https://github.com/budimirarandjelovicsyrmia updated https://github.com/llvm/llvm-project/pull/70024
From 9d49cf51be0ad67f57c862ef70221d37c727033f Mon Sep 17 00:00:00 2001 From: budimirarandjelovicsyrmia <budimir.arandjelo...@syrmia.com> Date: Fri, 13 Oct 2023 14:45:15 +0200 Subject: [PATCH] [clang] Catch missing format attributes --- clang/docs/ReleaseNotes.rst | 4 +- clang/include/clang/Basic/DiagnosticGroups.td | 2 +- .../clang/Basic/DiagnosticSemaKinds.td | 3 + clang/include/clang/Sema/Sema.h | 4 ++ clang/lib/Sema/SemaChecking.cpp | 4 +- clang/lib/Sema/SemaDeclAttr.cpp | 65 +++++++++++++++++++ clang/test/Sema/attr-format-missing.c | 58 +++++++++++++++++ 7 files changed, 137 insertions(+), 3 deletions(-) create mode 100644 clang/test/Sema/attr-format-missing.c diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 9cc2a72f4c864..1ca055f65f211 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -65,7 +65,9 @@ Improvements to Clang's diagnostics ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - We now generate a diagnostic for signed integer overflow due to unary minus in a non-constant expression context. This fixes - `Issue 31643 <https://github.com/llvm/llvm-project/issues/31643>`_ + `Issue 31643 <https://github.com/llvm/llvm-project/issues/31643>`_. +- We now generate a diagnostic for missing format attributes + `Issue 60718 <https://github.com/llvm/llvm-project/issues/60718>`_. Non-comprehensive list of changes in this release ------------------------------------------------- diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td index 17fdcffa2d427..b8b77df84beb2 100644 --- a/clang/include/clang/Basic/DiagnosticGroups.td +++ b/clang/include/clang/Basic/DiagnosticGroups.td @@ -482,7 +482,7 @@ def MainReturnType : DiagGroup<"main-return-type">; def MaxUnsignedZero : DiagGroup<"max-unsigned-zero">; def MissingBraces : DiagGroup<"missing-braces">; def MissingDeclarations: DiagGroup<"missing-declarations">; -def : DiagGroup<"missing-format-attribute">; +def MissingFormatAttribute: DiagGroup<"missing-format-attribute">; def : DiagGroup<"missing-include-dirs">; def MissingNoreturn : DiagGroup<"missing-noreturn">; def MultiChar : DiagGroup<"multichar">; diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 6d6f474f6dcda..3cd2270b2fc41 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -936,6 +936,9 @@ def err_opencl_invalid_param : Error< def err_opencl_invalid_return : Error< "declaring function return value of type %0 is not allowed %select{; did you forget * ?|}1">; def warn_enum_value_overflow : Warning<"overflow in enumeration value">; +def warn_missing_format_attribute : Warning< + "diagnostic behavior may be improved by adding the %0 format attribute to the declaration of %1">, + InGroup<MissingFormatAttribute>, DefaultIgnore; def warn_pragma_options_align_reset_failed : Warning< "#pragma options align=reset failed: %0">, InGroup<IgnoredPragmas>; diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h index 741c2503127af..064506e709603 100644 --- a/clang/include/clang/Sema/Sema.h +++ b/clang/include/clang/Sema/Sema.h @@ -10615,6 +10615,10 @@ class Sema final { ChangedStateAtExit }; + void DiagnoseMissingFormatAttributes(const FunctionDecl *FDecl, + ArrayRef<const Expr *> Args, + SourceLocation Loc); + void DiagnoseNonDefaultPragmaAlignPack(PragmaAlignPackDiagnoseKind Kind, SourceLocation IncludeLoc); void DiagnoseUnterminatedPragmaAlignPack(); diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 4602284309491..d3ac6cb519c56 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -6014,8 +6014,10 @@ void Sema::checkCall(NamedDecl *FDecl, const FunctionProtoType *Proto, } } - if (FD) + if (FD) { diagnoseArgDependentDiagnoseIfAttrs(FD, ThisArg, Args, Loc); + DiagnoseMissingFormatAttributes(FD, Args, Range.getBegin()); + } } /// CheckConstructorCall - Check a constructor call for correctness and safety diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp index 1a0bfb3d91bcc..87235a2975610 100644 --- a/clang/lib/Sema/SemaDeclAttr.cpp +++ b/clang/lib/Sema/SemaDeclAttr.cpp @@ -6849,6 +6849,71 @@ static void handleSwiftAsyncAttr(Sema &S, Decl *D, const ParsedAttr &AL) { checkSwiftAsyncErrorBlock(S, D, ErrorAttr, AsyncAttr); } +// Warn if parent function misses format attribute. Parent function misses +// format attribute if there is an argument format string forwarded to calling +// function with format attribute, parent function has a parameter which is +// either char or string or pointer to char and parent function format attribute +// type does not match with calling function format attribute type. +void Sema::DiagnoseMissingFormatAttributes(const FunctionDecl *FDecl, + ArrayRef<const Expr *> Args, + SourceLocation Loc) { + assert(FDecl); + + // Check if function has format attribute with forwarded format string. + IdentifierInfo *AttrType; + if (!llvm::any_of( + FDecl->specific_attrs<FormatAttr>(), [&](const FormatAttr *Attr) { + if (!Args[Attr->getFirstArg()]->getReferencedDeclOfCallee()) + return false; + + AttrType = Attr->getType(); + return true; + })) + return; + + const FunctionDecl *ParentFuncDecl = getCurFunctionDecl(); + if (!ParentFuncDecl) + return; + + // Check if parent function has char, string or pointer to char parameter. + unsigned int StringIndex = 0; + if (!llvm::any_of( + ParentFuncDecl->parameters(), [&](const ParmVarDecl *Param) { + StringIndex = Param->getFunctionScopeIndex() + 1; + QualType Ty = Param->getType(); + if (isNSStringType(Ty, Context, true)) + return true; + if (isCFStringType(Ty, Context)) + return true; + if (Ty->isPointerType() && + Ty->castAs<PointerType>()->getPointeeType()->isCharType()) + return true; + return false; + })) + return; + + // Check if there is parent function format attribute which type matches + // calling function format attribute type. + if (llvm::any_of( + ParentFuncDecl->specific_attrs<FormatAttr>(), + [&](const FormatAttr *Attr) { return Attr->getType() == AttrType; })) + return; + + unsigned int FirstToCheck = + ParentFuncDecl->isVariadic() ? (ParentFuncDecl->getNumParams() + 1) : 0; + + // Diagnose missing format attributes + std::string InsertionText; + llvm::raw_string_ostream OS(InsertionText); + OS << "__attribute__((format(" + AttrType->getName() + ", " + + std::to_string(StringIndex) + ", " + std::to_string(FirstToCheck) + + ")))"; + SourceLocation ParentFuncLoc = ParentFuncDecl->getLocation(); + Diag(ParentFuncLoc, diag::warn_missing_format_attribute) + << AttrType << ParentFuncDecl + << FixItHint::CreateInsertion(ParentFuncLoc, InsertionText); +} + //===----------------------------------------------------------------------===// // Microsoft specific attribute handlers. //===----------------------------------------------------------------------===// diff --git a/clang/test/Sema/attr-format-missing.c b/clang/test/Sema/attr-format-missing.c new file mode 100644 index 0000000000000..1384fde6eecf7 --- /dev/null +++ b/clang/test/Sema/attr-format-missing.c @@ -0,0 +1,58 @@ +// RUN: %clang_cc1 -fsyntax-only -verify -Wmissing-format-attribute %s +// RUN: %clang_cc1 -fsyntax-only -verify -std=c99 -Wmissing-format-attribute %s + +#include <stdarg.h> +#include <stdio.h> + +__attribute__((__format__ (__scanf__, 1, 4))) +void f1(char *out, const size_t len, const char *format, ... /* args */) +{ + va_list args; + vsnprintf(out, len, format, args); // expected-warning {{diagnostic behavior may be improved by adding the 'printf' format attribute to the declaration of 'f1'}} + // CHECK-FIXES: __attribute__((format(printf, 1, 4))) +} + +void f2(char *out, va_list args) +{ + vprintf(out, args); // expected-warning {{diagnostic behavior may be improved by adding the 'printf' format attribute to the declaration of 'f2'}} + // CHECK-FIXES: __attribute__((format(printf, 1, 0))) + vscanf(out, args); // expected-warning {{diagnostic behavior may be improved by adding the 'scanf' format attribute to the declaration of 'f2'}} + // CHECK-FIXES: __attribute__((format(scanf, 1, 0))) +} + +void f3(char* out, ... /* args */) +{ + va_list args; + vprintf("test", args); // no warning +} + +void f4(char *out, ... /* args */) +{ + const char *ch; + va_list args; + vscanf(ch, args); // expected-warning {{diagnostic behavior may be improved by adding the 'scanf' format attribute to the declaration of 'f4'}} + // CHECK-FIXES: __attribute__((format(scanf, 1, 2))) +} + +void f5(va_list args) +{ + char *ch; + vscanf(ch, args); // no warning +} + +void f6(char *out, va_list args) +{ + char *ch; + vscanf(ch, args); // expected-warning {{diagnostic behavior may be improved by adding the 'scanf' format attribute to the declaration of 'f6'}} + // CHECK-FIXES: __attribute__((format(scanf, 1, 0))) +} + +void f7(const char *out, ... /* args */) +{ + va_list args; + + vscanf(out, &args[0]); // expected-warning {{diagnostic behavior may be improved by adding the 'scanf' format attribute to the declaration of 'f7'}} + // CHECK-FIXES: __attribute__((format(scanf, 1, 2))) + vprintf(out, &args[0]); // expected-warning {{diagnostic behavior may be improved by adding the 'printf' format attribute to the declaration of 'f7'}} + // CHECK-FIXES: __attribute__((format(printf, 1, 2))) +} \ No newline at end of file _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
