Make printf warnings refer to intmax_t et al. by name

in addition to underlying type.

For example, the warning for printf("%zu", 42.0);
changes from "conversion specifies type 'unsigned long'" to "conversion
specifies type 'size_t' (aka 'unsigned long')"

(This is a second attempt after r145697, which got reverted.)

llvm-svn: 146032

clang/include/clang/Analysis/Analyses/FormatString.h

@@ -199,15 +199,17 @@ protected:
 class ArgTypeResult {
 public:
   enum Kind { UnknownTy, InvalidTy, SpecificTy, ObjCPointerTy, CPointerTy,
-              AnyCharTy, CStrTy, WCStrTy, WIntTy };
+              AnyCharTy, CStrTy, WCStrTy, WIntTy, TypedefTy };
 private:
   const Kind K;
   QualType T;
-  ArgTypeResult(bool) : K(InvalidTy) {}
+  const char *Name;
+  ArgTypeResult(bool) : K(InvalidTy), Name(0) {}
 public:
-  ArgTypeResult(Kind k = UnknownTy) : K(k) {}
-  ArgTypeResult(QualType t) : K(SpecificTy), T(t) {}
-  ArgTypeResult(CanQualType t) : K(SpecificTy), T(t) {}
+  ArgTypeResult(Kind k = UnknownTy) : K(k), Name(0) {}
+  ArgTypeResult(QualType t) : K(SpecificTy), T(t), Name(0) {}
+  ArgTypeResult(QualType t, const char *n) : K(TypedefTy), T(t), Name(n)  {}
+  ArgTypeResult(CanQualType t) : K(SpecificTy), T(t), Name(0) {}
 
   static ArgTypeResult Invalid() { return ArgTypeResult(true); }
 
@@ -222,6 +224,8 @@ public:
   bool matchesAnyObjCObjectRef() const { return K == ObjCPointerTy; }
 
   QualType getRepresentativeType(ASTContext &C) const;
+
+  std::string getRepresentativeTypeName(ASTContext &C) const;
 };
 
 class OptionalAmount {

clang/lib/Analysis/FormatString.cpp

@@ -228,6 +228,7 @@ bool ArgTypeResult::matchesType(ASTContext &C, QualType argTy) const {
       return false;
     }
       
+    case TypedefTy:
     case SpecificTy: {
       argTy = C.getCanonicalType(argTy).getUnqualifiedType();
       if (T == argTy)
@@ -331,6 +332,7 @@ QualType ArgTypeResult::getRepresentativeType(ASTContext &C) const {
     case AnyCharTy:
       return C.CharTy;
     case SpecificTy:
+    case TypedefTy:
       return T;
     case CStrTy:
       return C.getPointerType(C.CharTy);
@@ -351,6 +353,13 @@ QualType ArgTypeResult::getRepresentativeType(ASTContext &C) const {
   return QualType();
 }
 
+std::string ArgTypeResult::getRepresentativeTypeName(ASTContext &C) const {
+  if (K != TypedefTy)
+    return std::string("'") + getRepresentativeType(C).getAsString() + "'";
+  return std::string("'") + Name + "' (aka '" + T.getAsString() + "')";
+}
+
+
 //===----------------------------------------------------------------------===//
 // Methods on OptionalAmount.
 //===----------------------------------------------------------------------===//
@@ -485,5 +494,3 @@ bool FormatSpecifier::hasValidLengthModifier() const {
   }
   return false;
 }
-
-

clang/lib/Analysis/PrintfFormatString.cpp

@@ -301,11 +301,13 @@ ArgTypeResult PrintfSpecifier::getArgType(ASTContext &Ctx) const {
       case LengthModifier::AsShort: return Ctx.ShortTy;
       case LengthModifier::AsLong: return Ctx.LongTy;
       case LengthModifier::AsLongLong: return Ctx.LongLongTy;
-      case LengthModifier::AsIntMax: return Ctx.getIntMaxType();
+      case LengthModifier::AsIntMax:
+        return ArgTypeResult(Ctx.getIntMaxType(), "intmax_t");
       case LengthModifier::AsSizeT:
         // FIXME: How to get the corresponding signed version of size_t?
         return ArgTypeResult();
-      case LengthModifier::AsPtrDiff: return Ctx.getPointerDiffType();
+      case LengthModifier::AsPtrDiff:
+        return ArgTypeResult(Ctx.getPointerDiffType(), "ptrdiff_t");
     }
 
   if (CS.isUIntArg())
@@ -317,9 +319,10 @@ ArgTypeResult PrintfSpecifier::getArgType(ASTContext &Ctx) const {
       case LengthModifier::AsShort: return Ctx.UnsignedShortTy;
       case LengthModifier::AsLong: return Ctx.UnsignedLongTy;
       case LengthModifier::AsLongLong: return Ctx.UnsignedLongLongTy;
-      case LengthModifier::AsIntMax: return Ctx.getUIntMaxType();
+      case LengthModifier::AsIntMax:
+        return ArgTypeResult(Ctx.getUIntMaxType(), "uintmax_t");
       case LengthModifier::AsSizeT:
-        return Ctx.getSizeType();
+        return ArgTypeResult(Ctx.getSizeType(), "size_t");
       case LengthModifier::AsPtrDiff:
         // FIXME: How to get the corresponding unsigned
         // version of ptrdiff_t?

clang/lib/Sema/SemaChecking.cpp

@@ -2014,7 +2014,7 @@ bool CheckPrintfHandler::HandleAmount(
 
       if (!ATR.matchesType(S.Context, T)) {
         EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_wrong_type)
-                               << k << ATR.getRepresentativeType(S.Context)
+                               << k << ATR.getRepresentativeTypeName(S.Context)
                                << T << Arg->getSourceRange(),
                              getLocationOfByte(Amt.getStart()),
                              /*IsStringLocation*/true,
@@ -2234,7 +2234,7 @@ CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier
       // type is 'wint_t' (which is defined in the system headers).
       EmitFormatDiagnostic(
         S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
-          << ATR.getRepresentativeType(S.Context) << Ex->getType()
+          << ATR.getRepresentativeTypeName(S.Context) << Ex->getType()
           << Ex->getSourceRange(),
         getLocationOfByte(CS.getStart()),
         /*IsStringLocation*/true,
@@ -2246,7 +2246,7 @@ CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier
     else {
       S.Diag(getLocationOfByte(CS.getStart()),
              diag::warn_printf_conversion_argument_type_mismatch)
-        << ATR.getRepresentativeType(S.Context) << Ex->getType()
+        << ATR.getRepresentativeTypeName(S.Context) << Ex->getType()
         << getSpecifierRange(startSpecifier, specifierLen)
         << Ex->getSourceRange();
     }

clang/test/Sema/format-strings-int-typedefs.c

@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -fsyntax-only -verify %s
+
+int printf(char const *, ...);
+
+void test(void) {
+  printf("%jd", 42.0); // expected-warning {{conversion specifies type 'intmax_t' (aka 'long long')}}
+  printf("%ju", 42.0); // expected-warning {{conversion specifies type 'uintmax_t' (aka 'unsigned long long')}}
+  printf("%zu", 42.0); // expected-warning {{conversion specifies type 'size_t' (aka 'unsigned long')}}
+  printf("%td", 42.0); // expected-warning {{conversion specifies type 'ptrdiff_t' (aka 'int')}}
+
+  // typedef size_t et al. to something crazy.
+  typedef void *size_t;
+  typedef void *intmax_t;
+  typedef void *uintmax_t;
+  typedef void *ptrdiff_t;
+
+  // The warning still fires, because it checks the underlying type.
+  printf("%jd", (intmax_t)42); // expected-warning {{conversion specifies type 'intmax_t' (aka 'long long') but the argument has type 'intmax_t' (aka 'void *')}}
+  printf("%ju", (uintmax_t)42); // expected-warning {{conversion specifies type 'uintmax_t' (aka 'unsigned long long') but the argument has type 'uintmax_t' (aka 'void *')}}
+  printf("%zu", (size_t)42); // expected-warning {{conversion specifies type 'size_t' (aka 'unsigned long') but the argument has type 'size_t' (aka 'void *')}}
+  printf("%td", (ptrdiff_t)42); // expected-warning {{conversion specifies type 'ptrdiff_t' (aka 'int') but the argument has type 'ptrdiff_t' (aka 'void *')}}
+}

clang/test/Sema/format-strings-size_t.c

@@ -4,12 +4,12 @@ int printf(char const *, ...);
 
 void test(void) {
   // size_t
-  printf("%zu", (double)42); // expected-warning {{conversion specifies type 'unsigned long' but the argument has type 'double''}}
+  printf("%zu", (double)42); // expected-warning {{conversion specifies type 'size_t' (aka 'unsigned long') but the argument has type 'double''}}
 
   // intmax_t / uintmax_t
-  printf("%jd", (double)42); // expected-warning {{conversion specifies type 'long' but the argument has type 'double''}}
-  printf("%ju", (double)42); // expected-warning {{conversion specifies type 'unsigned long' but the argument has type 'double''}}
+  printf("%jd", (double)42); // expected-warning {{conversion specifies type 'intmax_t' (aka 'long') but the argument has type 'double''}}
+  printf("%ju", (double)42); // expected-warning {{conversion specifies type 'uintmax_t' (aka 'unsigned long') but the argument has type 'double''}}
 
   // ptrdiff_t
-  printf("%td", (double)42); // expected-warning {{conversion specifies type 'long' but the argument has type 'double''}}
+  printf("%td", (double)42); // expected-warning {{conversion specifies type 'ptrdiff_t' (aka 'long') but the argument has type 'double''}}
 }