r356222 - [analyzer] Support C++17 aggregates with bases without constructors.

Artem Dergachev via cfe-commits cfe-commits at lists.llvm.org
Tue Mar 19 10:24:19 PDT 2019


Hi,

I'll try to fix this ASAP!

It sounds as if i don't have nearly enough C++17 codebases for testing, 
are there any obvious open-source projects that you could recommend? I'd 
love to try to reincarnate 
http://green.lab.llvm.org/green/view/Experimental/job/StaticAnalyzerBenchmarks/ 
with those.

On 3/19/19 9:37 AM, Alexander Kornienko wrote:
> Filed this as https://bugs.llvm.org/show_bug.cgi?id=41142. Any hope 
> for a prompt fix here?
>
> On Tue, Mar 19, 2019 at 5:34 PM Alexander Kornienko <alexfh at google.com 
> <mailto:alexfh at google.com>> wrote:
>
>     A reduced test case:
>     $ cat test-RegionStoreManager__bindStruct.cc
>     struct a {};
>     class b : a {};
>     b c() { b d{c()}; }
>     $ ./clang-tidy -checks="-*,clang-analyzer*"
>     test-RegionStoreManager__bindStruct.cc -- -std=c++17
>     assert.h assertion failed at
>     tools/clang/lib/StaticAnalyzer/Core/RegionStore.cpp:2362 in
>     (anonymous namespace)::RegionBindingsRef (anonym
>     ous
>     namespace)::RegionStoreManager::bindStruct(RegionBindingsConstRef,
>     const clang::ento::TypedValueRegion *, clang::ento::SVal):
>     CRD->isAggregate() && "Non-aggregates are constructed with a
>     constructor!"
>         @     0x559908170326  __assert_fail
>         @     0x5599068d4854  (anonymous
>     namespace)::RegionStoreManager::bindStruct()
>         @     0x5599068c93c8  (anonymous
>     namespace)::RegionStoreManager::Bind()
>         @     0x5599068b409f clang::ento::ProgramState::bindLoc()
>         @     0x559906865935
>     clang::ento::ExprEngine::processPointerEscapedOnBind()
>         @     0x55990685d4b3 clang::ento::ExprEngine::evalBind()
>         @     0x559906872a43 clang::ento::ExprEngine::VisitDeclStmt()
>         @     0x55990685c16f clang::ento::ExprEngine::Visit()
>         @     0x559906858b1f clang::ento::ExprEngine::ProcessStmt()
>         @     0x559906858808 clang::ento::ExprEngine::processCFGElement()
>         @     0x55990684cb65 clang::ento::CoreEngine::HandlePostStmt()
>         @     0x55990684bf5c clang::ento::CoreEngine::ExecuteWorkList()
>         @     0x5599065b635b  (anonymous
>     namespace)::AnalysisConsumer::HandleCode()
>         @     0x5599065a0135  (anonymous
>     namespace)::AnalysisConsumer::HandleTranslationUnit()
>         @     0x559906bb7cbc
>     clang::MultiplexConsumer::HandleTranslationUnit()
>         @     0x559906d226d4  clang::ParseAST()
>         @     0x559906b98a83 clang::FrontendAction::Execute()
>         @     0x559906b31cd1 clang::CompilerInstance::ExecuteAction()
>         @     0x559906a9cf61
>     clang::tooling::FrontendActionFactory::runInvocation()
>         @     0x55990620cc07
>     clang::tidy::runClangTidy()::ActionFactory::runInvocation()
>         @     0x559906a9ccca
>     clang::tooling::ToolInvocation::runInvocation()
>         @     0x559906a9c646 clang::tooling::ToolInvocation::run()
>         @     0x559906a9ef22 clang::tooling::ClangTool::run()
>         @     0x559906207ecf  clang::tidy::runClangTidy()
>         @     0x559902d47c45  main
>
>     On Tue, Mar 19, 2019 at 1:14 AM Alexander Kornienko
>     <alexfh at google.com <mailto:alexfh at google.com>> wrote:
>
>         On Fri, Mar 15, 2019 at 1:21 AM Artem Dergachev via
>         cfe-commits <cfe-commits at lists.llvm.org
>         <mailto:cfe-commits at lists.llvm.org>> wrote:
>
>             Author: dergachev
>             Date: Thu Mar 14 17:22:59 2019
>             New Revision: 356222
>
>             URL: http://llvm.org/viewvc/llvm-project?rev=356222&view=rev
>             Log:
>             [analyzer] Support C++17 aggregates with bases without
>             constructors.
>
>             RegionStore now knows how to bind a nonloc::CompoundVal
>             that represents the
>             value of an aggregate initializer when it has its initial
>             segment of sub-values
>             correspond to base classes.
>
>             Additionally, fixes the crash from pr40022.
>
>             Differential Revision: https://reviews.llvm.org/D59054
>
>             Modified:
>             cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp
>             cfe/trunk/test/Analysis/array-struct-region.cpp
>
>             Modified: cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp
>             URL:
>             http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp?rev=356222&r1=356221&r2=356222&view=diff
>             ==============================================================================
>             --- cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp
>             (original)
>             +++ cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp Thu
>             Mar 14 17:22:59 2019
>             @@ -2334,12 +2334,57 @@ RegionBindingsRef
>             RegionStoreManager::bi
>                if (V.isUnknown() || !V.getAs<nonloc::CompoundVal>())
>                  return bindAggregate(B, R, UnknownVal());
>
>             +  // The raw CompoundVal is essentially a symbolic
>             InitListExpr: an (immutable)
>             +  // list of other values. It appears pretty much only
>             when there's an actual
>             +  // initializer list expression in the program, and the
>             analyzer tries to
>             +  // unwrap it as soon as possible.
>             +  // This code is where such unwrap happens: when the
>             compound value is put into
>             +  // the object that it was supposed to initialize (it's
>             an *initializer* list,
>             +  // after all), instead of binding the whole value to
>             the whole object, we bind
>             +  // sub-values to sub-objects. Sub-values may themselves
>             be compound values,
>             +  // and in this case the procedure becomes recursive.
>             +  // FIXME: The annoying part about compound values is
>             that they don't carry
>             +  // any sort of information about which value
>             corresponds to which sub-object.
>             +  // It's simply a list of values in the middle of
>             nowhere; we expect to match
>             +  // them to sub-objects, essentially, "by index": first
>             value binds to
>             +  // the first field, second value binds to the second
>             field, etc.
>             +  // It would have been much safer to organize non-lazy
>             compound values as
>             +  // a mapping from fields/bases to values.
>                const nonloc::CompoundVal& CV =
>             V.castAs<nonloc::CompoundVal>();
>                nonloc::CompoundVal::iterator VI = CV.begin(), VE =
>             CV.end();
>
>             -  RecordDecl::field_iterator FI, FE;
>                RegionBindingsRef NewB(B);
>
>             +  // In C++17 aggregates may have base classes, handle
>             those as well.
>             +  // They appear before fields in the initializer list /
>             compound value.
>             +  if (const auto *CRD = dyn_cast<CXXRecordDecl>(RD)) {
>             +    assert(CRD->isAggregate() &&
>             +           "Non-aggregates are constructed with a
>             constructor!");
>
>
>         Now we see this assertion being triggered on a substantial
>         number of files in our codebase:
>         llvm/tools/clang/lib/StaticAnalyzer/Core/RegionStore.cpp:2362
>         in (anonymous namespace)::RegionBindingsRef (anonymous
>         namespace)::RegionStoreManager::bindStruct(RegionBindingsConstRef,
>         const clang::ento::TypedValueRegion *, clang::ento::SVal):
>         CRD->isAggregate() && "Non-aggregates are constructed with a
>         constructor!"
>         Stack trace:
>             @     0x5596b00a84e6         96 __assert_fail
>             @     0x5596b6e6ea14        304 (anonymous
>         namespace)::RegionStoreManager::bindStruct()
>             @     0x5596afb30228        128 (anonymous
>         namespace)::RegionStoreManager::Bind()
>             @     0x5596af822abf        128
>         clang::ento::ProgramState::bindLoc()
>             @     0x5596b6e2b657        112
>         clang::ento::ExprEngine::processPointerEscapedOnBind()
>             @     0x5596b907f65f        512
>         clang::ento::ExprEngine::evalBind()
>             @     0x5596b6e30ea7        560
>         clang::ento::ExprEngine::VisitDeclStmt()
>             @     0x5596b8da1fe2        752
>         clang::ento::ExprEngine::Visit()
>             @     0x5596b8d9cb2f        400
>         clang::ento::ExprEngine::ProcessStmt()
>             @     0x5596af78431e        112
>         clang::ento::ExprEngine::processCFGElement()
>             @     0x5596af6578e0         48
>         clang::ento::CoreEngine::HandlePostStmt()
>             @     0x5596b03b151b        272
>         clang::ento::CoreEngine::ExecuteWorkList()
>             @     0x5596af6f8efe       1248 (anonymous
>         namespace)::AnalysisConsumer::HandleCode()
>             @     0x5596b6c54a77        448 (anonymous
>         namespace)::AnalysisConsumer::HandleTranslationUnit()
>             @     0x5596b706f08c         48
>         clang::MultiplexConsumer::HandleTranslationUnit()
>             @     0x5596aff72e24        144 clang::ParseAST()
>             @     0x5596b7053bc3         48
>         clang::FrontendAction::Execute()
>             @     0x5596b7002ba0        160
>         clang::CompilerInstance::ExecuteAction()
>             @     0x5596b6f91a61        464
>         clang::tooling::FrontendActionFactory::runInvocation()
>             @     0x5596b6f917ea         80
>         clang::tooling::ToolInvocation::runInvocation()
>             @     0x5596afe70af6       2352
>         clang::tooling::ToolInvocation::run()
>
>         Trying to get an isolated test case.
>
>             +
>             +    for (const auto &B : CRD->bases()) {
>             +      // (Multiple inheritance is fine though.)
>             +      assert(!B.isVirtual() && "Aggregates cannot have
>             virtual base classes!");
>             +
>             +      if (VI == VE)
>             +        break;
>             +
>             +      QualType BTy = B.getType();
>             +      assert(BTy->isStructureOrClassType() && "Base
>             classes must be classes!");
>             +
>             +      const CXXRecordDecl *BRD = BTy->getAsCXXRecordDecl();
>             +      assert(BRD && "Base classes must be C++ classes!");
>             +
>             +      const CXXBaseObjectRegion *BR =
>             +          MRMgr.getCXXBaseObjectRegion(BRD, R,
>             /*IsVirtual=*/false);
>             +
>             +      NewB = bindStruct(NewB, BR, *VI);
>             +
>             +      ++VI;
>             +    }
>             +  }
>             +
>             +  RecordDecl::field_iterator FI, FE;
>             +
>                for (FI = RD->field_begin(), FE = RD->field_end(); FI
>             != FE; ++FI) {
>
>                  if (VI == VE)
>
>             Modified: cfe/trunk/test/Analysis/array-struct-region.cpp
>             URL:
>             http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/array-struct-region.cpp?rev=356222&r1=356221&r2=356222&view=diff
>             ==============================================================================
>             --- cfe/trunk/test/Analysis/array-struct-region.cpp (original)
>             +++ cfe/trunk/test/Analysis/array-struct-region.cpp Thu
>             Mar 14 17:22:59 2019
>             @@ -1,7 +1,21 @@
>             -// RUN: %clang_analyze_cc1
>             -analyzer-checker=core,alpha.core,debug.ExprInspection
>             -verify -x c %s
>             -// RUN: %clang_analyze_cc1
>             -analyzer-checker=core,alpha.core,debug.ExprInspection
>             -verify -x c++ -analyzer-config c++-inlining=constructors %s
>             -// RUN: %clang_analyze_cc1
>             -analyzer-checker=core,alpha.core,debug.ExprInspection
>             -DINLINE -verify -x c %s
>             -// RUN: %clang_analyze_cc1
>             -analyzer-checker=core,alpha.core,debug.ExprInspection
>             -DINLINE -verify -x c++ -analyzer-config
>             c++-inlining=constructors %s
>             +// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.core\
>             +// RUN: -analyzer-checker=debug.ExprInspection -verify\
>             +// RUN:                    -x c %s
>             +// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.core\
>             +// RUN: -analyzer-checker=debug.ExprInspection -verify\
>             +// RUN:                    -x c++ -std=c++14 %s
>             +// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.core\
>             +// RUN: -analyzer-checker=debug.ExprInspection -verify\
>             +// RUN:                    -x c++ -std=c++17 %s
>             +// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.core\
>             +// RUN: -analyzer-checker=debug.ExprInspection -verify\
>             +// RUN:                    -DINLINE -x c %s
>             +// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.core\
>             +// RUN: -analyzer-checker=debug.ExprInspection -verify\
>             +// RUN:                    -DINLINE -x c++ -std=c++14 %s
>             +// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.core\
>             +// RUN: -analyzer-checker=debug.ExprInspection -verify\
>             +// RUN:                    -DINLINE -x c++ -std=c++17 %s
>
>              void clang_analyzer_eval(int);
>
>             @@ -196,4 +210,49 @@ namespace EmptyClass {
>                }
>              }
>
>             +#if __cplusplus >= 201703L
>             +namespace aggregate_inheritance_cxx17 {
>             +struct A {
>             +  int x;
>             +};
>             +
>             +struct B {
>             +  int y;
>             +};
>             +
>             +struct C: B {
>             +  int z;
>             +};
>             +
>             +struct D: A, C {
>             +  int w;
>             +};
>             +
>             +void foo() {
>             +  D d{1, 2, 3, 4};
>             +  clang_analyzer_eval(d.x == 1); // expected-warning{{TRUE}}
>             +  clang_analyzer_eval(d.y == 2); // expected-warning{{TRUE}}
>             +  clang_analyzer_eval(d.z == 3); // expected-warning{{TRUE}}
>             +  clang_analyzer_eval(d.w == 4); // expected-warning{{TRUE}}
>             +}
>             +} // namespace aggregate_inheritance_cxx17
>             +#endif
>             +
>             +namespace flex_array_inheritance_cxx17 {
>             +struct A {
>             +  int flexible_array[];
>             +};
>             +
>             +struct B {
>             +  long cookie;
>             +};
>             +
>             +struct C : B {
>             +  A a;
>             +};
>             +
>             +void foo() {
>             +  C c{}; // no-crash
>             +}
>             +} // namespace flex_array_inheritance_cxx17
>              #endif
>
>
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