[cfe-commits] r95940 - in /cfe/trunk: include/clang/Basic/DiagnosticSemaKinds.td include/clang/Frontend/PCHBitCodes.h include/clang/Frontend/PCHReader.h lib/Frontend/PCHReader.cpp lib/Frontend/PCHWriter.cpp lib/Sema/Sema.cpp lib/Sema/Sema.h lib/S
Daniel Dunbar
daniel at zuster.org
Tue Feb 16 09:15:13 PST 2010
I filed
http://llvm.org/bugs/show_bug.cgi?id=6321
for this. I'm going to turn the warning off for now because it breaks
various projects in my testing, and I think its because of this bug
(they fail due to -Werror).
- Daniel
On Fri, Feb 12, 2010 at 9:10 AM, Daniel Dunbar <daniel at zuster.org> wrote:
> Hi Tanya,
>
> This is giving a false positive on the following code, can you take a look?
>
> --
> ddunbar at lordcrumb:tmp$ cat t.c
> static void f0(void);
> void f1(void(*a0)(void));
> void f2(void) { f1(f0); }
> static void f0(void) {}
> ddunbar at lordcrumb:tmp$ clang -Wunused-function -fsyntax-only t.c
> t.c:4:13: warning: unused function 'f0' [-Wunused-function]
> static void f0(void) {}
> ^
> 1 diagnostic generated.
> ddunbar at lordcrumb:tmp$
> --
>
> - Daniel
>
> On Thu, Feb 11, 2010 at 4:07 PM, Tanya Lattner <tonic at nondot.org> wrote:
>> Author: tbrethou
>> Date: Thu Feb 11 18:07:30 2010
>> New Revision: 95940
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=95940&view=rev
>> Log:
>> Implementing unused function warning.
>>
>> Added:
>> cfe/trunk/test/Sema/warn-unused-function.c
>> Modified:
>> cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>> cfe/trunk/include/clang/Frontend/PCHBitCodes.h
>> cfe/trunk/include/clang/Frontend/PCHReader.h
>> cfe/trunk/lib/Frontend/PCHReader.cpp
>> cfe/trunk/lib/Frontend/PCHWriter.cpp
>> cfe/trunk/lib/Sema/Sema.cpp
>> cfe/trunk/lib/Sema/Sema.h
>> cfe/trunk/lib/Sema/SemaDecl.cpp
>> cfe/trunk/lib/Sema/SemaExpr.cpp
>>
>> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=95940&r1=95939&r2=95940&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
>> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Thu Feb 11 18:07:30 2010
>> @@ -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<UnusedFunction>, DefaultIgnore;
>> +
>> def warn_implicit_function_decl : Warning<
>> "implicit declaration of function %0">,
>> InGroup<ImplicitFunctionDeclare>, DefaultIgnore;
>>
>> Modified: cfe/trunk/include/clang/Frontend/PCHBitCodes.h
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Frontend/PCHBitCodes.h?rev=95940&r1=95939&r2=95940&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/include/clang/Frontend/PCHBitCodes.h (original)
>> +++ cfe/trunk/include/clang/Frontend/PCHBitCodes.h Thu Feb 11 18:07:30 2010
>> @@ -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.
>>
>> Modified: cfe/trunk/include/clang/Frontend/PCHReader.h
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Frontend/PCHReader.h?rev=95940&r1=95939&r2=95940&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/include/clang/Frontend/PCHReader.h (original)
>> +++ cfe/trunk/include/clang/Frontend/PCHReader.h Thu Feb 11 18:07:30 2010
>> @@ -306,6 +306,10 @@
>> /// \brief The set of tentative definitions stored in the the PCH
>> /// file.
>> llvm::SmallVector<uint64_t, 16> TentativeDefinitions;
>> +
>> + /// \brief The set of tentative definitions stored in the the PCH
>> + /// file.
>> + llvm::SmallVector<uint64_t, 16> UnusedStaticFuncs;
>>
>> /// \brief The set of locally-scoped external declarations stored in
>> /// the the PCH file.
>>
>> Modified: cfe/trunk/lib/Frontend/PCHReader.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/PCHReader.cpp?rev=95940&r1=95939&r2=95940&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Frontend/PCHReader.cpp (original)
>> +++ cfe/trunk/lib/Frontend/PCHReader.cpp Thu Feb 11 18:07:30 2010
>> @@ -1332,6 +1332,14 @@
>> 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");
>> @@ -2479,6 +2487,13 @@
>> VarDecl *Var = cast<VarDecl>(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<FunctionDecl>(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
>>
>> Modified: cfe/trunk/lib/Frontend/PCHWriter.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/PCHWriter.cpp?rev=95940&r1=95939&r2=95940&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Frontend/PCHWriter.cpp (original)
>> +++ cfe/trunk/lib/Frontend/PCHWriter.cpp Thu Feb 11 18:07:30 2010
>> @@ -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);
>> @@ -1982,6 +1983,11 @@
>> 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.
>> @@ -2083,6 +2089,10 @@
>> 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,
>>
>> Modified: cfe/trunk/lib/Sema/Sema.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/Sema.cpp?rev=95940&r1=95939&r2=95940&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/Sema.cpp (original)
>> +++ cfe/trunk/lib/Sema/Sema.cpp Thu Feb 11 18:07:30 2010
>> @@ -185,6 +185,12 @@
>> /// popped.
>> void Sema::ActOnEndOfTranslationUnit() {
>>
>> + // Remove functions that turned out to be used.
>> + UnusedStaticFuncs.erase(std::remove_if(UnusedStaticFuncs.begin(),
>> + UnusedStaticFuncs.end(),
>> + std::mem_fun(&FunctionDecl::isUsed)),
>> + UnusedStaticFuncs.end());
>> +
>> while (1) {
>> // C++: Perform implicit template instantiations.
>> //
>> @@ -265,6 +271,15 @@
>> Consumer.CompleteTentativeDefinition(VD);
>>
>> }
>> +
>> + // Output warning for unused functions.
>> + for (std::vector<FunctionDecl*>::iterator
>> + F = UnusedStaticFuncs.begin(),
>> + FEnd = UnusedStaticFuncs.end();
>> + F != FEnd;
>> + ++F)
>> + Diag((*F)->getLocation(), diag::warn_unused_function) << (*F)->getDeclName();
>> +
>> }
>>
>>
>>
>> Modified: cfe/trunk/lib/Sema/Sema.h
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/Sema.h?rev=95940&r1=95939&r2=95940&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/Sema.h (original)
>> +++ cfe/trunk/lib/Sema/Sema.h Thu Feb 11 18:07:30 2010
>> @@ -276,6 +276,9 @@
>> /// \brief All the tentative definitions encountered in the TU.
>> std::vector<VarDecl *> TentativeDefinitions;
>>
>> + /// \brief The set of static functions seen so far that have not been used.
>> + std::vector<FunctionDecl*> UnusedStaticFuncs;
>> +
>> /// An enum describing the kind of diagnostics to use when checking
>> /// access.
>> enum AccessDiagnosticsKind {
>>
>> Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=95940&r1=95939&r2=95940&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
>> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Thu Feb 11 18:07:30 2010
>> @@ -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;
>> }
>>
>>
>> Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=95940&r1=95939&r2=95940&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
>> +++ cfe/trunk/lib/Sema/SemaExpr.cpp Thu Feb 11 18:07:30 2010
>> @@ -7293,6 +7293,7 @@
>>
>> // FIXME: keep track of references to static functions
>> Function->setUsed(true);
>> +
>> return;
>> }
>>
>>
>> Added: cfe/trunk/test/Sema/warn-unused-function.c
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/warn-unused-function.c?rev=95940&view=auto
>>
>> ==============================================================================
>> --- cfe/trunk/test/Sema/warn-unused-function.c (added)
>> +++ cfe/trunk/test/Sema/warn-unused-function.c Thu Feb 11 18:07:30 2010
>> @@ -0,0 +1,16 @@
>> +// 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}}
>> +
>> +// FIXME: This will trigger a warning when it should not.
>> +// Update once PR6281 is fixed.
>> +//inline static void f4();
>> +//void f4() { }
>> \ No newline at end of file
>>
>>
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