Add support for analyzing FreeBSD kernel printf extensions.

This adds a new __freebsd_kprintf__ format string type, which enables
checking when used in __attribute__((format(...))) attributes.  It can
check the FreeBSD kernel specific %b, %D, %r and %y specifiers, using
existing diagnostic messages.  Also adds test cases for all these
specifiers.

Differential Revision: http://reviews.llvm.org/D7154

llvm-svn: 229921

2 files changed, 54 insertions, 5 deletions

diff --git a/clang/lib/Analysis/FormatString.cpp b/clang/lib/Analysis/FormatString.cpp
index 8c663d856f6..662166ccaac 100644
--- a/clang/lib/Analysis/FormatString.cpp
+++ b/clang/lib/Analysis/FormatString.cpp
@@ -552,6 +552,12 @@ const char *ConversionSpecifier::toString() const {
   // Objective-C specific specifiers.
   case ObjCObjArg: return "@";
 
+  // FreeBSD kernel specific specifiers.
+  case FreeBSDbArg: return "b";
+  case FreeBSDDArg: return "D";
+  case FreeBSDrArg: return "r";
+  case FreeBSDyArg: return "y";
+
   // GlibC specific specifiers.
   case PrintErrno: return "m";
 
@@ -647,6 +653,9 @@ bool FormatSpecifier::hasValidLengthModifier(const TargetInfo &Target) const {
         case ConversionSpecifier::XArg:
         case ConversionSpecifier::nArg:
           return true;
+        case ConversionSpecifier::FreeBSDrArg:
+        case ConversionSpecifier::FreeBSDyArg:
+          return Target.getTriple().isOSFreeBSD();
         default:
           return false;
       }
@@ -677,6 +686,9 @@ bool FormatSpecifier::hasValidLengthModifier(const TargetInfo &Target) const {
         case ConversionSpecifier::ScanListArg:
         case ConversionSpecifier::ZArg:
           return true;
+        case ConversionSpecifier::FreeBSDrArg:
+        case ConversionSpecifier::FreeBSDyArg:
+          return Target.getTriple().isOSFreeBSD();
         default:
           return false;
       }
@@ -807,6 +819,10 @@ bool FormatSpecifier::hasStandardConversionSpecifier(const LangOptions &LangOpt)
     case ConversionSpecifier::SArg:
       return LangOpt.ObjC1 || LangOpt.ObjC2;
     case ConversionSpecifier::InvalidSpecifier:
+    case ConversionSpecifier::FreeBSDbArg:
+    case ConversionSpecifier::FreeBSDDArg:
+    case ConversionSpecifier::FreeBSDrArg:
+    case ConversionSpecifier::FreeBSDyArg:
     case ConversionSpecifier::PrintErrno:
     case ConversionSpecifier::DArg:
     case ConversionSpecifier::OArg:
diff --git a/clang/lib/Analysis/PrintfFormatString.cpp b/clang/lib/Analysis/PrintfFormatString.cpp
index 146635b8870..b8d3ec18016 100644
--- a/clang/lib/Analysis/PrintfFormatString.cpp
+++ b/clang/lib/Analysis/PrintfFormatString.cpp
@@ -55,7 +55,8 @@ static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
                                                   unsigned &argIndex,
                                                   const LangOptions &LO,
                                                   const TargetInfo &Target,
-                                                  bool Warn) {
+                                                  bool Warn,
+                                                  bool isFreeBSDKPrintf) {
 
   using namespace clang::analyze_format_string;
   using namespace clang::analyze_printf;
@@ -206,9 +207,24 @@ static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
     case '@': k = ConversionSpecifier::ObjCObjArg; break;
     // Glibc specific.
     case 'm': k = ConversionSpecifier::PrintErrno; break;
+    // FreeBSD kernel specific.
+    case 'b':
+      if (isFreeBSDKPrintf)
+        k = ConversionSpecifier::FreeBSDbArg; // int followed by char *
+      break;
+    case 'r':
+      if (isFreeBSDKPrintf)
+        k = ConversionSpecifier::FreeBSDrArg; // int
+      break;
+    case 'y':
+      if (isFreeBSDKPrintf)
+        k = ConversionSpecifier::FreeBSDyArg; // int
+      break;
     // Apple-specific.
     case 'D':
-      if (Target.getTriple().isOSDarwin())
+      if (isFreeBSDKPrintf)
+        k = ConversionSpecifier::FreeBSDDArg; // void * followed by char *
+      else if (Target.getTriple().isOSDarwin())
         k = ConversionSpecifier::DArg;
       break;
     case 'O':
@@ -228,6 +244,10 @@ static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
   FS.setConversionSpecifier(CS);
   if (CS.consumesDataArgument() && !FS.usesPositionalArg())
     FS.setArgIndex(argIndex++);
+  // FreeBSD kernel specific.
+  if (k == ConversionSpecifier::FreeBSDbArg ||
+      k == ConversionSpecifier::FreeBSDDArg)
+    argIndex++;
 
   if (k == ConversionSpecifier::InvalidSpecifier) {
     // Assume the conversion takes one argument.
@@ -240,14 +260,16 @@ bool clang::analyze_format_string::ParsePrintfString(FormatStringHandler &H,
                                                      const char *I,
                                                      const char *E,
                                                      const LangOptions &LO,
-                                                     const TargetInfo &Target) {
+                                                     const TargetInfo &Target,
+                                                     bool isFreeBSDKPrintf) {
 
   unsigned argIndex = 0;
 
   // Keep looking for a format specifier until we have exhausted the string.
   while (I != E) {
     const PrintfSpecifierResult &FSR = ParsePrintfSpecifier(H, I, E, argIndex,
-                                                            LO, Target, true);
+                                                            LO, Target, true,
+                                                            isFreeBSDKPrintf);
     // Did a fail-stop error of any kind occur when parsing the specifier?
     // If so, don't do any more processing.
     if (FSR.shouldStop())
@@ -276,7 +298,8 @@ bool clang::analyze_format_string::ParseFormatStringHasSArg(const char *I,
   FormatStringHandler H;
   while (I != E) {
     const PrintfSpecifierResult &FSR = ParsePrintfSpecifier(H, I, E, argIndex,
-                                                            LO, Target, false);
+                                                            LO, Target, false,
+                                                            false);
     // Did a fail-stop error of any kind occur when parsing the specifier?
     // If so, don't do any more processing.
     if (FSR.shouldStop())
@@ -674,6 +697,8 @@ bool PrintfSpecifier::hasValidPlusPrefix() const {
   case ConversionSpecifier::GArg:
   case ConversionSpecifier::aArg:
   case ConversionSpecifier::AArg:
+  case ConversionSpecifier::FreeBSDrArg:
+  case ConversionSpecifier::FreeBSDyArg:
     return true;
 
   default:
@@ -699,6 +724,8 @@ bool PrintfSpecifier::hasValidAlternativeForm() const {
   case ConversionSpecifier::FArg:
   case ConversionSpecifier::gArg:
   case ConversionSpecifier::GArg:
+  case ConversionSpecifier::FreeBSDrArg:
+  case ConversionSpecifier::FreeBSDyArg:
     return true;
 
   default:
@@ -729,6 +756,8 @@ bool PrintfSpecifier::hasValidLeadingZeros() const {
   case ConversionSpecifier::FArg:
   case ConversionSpecifier::gArg:
   case ConversionSpecifier::GArg:
+  case ConversionSpecifier::FreeBSDrArg:
+  case ConversionSpecifier::FreeBSDyArg:
     return true;
 
   default:
@@ -753,6 +782,8 @@ bool PrintfSpecifier::hasValidSpacePrefix() const {
   case ConversionSpecifier::GArg:
   case ConversionSpecifier::aArg:
   case ConversionSpecifier::AArg:
+  case ConversionSpecifier::FreeBSDrArg:
+  case ConversionSpecifier::FreeBSDyArg:
     return true;
 
   default:
@@ -818,6 +849,8 @@ bool PrintfSpecifier::hasValidPrecision() const {
   case ConversionSpecifier::gArg:
   case ConversionSpecifier::GArg:
   case ConversionSpecifier::sArg:
+  case ConversionSpecifier::FreeBSDrArg:
+  case ConversionSpecifier::FreeBSDyArg:
     return true;
 
   default: