JonasToth updated this revision to Diff 168091.
JonasToth marked 2 inline comments as done.
JonasToth added a comment.
- remove spurious local variable
Repository:
rCTE Clang Tools Extra
https://reviews.llvm.org/D51949
Files:
clang-tidy/readability/CMakeLists.txt
clang-tidy/readability/IsolateDeclarationCheck.cpp
clang-tidy/readability/IsolateDeclarationCheck.h
clang-tidy/readability/ReadabilityTidyModule.cpp
clang-tidy/utils/LexerUtils.cpp
clang-tidy/utils/LexerUtils.h
docs/ReleaseNotes.rst
docs/clang-tidy/checks/list.rst
docs/clang-tidy/checks/readability-isolate-declaration.rst
test/clang-tidy/readability-isolate-declaration-cxx17.cpp
test/clang-tidy/readability-isolate-declaration-fixing.cpp
test/clang-tidy/readability-isolate-declaration.c
test/clang-tidy/readability-isolate-declaration.cpp
Index: test/clang-tidy/readability-isolate-declaration.cpp
===================================================================
--- /dev/null
+++ test/clang-tidy/readability-isolate-declaration.cpp
@@ -0,0 +1,412 @@
+// RUN: %check_clang_tidy %s readability-isolate-declaration %t
+
+void f() {
+ int i;
+}
+
+void f2() {
+ int i, j, *k, lala = 42;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int i;
+ // CHECK-FIXES: {{^ }}int j;
+ // CHECK-FIXES: {{^ }}int *k;
+ // CHECK-FIXES: {{^ }}int lala = 42;
+
+ int normal, weird = /* comment */ 42;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int normal;
+ // CHECK-FIXES: {{^ }}int weird = /* comment */ 42;
+
+ int /* here is a comment */ v1,
+ // another comment
+ v2 = 42 // Ok, more comments
+ ;
+ // CHECK-MESSAGES: [[@LINE-4]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int /* here is a comment */ v1;
+ // CHECK-FIXES: {{^ }}int /* here is a comment */ // another comment
+ // CHECK-FIXES: {{^ }}v2 = 42 // Ok, more comments
+ // CHECK-FIXES: {{^ }};
+
+ auto int1 = 42, int2 = 0, int3 = 43;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: auto int1 = 42;
+ // CHECK-FIXES: {{^ }}auto int2 = 0;
+ // CHECK-FIXES: {{^ }}auto int3 = 43;
+
+ decltype(auto) ptr1 = &int1, ptr2 = &int1;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: decltype(auto) ptr1 = &int1;
+ // CHECK-FIXES: {{^ }}decltype(auto) ptr2 = &int1;
+
+ decltype(k) ptr3 = &int1, ptr4 = &int1;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: decltype(k) ptr3 = &int1;
+ // CHECK-FIXES: {{^ }}decltype(k) ptr4 = &int1;
+}
+
+void f3() {
+ int i, *pointer1;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int i;
+ // CHECK-FIXES: {{^ }}int *pointer1;
+ //
+ int *pointer2 = nullptr, *pointer3 = &i;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int *pointer2 = nullptr;
+ // CHECK-FIXES: {{^ }}int *pointer3 = &i;
+
+ int *(i_ptr) = nullptr, *((i_ptr2));
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int *(i_ptr) = nullptr;
+ // CHECK-FIXES: {{^ }}int *((i_ptr2));
+
+ float(*f_ptr)[42], (((f_value))) = 42;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: float (*f_ptr)[42];
+ // CHECK-FIXES: {{^ }}float (((f_value))) = 42;
+
+ float(((*f_ptr2)))[42], ((*f_ptr3)), f_value2 = 42.f;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: float (((*f_ptr2)))[42];
+ // CHECK-FIXES: {{^ }}float ((*f_ptr3));
+ // CHECK-FIXES: {{^ }}float f_value2 = 42.f;
+
+ float(((*f_ptr4)))[42], *f_ptr5, ((f_value3));
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: float (((*f_ptr4)))[42];
+ // CHECK-FIXES: {{^ }}float *f_ptr5;
+ // CHECK-FIXES: {{^ }}float ((f_value3));
+
+ void(((*f2))(int)), (*g2)(int, float);
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: void (((*f2))(int));
+ // CHECK-FIXES: {{^ }}void (*g2)(int, float);
+
+ float(*(*(*f_ptr6)))[42], (*f_ptr7);
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: float (*(*(*f_ptr6)))[42];
+ // CHECK-FIXES: {{^ }}float (*f_ptr7);
+}
+
+void f4() {
+ double d = 42. /* foo */, z = 43., /* hi */ y, c /* */ /* */, l = 2.;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: double d = 42. /* foo */;
+ // CHECK-FIXES: {{^ }}double z = 43.;
+ // CHECK-FIXES: {{^ }}double /* hi */ y;
+ // CHECK-FIXES: {{^ }}double c /* */ /* */;
+ // CHECK-FIXES: {{^ }}double l = 2.;
+}
+
+struct SomeClass {
+ SomeClass() = default;
+ SomeClass(int value);
+};
+
+class Point {
+ double x;
+ double y;
+
+public:
+ Point(double x, double y) : x(x), y(y) {}
+};
+
+class Rectangle {
+ Point TopLeft;
+ Point BottomRight;
+
+public:
+ Rectangle(Point TopLeft, Point BottomRight) : TopLeft(TopLeft), BottomRight(BottomRight) {}
+};
+
+void f5() {
+ SomeClass v1, v2(42), v3{42}, v4(42.5);
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: SomeClass v1;
+ // CHECK-FIXES: {{^ }}SomeClass v2(42);
+ // CHECK-FIXES: {{^ }}SomeClass v3{42};
+ // CHECK-FIXES: {{^ }}SomeClass v4(42.5);
+
+ SomeClass v5 = 42, *p1 = nullptr;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: SomeClass v5 = 42;
+ // CHECK-FIXES: {{^ }}SomeClass *p1 = nullptr;
+
+ Point P1(0., 2.), P2{2., 0.};
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: Point P1(0., 2.);
+ // CHECK-FIXES: {{^ }}Point P2{2., 0.};
+
+ Rectangle R1({0., 0.}, {1., -2.}), R2{{0., 1.}, {1., 0.}}, R3(P1, P2), R4{P1, P2};
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: Rectangle R1({0., 0.}, {1., -2.});
+ // CHECK-FIXES: {{^ }}Rectangle R2{{[{][{]}}0., 1.}, {1., 0.{{[}][}]}};
+ // CHECK-FIXES: {{^ }}Rectangle R3(P1, P2);
+ // CHECK-FIXES: {{^ }}Rectangle R4{P1, P2};
+}
+
+void f6() {
+ int array1[] = {1, 2, 3, 4}, array2[] = {1, 2, 3}, value1, value2 = 42;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int array1[] = {1, 2, 3, 4};
+ // CHECK-FIXES: {{^ }}int array2[] = {1, 2, 3};
+ // CHECK-FIXES: {{^ }}int value1;
+ // CHECK-FIXES: {{^ }}int value2 = 42;
+}
+
+template <typename T>
+struct TemplatedType {
+ TemplatedType() = default;
+ TemplatedType(T value);
+};
+
+void f7() {
+ TemplatedType<int> TT1(42), TT2{42}, TT3;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: TemplatedType<int> TT1(42);
+ // CHECK-FIXES: {{^ }}TemplatedType<int> TT2{42};
+ // CHECK-FIXES: {{^ }}TemplatedType<int> TT3;
+ //
+ TemplatedType<int *> *TT4(nullptr), TT5, **TT6 = nullptr, *const *const TT7{nullptr};
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: TemplatedType<int *> *TT4(nullptr);
+ // CHECK-FIXES: {{^ }}TemplatedType<int *> TT5;
+ // CHECK-FIXES: {{^ }}TemplatedType<int *> **TT6 = nullptr;
+ // CHECK-FIXES: {{^ }}TemplatedType<int *> *const *const TT7{nullptr};
+
+ TemplatedType<int &> **TT8(nullptr), *TT9;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: TemplatedType<int &> **TT8(nullptr);
+ // CHECK-FIXES: {{^ }}TemplatedType<int &> *TT9;
+
+ TemplatedType<int *> TT10{nullptr}, *TT11(nullptr);
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: TemplatedType<int *> TT10{nullptr};
+ // CHECK-FIXES: {{^ }}TemplatedType<int *> *TT11(nullptr);
+}
+
+void forbidden_transformations() {
+ for (int i = 0, j = 42; i < j; ++i)
+ ;
+}
+
+#define NULL 0
+#define MY_NICE_TYPE int **
+#define VAR_NAME(name) name##__LINE__
+#define A_BUNCH_OF_VARIABLES int m1 = 42, m2 = 43, m3 = 44;
+
+void macros() {
+ int *p1 = NULL, *p2 = NULL;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int *p1 = NULL;
+ // CHECK-FIXES: {{^ }}int *p2 = NULL;
+
+ // Macros are involved, so there will be no transformation
+ MY_NICE_TYPE p3, v1, v2;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+
+ int VAR_NAME(v3),
+ VAR_NAME(v4),
+ VAR_NAME(v5);
+ // CHECK-MESSAGES: [[@LINE-3]]:3: warning: multiple declarations in a single statement reduces readability
+
+ A_BUNCH_OF_VARIABLES
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+
+ int Unconditional,
+ // Explanatory comment.
+#if CONFIGURATION
+ IfConfigured = 42,
+#else
+ IfConfigured = 0;
+#endif
+ // CHECK-MESSAGES: [[@LINE-7]]:3: warning: multiple declarations in a single statement reduces readability
+}
+
+void dontTouchParameter(int param1, int param2) {}
+
+struct StructOne {
+ StructOne() {}
+ StructOne(int b) {}
+
+ int member1, member2;
+ // TODO: Transform FieldDecl's as well
+};
+
+using PointerType = int;
+
+struct {
+ int i;
+} AS1, AS2;
+struct TemT {
+ template <typename T>
+ T *getAs() {
+ return nullptr;
+ }
+} TT1, TT2;
+
+void complex_typedefs() {
+ typedef int *IntPtr;
+ typedef int ArrayType[2];
+ typedef int FunType(void);
+
+ IntPtr intptr1, intptr2 = nullptr, intptr3;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: IntPtr intptr1;
+ // CHECK-FIXES: {{^ }}IntPtr intptr2 = nullptr;
+ // CHECK-FIXES: {{^ }}IntPtr intptr3;
+
+ IntPtr *DoublePtr1 = nullptr, **TriplePtr, SinglePtr = nullptr;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: IntPtr *DoublePtr1 = nullptr;
+ // CHECK-FIXES: {{^ }}IntPtr **TriplePtr;
+ // CHECK-FIXES: {{^ }}IntPtr SinglePtr = nullptr;
+
+ IntPtr intptr_array1[2], intptr_array2[4] = {nullptr, nullptr, nullptr, nullptr};
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: IntPtr intptr_array1[2];
+ // CHECK-FIXES: {{^ }}IntPtr intptr_array2[4] = {nullptr, nullptr, nullptr, nullptr};
+
+ ArrayType arraytype1, arraytype2 = {1}, arraytype3;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: ArrayType arraytype1;
+ // CHECK-FIXES: {{^ }}ArrayType arraytype2 = {1};
+ // CHECK-FIXES: {{^ }}ArrayType arraytype3;
+
+ // Don't touch function declarations.
+ FunType funtype1, funtype2, functype3;
+
+ for (int index1 = 0, index2 = 0;;) {
+ int localFor1 = 1, localFor2 = 2;
+ // CHECK-MESSAGES: [[@LINE-1]]:5: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int localFor1 = 1;
+ // CHECK-FIXES: {{^ }}int localFor2 = 2;
+ }
+
+ StructOne s1, s2(23), s3, s4(3), *sptr = new StructOne(2);
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: StructOne s1;
+ // CHECK-FIXES: {{^ }}StructOne s2(23);
+ // CHECK-FIXES: {{^ }}StructOne s3;
+ // CHECK-FIXES: {{^ }}StructOne s4(3);
+ // CHECK-FIXES: {{^ }}StructOne *sptr = new StructOne(2);
+
+ struct StructOne cs1, cs2(42);
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: struct StructOne cs1;
+ // CHECK-FIXES: {{^ }}struct StructOne cs2(42);
+
+ int *ptrArray[3], dummy, **ptrArray2[5], twoDim[2][3], *twoDimPtr[2][3];
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int *ptrArray[3];
+ // CHECK-FIXES: {{^ }}int dummy;
+ // CHECK-FIXES: {{^ }}int **ptrArray2[5];
+ // CHECK-FIXES: {{^ }}int twoDim[2][3];
+ // CHECK-FIXES: {{^ }}int *twoDimPtr[2][3];
+
+ {
+ void f1(int), g1(int, float);
+ }
+
+ {
+ void gg(int, float);
+
+ void (*f2)(int), (*g2)(int, float) = gg;
+ // CHECK-MESSAGES: [[@LINE-1]]:5: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: void (*f2)(int);
+ // CHECK-FIXES: {{^ }}void (*g2)(int, float) = gg;
+
+ void /*(*/ (/*(*/ *f3)(int), (*g3)(int, float);
+ // CHECK-MESSAGES: [[@LINE-1]]:5: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: void /*(*/ (/*(*/ *f3)(int);
+ // CHECK-FIXES: {{^ }}void /*(*/ (*g3)(int, float);
+ }
+
+ // clang-format off
+ auto returner = []() { return int(32); };
+ int intfunction = returner(), intarray[] =
+ {
+ 1,
+ 2,
+ 3,
+ 4
+ }, bb = 4;
+ // CHECK-MESSAGES: [[@LINE-7]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int intfunction = returner();
+ // CHECK-FIXES: {{^ }}int intarray[] =
+ // CHECK-FIXES: {{^ }}{
+ // CHECK-FIXES: {{^ }}1,
+ // CHECK-FIXES: {{^ }}2,
+ // CHECK-FIXES: {{^ }}3,
+ // CHECK-FIXES: {{^ }}4
+ // CHECK-FIXES: {{^ }}};
+ // CHECK-FIXES: {{^ }}int bb = 4;
+ // clang-format on
+
+ TemT *T1 = &TT1, *T2 = &TT2;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: TemT *T1 = &TT1;
+ // CHECK-FIXES: {{^ }}TemT *T2 = &TT2;
+
+ const PointerType *PT1 = T1->getAs<PointerType>(),
+ *PT2 = T2->getAs<PointerType>();
+ // CHECK-MESSAGES: [[@LINE-2]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: const PointerType *PT1 = T1->getAs<PointerType>();
+ // CHECK-FIXES: {{^ }}const PointerType *PT2 = T2->getAs<PointerType>();
+
+ const int *p1 = nullptr;
+ const int *p2 = nullptr;
+
+ const int *&pref1 = p1, *&pref2 = p2;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: const int *&pref1 = p1;
+ // CHECK-FIXES: {{^ }}const int *&pref2 = p2;
+
+ // clang-format off
+ const char *literal1 = "clang" "test"\
+ "one",
+ *literal2 = "empty", literal3[] = "three";
+ // CHECK-MESSAGES: [[@LINE-3]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: const char *literal1 = "clang" "test"\
+ // CHECK-FIXES: {{^ }}"one";
+ // CHECK-FIXES: {{^ }}const char *literal2 = "empty";
+ // CHECK-FIXES: {{^ }}const char literal3[] = "three";
+ // clang-format on
+}
+
+void g() try {
+ int i, j;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int i;
+ // CHECK-FIXES: {{^ }}int j;
+} catch (...) {
+}
+
+struct S {
+ int a;
+ const int b;
+ void f() {}
+};
+
+void memberPointers() {
+ typedef const int S::*MemPtr;
+ MemPtr aaa = &S::a, bbb = &S::b;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: MemPtr aaa = &S::a;
+ // CHECK-FIXES: {{^ }}MemPtr bbb = &S::b;
+}
+
+typedef int *tptr, tbt;
+typedef int (&tfp)(int, long), tarr[10];
+typedef int tarr2[10], tct;
+
+template <typename A, typename B>
+void should_not_be_touched(A, B);
+
+int variable, function(void);
+
+int call_func_with_sideeffect();
+void bad_if_decl() {
+ if (true)
+ int i, j, k = call_func_with_sideeffect();
+}
Index: test/clang-tidy/readability-isolate-declaration.c
===================================================================
--- /dev/null
+++ test/clang-tidy/readability-isolate-declaration.c
@@ -0,0 +1,13 @@
+// RUN: %check_clang_tidy %s readability-isolate-declaration %t
+
+void c_specific() {
+ void (*signal(int sig, void (*func)(int)))(int);
+ int i = sizeof(struct S { int i; });
+ int j = sizeof(struct T { int i; }), k;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int j = sizeof(struct T { int i; });
+ // CHECK-FIXES: {{^ }}int k;
+
+ void g(struct U { int i; } s); // One decl
+ void h(struct V { int i; } s), m(int i, ...); // Two decls
+}
Index: test/clang-tidy/readability-isolate-declaration-fixing.cpp
===================================================================
--- /dev/null
+++ test/clang-tidy/readability-isolate-declaration-fixing.cpp
@@ -0,0 +1,64 @@
+// RUN: %check_clang_tidy %s readability-isolate-declaration %t
+// XFAIL: *
+
+struct S {
+ int a;
+ const int b;
+ void f() {}
+};
+
+void member_pointers() {
+ // FIXME: Memberpointers are transformed incorrect. Emit only a warning
+ // for now.
+ int S::*p = &S::a, S::*const q = &S::a;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int S::*p = &S::a;
+ // CHECK-FIXES: {{^ }}int S::*const q = &S::a;
+
+ int /* :: */ S::*pp2 = &S::a, var1 = 0;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int /* :: */ S::*pp2 = &S::a;
+ // CHECK-FIXES: {{^ }}int var1 = 0;
+
+ const int S::*r = &S::b, S::*t;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: const int S::*r = &S::b;
+ // CHECK-FIXES: {{^ }}const int S::*t;
+
+ {
+ int S::*mdpa1[2] = {&S::a, &S::a}, var1 = 0;
+ // CHECK-MESSAGES: [[@LINE-1]]:5: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int S::*mdpa1[2] = {&S::a, &S::a};
+ // CHECK-FIXES: {{^ }}int var1 = 0;
+
+ int S ::**mdpa2[2] = {&p, &pp2}, var2 = 0;
+ // CHECK-MESSAGES: [[@LINE-1]]:5: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int S ::**mdpa2[2] = {&p, &pp2};
+ // CHECK-FIXES: {{^ }}int var2 = 0;
+
+ void (S::*mdfp1)() = &S::f, (S::*mdfp2)() = &S::f;
+ // CHECK-MESSAGES: [[@LINE-1]]:5: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: void (S::*mdfp1)() = &S::f;
+ // CHECK-FIXES: {{^ }}void (S::*mdfp2)() = &S::f;
+
+ void (S::*mdfpa1[2])() = {&S::f, &S::f}, (S::*mdfpa2)() = &S::f;
+ // CHECK-MESSAGES: [[@LINE-1]]:5: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: void (S::*mdfpa1[2])() = {&S::f, &S::f};
+ // CHECK-FIXES: {{^ }}void (S::*mdfpa2)() = &S::f;
+
+ void (S::* * mdfpa3[2])() = {&mdfpa1[0], &mdfpa1[1]}, (S::*mdfpa4)() = &S::f;
+ // CHECK-MESSAGES: [[@LINE-1]]:5: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: void (S::* * mdfpa3[2])() = {&mdfpa1[0], &mdfpa1[1]};
+ // CHECK-FIXES: {{^ }}void (S::*mdfpa4)() = &S::f;
+ }
+
+ class CS {
+ public:
+ int a;
+ const int b;
+ };
+ int const CS ::*pp = &CS::a, CS::*const qq = &CS::a;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: int const CS ::*pp = &CS::a;
+ // CHECK-FIXES: {{^ }}int const CS::*const qq = &CS::a;
+}
Index: test/clang-tidy/readability-isolate-declaration-cxx17.cpp
===================================================================
--- /dev/null
+++ test/clang-tidy/readability-isolate-declaration-cxx17.cpp
@@ -0,0 +1,103 @@
+// RUN: %check_clang_tidy %s readability-isolate-declaration %t -- -- -std=c++17
+
+template <typename T1, typename T2>
+struct pair {
+ T1 first;
+ T2 second;
+ pair(T1 v1, T2 v2) : first(v1), second(v2) {}
+
+ template <int N>
+ decltype(auto) get() const {
+ if constexpr (N == 0)
+ return first;
+ else if constexpr (N == 1)
+ return second;
+ }
+};
+
+void forbidden_transformations() {
+ if (int i = 42, j = i; i == j)
+ ;
+ switch (int i = 12, j = 14; i)
+ ;
+
+ auto [i, j] = pair<int, int>(42, 42);
+}
+
+struct SomeClass {
+ SomeClass() = default;
+ SomeClass(int value);
+};
+
+namespace std {
+template <typename T>
+class initializer_list {};
+
+template <typename T>
+class vector {
+public:
+ vector() = default;
+ vector(initializer_list<T> init) {}
+};
+
+class string {
+public:
+ string() = default;
+ string(const char *) {}
+};
+
+namespace string_literals {
+string operator""s(const char *, decltype(sizeof(int))) {
+ return string();
+}
+} // namespace string_literals
+} // namespace std
+
+namespace Types {
+typedef int MyType;
+} // namespace Types
+
+int touch1, touch2;
+
+void modern() {
+ auto autoInt1 = 3, autoInt2 = 4;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: auto autoInt1 = 3;
+ // CHECK-FIXES: {{^ }}auto autoInt2 = 4;
+
+ decltype(int()) declnottouch = 4;
+ decltype(int()) declint1 = 5, declint2 = 3;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: decltype(int()) declint1 = 5;
+ // CHECK-FIXES: {{^ }}decltype(int()) declint2 = 3;
+
+ std::vector<int> vectorA = {1, 2}, vectorB = {1, 2, 3}, vectorC({1, 1, 1});
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: std::vector<int> vectorA = {1, 2};
+ // CHECK-FIXES: {{^ }}std::vector<int> vectorB = {1, 2, 3};
+ // CHECK-FIXES: {{^ }}std::vector<int> vectorC({1, 1, 1});
+
+ using uType = int;
+ uType utype1, utype2;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: uType utype1;
+ // CHECK-FIXES: {{^ }}uType utype2;
+
+ Types::MyType mytype1, mytype2, mytype3 = 3;
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: Types::MyType mytype1;
+ // CHECK-FIXES: {{^ }}Types::MyType mytype2;
+ // CHECK-FIXES: {{^ }}Types::MyType mytype3 = 3;
+
+ {
+ using namespace std::string_literals;
+
+ std::vector<std::string> s{"foo"s, "bar"s}, t{"foo"s}, u, a({"hey", "you"}), bb = {"h", "a"};
+ // CHECK-MESSAGES: [[@LINE-1]]:5: warning: multiple declarations in a single statement reduces readability
+ // CHECK-FIXES: std::vector<std::string> s{"foo"s, "bar"s};
+ // CHECK-FIXES: {{^ }}std::vector<std::string> t{"foo"s};
+ // CHECK-FIXES: {{^ }}std::vector<std::string> u;
+ // CHECK-FIXES: {{^ }}std::vector<std::string> a({"hey", "you"});
+ // CHECK-FIXES: {{^ }}std::vector<std::string> bb = {"h", "a"};
+ }
+}
Index: docs/clang-tidy/checks/readability-isolate-declaration.rst
===================================================================
--- /dev/null
+++ docs/clang-tidy/checks/readability-isolate-declaration.rst
@@ -0,0 +1,99 @@
+.. title:: clang-tidy - readability-isolate-declaration
+
+readability-isolate-declarationaration
+===============================
+
+Diagnoses local variable declarations declaring more than one variable and
+tries to refactor the code to one statement per declaration.
+
+The automatic code-transformation will use the same indentation as the original
+for every created statement and add a linebreak after each statement.
+
+.. code-block:: c++
+
+ void f() {
+ int * pointer = nullptr, value = 42, * const const_ptr = &value;
+ // This declaration will be diagnosed and transformed into:
+ // int * pointer = nullptr;
+ // int value = 42;
+ // int * const const_ptr = &value;
+ }
+
+
+The check does exclude places where it is necessary or commong to declare
+multiple variables in one statement and there is no other way supported in the
+language. Please note that structured bindings are not considered.
+
+.. code-block:: c++
+
+ // It is not possible to transform this declaration and doing the declaration
+ // before the loop will increase the scope of the variable 'Begin' and 'End'
+ // which is undesired in it's own.
+ for (int Begin = 0, End = 100; Begin < End; ++Begin);
+ if (int Begin = 42, Result = some_function(Begin); Begin == Result);
+
+ // It is not possible to transform this declaration because the result is
+ // not functionality preserving as 'j' and 'k' would not be part of the
+ // 'if' statement anymore.
+ if (SomeCondition())
+ int i = 42, j = 43, k = function(i,j);
+
+
+Limitations
+-----------
+
+Global variables and member variables are excluded.
+
+The check currently does not support the automatic transformation of
+member-pointer-types.
+
+.. code-block:: c++
+
+ struct S {
+ int a;
+ const int b;
+ void f() {}
+ };
+
+ void f() {
+ // Only a diagnostic message is emitted
+ int S::*p = &S::a, S::*const q = &S::a;
+ }
+
+Furthermore the transformation is very cautious when it detects various kinds
+of macros or preprocessor directives in the range of the statement. In this
+case the transformation will not happen to avoid unexpected side-effects due to
+macros.
+
+.. code-block:: c++
+
+ #define NULL 0
+ #define MY_NICE_TYPE int **
+ #define VAR_NAME(name) name##__LINE__
+ #define A_BUNCH_OF_VARIABLES int m1 = 42, m2 = 43, m3 = 44;
+
+ void macros() {
+ int *p1 = NULL, *p2 = NULL;
+ // Will be transformed to
+ // int *p1 = NULL;
+ // int *p2 = NULL;
+
+ MY_NICE_TYPE p3, v1, v2;
+ // Won't be transformed, but a diagnostic is emitted.
+
+ int VAR_NAME(v3),
+ VAR_NAME(v4),
+ VAR_NAME(v5);
+ // Won't be transformed, but a diagnostic is emitted.
+
+ A_BUNCH_OF_VARIABLES
+ // Won't be transformed, but a diagnostic is emitted.
+
+ int Unconditional,
+ #if CONFIGURATION
+ IfConfigured = 42,
+ #else
+ IfConfigured = 0;
+ #endif
+ // Won't be transformed, but a diagnostic is emitted.
+ }
Index: docs/clang-tidy/checks/list.rst
===================================================================
--- docs/clang-tidy/checks/list.rst
+++ docs/clang-tidy/checks/list.rst
@@ -226,6 +226,7 @@
readability-identifier-naming
readability-implicit-bool-conversion
readability-inconsistent-declaration-parameter-name
+ readability-isolate-declaration
readability-magic-numbers
readability-misleading-indentation
readability-misplaced-array-index
Index: docs/ReleaseNotes.rst
===================================================================
--- docs/ReleaseNotes.rst
+++ docs/ReleaseNotes.rst
@@ -100,6 +100,12 @@
``namespace a { namespace b { ... }}`` and offers change to
syntax introduced in C++17 standard: ``namespace a::b { ... }``.
+- New :doc:`readability-isolate-decl
+ <clang-tidy/checks/readability-isolate-decl>` check.
+
+ Diagnoses local variable declarations declaring more than one variable and
+ tries to refactor the code to one statement per declaration.
+
- New :doc:`readability-magic-numbers
<clang-tidy/checks/readability-magic-numbers>` check.
Index: clang-tidy/utils/LexerUtils.h
===================================================================
--- clang-tidy/utils/LexerUtils.h
+++ clang-tidy/utils/LexerUtils.h
@@ -19,8 +19,67 @@
namespace lexer {
/// Returns previous token or ``tok::unknown`` if not found.
-Token getPreviousToken(const ASTContext &Context, SourceLocation Location,
- bool SkipComments = true);
+Token getPreviousToken(SourceLocation Location, const SourceManager &SM,
+ const LangOptions &LangOpts, bool SkipComments = true);
+
+SourceLocation findPreviousTokenStart(SourceLocation Start,
+ const SourceManager &SM,
+ const LangOptions &LangOpts);
+
+SourceLocation findPreviousTokenKind(SourceLocation Start,
+ const SourceManager &SM,
+ const LangOptions &LangOpts,
+ tok::TokenKind TK);
+
+SourceLocation findNextTerminator(SourceLocation Start, const SourceManager &SM,
+ const LangOptions &LangOpts);
+
+template <typename TokenKind, typename... TokenKinds>
+SourceLocation findPreviousAnyTokenKind(SourceLocation Start,
+ const SourceManager &SM,
+ const LangOptions &LangOpts,
+ TokenKind TK, TokenKinds... TKs) {
+ while (true) {
+ SourceLocation L = findPreviousTokenStart(Start, SM, LangOpts);
+ if (L.isInvalid() || L.isMacroID())
+ return SourceLocation();
+
+ Token T;
+ // Returning 'true' is used to signal failure to retrieve the token.
+ if (Lexer::getRawToken(L, T, SM, LangOpts))
+ return SourceLocation();
+
+ if (T.isOneOf(TK, TKs...))
+ return T.getLocation();
+
+ Start = L;
+ }
+}
+
+template <typename TokenKind, typename... TokenKinds>
+SourceLocation findNextAnyTokenKind(SourceLocation Start,
+ const SourceManager &SM,
+ const LangOptions &LangOpts, TokenKind TK,
+ TokenKinds... TKs) {
+ while (true) {
+ Optional<Token> CurrentToken = Lexer::findNextToken(Start, SM, LangOpts);
+
+ if (!CurrentToken)
+ return SourceLocation();
+
+ Token PotentialMatch = *CurrentToken;
+ if (PotentialMatch.isOneOf(TK, TKs...))
+ return PotentialMatch.getLocation();
+
+ Start = PotentialMatch.getLastLoc();
+ }
+}
+
+/// Relex the provide \p Range and return \c false if either a macro spanning
+/// multiple tokens, a pre-processor directive or failure to retrieve the
+/// next token is found, otherwise \c true.
+bool saveFromPreProcessor(SourceRange Range, const SourceManager &SM,
+ const LangOptions &LangOpts);
} // namespace lexer
} // namespace utils
Index: clang-tidy/utils/LexerUtils.cpp
===================================================================
--- clang-tidy/utils/LexerUtils.cpp
+++ clang-tidy/utils/LexerUtils.cpp
@@ -14,27 +14,83 @@
namespace utils {
namespace lexer {
-Token getPreviousToken(const ASTContext &Context, SourceLocation Location,
- bool SkipComments) {
- const auto &SourceManager = Context.getSourceManager();
+Token getPreviousToken(SourceLocation Location, const SourceManager &SM,
+ const LangOptions &LangOpts, bool SkipComments) {
Token Token;
Token.setKind(tok::unknown);
Location = Location.getLocWithOffset(-1);
- auto StartOfFile =
- SourceManager.getLocForStartOfFile(SourceManager.getFileID(Location));
+ auto StartOfFile = SM.getLocForStartOfFile(SM.getFileID(Location));
while (Location != StartOfFile) {
- Location = Lexer::GetBeginningOfToken(Location, SourceManager,
- Context.getLangOpts());
- if (!Lexer::getRawToken(Location, Token, SourceManager,
- Context.getLangOpts()) &&
+ Location = Lexer::GetBeginningOfToken(Location, SM, LangOpts);
+ if (!Lexer::getRawToken(Location, Token, SM, LangOpts) &&
(!SkipComments || !Token.is(tok::comment))) {
break;
}
Location = Location.getLocWithOffset(-1);
}
return Token;
}
+SourceLocation findPreviousTokenStart(SourceLocation Start,
+ const SourceManager &SM,
+ const LangOptions &LangOpts) {
+ if (Start.isInvalid() || Start.isMacroID())
+ return SourceLocation();
+
+ SourceLocation BeforeStart = Start.getLocWithOffset(-1);
+ if (BeforeStart.isInvalid() || BeforeStart.isMacroID())
+ return SourceLocation();
+
+ return Lexer::GetBeginningOfToken(BeforeStart, SM, LangOpts);
+}
+
+SourceLocation findPreviousTokenKind(SourceLocation Start,
+ const SourceManager &SM,
+ const LangOptions &LangOpts,
+ tok::TokenKind TK) {
+ while (true) {
+ SourceLocation L = findPreviousTokenStart(Start, SM, LangOpts);
+ if (L.isInvalid() || L.isMacroID())
+ return SourceLocation();
+
+ Token T;
+ if (Lexer::getRawToken(L, T, SM, LangOpts, /*IgnoreWhiteSpace=*/true))
+ return SourceLocation();
+
+ if (T.is(TK))
+ return T.getLocation();
+
+ Start = L;
+ }
+}
+
+SourceLocation findNextTerminator(SourceLocation Start, const SourceManager &SM,
+ const LangOptions &LangOpts) {
+ return findNextAnyTokenKind(Start, SM, LangOpts, tok::comma, tok::semi);
+}
+
+bool saveFromPreProcessor(SourceRange Range, const SourceManager &SM,
+ const LangOptions &LangOpts) {
+ assert(Range.isValid() && "Invalid Range for relexing provided");
+ SourceLocation Loc = Range.getBegin();
+
+ while (Loc < Range.getEnd()) {
+ if (Loc.isMacroID())
+ return false;
+
+ llvm::Optional<Token> Tok = Lexer::findNextToken(Loc, SM, LangOpts);
+
+ if (!Tok)
+ return false;
+
+ if ((*Tok).is(tok::hash))
+ return false;
+
+ Loc = Lexer::getLocForEndOfToken(Loc, 0, SM, LangOpts).getLocWithOffset(1);
+ }
+
+ return true;
+}
} // namespace lexer
} // namespace utils
} // namespace tidy
Index: clang-tidy/readability/ReadabilityTidyModule.cpp
===================================================================
--- clang-tidy/readability/ReadabilityTidyModule.cpp
+++ clang-tidy/readability/ReadabilityTidyModule.cpp
@@ -20,6 +20,7 @@
#include "IdentifierNamingCheck.h"
#include "ImplicitBoolConversionCheck.h"
#include "InconsistentDeclarationParameterNameCheck.h"
+#include "IsolateDeclarationCheck.h"
#include "MagicNumbersCheck.h"
#include "MisleadingIndentationCheck.h"
#include "MisplacedArrayIndexCheck.h"
@@ -66,6 +67,8 @@
"readability-implicit-bool-conversion");
CheckFactories.registerCheck<InconsistentDeclarationParameterNameCheck>(
"readability-inconsistent-declaration-parameter-name");
+ CheckFactories.registerCheck<IsolateDeclarationCheck>(
+ "readability-isolate-declaration");
CheckFactories.registerCheck<MagicNumbersCheck>(
"readability-magic-numbers");
CheckFactories.registerCheck<MisleadingIndentationCheck>(
Index: clang-tidy/readability/IsolateDeclarationCheck.h
===================================================================
--- /dev/null
+++ clang-tidy/readability/IsolateDeclarationCheck.h
@@ -0,0 +1,36 @@
+//===--- IsolateDeclarationCheck.h - clang-tidy -----------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_ISOLATEDECLCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_ISOLATEDECLCHECK_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+/// This check diagnoses all DeclStmt's declaring more than one variable and
+/// tries to refactor the code to one statement per declaration.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/readability-isolate-declaration.html
+class IsolateDeclarationCheck : public ClangTidyCheck {
+public:
+ IsolateDeclarationCheck(StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context) {}
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_ISOLATEDECLCHECK_H
Index: clang-tidy/readability/IsolateDeclarationCheck.cpp
===================================================================
--- /dev/null
+++ clang-tidy/readability/IsolateDeclarationCheck.cpp
@@ -0,0 +1,287 @@
+//===--- IsolateDeclarationCheck.cpp - clang-tidy -------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "IsolateDeclarationCheck.h"
+#include "../utils/LexerUtils.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+using namespace clang::tidy::utils::lexer;
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+namespace {
+AST_MATCHER(DeclStmt, isSingleDecl) { return Node.isSingleDecl(); }
+AST_MATCHER(DeclStmt, onlyDeclaresVariables) {
+ return std::all_of(Node.decl_begin(), Node.decl_end(),
+ [](Decl *D) { return isa<VarDecl>(D); });
+}
+
+AST_MATCHER_P(IfStmt, hasInit, ast_matchers::internal::Matcher<Stmt>,
+ InnerMatcher) {
+ const Stmt *InitStmt = Node.getInit();
+ return InitStmt ? InnerMatcher.matches(*InitStmt, Finder, Builder) : false;
+}
+} // namespace
+
+void IsolateDeclarationCheck::registerMatchers(MatchFinder *Finder) {
+ Finder->addMatcher(
+ declStmt(allOf(onlyDeclaresVariables(), unless(isSingleDecl()),
+ hasParent(compoundStmt())))
+ .bind("decl_stmt"),
+ this);
+}
+
+static SourceLocation findStartOfIndirection(SourceLocation Start,
+ int Indirections,
+ const SourceManager &SM,
+ const LangOptions &LangOpts) {
+ assert(Indirections >= 0 && "Indirections must be non-negative");
+ if (Indirections == 0)
+ return Start;
+
+ // Note that the post-fix decrement is necessary to perform the correct
+ // number of transformations.
+ while (Indirections-- != 0) {
+ Start = findPreviousAnyTokenKind(Start, SM, LangOpts, tok::star, tok::amp);
+ if (Start.isInvalid() || Start.isMacroID())
+ return SourceLocation();
+ }
+ return Start;
+}
+
+static bool isMacroID(SourceRange R) {
+ return R.getBegin().isMacroID() || R.getEnd().isMacroID();
+}
+
+/// This function counts the number of written indirections for the given
+/// Type \p T. It does \b NOT resolve typedefs as it's a helper for lexing
+/// the source code.
+/// \see declRanges
+static int countIndirections(const Type *T, int Indirections = 0) {
+ if (isa<PointerType>(T) && T->isFunctionPointerType()) {
+ const auto *Pointee =
+ T->getPointeeType().getTypePtr()->castAs<FunctionType>();
+ return countIndirections(
+ Pointee->getReturnType().IgnoreParens().getTypePtr(), ++Indirections);
+ }
+
+ // Note: Do not increment the 'Indirections' because it is not yet clear
+ // if there is an indirection added in the source code of the array
+ // declaration.
+ if (const auto *AT = dyn_cast<ArrayType>(T))
+ return countIndirections(AT->getElementType().IgnoreParens().getTypePtr(),
+ Indirections);
+
+ if (isa<PointerType>(T) || isa<ReferenceType>(T))
+ return countIndirections(T->getPointeeType().IgnoreParens().getTypePtr(),
+ ++Indirections);
+
+ return Indirections;
+}
+
+static bool typeIsMemberPointer(const Type *T) {
+ if (isa<ArrayType>(T))
+ return typeIsMemberPointer(T->getArrayElementTypeNoTypeQual());
+
+ if ((isa<PointerType>(T) || isa<ReferenceType>(T)) &&
+ isa<PointerType>(T->getPointeeType()))
+ return typeIsMemberPointer(T->getPointeeType().getTypePtr());
+
+ return isa<MemberPointerType>(T);
+}
+
+/// This function tries to extract the SourceRanges that make up all
+/// declarations in this \c DeclStmt.
+///
+/// The resulting vector has the structure {UnderlyingType, Decl1, Decl2, ...}.
+/// Each \c SourceRange is of the form [Begin, End).
+/// If any of the create ranges is invalid or in a macro the result will be
+/// \c None.
+/// If the \c DeclStmt contains only one declaration, the result is \c None.
+/// If the \c DeclStmt contains declarations other than \c VarDecl the result
+/// is \c None.
+///
+/// \code
+/// int * ptr1 = nullptr, value = 42;
+/// // [ ][ ] [ ] - The ranges here are inclusive
+/// \endcode
+/// \todo Generalize this function to take other declarations than \c VarDecl.
+static Optional<std::vector<SourceRange>>
+declRanges(const DeclStmt *DS, const SourceManager &SM,
+ const LangOptions &LangOpts) {
+ std::size_t DeclCount = std::distance(DS->decl_begin(), DS->decl_end());
+ if (DeclCount < 2)
+ return None;
+
+ if (!saveFromPreProcessor(DS->getSourceRange(), SM, LangOpts))
+ return None;
+
+ // The initial type of the declaration and each declaration has it's own
+ // slice. This is necessary, because pointers and references bind only
+ // to the local variable and not to all variables in the declaration.
+ // Example: 'int *pointer, value = 42;'
+ std::vector<SourceRange> Slices;
+ Slices.reserve(DeclCount + 1);
+
+ // Calculate the first slice, for now only variables are handled but in the
+ // future this should be relaxed and support various kinds of declarations.
+ const auto *FirstDecl = dyn_cast<VarDecl>(*DS->decl_begin());
+
+ if (FirstDecl == nullptr)
+ return None;
+
+ // FIXME: Member pointer are not transformed correctly right now, that's
+ // why they are treated as problematic here.
+ if (typeIsMemberPointer(FirstDecl->getType().IgnoreParens().getTypePtr()))
+ return None;
+
+ // Consider the following case: 'int * pointer, value = 42;'
+ // Created slices (inclusive) [ ][ ] [ ]
+ // Because 'getBeginLoc' points to the start of the variable *name*, the
+ // location of the pointer must be determined separatly.
+ SourceLocation Start = findStartOfIndirection(
+ FirstDecl->getLocation(),
+ countIndirections(FirstDecl->getType().IgnoreParens().getTypePtr()), SM,
+ LangOpts);
+
+ // Fix function-pointer declarations that have a '(' in front of the
+ // pointer.
+ // Example: 'void (*f2)(int), (*g2)(int, float) = gg;'
+ // Slices: [ ][ ] [ ]
+ if (FirstDecl->getType()->isFunctionPointerType())
+ Start = findPreviousTokenKind(Start, SM, LangOpts, tok::l_paren);
+
+ // It is popssible that a declarator is wrapped with parens.
+ // Example: 'float (((*f_ptr2)))[42], *f_ptr3, ((f_value2)) = 42.f;'
+ // The slice for the type-part must not contain these parens. Consequently
+ // 'Start' is moved to the most left paren if there are parens.
+ while (true) {
+ if (Start.isInvalid() || Start.isMacroID())
+ break;
+
+ Token T = getPreviousToken(Start, SM, LangOpts);
+ if (T.is(tok::l_paren)) {
+ Start = findPreviousTokenStart(Start, SM, LangOpts);
+ continue;
+ }
+ break;
+ }
+
+ SourceRange DeclRange(DS->getBeginLoc(), Start);
+ if (DeclRange.isInvalid() || isMacroID(DeclRange))
+ return None;
+
+ // The first slice, that is prepended to every isolated declaration, is
+ // created.
+ Slices.emplace_back(DeclRange);
+
+ // Create all following slices that each declare a variable.
+ SourceLocation DeclBegin = Start;
+ for (const auto &Decl : DS->decls()) {
+ const auto *CurrentDecl = cast<VarDecl>(Decl);
+
+ // FIXME: Member pointer are not transformed correctly right now, that's
+ // why they are treated as problematic here.
+ if (typeIsMemberPointer(CurrentDecl->getType().IgnoreParens().getTypePtr()))
+ return None;
+
+ SourceLocation DeclEnd =
+ CurrentDecl->hasInit()
+ ? findNextTerminator(CurrentDecl->getInit()->getEndLoc(), SM,
+ LangOpts)
+ : findNextTerminator(CurrentDecl->getEndLoc(), SM, LangOpts);
+
+ SourceRange VarNameRange(DeclBegin, DeclEnd);
+ if (VarNameRange.isInvalid() || isMacroID(VarNameRange))
+ return None;
+
+ Slices.emplace_back(VarNameRange);
+ DeclBegin = DeclEnd.getLocWithOffset(1);
+ }
+ return Slices;
+}
+
+static Optional<std::vector<StringRef>>
+collectSourceRanges(llvm::ArrayRef<SourceRange> Ranges, const SourceManager &SM,
+ const LangOptions &LangOpts) {
+ std::vector<StringRef> Snippets;
+ Snippets.reserve(Ranges.size());
+
+ for (const auto &Range : Ranges) {
+ CharSourceRange CharRange = Lexer::getAsCharRange(
+ CharSourceRange::getCharRange(Range.getBegin(), Range.getEnd()), SM,
+ LangOpts);
+
+ if (CharRange.isInvalid())
+ return None;
+
+ bool InvalidText = false;
+ StringRef Snippet =
+ Lexer::getSourceText(CharRange, SM, LangOpts, &InvalidText);
+
+ if (InvalidText)
+ return None;
+
+ Snippets.emplace_back(Snippet);
+ }
+
+ return Snippets;
+}
+
+/// Expects a vector {TypeSnippet, Firstdecl, SecondDecl, ...}.
+static std::vector<std::string>
+createIsolatedDecls(llvm::ArrayRef<StringRef> Snippets) {
+ // The first section is the type snippet, which does not make a decl itself.
+ assert(Snippets.size() > 2 && "Not enough snippets to create isolated decls");
+ std::vector<std::string> Decls(Snippets.size() - 1);
+
+ for (std::size_t I = 1; I < Snippets.size(); ++I)
+ Decls[I - 1] = Twine(Snippets[0])
+ .concat(Snippets[0].endswith(" ") ? "" : " ")
+ .concat(Snippets[I].ltrim())
+ .concat(";")
+ .str();
+
+ return Decls;
+}
+
+void IsolateDeclarationCheck::check(const MatchFinder::MatchResult &Result) {
+ const auto *WholeDecl = Result.Nodes.getNodeAs<DeclStmt>("decl_stmt");
+
+ auto Diag =
+ diag(WholeDecl->getBeginLoc(),
+ "multiple declarations in a single statement reduces readability");
+
+ Optional<std::vector<SourceRange>> PotentialRanges =
+ declRanges(WholeDecl, *Result.SourceManager, getLangOpts());
+ if (!PotentialRanges)
+ return;
+
+ Optional<std::vector<StringRef>> PotentialSnippets = collectSourceRanges(
+ *PotentialRanges, *Result.SourceManager, getLangOpts());
+
+ if (!PotentialSnippets)
+ return;
+
+ std::vector<std::string> NewDecls = createIsolatedDecls(*PotentialSnippets);
+ std::string Replacement = llvm::join(
+ NewDecls,
+ (Twine("\n") + Lexer::getIndentationForLine(WholeDecl->getBeginLoc(),
+ *Result.SourceManager))
+ .str());
+
+ Diag << FixItHint::CreateReplacement(WholeDecl->getSourceRange(),
+ Replacement);
+}
+} // namespace readability
+} // namespace tidy
+} // namespace clang
Index: clang-tidy/readability/CMakeLists.txt
===================================================================
--- clang-tidy/readability/CMakeLists.txt
+++ clang-tidy/readability/CMakeLists.txt
@@ -11,6 +11,7 @@
IdentifierNamingCheck.cpp
ImplicitBoolConversionCheck.cpp
InconsistentDeclarationParameterNameCheck.cpp
+ IsolateDeclarationCheck.cpp
MagicNumbersCheck.cpp
MisleadingIndentationCheck.cpp
MisplacedArrayIndexCheck.cpp
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