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Format strings: correct signedness if already correcting width (%d,%u). 

It is valid to do this:
  printf("%u", (int)x);

But if we see this:
  printf("%lu", (int)x);

...our fixit should suggest %d, not %u.

llvm-svn: 172739
This commit is contained in:
Jordan Rose 2013-01-17 18:47:16 +00:00
parent b169ccc118
commit aa7a3b3e75
3 changed files with 48 additions and 1 deletions
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20
clang/lib/Analysis/PrintfFormatString.cpp
View File

@ -499,8 +499,26 @@ bool PrintfSpecifier::fixType(QualType QT, const LangOptions &LangOpt,
if (isa<TypedefType>(QT) && (LangOpt.C99 || LangOpt.CPlusPlus11))
namedTypeToLengthModifier(QT, LM);
// If fixing the length modifier was enough, we are done.
// If fixing the length modifier was enough, we might be done.
if (hasValidLengthModifier(Ctx.getTargetInfo())) {
// If we're going to offer a fix anyway, make sure the sign matches.
switch (CS.getKind()) {
case ConversionSpecifier::uArg:
case ConversionSpecifier::UArg:
if (QT->isSignedIntegerType())
CS.setKind(clang::analyze_format_string::ConversionSpecifier::dArg);
break;
case ConversionSpecifier::dArg:
case ConversionSpecifier::DArg:
case ConversionSpecifier::iArg:
if (QT->isUnsignedIntegerType())
CS.setKind(clang::analyze_format_string::ConversionSpecifier::uArg);
break;
default:
// Other specifiers do not have signed/unsigned variants.
break;
}
const analyze_printf::ArgType &ATR = getArgType(Ctx, IsObjCLiteral);
if (ATR.isValid() && ATR.matchesType(Ctx, QT))
return true;

18
clang/test/FixIt/format-darwin.m
View File

@ -118,6 +118,16 @@ void testPreserveHex() {
// CHECK-64: fix-it:"{{.*}}":{[[@LINE-6]]:16-[[@LINE-6]]:16}:"(unsigned long)"
}
void testSignedness(NSInteger i, NSUInteger u) {
printf("%d", u); // expected-warning{{values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead}}
printf("%i", u); // expected-warning{{values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead}}
printf("%u", i); // expected-warning{{values of type 'NSInteger' should not be used as format arguments; add an explicit cast to 'long' instead}}
// CHECK-64: fix-it:"{{.*}}":{[[@LINE-4]]:11-[[@LINE-4]]:13}:"%lu"
// CHECK-64: fix-it:"{{.*}}":{[[@LINE-4]]:11-[[@LINE-4]]:13}:"%lu"
// CHECK-64: fix-it:"{{.*}}":{[[@LINE-4]]:11-[[@LINE-4]]:13}:"%ld"
}
void testNoWarn() {
printf("%ld", getNSInteger()); // no-warning
printf("%lu", getNSUInteger()); // no-warning
@ -154,6 +164,14 @@ void testNoWarn() {
printf("%lu", getUInt32()); // no-warning
}
void testSignedness(NSInteger i, NSUInteger u) {
// It is valid to use a specifier with the opposite signedness as long as
// the type is correct.
printf("%d", u); // no-warning
printf("%i", u); // no-warning
printf("%u", i); // no-warning
}
#endif

11
clang/test/FixIt/format.m
View File

@ -213,3 +213,14 @@ void test_percent_C() {
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:11-[[@LINE-1]]:13}:"%c"
// CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-2]]:16-[[@LINE-2]]:22}:"(unichar)"
}
void testSignedness(long i, unsigned long u) {
printf("%d", u); // expected-warning{{format specifies type 'int' but the argument has type 'unsigned long'}}
printf("%i", u); // expected-warning{{format specifies type 'int' but the argument has type 'unsigned long'}}
printf("%u", i); // expected-warning{{format specifies type 'unsigned int' but the argument has type 'long'}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:11-[[@LINE-4]]:13}:"%lu"
// CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:11-[[@LINE-4]]:13}:"%lu"
// CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:11-[[@LINE-4]]:13}:"%ld"
}