arphaman created this revision.
arphaman added a reviewer: jfb.
Herald added a subscriber: dexonsmith.
The '%tu'/'%td' as formatting specifiers have been used to print out the
NSInteger/NSUInteger values for a long time. Typically their ABI matches (i.e.
ptrdiff_t = NSInteger), but that's not the case on watchOS (ptrdiff_t = long,
NSInteger = int). These specifiers trigger -Wformat warnings only for watchOS
builds, which is really inconvenient for cross-platform code.
This patch avoids this `-Wformat` warning for '%tu'/'%td' and NS[U]Integer
only, and instead uses the new `-Wformat-pedantic` warning that JF introduced
in https://reviews.llvm.org/D47290. This is acceptable because Darwin
guarantees that, despite the watchOS ABI differences, sizeof(ptrdiff_t) ==
sizeof(NS[U]Integer), so the warning is therefore noisy for pedantic reasons.
Once this is in I'll update public documentation.
rdar://41739204
Repository:
rC Clang
https://reviews.llvm.org/D48852
Files:
include/clang/Analysis/Analyses/FormatString.h
lib/Analysis/PrintfFormatString.cpp
lib/Sema/SemaChecking.cpp
test/SemaObjC/format-size-spec-nsinteger.m
Index: test/SemaObjC/format-size-spec-nsinteger.m
===================================================================
--- test/SemaObjC/format-size-spec-nsinteger.m
+++ test/SemaObjC/format-size-spec-nsinteger.m
@@ -1,16 +1,25 @@
// RUN: %clang_cc1 -triple thumbv7-apple-ios -Wno-objc-root-class -fsyntax-only -verify -Wformat %s
// RUN: %clang_cc1 -triple thumbv7-apple-ios -Wno-objc-root-class -fsyntax-only -verify -Wformat-pedantic -DPEDANTIC %s
+// RUN: %clang_cc1 -triple thumbv7k-apple-watchos2.0.0 -fsyntax-only -fblocks -verify %s
+// RUN: %clang_cc1 -triple thumbv7k-apple-watchos2.0.0 -fsyntax-only -fblocks -verify -Wformat-pedantic -DPEDANTIC %s
#if !defined(PEDANTIC)
// expected-no-diagnostics
#endif
#if __LP64__
typedef unsigned long NSUInteger;
typedef long NSInteger;
+typedef long ptrdiff_t;
#else
typedef unsigned int NSUInteger;
typedef int NSInteger;
+#if __is_target_os(watchos)
+ // Watch ABI uses long for ptrdiff_t.
+ typedef long ptrdiff_t;
+#else
+ typedef int ptrdiff_t;
+#endif
#endif
@class NSString;
@@ -28,3 +37,16 @@
// expected-warning@-4 {{values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead}}
#endif
}
+
+void testPtrdiffSpecifier(ptrdiff_t x) {
+ NSInteger i = 0;
+ NSUInteger j = 0;
+
+ NSLog(@"ptrdiff_t NSUinteger: %tu", j);
+ NSLog(@"ptrdiff_t NSInteger: %td", i);
+ NSLog(@"ptrdiff_t %tu, %td", x, x);
+#if __is_target_os(watchos) && defined(PEDANTIC)
+ // expected-warning@-4 {{values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead}}
+ // expected-warning@-4 {{values of type 'NSInteger' should not be used as format arguments; add an explicit cast to 'long' instead}}
+#endif
+}
Index: lib/Sema/SemaChecking.cpp
===================================================================
--- lib/Sema/SemaChecking.cpp
+++ lib/Sema/SemaChecking.cpp
@@ -6885,10 +6885,11 @@
QualType CastTy;
std::tie(CastTy, CastTyName) = shouldNotPrintDirectly(S.Context, IntendedTy, E);
if (!CastTy.isNull()) {
- // %zi/%zu are OK to use for NSInteger/NSUInteger of type int
+ // %zi/%zu and %td/%tu are OK to use for NSInteger/NSUInteger of type int
// (long in ASTContext). Only complain to pedants.
if ((CastTyName == "NSInteger" || CastTyName == "NSUInteger") &&
- AT.isSizeT() && AT.matchesType(S.Context, CastTy))
+ (AT.isSizeT() || AT.isPtrdiffT()) &&
+ AT.matchesType(S.Context, CastTy))
Pedantic = true;
IntendedTy = CastTy;
ShouldNotPrintDirectly = true;
Index: lib/Analysis/PrintfFormatString.cpp
===================================================================
--- lib/Analysis/PrintfFormatString.cpp
+++ lib/Analysis/PrintfFormatString.cpp
@@ -472,7 +472,8 @@
? ArgType(Ctx.LongLongTy, "__int64")
: ArgType(Ctx.IntTy, "__int32");
case LengthModifier::AsPtrDiff:
- return ArgType(Ctx.getPointerDiffType(), "ptrdiff_t");
+ return ArgType::makePtrdiffT(
+ ArgType(Ctx.getPointerDiffType(), "ptrdiff_t"));
case LengthModifier::AsAllocate:
case LengthModifier::AsMAllocate:
case LengthModifier::AsWide:
@@ -505,7 +506,8 @@
? ArgType(Ctx.UnsignedLongLongTy, "unsigned __int64")
: ArgType(Ctx.UnsignedIntTy, "unsigned __int32");
case LengthModifier::AsPtrDiff:
- return ArgType(Ctx.getUnsignedPointerDiffType(), "unsigned ptrdiff_t");
+ return ArgType::makePtrdiffT(
+ ArgType(Ctx.getUnsignedPointerDiffType(), "unsigned ptrdiff_t"));
case LengthModifier::AsAllocate:
case LengthModifier::AsMAllocate:
case LengthModifier::AsWide:
Index: include/clang/Analysis/Analyses/FormatString.h
===================================================================
--- include/clang/Analysis/Analyses/FormatString.h
+++ include/clang/Analysis/Analyses/FormatString.h
@@ -257,7 +257,12 @@
const Kind K;
QualType T;
const char *Name = nullptr;
- bool Ptr = false, IsSizeT = false;
+ bool Ptr = false;
+
+ /// The TypeKind identifies certain well-known types like size_t and
+ /// ptrdiff_t.
+ enum class TypeKind { Unspecified, SizeT, PtrdiffT };
+ TypeKind TK = TypeKind::Unspecified;
public:
ArgType(Kind K = UnknownTy, const char *N = nullptr) : K(K), Name(N) {}
@@ -267,7 +272,9 @@
static ArgType Invalid() { return ArgType(InvalidTy); }
bool isValid() const { return K != InvalidTy; }
- bool isSizeT() const { return IsSizeT; }
+ bool isSizeT() const { return TK == TypeKind::SizeT; }
+
+ bool isPtrdiffT() const { return TK == TypeKind::PtrdiffT; }
/// Create an ArgType which corresponds to the type pointer to A.
static ArgType PtrTo(const ArgType& A) {
@@ -280,7 +287,15 @@
/// Create an ArgType which corresponds to the size_t/ssize_t type.
static ArgType makeSizeT(const ArgType &A) {
ArgType Res = A;
- Res.IsSizeT = true;
+ Res.TK = TypeKind::SizeT;
+ return Res;
+ }
+
+ /// Create an ArgType which corresponds to the ptrdiff_t/unsigned ptrdiff_t
+ /// type.
+ static ArgType makePtrdiffT(const ArgType &A) {
+ ArgType Res = A;
+ Res.TK = TypeKind::PtrdiffT;
return Res;
}
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