diff --git a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp --- a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp @@ -568,19 +568,24 @@ return findFunctionSummary(FD, C); } -llvm::Optional -lookupGlobalCFunction(StringRef Name, const ASTContext &ACtx) { +llvm::Optional lookupType(StringRef Name, const ASTContext &ACtx) { IdentifierInfo &II = ACtx.Idents.get(Name); auto LookupRes = ACtx.getTranslationUnitDecl()->lookup(&II); if (LookupRes.size() == 0) return None; - assert(LookupRes.size() == 1 && "In C, identifiers should be unique"); - Decl *D = LookupRes.front()->getCanonicalDecl(); - auto *FD = dyn_cast(D); - if (!FD) - return None; - return FD->getCanonicalDecl(); + // Prioritze typedef declarations. + // This is needed in case of C struct typedefs. E.g.: + // typedef struct FILE FILE; + // In this case, we have a RecordDecl 'struct FILE' with the name 'FILE' and + // we have a TypedefDecl with the name 'FILE'. + for (Decl *D : LookupRes) { + if (auto *TD = dyn_cast(D)) + return ACtx.getTypeDeclType(TD).getCanonicalType(); + } + assert(LookupRes.size() == 1 && "Type identifier should be unique"); + auto *D = cast(LookupRes.front()); + return ACtx.getTypeDeclType(D).getCanonicalType(); } void StdLibraryFunctionsChecker::initFunctionSummaries( @@ -607,13 +612,16 @@ const QualType SizeTy = ACtx.getSizeType(); const QualType VoidPtrTy = ACtx.VoidPtrTy; // void * const QualType VoidPtrRestrictTy = - ACtx.getRestrictType(VoidPtrTy); // void *restrict + ACtx.getLangOpts().C99 ? ACtx.getRestrictType(VoidPtrTy) // void *restrict + : VoidPtrTy; const QualType ConstVoidPtrTy = ACtx.getPointerType(ACtx.VoidTy.withConst()); // const void * const QualType ConstCharPtrTy = ACtx.getPointerType(ACtx.CharTy.withConst()); // const char * const QualType ConstVoidPtrRestrictTy = - ACtx.getRestrictType(ConstVoidPtrTy); // const void *restrict + ACtx.getLangOpts().C99 + ? ACtx.getRestrictType(ConstVoidPtrTy) // const void *restrict + : ConstVoidPtrTy; const RangeInt IntMax = BVF.getMaxValue(IntTy).getLimitedValue(); const RangeInt LongMax = BVF.getMaxValue(LongTy).getLimitedValue(); @@ -728,10 +736,20 @@ return std::make_shared(ArgN); }; + Optional FileTy = lookupType("FILE", ACtx); + Optional FilePtrTy = + FileTy ? Optional(ACtx.getPointerType(*FileTy)) : None; + Optional FilePtrRestrictTy = + FilePtrTy ? Optional( + ACtx.getLangOpts().C99 + ? ACtx.getRestrictType(*FilePtrTy) // FILE *restrict + : *FilePtrTy) + : None; + using RetType = QualType; // Templates for summaries that are reused by many functions. auto Getc = [&]() { - return Summary(ArgTypes{Irrelevant}, RetType{IntTy}, NoEvalCall) + return Summary(ArgTypes{*FilePtrTy}, RetType{IntTy}, NoEvalCall) .Case({ReturnValueCondition(WithinRange, {{EOFv, EOFv}, {0, UCharRangeMax}})}); }; @@ -742,17 +760,18 @@ ReturnValueCondition(WithinRange, Range(-1, Max))}); }; auto Fread = [&]() { - return Summary(ArgTypes{VoidPtrRestrictTy, Irrelevant, SizeTy, Irrelevant}, - RetType{SizeTy}, NoEvalCall) + return Summary( + ArgTypes{VoidPtrRestrictTy, SizeTy, SizeTy, *FilePtrRestrictTy}, + RetType{SizeTy}, NoEvalCall) .Case({ ReturnValueCondition(LessThanOrEq, ArgNo(2)), }) .ArgConstraint(NotNull(ArgNo(0))); }; auto Fwrite = [&]() { - return Summary( - ArgTypes{ConstVoidPtrRestrictTy, Irrelevant, SizeTy, Irrelevant}, - RetType{SizeTy}, NoEvalCall) + return Summary(ArgTypes{ConstVoidPtrRestrictTy, SizeTy, SizeTy, + *FilePtrRestrictTy}, + RetType{SizeTy}, NoEvalCall) .Case({ ReturnValueCondition(LessThanOrEq, ArgNo(2)), }) @@ -899,23 +918,33 @@ ReturnValueCondition(WithinRange, SingleValue(0))})); // The getc() family of functions that returns either a char or an EOF. - addToFunctionSummaryMap("getc", Getc()); - addToFunctionSummaryMap("fgetc", Getc()); + if (FilePtrTy) { + addToFunctionSummaryMap("getc", Getc()); + addToFunctionSummaryMap("fgetc", Getc()); + } addToFunctionSummaryMap( "getchar", Summary(ArgTypes{}, RetType{IntTy}, NoEvalCall) .Case({ReturnValueCondition( WithinRange, {{EOFv, EOFv}, {0, UCharRangeMax}})})); // read()-like functions that never return more than buffer size. + if (FilePtrRestrictTy) { + addToFunctionSummaryMap("fread", Fread()); + addToFunctionSummaryMap("fwrite", Fwrite()); + } + // We are not sure how ssize_t is defined on every platform, so we // provide three variants that should cover common cases. + // FIXME these are actually defined by POSIX and not by the C standard, we + // should handle them together with the rest of the POSIX functions. addToFunctionSummaryMap("read", {Read(IntTy, IntMax), Read(LongTy, LongMax), Read(LongLongTy, LongLongMax)}); addToFunctionSummaryMap("write", {Read(IntTy, IntMax), Read(LongTy, LongMax), Read(LongLongTy, LongLongMax)}); - addToFunctionSummaryMap("fread", Fread()); - addToFunctionSummaryMap("fwrite", Fwrite()); + // getline()-like functions either fail or read at least the delimiter. + // FIXME these are actually defined by POSIX and not by the C standard, we + // should handle them together with the rest of the POSIX functions. addToFunctionSummaryMap("getline", {Getline(IntTy, IntMax), Getline(LongTy, LongMax), Getline(LongLongTy, LongLongMax)}); diff --git a/clang/test/Analysis/std-c-library-functions-arg-constraints.c b/clang/test/Analysis/std-c-library-functions-arg-constraints.c --- a/clang/test/Analysis/std-c-library-functions-arg-constraints.c +++ b/clang/test/Analysis/std-c-library-functions-arg-constraints.c @@ -64,7 +64,7 @@ typedef struct FILE FILE; typedef typeof(sizeof(int)) size_t; -size_t fread(void *restrict, size_t, size_t, FILE *); +size_t fread(void *restrict, size_t, size_t, FILE *restrict); void test_notnull_concrete(FILE *fp) { fread(0, sizeof(int), 10, fp); // \ // report-warning{{Function argument constraint is not satisfied}} \ diff --git a/clang/test/Analysis/std-c-library-functions-lookup.c b/clang/test/Analysis/std-c-library-functions-lookup.c new file mode 100644 --- /dev/null +++ b/clang/test/Analysis/std-c-library-functions-lookup.c @@ -0,0 +1,19 @@ +// RUN: %clang_analyze_cc1 %s \ +// RUN: -analyzer-checker=core \ +// RUN: -analyzer-checker=apiModeling.StdCLibraryFunctions \ +// RUN: -analyzer-config apiModeling.StdCLibraryFunctions:DisplayLoadedSummaries=true \ +// RUN: -analyzer-checker=debug.ExprInspection \ +// RUN: -analyzer-config eagerly-assume=false \ +// RUN: -triple i686-unknown-linux 2>&1 | FileCheck %s + +// CHECK: Loaded summary for: unsigned int fread(void *restrict, size_t, size_t, FILE *restrict) + +typedef typeof(sizeof(int)) size_t; +typedef struct FILE FILE; +size_t fread(void *restrict, size_t, size_t, FILE *restrict); + +// Must have at least one call expression to initialize the summary map. +int bar(void); +void foo() { + bar(); +} diff --git a/clang/test/Analysis/std-c-library-functions-lookup.cpp b/clang/test/Analysis/std-c-library-functions-lookup.cpp new file mode 100644 --- /dev/null +++ b/clang/test/Analysis/std-c-library-functions-lookup.cpp @@ -0,0 +1,23 @@ +// RUN: %clang_analyze_cc1 %s \ +// RUN: -analyzer-checker=core \ +// RUN: -analyzer-checker=apiModeling.StdCLibraryFunctions \ +// RUN: -analyzer-config apiModeling.StdCLibraryFunctions:DisplayLoadedSummaries=true \ +// RUN: -analyzer-checker=debug.ExprInspection \ +// RUN: -analyzer-config eagerly-assume=false \ +// RUN: -triple i686-unknown-linux 2>&1 | FileCheck %s + +// CHECK: Loaded summary for: size_t fread(void *, size_t, size_t, FILE *) +// CHECK-NOT: Loaded summary for: size_t fread(void *, size_t, size_t, MyFile *) + +typedef unsigned int size_t; +typedef struct FILE FILE; +size_t fread(void *, size_t, size_t, FILE *); + +struct MyFile; +size_t fread(void *, size_t, size_t, MyFile *); + +// Must have at least one call expression to initialize the summary map. +int bar(void); +void foo() { + bar(); +} diff --git a/clang/test/Analysis/std-c-library-functions.c b/clang/test/Analysis/std-c-library-functions.c --- a/clang/test/Analysis/std-c-library-functions.c +++ b/clang/test/Analysis/std-c-library-functions.c @@ -53,10 +53,10 @@ // CHECK-NEXT: Loaded summary for: int getc(FILE *) // CHECK-NEXT: Loaded summary for: int fgetc(FILE *) // CHECK-NEXT: Loaded summary for: int getchar() +// CHECK-NEXT: Loaded summary for: unsigned int fread(void *restrict, size_t, size_t, FILE *restrict) +// CHECK-NEXT: Loaded summary for: unsigned int fwrite(const void *restrict, size_t, size_t, FILE *restrict) // CHECK-NEXT: Loaded summary for: ssize_t read(int, void *, size_t) // CHECK-NEXT: Loaded summary for: ssize_t write(int, const void *, size_t) -// CHECK-NEXT: Loaded summary for: unsigned int fread(void *restrict, size_t, size_t, FILE *) -// CHECK-NEXT: Loaded summary for: unsigned int fwrite(const void *restrict, size_t, size_t, FILE *restrict) // CHECK-NEXT: Loaded summary for: ssize_t getline(char **, size_t *, FILE *) void clang_analyzer_eval(int); @@ -104,7 +104,7 @@ } } -size_t fread(void *restrict, size_t, size_t, FILE *); +size_t fread(void *restrict, size_t, size_t, FILE *restrict); size_t fwrite(const void *restrict, size_t, size_t, FILE *restrict); void test_fread_fwrite(FILE *fp, int *buf) {