1 files changed, 48 insertions, 45 deletions

diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 50ebb49e7d5b..341d49ead418 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -1202,6 +1202,35 @@ static void HandleFormatArgAttr(Decl *d, const AttributeList &Attr, Sema &S) {
   d->addAttr(::new (S.Context) FormatArgAttr(Idx.getZExtValue()));
 }
 
+enum FormatAttrKind {
+  CFStringFormat,
+  NSStringFormat,
+  StrftimeFormat,
+  SupportedFormat,
+  InvalidFormat
+};
+
+/// getFormatAttrKind - Map from format attribute names to supported format
+/// types.
+static FormatAttrKind getFormatAttrKind(llvm::StringRef Format) {
+  // Check for formats that get handled specially.
+  if (Format == "NSString")
+    return NSStringFormat;
+  if (Format == "CFString")
+    return CFStringFormat;
+  if (Format == "strftime")
+    return StrftimeFormat;
+
+  // Otherwise, check for supported formats.
+  if (Format == "scanf" || Format == "printf" || Format == "printf0" ||
+      Format == "strfmon" || Format == "cmn_err" || Format == "strftime" ||
+      Format == "NSString" || Format == "CFString" || Format == "vcmn_err" ||
+      Format == "zcmn_err")
+    return SupportedFormat;
+
+  return InvalidFormat;
+}
+
 /// Handle __attribute__((format(type,idx,firstarg))) attributes based on
 /// http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
 static void HandleFormatAttr(Decl *d, const AttributeList &Attr, Sema &S) {
@@ -1226,38 +1255,15 @@ static void HandleFormatAttr(Decl *d, const AttributeList &Attr, Sema &S) {
   unsigned NumArgs  = getFunctionOrMethodNumArgs(d);
   unsigned FirstIdx = 1;
 
-  const char *Format = Attr.getParameterName()->getName();
-  unsigned FormatLen = Attr.getParameterName()->getLength();
+  llvm::StringRef Format = Attr.getParameterName()->getName();
 
   // Normalize the argument, __foo__ becomes foo.
-  if (FormatLen > 4 && Format[0] == '_' && Format[1] == '_' &&
-      Format[FormatLen - 2] == '_' && Format[FormatLen - 1] == '_') {
-    Format += 2;
-    FormatLen -= 4;
-  }
-
-  bool Supported = false;
-  bool is_NSString = false;
-  bool is_strftime = false;
-  bool is_CFString = false;
-
-  switch (FormatLen) {
-  default: break;
-  case 5: Supported = !memcmp(Format, "scanf", 5); break;
-  case 6: Supported = !memcmp(Format, "printf", 6); break;
-  case 7: Supported = !memcmp(Format, "printf0", 7) ||
-                      !memcmp(Format, "strfmon", 7) ||
-                      !memcmp(Format, "cmn_err", 7); break;
-  case 8:
-    Supported = (is_strftime = !memcmp(Format, "strftime", 8)) ||
-                (is_NSString = !memcmp(Format, "NSString", 8)) ||
-                !memcmp(Format, "vcmn_err", 8) ||
-                !memcmp(Format, "zcmn_err", 8) ||
-                (is_CFString = !memcmp(Format, "CFString", 8));
-    break;
-  }
+  if (Format.startswith("__") && Format.endswith("__"))
+    Format = Format.substr(2, Format.size() - 4);
 
-  if (!Supported) {
+  // Check for supported formats.
+  FormatAttrKind Kind = getFormatAttrKind(Format);
+  if (Kind == InvalidFormat) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_type_not_supported)
       << "format" << Attr.getParameterName()->getName();
     return;
@@ -1296,13 +1302,13 @@ static void HandleFormatAttr(Decl *d, const AttributeList &Attr, Sema &S) {
   // make sure the format string is really a string
   QualType Ty = getFunctionOrMethodArgType(d, ArgIdx);
 
-  if (is_CFString) {
+  if (Kind == CFStringFormat) {
     if (!isCFStringType(Ty, S.Context)) {
       S.Diag(Attr.getLoc(), diag::err_format_attribute_not)
         << "a CFString" << IdxExpr->getSourceRange();
       return;
     }
-  } else if (is_NSString) {
+  } else if (Kind == NSStringFormat) {
     // FIXME: do we need to check if the type is NSString*?  What are the
     // semantics?
     if (!isNSStringType(Ty, S.Context)) {
@@ -1340,7 +1346,7 @@ static void HandleFormatAttr(Decl *d, const AttributeList &Attr, Sema &S) {
 
   // strftime requires FirstArg to be 0 because it doesn't read from any
   // variable the input is just the current time + the format string.
-  if (is_strftime) {
+  if (Kind == StrftimeFormat) {
     if (FirstArg != 0) {
       S.Diag(Attr.getLoc(), diag::err_format_strftime_third_parameter)
         << FirstArgExpr->getSourceRange();
@@ -1353,8 +1359,8 @@ static void HandleFormatAttr(Decl *d, const AttributeList &Attr, Sema &S) {
     return;
   }
 
-  d->addAttr(::new (S.Context) FormatAttr(std::string(Format, FormatLen),
-                            Idx.getZExtValue(), FirstArg.getZExtValue()));
+  d->addAttr(::new (S.Context) FormatAttr(Format, Idx.getZExtValue(),
+                                          FirstArg.getZExtValue()));
 }
 
 static void HandleTransparentUnionAttr(Decl *d, const AttributeList &Attr,
@@ -1496,20 +1502,17 @@ static void HandleModeAttr(Decl *D, const AttributeList &Attr, Sema &S) {
     S.Diag(Attr.getLoc(), diag::err_attribute_missing_parameter_name);
     return;
   }
-  const char *Str = Name->getName();
-  unsigned Len = Name->getLength();
+
+  llvm::StringRef Str = Attr.getParameterName()->getName();
 
   // Normalize the attribute name, __foo__ becomes foo.
-  if (Len > 4 && Str[0] == '_' && Str[1] == '_' &&
-      Str[Len - 2] == '_' && Str[Len - 1] == '_') {
-    Str += 2;
-    Len -= 4;
-  }
+  if (Str.startswith("__") && Str.endswith("__"))
+    Str = Str.substr(2, Str.size() - 4);
 
   unsigned DestWidth = 0;
   bool IntegerMode = true;
   bool ComplexMode = false;
-  switch (Len) {
+  switch (Str.size()) {
   case 2:
     switch (Str[0]) {
     case 'Q': DestWidth = 8; break;
@@ -1531,13 +1534,13 @@ static void HandleModeAttr(Decl *D, const AttributeList &Attr, Sema &S) {
   case 4:
     // FIXME: glibc uses 'word' to define register_t; this is narrower than a
     // pointer on PIC16 and other embedded platforms.
-    if (!memcmp(Str, "word", 4))
+    if (Str == "word")
       DestWidth = S.Context.Target.getPointerWidth(0);
-    if (!memcmp(Str, "byte", 4))
+    else if (Str == "byte")
       DestWidth = S.Context.Target.getCharWidth();
     break;
   case 7:
-    if (!memcmp(Str, "pointer", 7))
+    if (Str == "pointer")
       DestWidth = S.Context.Target.getPointerWidth(0);
     break;
   }