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[Fix] Speedup -Wunsafe-buffer-usage when using clang modules. #127161

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Merged
ChuanqiXu9 merged 2 commits into from
Apr 15, 2025
Merged

[Fix] Speedup -Wunsafe-buffer-usage when using clang modules. #127161

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46dc273
[Fix] Speedup -Wunsafe-buffer-usage when using clang modules.
matts1 Feb 14, 2025
c8887e7
Merge branch 'main' into push-lmuqnquptpuy
matts1 Feb 20, 2025
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18 changes: 15 additions & 3 deletions clang/lib/Sema/AnalysisBasedWarnings.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2502,14 +2502,25 @@ static void flushDiagnostics(Sema &S, const sema::FunctionScopeInfo *fscope) {
class CallableVisitor : public DynamicRecursiveASTVisitor {
private:
llvm::function_ref<void(const Decl *)> Callback;
const Module *const TUModule;

public:
CallableVisitor(llvm::function_ref<void(const Decl *)> Callback)
: Callback(Callback) {
CallableVisitor(llvm::function_ref<void(const Decl *)> Callback,
const Module *const TUModule)
: Callback(Callback), TUModule(TUModule) {
ShouldVisitTemplateInstantiations = true;
ShouldVisitImplicitCode = false;
}

bool TraverseDecl(Decl *Node) override {
// For performance reasons, only validate the current translation unit's
// module, and not modules it depends on.
// See https://issues.chromium.org/issues/351909443 for details.
if (Node && Node->getOwningModule() == TUModule)
return DynamicRecursiveASTVisitor::TraverseDecl(Node);
return true;
}

bool VisitFunctionDecl(FunctionDecl *Node) override {
if (cast<DeclContext>(Node)->isDependentContext())
return true; // Not to analyze dependent decl
Expand Down Expand Up @@ -2589,7 +2600,8 @@ void clang::sema::AnalysisBasedWarnings::IssueWarnings(
SourceLocation()) ||
(!Diags.isIgnored(diag::warn_unsafe_buffer_libc_call, SourceLocation()) &&
S.getLangOpts().CPlusPlus /* only warn about libc calls in C++ */)) {
CallableVisitor(CallAnalyzers).TraverseTranslationUnitDecl(TU);
CallableVisitor(CallAnalyzers, TU->getOwningModule())
.TraverseTranslationUnitDecl(TU);
}
}

Expand Down
28 changes: 8 additions & 20 deletions clang/test/Modules/safe_buffers_optout.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -95,18 +95,10 @@ int textual(int *p) {
// `safe_buffers_test_optout`, which uses another top-level module
// `safe_buffers_test_base`. (So the module dependencies form a DAG.)

// No expected warnings from base.h because base.h is a separate
// module and in a separate TU that is not textually included. The
// explicit command that builds base.h has no `-Wunsafe-buffer-usage`.

// [email protected]:3{{unsafe buffer access}}
// [email protected]:3{{pass -fsafe-buffer-usage-suggestions to receive code hardening suggestions}}
// expected-warning@test_sub1.h:5{{unsafe buffer access}}
// expected-note@test_sub1.h:5{{pass -fsafe-buffer-usage-suggestions to receive code hardening suggestions}}
// expected-warning@test_sub1.h:14{{unsafe buffer access}}
// expected-note@test_sub1.h:14{{pass -fsafe-buffer-usage-suggestions to receive code hardening suggestions}}
// expected-warning@test_sub2.h:5{{unsafe buffer access}}
// expected-note@test_sub2.h:5{{pass -fsafe-buffer-usage-suggestions to receive code hardening suggestions}}
// No expected warnings from base.h, test_sub1, or test_sub2 because they are
// in seperate modules, and the explicit commands that builds them have no
// `-Wunsafe-buffer-usage`.

int foo(int * p) {
int x = p[5]; // expected-warning{{unsafe buffer access}} expected-note{{pass -fsafe-buffer-usage-suggestions to receive code hardening suggestions}}
#pragma clang unsafe_buffer_usage begin
Expand All @@ -129,14 +121,10 @@ int foo(int * p) {
// `safe_buffers_test_optout`, which uses another top-level module
// `safe_buffers_test_base`. (So the module dependencies form a DAG.)

// [email protected]:3{{unsafe buffer access}}
// [email protected]:3{{pass -fsafe-buffer-usage-suggestions to receive code hardening suggestions}}
// expected-warning@test_sub1.h:5{{unsafe buffer access}}
// expected-note@test_sub1.h:5{{pass -fsafe-buffer-usage-suggestions to receive code hardening suggestions}}
// expected-warning@test_sub1.h:14{{unsafe buffer access}}
// expected-note@test_sub1.h:14{{pass -fsafe-buffer-usage-suggestions to receive code hardening suggestions}}
// expected-warning@test_sub2.h:5{{unsafe buffer access}}
// expected-note@test_sub2.h:5{{pass -fsafe-buffer-usage-suggestions to receive code hardening suggestions}}
// No expected warnings from base.h, test_sub1, or test_sub2 because they are
// in seperate modules, and the explicit commands that builds them have no
// `-Wunsafe-buffer-usage`.

int foo(int * p) {
int x = p[5]; // expected-warning{{unsafe buffer access}} expected-note{{pass -fsafe-buffer-usage-suggestions to receive code hardening suggestions}}
#pragma clang unsafe_buffer_usage begin
Expand Down