From bfe63ab63e22b61bd5898c65425e8ebe43189913 Mon Sep 17 00:00:00 2001 From: Aaron Puchert Date: Thu, 14 Jul 2022 13:36:11 +0200 Subject: [PATCH] Thread safety analysis: Support builtin pointer-to-member operators We consider an access to x.*pm as access of the same kind into x, and an access to px->*pm as access of the same kind into *px. Previously we missed reads and writes in the .* case, and operations to the pointed-to data for ->* (we didn't miss accesses to the pointer itself, because that requires an LValueToRValue cast that we treat independently). We added support for overloaded operator->* in D124966. Reviewed By: aaron.ballman Differential Revision: https://reviews.llvm.org/D129514 --- clang/lib/Analysis/ThreadSafety.cpp | 11 +++++++++++ clang/test/SemaCXX/warn-thread-safety-analysis.cpp | 5 +++++ 2 files changed, 16 insertions(+) diff --git a/clang/lib/Analysis/ThreadSafety.cpp b/clang/lib/Analysis/ThreadSafety.cpp index 03bbf078d7e8..32d950864ce7 100644 --- a/clang/lib/Analysis/ThreadSafety.cpp +++ b/clang/lib/Analysis/ThreadSafety.cpp @@ -1679,6 +1679,17 @@ void BuildLockset::checkAccess(const Expr *Exp, AccessKind AK, return; } + if (const auto *BO = dyn_cast(Exp)) { + switch (BO->getOpcode()) { + case BO_PtrMemD: // .* + return checkAccess(BO->getLHS(), AK, POK); + case BO_PtrMemI: // ->* + return checkPtAccess(BO->getLHS(), AK, POK); + default: + return; + } + } + if (const auto *AE = dyn_cast(Exp)) { checkPtAccess(AE->getLHS(), AK, POK); return; diff --git a/clang/test/SemaCXX/warn-thread-safety-analysis.cpp b/clang/test/SemaCXX/warn-thread-safety-analysis.cpp index ea229fef649b..ac854dce0f7b 100644 --- a/clang/test/SemaCXX/warn-thread-safety-analysis.cpp +++ b/clang/test/SemaCXX/warn-thread-safety-analysis.cpp @@ -4870,6 +4870,8 @@ class PtGuardedByCorrectnessTest { int sa[10] GUARDED_BY(mu1); Cell sc[10] GUARDED_BY(mu1); + static constexpr int Cell::*pa = &Cell::a; + void test1() { mu1.Lock(); if (a == 0) doSomething(); // OK, we don't dereference. @@ -4889,9 +4891,11 @@ class PtGuardedByCorrectnessTest { if (c->a == 0) doSomething(); // expected-warning {{reading the value pointed to by 'c' requires holding mutex 'mu2'}} c->a = 0; // expected-warning {{writing the value pointed to by 'c' requires holding mutex 'mu2' exclusively}} + c->*pa = 0; // expected-warning {{writing the value pointed to by 'c' requires holding mutex 'mu2' exclusively}} if ((*c).a == 0) doSomething(); // expected-warning {{reading the value pointed to by 'c' requires holding mutex 'mu2'}} (*c).a = 0; // expected-warning {{writing the value pointed to by 'c' requires holding mutex 'mu2' exclusively}} + (*c).*pa = 0; // expected-warning {{writing the value pointed to by 'c' requires holding mutex 'mu2' exclusively}} if (a[0] == 42) doSomething(); // expected-warning {{reading the value pointed to by 'a' requires holding mutex 'mu2'}} a[0] = 57; // expected-warning {{writing the value pointed to by 'a' requires holding mutex 'mu2' exclusively}} @@ -4923,6 +4927,7 @@ class PtGuardedByCorrectnessTest { sa[0] = 57; // expected-warning {{writing variable 'sa' requires holding mutex 'mu1' exclusively}} if (sc[0].a == 42) doSomething(); // expected-warning {{reading variable 'sc' requires holding mutex 'mu1'}} sc[0].a = 57; // expected-warning {{writing variable 'sc' requires holding mutex 'mu1' exclusively}} + sc[0].*pa = 57; // expected-warning {{writing variable 'sc' requires holding mutex 'mu1' exclusively}} if (*sa == 42) doSomething(); // expected-warning {{reading variable 'sa' requires holding mutex 'mu1'}} *sa = 57; // expected-warning {{writing variable 'sa' requires holding mutex 'mu1' exclusively}}