim(); }); + IgnoredExceptions.insert(IgnoredExceptionsVec.begin(), + IgnoredExceptionsVec.end()); + Tracer.ignoreExceptions(std::move(IgnoredExceptions)); + Tracer.ignoreBadAlloc(true); +} + +void ExceptionEscapeCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) { + Options.store(Opts, "IgnoredExceptions", RawIgnoredExceptions); +} + +void ExceptionEscapeCheck::registerMatchers(MatchFinder *Finder) { + // Don't register the check if OpenMP is not enabled; the OpenMP pragmas are + // completely ignored then, so no OpenMP entires will be present in the AST. + if (!getLangOpts().OpenMP) + return; + // Similarly, if C++ Exceptions are not enabled, nothing to do. + if (!getLangOpts().CPlusPlus || !getLangOpts().CXXExceptions) + return; + + Finder->addMatcher(ompExecutableDirective( + unless(isStandaloneDirective()), + hasStructuredBlock(stmt().bind("structured-block"))) + .bind("directive"), + this); +} + +void ExceptionEscapeCheck::check(const MatchFinder::MatchResult &Result) { + const auto *Directive = + Result.Nodes.getNodeAs("directive"); + assert(Directive && "Expected to match some OpenMP Executable directive."); + const auto *StructuredBlock = + Result.Nodes.getNodeAs("structured-block"); + assert(StructuredBlock && "Expected to get some OpenMP Structured Block."); + + if (Tracer.analyze(StructuredBlock).getBehaviour() != + utils::ExceptionAnalyzer::State::Throwing) + return; // No exceptions have been proven to escape out of the struc. block. + + // FIXME: We should provide more information about the exact location where + // the exception is thrown, maybe the full path the exception escapes. + + diag(Directive->getBeginLoc(), + "an exception thrown inside of the OpenMP '%0' region is not caught in " + "that same region") + << getOpenMPDirectiveName(Directive->getDirectiveKind()); +} + +} // namespace openmp +} // namespace tidy +} // namespace clang diff --git a/clang-tools-extra/clang-tidy/openmp/ExceptionEscapeCheck.h b/clang-tools-extra/clang-tidy/openmp/ExceptionEscapeCheck.h new file mode 100644 index 0000000..bcbeccd --- /dev/null +++ b/clang-tools-extra/clang-tidy/openmp/ExceptionEscapeCheck.h @@ -0,0 +1,41 @@ +//===--- ExceptionEscapeCheck.h - clang-tidy --------------------*- 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 +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_OPENMP_EXCEPTIONESCAPECHECK_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_OPENMP_EXCEPTIONESCAPECHECK_H + +#include "../ClangTidy.h" +#include "../utils/ExceptionAnalyzer.h" + +namespace clang { +namespace tidy { +namespace openmp { + +/// Analyzes OpenMP Structured Blocks and checks that no exception escapes +/// out of the Structured Block it was thrown in. +/// +/// For the user-facing documentation see: +/// http://clang.llvm.org/extra/clang-tidy/checks/openmp-exception-escape.html +class ExceptionEscapeCheck : public ClangTidyCheck { +public: + ExceptionEscapeCheck(StringRef Name, ClangTidyContext *Context); + void storeOptions(ClangTidyOptions::OptionMap &Opts) override; + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; + +private: + std::string RawIgnoredExceptions; + + utils::ExceptionAnalyzer Tracer; +}; + +} // namespace openmp +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_OPENMP_EXCEPTIONESCAPECHECK_H diff --git a/clang-tools-extra/clang-tidy/openmp/OpenMPTidyModule.cpp b/clang-tools-extra/clang-tidy/openmp/OpenMPTidyModule.cpp index d200f49..cb0e247 100644 --- a/clang-tools-extra/clang-tidy/openmp/OpenMPTidyModule.cpp +++ b/clang-tools-extra/clang-tidy/openmp/OpenMPTidyModule.cpp @@ -9,6 +9,7 @@ #include "../ClangTidy.h" #include "../ClangTidyModule.h" #include "../ClangTidyModuleRegistry.h" +#include "ExceptionEscapeCheck.h" #include "UseDefaultNoneCheck.h" namespace clang { @@ -19,6 +20,8 @@ namespace openmp { class OpenMPModule : public ClangTidyModule { public: void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override { + CheckFactories.registerCheck( + "openmp-exception-escape"); CheckFactories.registerCheck( "openmp-use-default-none"); } diff --git a/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.cpp b/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.cpp index f0ec230..09fce32 100644 --- a/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.cpp +++ b/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.cpp @@ -224,6 +224,12 @@ ExceptionAnalyzer::analyzeImpl(const FunctionDecl *Func) { return ExceptionList; } +ExceptionAnalyzer::ExceptionInfo +ExceptionAnalyzer::analyzeImpl(const Stmt *Stmt) { + llvm::SmallSet CallStack; + return throwsException(Stmt, ExceptionInfo::Throwables(), CallStack); +} + template ExceptionAnalyzer::ExceptionInfo ExceptionAnalyzer::analyzeDispatch(const T *Node) { @@ -245,6 +251,11 @@ ExceptionAnalyzer::analyze(const FunctionDecl *Func) { return analyzeDispatch(Func); } +ExceptionAnalyzer::ExceptionInfo +ExceptionAnalyzer::analyze(const Stmt *Stmt) { + return analyzeDispatch(Stmt); +} + } // namespace utils } // namespace tidy diff --git a/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.h b/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.h index f924a91..2caa1aa 100644 --- a/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.h +++ b/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.h @@ -129,6 +129,7 @@ public: } ExceptionInfo analyze(const FunctionDecl *Func); + ExceptionInfo analyze(const Stmt *Stmt); private: ExceptionInfo @@ -139,6 +140,7 @@ private: llvm::SmallSet &CallStack); ExceptionInfo analyzeImpl(const FunctionDecl *Func); + ExceptionInfo analyzeImpl(const Stmt *Stmt); template ExceptionInfo analyzeDispatch(const T *Node); diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst index fcbf6d9..fa473d7 100644 --- a/clang-tools-extra/docs/ReleaseNotes.rst +++ b/clang-tools-extra/docs/ReleaseNotes.rst @@ -130,6 +130,12 @@ Improvements to clang-tidy ` now supports `OverrideSpelling` and `FinalSpelling` options. +- New :doc:`openmp-exception-escape + ` check. + + Analyzes OpenMP Structured Blocks and checks that no exception escapes + out of the Structured Block it was thrown in. + - New :doc:`openmp-use-default-none ` check. diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst index 428c22c..1b11a1a 100644 --- a/clang-tools-extra/docs/clang-tidy/checks/list.rst +++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst @@ -227,6 +227,7 @@ Clang-Tidy Checks objc-avoid-spinlock objc-forbidden-subclassing objc-property-declaration + openmp-exception-escape openmp-use-default-none performance-faster-string-find performance-for-range-copy diff --git a/clang-tools-extra/docs/clang-tidy/checks/openmp-exception-escape.rst b/clang-tools-extra/docs/clang-tidy/checks/openmp-exception-escape.rst new file mode 100644 index 0000000..d85e4fd --- /dev/null +++ b/clang-tools-extra/docs/clang-tidy/checks/openmp-exception-escape.rst @@ -0,0 +1,25 @@ +.. title:: clang-tidy - openmp-exception-escape + +openmp-exception-escape +======================= + +Analyzes OpenMP Structured Blocks and checks that no exception escapes +out of the Structured Block it was thrown in. + +As per the OpenMP specification, a structured block is an executable statement, +possibly compound, with a single entry at the top and a single exit at the +bottom. Which means, ``throw`` may not be used to to 'exit' out of the +structured block. If an exception is not caught in the same structured block +it was thrown in, the behaviour is undefined. + +FIXME: this check does not model SEH, ``setjmp``/``longjmp``. + +WARNING! This check may be expensive on large source files. + +Options +------- + +.. option:: IgnoredExceptions + + Comma-separated list containing type names which are not counted as thrown + exceptions in the check. Default value is an empty string. diff --git a/clang-tools-extra/test/clang-tidy/bugprone-exception-escape-openmp.cpp b/clang-tools-extra/test/clang-tidy/bugprone-exception-escape-openmp.cpp new file mode 100644 index 0000000..101c339 --- /dev/null +++ b/clang-tools-extra/test/clang-tidy/bugprone-exception-escape-openmp.cpp @@ -0,0 +1,29 @@ +// RUN: %check_clang_tidy %s bugprone-exception-escape %t -- -extra-arg=-fopenmp=libomp -extra-arg=-fexceptions -- + +int thrower() { + throw 42; +} + +void ok_parallel() { +#pragma omp parallel + thrower(); +} + +void bad_for_header_XFAIL(const int a) noexcept { +#pragma omp for + for (int i = 0; i < thrower(); i++) + ; + // FIXME: this really should be caught by bugprone-exception-escape. + // https://bugs.llvm.org/show_bug.cgi?id=41102 +} + +void ok_forloop(const int a) { +#pragma omp for + for (int i = 0; i < a; i++) + thrower(); +} + +void some_exception_just_so_that_check_clang_tidy_shuts_up() noexcept { + thrower(); +} +// CHECK-MESSAGES: :[[@LINE-3]]:6: warning: an exception may be thrown in function 'some_exception_just_so_that_check_clang_tidy_shuts_up' which should not throw exceptions diff --git a/clang-tools-extra/test/clang-tidy/openmp-exception-escape.cpp b/clang-tools-extra/test/clang-tidy/openmp-exception-escape.cpp new file mode 100644 index 0000000..d620b5c --- /dev/null +++ b/clang-tools-extra/test/clang-tidy/openmp-exception-escape.cpp @@ -0,0 +1,132 @@ +// RUN: %check_clang_tidy %s openmp-exception-escape %t -- -extra-arg=-fopenmp=libomp -extra-arg=-fexceptions -config="{CheckOptions: [{key: openmp-exception-escape.IgnoredExceptions, value: 'ignored, ignored2'}]}" -- + +int thrower() { + throw 42; +} + +class ignored {}; +class ignored2 {}; +namespace std { +class bad_alloc {}; +} // namespace std + +void parallel() { +#pragma omp parallel + thrower(); + // CHECK-MESSAGES: :[[@LINE-2]]:9: warning: an exception thrown inside of the OpenMP 'parallel' region is not caught in that same region +} + +void ignore() { +#pragma omp parallel + throw ignored(); +} + +void ignore2() { +#pragma omp parallel + throw ignored2(); +} + +void standalone_directive() { +#pragma omp taskwait + throw ignored(); // not structured block +} + +void ignore_alloc() { +#pragma omp parallel + throw std::bad_alloc(); +} + +void parallel_caught() { +#pragma omp parallel + { + try { + thrower(); + } catch (...) { + } + } +} + +void for_header(const int a) { + // Only the body of the loop counts. +#pragma omp for + for (int i = 0; i < thrower(); i++) + ; +} + +void forloop(const int a) { +#pragma omp for + for (int i = 0; i < a; i++) + thrower(); + // CHECK-MESSAGES: :[[@LINE-3]]:9: warning: an exception thrown inside of the OpenMP 'for' region is not caught in that same region +} + +void parallel_forloop(const int a) { +#pragma omp parallel + { +#pragma omp for + for (int i = 0; i < a; i++) + thrower(); + thrower(); + // CHECK-MESSAGES: :[[@LINE-6]]:9: warning: an exception thrown inside of the OpenMP 'parallel' region is not caught in that same region + // CHECK-MESSAGES: :[[@LINE-5]]:9: warning: an exception thrown inside of the OpenMP 'for' region is not caught in that same region + } +} + +void parallel_forloop_caught(const int a) { +#pragma omp parallel + { +#pragma omp for + for (int i = 0; i < a; i++) { + try { + thrower(); + } catch (...) { + } + } + thrower(); + // CHECK-MESSAGES: :[[@LINE-10]]:9: warning: an exception thrown inside of the OpenMP 'parallel' region is not caught in that same region + } +} + +void parallel_caught_forloop(const int a) { +#pragma omp parallel + { +#pragma omp for + for (int i = 0; i < a; i++) + thrower(); + try { + thrower(); + } catch (...) { + } + // CHECK-MESSAGES: :[[@LINE-7]]:9: warning: an exception thrown inside of the OpenMP 'for' region is not caught in that same region + } +} + +void parallel_outercaught_forloop(const int a) { +#pragma omp parallel + { + try { +#pragma omp for + for (int i = 0; i < a; i++) + thrower(); + thrower(); + } catch (...) { + } + // CHECK-MESSAGES: :[[@LINE-6]]:9: warning: an exception thrown inside of the OpenMP 'for' region is not caught in that same region + } +} + +void parallel_outercaught_forloop_caught(const int a) { +#pragma omp parallel + { + try { +#pragma omp for + for (int i = 0; i < a; i++) { + try { + thrower(); + } catch (...) { + } + } + } catch (...) { + } + } +} -- 2.7.4