clang-tools-extra/test/clang-tidy/checkers/bugprone-implicit-widening-of-multiplication-result-array-subscript-expression.cpp

// RUN: %check_clang_tidy -check-suffixes=ALL,C -std=c99 %s bugprone-implicit-widening-of-multiplication-result %t -- -- -target x86_64-unknown-unknown -x c
// RUN: %check_clang_tidy -check-suffixes=ALL,CXX %s bugprone-implicit-widening-of-multiplication-result %t -- -- -target x86_64-unknown-unknown -x c++

// RUN: %check_clang_tidy -check-suffixes=ALL,C -std=c99 %s bugprone-implicit-widening-of-multiplication-result %t -- \
// RUN:     -config='{CheckOptions: [ \
// RUN:         {key: bugprone-implicit-widening-of-multiplication-result.UseCXXStaticCastsInCppSources, value: false} \
// RUN:     ]}' -- -target x86_64-unknown-unknown -x c
// RUN: %check_clang_tidy -check-suffixes=ALL,C %s bugprone-implicit-widening-of-multiplication-result %t -- \
// RUN:     -config='{CheckOptions: [ \
// RUN:         {key: bugprone-implicit-widening-of-multiplication-result.UseCXXStaticCastsInCppSources, value: false} \
// RUN:     ]}' -- -target x86_64-unknown-unknown -x c++

char *t0(char *base, int a, int b) {
  return &base[a * b];
  // CHECK-NOTES-ALL: :[[@LINE-1]]:11: warning: result of multiplication in type 'int' is used as a pointer offset after an implicit widening conversion to type 'ptrdiff_t'
  // CHECK-NOTES-ALL: :[[@LINE-2]]:16: note: make conversion explicit to silence this warning
  // CHECK-NOTES-C:                    (ptrdiff_t)( )
  // CHECK-NOTES-CXX:                  static_cast<ptrdiff_t>( )
  // CHECK-NOTES-ALL: :[[@LINE-5]]:16: note: perform multiplication in a wider type
  // CHECK-NOTES-C:                    (ptrdiff_t)
  // CHECK-NOTES-CXX:                  static_cast<ptrdiff_t>()
}
void *t1(char *base, int a, int b) {
  return &((a * b)[base]);
  // CHECK-NOTES-ALL: :[[@LINE-1]]:12: warning: result of multiplication in type 'int' is used as a pointer offset after an implicit widening conversion to type 'ptrdiff_t'
  // CHECK-NOTES-ALL: :[[@LINE-2]]:13: note: make conversion explicit to silence this warning
  // CHECK-NOTES-ALL: :[[@LINE-3]]:13: note: perform multiplication in a wider type
}

char *t2(char *base, unsigned int a, int b) {
  return &base[a * b];
  // CHECK-NOTES-ALL: :[[@LINE-1]]:11: warning: result of multiplication in type 'unsigned int' is used as a pointer offset after an implicit widening conversion to type 'size_t'
  // CHECK-NOTES-ALL: :[[@LINE-2]]:16: note: make conversion explicit to silence this warning
  // CHECK-NOTES-C:                    (size_t)
  // CHECK-NOTES-CXX:                  static_cast<size_t>( )
  // CHECK-NOTES-ALL: :[[@LINE-5]]:16: note: perform multiplication in a wider type
  // CHECK-NOTES-C:                    (size_t)
  // CHECK-NOTES-CXX:                  static_cast<size_t>()
}

char *t3(char *base, int a, unsigned int b) {
  return &base[a * b];
  // CHECK-NOTES-ALL: :[[@LINE-1]]:11: warning: result of multiplication in type 'unsigned int' is used as a pointer offset after an implicit widening conversion to type 'size_t'
  // CHECK-NOTES-ALL: :[[@LINE-2]]:16: note: make conversion explicit to silence this warning
  // CHECK-NOTES-ALL: :[[@LINE-3]]:16: note: perform multiplication in a wider type
}

char *t4(char *base, unsigned int a, unsigned int b) {
  return &base[a * b];
  // CHECK-NOTES-ALL: :[[@LINE-1]]:11: warning: result of multiplication in type 'unsigned int' is used as a pointer offset after an implicit widening conversion to type 'size_t'
  // CHECK-NOTES-ALL: :[[@LINE-2]]:16: note: make conversion explicit to silence this warning
  // CHECK-NOTES-ALL: :[[@LINE-3]]:16: note: perform multiplication in a wider type
}

char *n5(char *base, int a, int b, int c) {
  return &base[a * b + c];
}
char *n6(char *base, int a, int b, int c) {
  return &base[a + b * c];
}

char *t7(char *base, int a, int b) {
  return &base[(a * b)];
  // CHECK-NOTES-ALL: :[[@LINE-1]]:11: warning: result of multiplication in type 'int' is used as a pointer offset after an implicit widening conversion to type 'ptrdiff_t'
  // CHECK-NOTES-ALL: :[[@LINE-2]]:17: note: make conversion explicit to silence this warning
  // CHECK-NOTES-ALL: :[[@LINE-3]]:17: note: perform multiplication in a wider type
}
char *n8(char *base, int a, int b, int c) {
  return &base[(a * b + c)];
}
char *n9(char *base, int a, int b, int c) {
  return &base[(a * b) + c];
}

char *n10(char *base, int a, int b) {
  return &base[(long)(a * b)];
}
char *n11(char *base, int a, int b) {
  return &base[(unsigned long)(a * b)];
}

#ifdef __cplusplus
template <typename T>
char *template_test(char *base, T a, T b) {
  return &base[a * b];
}
char *template_test_instantiation(char *base, int a, int b) {
  return template_test(base, a, b);
}
#endif