Index: test/Sema/warn-unused-function.c =================================================================== --- test/Sema/warn-unused-function.c (revision 0) +++ test/Sema/warn-unused-function.c (revision 0) @@ -0,0 +1,13 @@ +// RUN: %clang_cc1 -fsyntax-only -Wunused-function -verify %s + +void foo() {} +static void f2() {} +static void f1() {f2();} // expected-warning{{unused}} + +static int f0() { return 17; } // expected-warning{{unused}} +int x = sizeof(f0()); + +static void f3(); +extern void f3() { } // expected-warning{{unused}} +inline static void f4(); +void f4() { } \ No newline at end of file Index: include/clang/Frontend/PCHBitCodes.h =================================================================== --- include/clang/Frontend/PCHBitCodes.h (revision 95744) +++ include/clang/Frontend/PCHBitCodes.h (working copy) @@ -221,7 +221,11 @@ /// \brief Record code for the version control branch and revision /// information of the compiler used to build this PCH file. - VERSION_CONTROL_BRANCH_REVISION = 21 + VERSION_CONTROL_BRANCH_REVISION = 21, + + /// \brief Record code for the array of unused static functions. + UNUSED_STATIC_FUNCS = 22 + }; /// \brief Record types used within a source manager block. Index: include/clang/Frontend/PCHReader.h =================================================================== --- include/clang/Frontend/PCHReader.h (revision 95744) +++ include/clang/Frontend/PCHReader.h (working copy) @@ -306,6 +306,10 @@ /// \brief The set of tentative definitions stored in the the PCH /// file. llvm::SmallVector TentativeDefinitions; + + /// \brief The set of tentative definitions stored in the the PCH + /// file. + llvm::SmallVector UnusedStaticFuncs; /// \brief The set of locally-scoped external declarations stored in /// the the PCH file. Index: include/clang/Basic/DiagnosticSemaKinds.td =================================================================== --- include/clang/Basic/DiagnosticSemaKinds.td (revision 95744) +++ include/clang/Basic/DiagnosticSemaKinds.td (working copy) @@ -87,7 +87,9 @@ "declaration of %0 will not be visible outside of this function">; def err_array_star_in_function_definition : Error< "variable length array must be bound in function definition">; - +def warn_unused_function : Warning<"unused function %0">, + InGroup, DefaultIgnore; + def warn_implicit_function_decl : Warning< "implicit declaration of function %0">, InGroup, DefaultIgnore; Index: lib/Frontend/PCHWriter.cpp =================================================================== --- lib/Frontend/PCHWriter.cpp (revision 95744) +++ lib/Frontend/PCHWriter.cpp (working copy) @@ -545,6 +545,7 @@ RECORD(SPECIAL_TYPES); RECORD(STATISTICS); RECORD(TENTATIVE_DEFINITIONS); + RECORD(UNUSED_STATIC_FUNCS); RECORD(LOCALLY_SCOPED_EXTERNAL_DECLS); RECORD(SELECTOR_OFFSETS); RECORD(METHOD_POOL); @@ -1981,6 +1982,11 @@ AddDeclRef(SemaRef.TentativeDefinitions[i], TentativeDefinitions); } + // Build a record containing all of the static unused functions in this file. + RecordData UnusedStaticFuncs; + for (unsigned i=0, e = SemaRef.UnusedStaticFuncs.size(); i !=e; ++i) + AddDeclRef(SemaRef.UnusedStaticFuncs[i], UnusedStaticFuncs); + // Build a record containing all of the locally-scoped external // declarations in this header file. Generally, this record will be // empty. @@ -2082,6 +2088,10 @@ if (!TentativeDefinitions.empty()) Stream.EmitRecord(pch::TENTATIVE_DEFINITIONS, TentativeDefinitions); + // Write the record containing unused static functions. + if (!UnusedStaticFuncs.empty()) + Stream.EmitRecord(pch::UNUSED_STATIC_FUNCS, UnusedStaticFuncs); + // Write the record containing locally-scoped external definitions. if (!LocallyScopedExternalDecls.empty()) Stream.EmitRecord(pch::LOCALLY_SCOPED_EXTERNAL_DECLS, Index: lib/Frontend/PCHReader.cpp =================================================================== --- lib/Frontend/PCHReader.cpp (revision 95744) +++ lib/Frontend/PCHReader.cpp (working copy) @@ -1327,6 +1327,14 @@ TentativeDefinitions.swap(Record); break; + case pch::UNUSED_STATIC_FUNCS: + if (!UnusedStaticFuncs.empty()) { + Error("duplicate UNUSED_STATIC_FUNCS record in PCH file"); + return Failure; + } + UnusedStaticFuncs.swap(Record); + break; + case pch::LOCALLY_SCOPED_EXTERNAL_DECLS: if (!LocallyScopedExternalDecls.empty()) { Error("duplicate LOCALLY_SCOPED_EXTERNAL_DECLS record in PCH file"); @@ -2473,6 +2481,13 @@ VarDecl *Var = cast(GetDecl(TentativeDefinitions[I])); SemaObj->TentativeDefinitions.push_back(Var); } + + // If there were any unused static functions, deserialize them and add to + // Sema's list of unused static functions. + for (unsigned I = 0, N = UnusedStaticFuncs.size(); I != N; ++I) { + FunctionDecl *FD = cast(GetDecl(UnusedStaticFuncs[I])); + SemaObj->UnusedStaticFuncs.push_back(FD); + } // If there were any locally-scoped external declarations, // deserialize them and add them to Sema's table of locally-scoped Index: lib/Sema/SemaDecl.cpp =================================================================== --- lib/Sema/SemaDecl.cpp (revision 95744) +++ lib/Sema/SemaDecl.cpp (working copy) @@ -3129,6 +3129,15 @@ if (FunctionTemplate) return FunctionTemplate; + + // Keep track of static, non-inlined function definitions that + // have not been used. We will warn later. + // FIXME: Also include static functions declared but not defined. + if (!NewFD->isInvalidDecl() && IsFunctionDefinition + && !NewFD->isInlined() && NewFD->getLinkage() == InternalLinkage + && !NewFD->isUsed()) + UnusedStaticFuncs.push_back(NewFD); + return NewFD; } Index: lib/Sema/Sema.h =================================================================== --- lib/Sema/Sema.h (revision 95744) +++ lib/Sema/Sema.h (working copy) @@ -275,6 +275,9 @@ /// \brief All the tentative definitions encountered in the TU. std::vector TentativeDefinitions; + /// \brief The set of static functions seen so far that have not been used. + std::vector UnusedStaticFuncs; + struct DelayedDiagnostic { enum DDKind { Deprecation, Access }; Index: lib/Sema/SemaExpr.cpp =================================================================== --- lib/Sema/SemaExpr.cpp (revision 95744) +++ lib/Sema/SemaExpr.cpp (working copy) @@ -7291,6 +7291,7 @@ // FIXME: keep track of references to static functions Function->setUsed(true); + return; } Index: lib/Sema/Sema.cpp =================================================================== --- lib/Sema/Sema.cpp (revision 95744) +++ lib/Sema/Sema.cpp (working copy) @@ -185,6 +185,16 @@ /// popped. void Sema::ActOnEndOfTranslationUnit() { + // Remove functions that turned out to be used. + for (std::vector::iterator + F = UnusedStaticFuncs.begin(); + F != UnusedStaticFuncs.end();) { + if ((*F)->isUsed()) + UnusedStaticFuncs.erase(F); + else + ++F; + } + while (1) { // C++: Perform implicit template instantiations. // @@ -265,6 +275,15 @@ Consumer.CompleteTentativeDefinition(VD); } + + // Output warning for unused functions. + for (std::vector::iterator + F = UnusedStaticFuncs.begin(), + FEnd = UnusedStaticFuncs.end(); + F != FEnd; + ++F) + Diag((*F)->getLocation(), diag::warn_unused_function) << (*F)->getDeclName(); + }