r336396 - [Sema] -Wformat-pedantic only for NSInteger/NSUInteger %tu/%td on Darwin
Alex Lorenz via cfe-commits
cfe-commits at lists.llvm.org
Thu Jul 5 15:51:11 PDT 2018
Author: arphaman
Date: Thu Jul 5 15:51:11 2018
New Revision: 336396
URL: http://llvm.org/viewvc/llvm-project?rev=336396&view=rev
Log:
[Sema] -Wformat-pedantic only for NSInteger/NSUInteger %tu/%td on Darwin
The '%tu'/'%td' as formatting specifiers have been used to print out the
NSInteger/NSUInteger values for a long time. Typically their ABI matches, but that's
not the case on watchOS. The ABI difference boils down to the following:
- Regular 32-bit darwin targets (like armv7) use 'ptrdiff_t' of type 'int',
which matches 'NSInteger'.
- WatchOS arm target (armv7k) uses 'ptrdiff_t' of type 'long', which doesn't
match 'NSInteger' of type 'int'.
Because of this ABI difference 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),
and alignof(ptrdiff_t) == alignof(NS[U]Integer) so the warning is therefore noisy
for pedantic reasons.
I'll update public documentation to ensure that this behaviour is properly
communicated.
rdar://41739204
Differential Revision: https://reviews.llvm.org/D48852
Modified:
cfe/trunk/include/clang/Analysis/Analyses/FormatString.h
cfe/trunk/lib/Analysis/PrintfFormatString.cpp
cfe/trunk/lib/Sema/SemaChecking.cpp
cfe/trunk/test/SemaObjC/format-size-spec-nsinteger.m
Modified: cfe/trunk/include/clang/Analysis/Analyses/FormatString.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/Analyses/FormatString.h?rev=336396&r1=336395&r2=336396&view=diff
==============================================================================
--- cfe/trunk/include/clang/Analysis/Analyses/FormatString.h (original)
+++ cfe/trunk/include/clang/Analysis/Analyses/FormatString.h Thu Jul 5 15:51:11 2018
@@ -257,7 +257,12 @@ private:
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 { DontCare, SizeT, PtrdiffT };
+ TypeKind TK = TypeKind::DontCare;
public:
ArgType(Kind K = UnknownTy, const char *N = nullptr) : K(K), Name(N) {}
@@ -267,7 +272,9 @@ public:
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 @@ public:
/// 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;
}
Modified: cfe/trunk/lib/Analysis/PrintfFormatString.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/PrintfFormatString.cpp?rev=336396&r1=336395&r2=336396&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/PrintfFormatString.cpp (original)
+++ cfe/trunk/lib/Analysis/PrintfFormatString.cpp Thu Jul 5 15:51:11 2018
@@ -472,7 +472,8 @@ ArgType PrintfSpecifier::getArgType(ASTC
? 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 PrintfSpecifier::getArgType(ASTC
? 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:
Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=336396&r1=336395&r2=336396&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
+++ cfe/trunk/lib/Sema/SemaChecking.cpp Thu Jul 5 15:51:11 2018
@@ -6894,10 +6894,11 @@ CheckPrintfHandler::checkFormatExpr(cons
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;
Modified: cfe/trunk/test/SemaObjC/format-size-spec-nsinteger.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/format-size-spec-nsinteger.m?rev=336396&r1=336395&r2=336396&view=diff
==============================================================================
--- cfe/trunk/test/SemaObjC/format-size-spec-nsinteger.m (original)
+++ cfe/trunk/test/SemaObjC/format-size-spec-nsinteger.m Thu Jul 5 15:51:11 2018
@@ -1,5 +1,7 @@
// 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
@@ -8,9 +10,16 @@
#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 @@ void testSizeSpecifier() {
// expected-warning at -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 at -4 {{values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead}}
+ // expected-warning at -4 {{values of type 'NSInteger' should not be used as format arguments; add an explicit cast to 'long' instead}}
+#endif
+}
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