OpenCL: Don't warn on v printf modifier

[arsenm]

Summary

This avoids spurious warnings, but could use
a lot of work. For example the number of vector
elements is not verified, and the passed
value type is not checked.

[Anastasia]

LGTM! Thanks! Seems like a reasonable start.

[arsenm]

r346806

include/clang/AST/FormatString.h

enum Kind {
     // to be copied by os_log. The precision indicates the number of bytes to
     // copy.
     PArg,
 
     // ** Printf-specific **
 
     ZArg, // MS extension
 
+    VArg, // OpenCL vectors
+
     // Objective-C specific specifiers.
     ObjCObjArg, // '@'
     ObjCBeg = ObjCObjArg,
     ObjCEnd = ObjCObjArg,
 
     // FreeBSD kernel specific specifiers.
     FreeBSDbArg,
     FreeBSDDArg,

lib/AST/FormatString.cpp

const char *ConversionSpecifier::toString() const {
   case FreeBSDrArg: return "r";
   case FreeBSDyArg: return "y";
 
   // GlibC specific specifiers.
   case PrintErrno: return "m";
 
   // MS specific specifiers.
   case ZArg: return "Z";
+
+ // OpenCL specific specifiers.
+  case VArg: return "v";
   }
   return nullptr;
 }
 
 Optional<ConversionSpecifier>
 ConversionSpecifier::getStandardSpecifier() const {
   ConversionSpecifier::Kind NewKind;
 
switch (CS.getKind()) {
     case ConversionSpecifier::ObjCObjArg:
     case ConversionSpecifier::ScanListArg:
     case ConversionSpecifier::PercentArg:
     case ConversionSpecifier::PArg:
       return true;
     case ConversionSpecifier::CArg:
     case ConversionSpecifier::SArg:
       return LangOpt.ObjC;
+    case ConversionSpecifier::VArg:
+      return LangOpt.OpenCL;
     case ConversionSpecifier::InvalidSpecifier:
     case ConversionSpecifier::FreeBSDbArg:
     case ConversionSpecifier::FreeBSDDArg:
     case ConversionSpecifier::FreeBSDrArg:
     case ConversionSpecifier::FreeBSDyArg:
     case ConversionSpecifier::PrintErrno:
     case ConversionSpecifier::DArg:
     case ConversionSpecifier::OArg:

lib/AST/PrintfFormatString.cpp

switch (*conversionPosition) {
     case 'U':
       if (Target.getTriple().isOSDarwin())
         k = ConversionSpecifier::UArg;
       break;
     // MS specific.
     case 'Z':
       if (Target.getTriple().isOSMSVCRT())
         k = ConversionSpecifier::ZArg;
+      break;
+    // OpenCL specific.
+    case 'v':
+      if (LO.OpenCL)
+        k = ConversionSpecifier::VArg;
+      break;
   }
 
   // Check to see if we used the Objective-C modifier flags with
   // a conversion specifier other than '@'.
   if (k != ConversionSpecifier::ObjCObjArg &&
       k != ConversionSpecifier::InvalidSpecifier &&
       ObjCModifierFlagsStart) {
     H.HandleObjCFlagsWithNonObjCConversion(ObjCModifierFlagsStart,
bool PrintfSpecifier::hasValidPrecision() const {
   case ConversionSpecifier::fArg:
   case ConversionSpecifier::FArg:
   case ConversionSpecifier::gArg:
   case ConversionSpecifier::GArg:
   case ConversionSpecifier::sArg:
   case ConversionSpecifier::FreeBSDrArg:
   case ConversionSpecifier::FreeBSDyArg:
   case ConversionSpecifier::PArg:
+  case ConversionSpecifier::VArg:
     return true;
 
   default:
     return false;
   }
 }
 bool PrintfSpecifier::hasValidFieldWidth() const {
   if (FieldWidth.getHowSpecified() == OptionalAmount::NotSpecified)

test/Sema/format-strings.c

void test_unused_system_args(int x) {
   PRINT1("%d\n", x); // no-warning{{extra argument is system header is OK}}
 }
 
 void pr12761(char c) {
   // This should not warn even with -fno-signed-char.
   printf("%hhx", c);
 }
 
+void test_opencl_vector_format(int x) {
+  printf("%v4d", x); // expected-warning{{invalid conversion specifier 'v'}}
+  printf("%vd", x); // expected-warning{{invalid conversion specifier 'v'}}
+  printf("%0vd", x); // expected-warning{{invalid conversion specifier 'v'}}
+}
 
 // Test that we correctly merge the format in both orders.
 extern void test14_foo(const char *, const char *, ...)
      __attribute__((__format__(__printf__, 1, 3)));
 extern void test14_foo(const char *, const char *, ...)
      __attribute__((__format__(__scanf__, 2, 3)));
 
 extern void test14_bar(const char *, const char *, ...)

test/SemaOpenCL/printf-format-strings.cl

+// RUN: %clang_cc1 -cl-std=CL1.2 -fsyntax-only -verify %s
+
+typedef __attribute__((ext_vector_type(2))) float float2;
+typedef __attribute__((ext_vector_type(4))) float float4;
+typedef __attribute__((ext_vector_type(4))) int int4;
+
+int printf(__constant const char* st, ...) __attribute__((format(printf, 1, 2)));
+
+kernel void format_v4f32(float4 arg)
+{
+    printf("%v4f\n", arg); // expected-no-diagnostics
+}
+
+kernel void format_v4f32_wrong_num_elts(float2 arg)
+{
+    printf("%v4f\n", arg); // expected-no-diagnostics
+}
+
+kernel void vector_precision_modifier_v4f32(float4 arg)
+{
+    printf("%.2v4f\n", arg); // expected-no-diagnostics
+}
+
+// FIXME: This should warn
+kernel void format_missing_num_elts(float4 arg)
+{
+    printf("%vf\n", arg); // expected-no-diagnostics
+}
+
+// FIXME: This should warn
+kernel void vector_precision_modifier_v4i32(int4 arg)
+{
+    printf("%.2v4f\n", arg); // expected-no-diagnostics
+}