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YexuanXiaoYexuanXiao
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Relax the checks on the 'z' and 't' format specifiers and avoid meaningless repetition (size_t aka __size_t)
1 parent 60a2794 commit 27c5862

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5 files changed

+46
-56
lines changed

5 files changed

+46
-56
lines changed

‎clang/lib/AST/FormatString.cpp‎

Lines changed: 14 additions & 36 deletions
Original file line numberDiff line numberDiff line change
@@ -363,41 +363,25 @@ static bool namedTypeToLengthModifierKind(ASTContext &Ctx, QualType QT,
363363
return false;
364364
}
365365

366-
// Check whether T and E are compatible size_t/ptrdiff_t typedefs. E must be
366+
// Check whether T and E are compatible size_t/ptrdiff_t types. E must be
367367
// consistent with LE.
368368
// T is the type of the actual expression in the code to be checked, and E is
369369
// the expected type parsed from the format string.
370370
static clang::analyze_format_string::ArgType::MatchKind
371-
matchesSizeTPtrdiffT(ASTContext &C, QualType T, QualType E,
372-
LengthModifier::Kind LE) {
373-
using Kind = LengthModifier::Kind;
371+
matchesSizeTPtrdiffT(ASTContext &C, QualType T, QualType E) {
374372
using MatchKind = clang::analyze_format_string::ArgType::MatchKind;
375-
assert(LE == Kind::AsPtrDiff || LE == Kind::AsSizeT);
376373

377374
if (!T->isIntegerType())
378375
return MatchKind::NoMatch;
379376

377+
if (C.hasSameType(T, E))
378+
return MatchKind::Match;
379+
380380
if (C.getCorrespondingSignedType(T.getCanonicalType()) !=
381381
C.getCorrespondingSignedType(E.getCanonicalType()))
382382
return MatchKind::NoMatch;
383383

384-
// signed size_t and unsigned ptrdiff_t does not have typedefs in C and C++.
385-
if (LE == Kind::AsSizeT && E->isSignedIntegerType())
386-
return T->isSignedIntegerType() ? MatchKind::Match
387-
: MatchKind::NoMatchSignedness;
388-
389-
if (LE == LengthModifier::Kind::AsPtrDiff && E->isUnsignedIntegerType())
390-
return T->isUnsignedIntegerType() ? MatchKind::Match
391-
: MatchKind::NoMatchSignedness;
392-
393-
if (Kind Actual = Kind::None; namedTypeToLengthModifierKind(C, T, Actual)) {
394-
if (Actual == LE)
395-
return MatchKind::Match;
396-
else if (Actual == Kind::AsPtrDiff || Actual == Kind::AsSizeT)
397-
return MatchKind::NoMatchSignedness;
398-
}
399-
400-
return MatchKind::NoMatch;
384+
return MatchKind::NoMatchSignedness;
401385
}
402386

403387
clang::analyze_format_string::ArgType::MatchKind
@@ -475,10 +459,7 @@ ArgType::matchesType(ASTContext &C, QualType argTy) const {
475459

476460
case SpecificTy: {
477461
if (TK != TypeKind::DontCare) {
478-
return matchesSizeTPtrdiffT(C, argTy, T,
479-
TK == TypeKind::SizeT
480-
? LengthModifier::Kind::AsSizeT
481-
: LengthModifier::AsPtrDiff);
462+
return matchesSizeTPtrdiffT(C, argTy, T);
482463
}
483464

484465
if (const EnumType *ETy = argTy->getAs<EnumType>()) {
@@ -741,15 +722,9 @@ ArgType::matchesArgType(ASTContext &C, const ArgType &Other) const {
741722
if (Left.K == AK::SpecificTy) {
742723
if (Right.K == AK::SpecificTy) {
743724
if (Left.TK != TypeKind::DontCare) {
744-
return matchesSizeTPtrdiffT(C, Right.T, Left.T,
745-
Left.TK == TypeKind::SizeT
746-
? LengthModifier::Kind::AsSizeT
747-
: LengthModifier::AsPtrDiff);
725+
return matchesSizeTPtrdiffT(C, Right.T, Left.T);
748726
} else if (Right.TK != TypeKind::DontCare) {
749-
return matchesSizeTPtrdiffT(C, Left.T, Right.T,
750-
Right.TK == TypeKind::SizeT
751-
? LengthModifier::Kind::AsSizeT
752-
: LengthModifier::AsPtrDiff);
727+
return matchesSizeTPtrdiffT(C, Left.T, Right.T);
753728
}
754729

755730
auto Canon1 = C.getCanonicalType(Left.T);
@@ -805,7 +780,11 @@ QualType ArgType::getRepresentativeType(ASTContext &C) const {
805780
Res = C.CharTy;
806781
break;
807782
case SpecificTy:
808-
Res = T;
783+
if (TK == TypeKind::PtrdiffT || TK == TypeKind::SizeT)
784+
// Using Name as name, so no need to show the uglified name.
785+
Res = T->getCanonicalTypeInternal();
786+
else
787+
Res = T;
809788
break;
810789
case CStrTy:
811790
Res = C.getPointerType(C.CharTy);
@@ -832,7 +811,6 @@ QualType ArgType::getRepresentativeType(ASTContext &C) const {
832811

833812
std::string ArgType::getRepresentativeTypeName(ASTContext &C) const {
834813
std::string S = getRepresentativeType(C).getAsString(C.getPrintingPolicy());
835-
836814
std::string Alias;
837815
if (Name) {
838816
// Use a specific name for this type, e.g. "size_t".

‎clang/test/Sema/format-strings-int-typedefs.c‎

Lines changed: 6 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -6,17 +6,17 @@ int scanf(char const *, ...);
66
void test(void) {
77
printf("%jd", 42.0); // expected-warning {{format specifies type 'intmax_t' (aka 'long long')}}
88
printf("%ju", 42.0); // expected-warning {{format specifies type 'uintmax_t' (aka 'unsigned long long')}}
9-
printf("%zu", 42.0); // expected-warning {{format specifies type 'size_t' (aka '__size_t')}}
10-
printf("%td", 42.0); // expected-warning {{format specifies type 'ptrdiff_t' (aka '__ptrdiff_t')}}
9+
printf("%zu", 42.0); // expected-warning {{format specifies type 'size_t' (aka 'unsigned long')}}
10+
printf("%td", 42.0); // expected-warning {{format specifies type 'ptrdiff_t' (aka 'int')}}
1111
printf("%lc", 42.0); // expected-warning {{format specifies type 'wint_t' (aka 'int')}}
1212
printf("%ls", 42.0); // expected-warning {{format specifies type 'wchar_t *' (aka 'int *')}}
1313
printf("%S", 42.0); // expected-warning {{format specifies type 'wchar_t *' (aka 'int *')}}
1414
printf("%C", 42.0); // expected-warning {{format specifies type 'wchar_t' (aka 'int')}}
1515

1616
scanf("%jd", 0); // expected-warning {{format specifies type 'intmax_t *' (aka 'long long *')}}
1717
scanf("%ju", 0); // expected-warning {{format specifies type 'uintmax_t *' (aka 'unsigned long long *')}}
18-
scanf("%zu", 0); // expected-warning {{format specifies type 'size_t *' (aka '__size_t *')}}
19-
scanf("%td", 0); // expected-warning {{format specifies type 'ptrdiff_t *' (aka '__ptrdiff_t *')}}
18+
scanf("%zu", 0); // expected-warning {{format specifies type 'size_t *' (aka 'unsigned long *')}}
19+
scanf("%td", 0); // expected-warning {{format specifies type 'ptrdiff_t *' (aka 'int *')}}
2020
scanf("%lc", 0); // expected-warning {{format specifies type 'wchar_t *' (aka 'int *')}}
2121
scanf("%ls", 0); // expected-warning {{format specifies type 'wchar_t *' (aka 'int *')}}
2222
scanf("%S", 0); // expected-warning {{format specifies type 'wchar_t *' (aka 'int *')}}
@@ -32,6 +32,6 @@ void test(void) {
3232
// The warning still fires, because it checks the underlying type.
3333
printf("%jd", (intmax_t)42); // expected-warning {{format specifies type 'intmax_t' (aka 'long long') but the argument has type 'intmax_t' (aka 'void *')}}
3434
printf("%ju", (uintmax_t)42); // expected-warning {{format specifies type 'uintmax_t' (aka 'unsigned long long') but the argument has type 'uintmax_t' (aka 'void *')}}
35-
printf("%zu", (size_t)42); // expected-warning {{format specifies type 'size_t' (aka '__size_t') but the argument has type 'size_t' (aka 'void *')}}
36-
printf("%td", (ptrdiff_t)42); // expected-warning {{format specifies type 'ptrdiff_t' (aka '__ptrdiff_t') but the argument has type 'ptrdiff_t' (aka 'void *')}}
35+
printf("%zu", (size_t)42); // expected-warning {{format specifies type 'size_t' (aka 'unsigned long') but the argument has type 'size_t' (aka 'void *')}}
36+
printf("%td", (ptrdiff_t)42); // expected-warning {{format specifies type 'ptrdiff_t' (aka 'int') but the argument has type 'ptrdiff_t' (aka 'void *')}}
3737
}

‎clang/test/Sema/format-strings-scanf.c‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -231,13 +231,13 @@ void test_ptrdiff_t_types(void) {
231231
scanf("%td", &p2); // No warning.
232232

233233
double d2 = 0.;
234-
scanf("%td", &d2); // expected-warning{{format specifies type 'ptrdiff_t *' (aka '__ptrdiff_t *') but the argument has type 'double *'}}
234+
scanf("%td", &d2); // expected-warning{{format specifies type 'ptrdiff_t *' (aka 'long *') but the argument has type 'double *'}}
235235

236236
ptrdiff_t p3 = 0;
237237
scanf("%tn", &p3); // No warning.
238238

239239
double d3 = 0.;
240-
scanf("%tn", &d3); // expected-warning{{format specifies type 'ptrdiff_t *' (aka '__ptrdiff_t *') but the argument has type 'double *'}}
240+
scanf("%tn", &d3); // expected-warning{{format specifies type 'ptrdiff_t *' (aka 'long *') but the argument has type 'double *'}}
241241
}
242242

243243
void check_conditional_literal(char *s, int *i) {

‎clang/test/Sema/format-strings-size_t.c‎

Lines changed: 12 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -2,26 +2,31 @@
22

33
int printf(char const *, ...);
44

5+
#include <stddef.h>
6+
57
void test(void) {
68
// size_t
7-
printf("%zu", (double)42); // expected-warning {{format specifies type 'size_t' (aka '__size_t') but the argument has type 'double'}}
8-
9+
printf("%zu", (size_t)0); // no-warning
10+
printf("%zu", sizeof(int)); // no-warning
11+
printf("%zu", (size_t)0 + sizeof(int)); // no-warning
12+
printf("%zu", (double)42); // expected-warning {{format specifies type 'size_t' (aka 'unsigned long') but the argument has type 'double'}}
913
// intmax_t / uintmax_t
1014
printf("%jd", (double)42); // expected-warning {{format specifies type 'intmax_t' (aka 'long') but the argument has type 'double'}}
1115
printf("%ju", (double)42); // expected-warning {{format specifies type 'uintmax_t' (aka 'unsigned long') but the argument has type 'double'}}
1216

1317
// ptrdiff_t
14-
printf("%td", (double)42); // expected-warning {{format specifies type 'ptrdiff_t' (aka '__ptrdiff_t') but the argument has type 'double'}}
18+
printf("%td", (double)42); // expected-warning {{format specifies type 'ptrdiff_t' (aka 'long') but the argument has type 'double'}}
1519
}
1620

1721
void test_writeback(void) {
1822
printf("%jn", (long*)0); // no-warning
1923
printf("%jn", (unsigned long*)0); // no-warning
2024
printf("%jn", (int*)0); // expected-warning{{format specifies type 'intmax_t *' (aka 'long *') but the argument has type 'int *'}}
2125

22-
printf("%zn", (int*)0); // expected-warning{{format specifies type 'signed size_t *' (aka '__signed_size_t *') but the argument has type 'int *'}}
26+
printf("%zn", (long*)0); // no-warning
27+
// FIXME: Warn about %zn with non-ssize_t argument.
2328

24-
printf("%tn", (long*)0); // expected-warning{{format specifies type 'ptrdiff_t *' (aka '__ptrdiff_t *') but the argument has type 'long *'}}
25-
printf("%tn", (unsigned long*)0); // expected-warning{{format specifies type 'ptrdiff_t *' (aka '__ptrdiff_t *') but the argument has type 'unsigned long *'}}
26-
printf("%tn", (int*)0); // expected-warning{{format specifies type 'ptrdiff_t *' (aka '__ptrdiff_t *') but the argument has type 'int *'}}
29+
printf("%tn", (long*)0); // no-warning
30+
printf("%tn", (unsigned long*)0); // no-warning
31+
printf("%tn", (int*)0); // expected-warning{{format specifies type 'ptrdiff_t *' (aka 'long *') but the argument has type 'int *'}}
2732
}

‎clang/test/SemaObjC/format-size-spec-nsinteger.m‎

Lines changed: 12 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -3,6 +3,10 @@
33
// RUN: %clang_cc1 -triple thumbv7k-apple-watchos2.0.0 -fsyntax-only -fblocks -verify %s
44
// RUN: %clang_cc1 -triple thumbv7k-apple-watchos2.0.0 -fsyntax-only -fblocks -verify -Wformat-pedantic -DPEDANTIC %s
55

6+
#if !defined(PEDANTIC)
7+
// expected-no-diagnostics
8+
#endif
9+
610
#if __LP64__
711
typedef unsigned long NSUInteger;
812
typedef long NSInteger;
@@ -26,20 +30,23 @@ void testSizeSpecifier(void) {
2630
NSInteger i = 0;
2731
NSUInteger j = 0;
2832
NSLog(@"max NSInteger = %zi", i);
33+
NSLog(@"max NSUinteger = %zu", j);
34+
2935
#if defined(PEDANTIC)
30-
// expected-warning@-2 {{values of type 'NSInteger' should not be used as format arguments; add an explicit cast to 'long' instead}}
36+
// expected-warning@-4 {{values of type 'NSInteger' should not be used as format arguments; add an explicit cast to 'long' instead}}
37+
// expected-warning@-4 {{values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead}}
3138
#endif
32-
NSLog(@"max NSUinteger = %zu", j); // expected-warning {{values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead}}
3339
}
3440

3541
void testPtrdiffSpecifier(ptrdiff_t x) {
3642
NSInteger i = 0;
3743
NSUInteger j = 0;
3844

3945
NSLog(@"ptrdiff_t NSUinteger: %tu", j);
46+
NSLog(@"ptrdiff_t NSInteger: %td", i);
47+
NSLog(@"ptrdiff_t %tu, %td", x, x);
4048
#if __is_target_os(watchos) && defined(PEDANTIC)
41-
// expected-warning@-2 {{values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead}}
49+
// expected-warning@-4 {{values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead}}
50+
// expected-warning@-4 {{values of type 'NSInteger' should not be used as format arguments; add an explicit cast to 'long' instead}}
4251
#endif
43-
NSLog(@"ptrdiff_t NSInteger: %td", i); // expected-warning {{values of type 'NSInteger' should not be used as format arguments; add an explicit cast to 'long' instead}}
44-
NSLog(@"ptrdiff_t %tu, %td", x, x); // no-warning
4552
}

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