v) {\n"
" auto x = [&v] { v.push_back(1); };\n"
" if(v.empty()) {\n"
" g(x);\n"
" }\n"
" if(v.empty())\n"
" return;\n"
" return;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("struct S { int i; };\n"
"int f(const S& s) {\n"
" int a = 0, b = 0;\n"
" if (s.i == 0)\n"
" a = 1;\n"
" if (s.i == 0)\n"
" b = 1;\n"
" return a + b;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:6]: (style) The if condition is the same as the previous if condition\n", errout.str());
// do not crash
check("void assign(const MMA& other) {\n"
" if (mPA.cols != other.mPA.cols || mPA.rows != other.mPA.rows)\n"
" ;\n"
" if (other.mPA.cols > 0 && other.mPA.rows > 0)\n"
" ;\n"
"}");
}
void checkInvalidTestForOverflow() {
check("void f(char *p, unsigned int x) {\n"
" assert((p + x) < p);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Invalid test for overflow '(p+x)= p);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Invalid test for overflow '(p+x)>=p'; pointer overflow is undefined behavior. Some mainstream compilers remove such overflow tests when optimising the code and assume it's always true.\n", errout.str());
check("void f(char *p, unsigned int x) {\n"
" assert(p > (p + x));\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Invalid test for overflow 'p>(p+x)'; pointer overflow is undefined behavior. Some mainstream compilers remove such overflow tests when optimising the code and assume it's always false.\n", errout.str());
check("void f(char *p, unsigned int x) {\n"
" assert(p <= (p + x));\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Invalid test for overflow 'p<=(p+x)'; pointer overflow is undefined behavior. Some mainstream compilers remove such overflow tests when optimising the code and assume it's always true.\n", errout.str());
check("void f(signed int x) {\n" // unsigned overflow => don't warn
" assert(x + 100U < x);\n"
"}");
ASSERT_EQUALS("", errout.str());
// x + c < x
#define MSG(EXPR, RESULT) "[test.cpp:1]: (warning) Invalid test for overflow '" EXPR "'; signed integer overflow is undefined behavior. Some mainstream compilers remove such overflow tests when optimising the code and assume it's always " RESULT ".\n"
check("int f(int x) { return x + 10 > x; }");
ASSERT_EQUALS(MSG("x+10>x", "true"), errout.str());
check("int f(int x) { return x + 10 >= x; }");
ASSERT_EQUALS(MSG("x+10>=x", "true"), errout.str());
check("int f(int x) { return x + 10 < x; }");
ASSERT_EQUALS(MSG("x+10 x; }");
ASSERT_EQUALS(MSG("x-10>x", "false"), errout.str());
check("int f(int x) { return x - 10 >= x; }");
ASSERT_EQUALS(MSG("x-10>=x", "false"), errout.str());
check("int f(int x) { return x - 10 < x; }");
ASSERT_EQUALS(MSG("x-10 x; }");
ASSERT_EQUALS(MSG("x+y>x", "y>0"), errout.str());
check("int f(int x, int y) { return x + y >= x; }");
ASSERT_EQUALS(MSG("x+y>=x", "y>=0"), errout.str());
// x - y < x
check("int f(int x, int y) { return x - y < x; }");
ASSERT_EQUALS(MSG("x-y0"), errout.str());
check("int f(int x, int y) { return x - y <= x; }");
ASSERT_EQUALS(MSG("x-y<=x", "y>=0"), errout.str());
check("int f(int x, int y) { return x - y > x; }");
ASSERT_EQUALS(MSG("x-y>x", "y<0"), errout.str());
check("int f(int x, int y) { return x - y >= x; }");
ASSERT_EQUALS(MSG("x-y>=x", "y<=0"), errout.str());
}
void checkConditionIsAlwaysTrueOrFalseInsideIfWhile() {
check("void f() {\n"
" enum states {A,B,C};\n"
" const unsigned g_flags = B|C;\n"
" if(g_flags & A) {}\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (style) Condition 'g_flags&A' is always false\n", errout.str());
check("void f() {\n"
" int a = 5;"
" if(a) {}\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (style) Condition 'a' is always true\n", errout.str());
check("void f() {\n"
" int a = 5;"
" while(a + 1) { a--; }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" int a = 5;"
" while(a + 1) { return; }\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (style) Condition 'a+1' is always true\n", errout.str());
}
void alwaysTrueFalseInLogicalOperators() {
check("bool f();\n"
"void foo() { bool x = true; if(x||f()) {}}");
ASSERT_EQUALS("[test.cpp:2]: (style) Condition 'x' is always true\n", errout.str());
check("void foo(bool b) { bool x = true; if(x||b) {}}");
ASSERT_EQUALS("[test.cpp:1]: (style) Condition 'x' is always true\n", errout.str());
check("void foo(bool b) { if(true||b) {}}");
ASSERT_EQUALS("", errout.str());
check("bool f();\n"
"void foo() { bool x = false; if(x||f()) {}}");
ASSERT_EQUALS("[test.cpp:2]: (style) Condition 'x' is always false\n", errout.str());
check("bool f();\n"
"void foo() { bool x = false; if(x&&f()) {}}");
ASSERT_EQUALS("[test.cpp:2]: (style) Condition 'x' is always false\n", errout.str());
check("void foo(bool b) { bool x = false; if(x&&b) {}}");
ASSERT_EQUALS("[test.cpp:1]: (style) Condition 'x' is always false\n", errout.str());
check("void foo(bool b) { if(false&&b) {}}");
ASSERT_EQUALS("", errout.str());
check("bool f();\n"
"void foo() { bool x = true; if(x&&f()) {}}");
ASSERT_EQUALS("[test.cpp:2]: (style) Condition 'x' is always true\n", errout.str());
// #9578
check("bool f(const std::string &s) {\n"
" return s.size()>2U && s[0]=='4' && s[0]=='2';\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:2]: (style) Return value 's[0]=='2'' is always false\n", errout.str());
}
void pointerAdditionResultNotNull() {
check("void f(char *ptr) {\n"
" if (ptr + 1 != 0);\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) Comparison is wrong. Result of 'ptr+1' can't be 0 unless there is pointer overflow, and pointer overflow is undefined behaviour.\n", errout.str());
}
void duplicateConditionalAssign() {
setMultiline();
check("void f(int& x, int y) {\n"
" if (x == y)\n"
" x = y;\n"
"}");
ASSERT_EQUALS("test.cpp:3:style:Assignment 'x=y' is redundant with condition 'x==y'.\n"
"test.cpp:2:note:Condition 'x==y'\n"
"test.cpp:3:note:Assignment 'x=y' is redundant\n", errout.str());
check("void f(int& x, int y) {\n"
" if (x != y)\n"
" x = y;\n"
"}");
ASSERT_EQUALS("test.cpp:2:style:The statement 'if (x!=y) x=y' is logically equivalent to 'x=y'.\n"
"test.cpp:3:note:Assignment 'x=y'\n"
"test.cpp:2:note:Condition 'x!=y' is redundant\n", errout.str());
check("void f(int& x, int y) {\n"
" if (x == y)\n"
" x = y;\n"
" else\n"
" x = 1;\n"
"}");
ASSERT_EQUALS("test.cpp:3:style:Assignment 'x=y' is redundant with condition 'x==y'.\n"
"test.cpp:2:note:Condition 'x==y'\n"
"test.cpp:3:note:Assignment 'x=y' is redundant\n", errout.str());
check("void f(int& x, int y) {\n"
" if (x != y)\n"
" x = y;\n"
" else\n"
" x = 1;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(int& x, int y) {\n"
" if (x == y)\n"
" x = y + 1;\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void g();\n"
"void f(int& x, int y) {\n"
" if (x == y) {\n"
" x = y;\n"
" g();\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
check("bool f(bool b) {\n"
" if (b)\n"
" b = false;\n"
" else\n"
" g();\n"
" return b;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("void f(int& i) {\n"
" if (!i)\n"
" i = 1; \n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("struct S {\n" // #9406
" S() : b(false) {}\n"
" void f() {\n"
" if (b) b = true;\n"
" if (b) b = false;\n"
" if (!b) b = true;\n"
" if (!b) b = false;\n"
" }\n"
" bool b;\n"
"};\n");
ASSERT_EQUALS("test.cpp:4:style:The statement 'if (b) b=true' is redundant.\n"
"test.cpp:4:note:Assignment 'b=true'\n"
"test.cpp:4:note:Condition 'b' is redundant\n"
"test.cpp:5:style:The statement 'if (b) b=false' is logically equivalent to 'b=false'.\n"
"test.cpp:5:note:Assignment 'b=false'\n"
"test.cpp:5:note:Condition 'b' is redundant\n"
"test.cpp:6:style:The statement 'if (!b) b=true' is logically equivalent to 'b=true'.\n"
"test.cpp:6:note:Assignment 'b=true'\n"
"test.cpp:6:note:Condition '!b' is redundant\n"
"test.cpp:7:style:The statement 'if (!b) b=false' is redundant.\n"
"test.cpp:7:note:Assignment 'b=false'\n"
"test.cpp:7:note:Condition '!b' is redundant\n",
errout.str());
}
void checkAssignmentInCondition() {
check("void f(std::string s) {\n"
" if (s=\"123\"){}\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (style) Suspicious assignment in condition. Condition 's=\"123\"' is always true.\n", errout.str());
check("void f(std::string *p) {\n"
" if (p=foo()){}\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void f(uint32_t u) {\n" // #2490
" if ((u = 0x00000000) || (u = 0xffffffff)) {}\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2]: (style) Condition 'u=0x00000000' is always false\n"
"[test.cpp:2]: (style) Condition 'u=0xffffffff' is always true\n",
errout.str());
}
void compareOutOfTypeRange() {
const Settings settingsUnix64 = settingsBuilder().severity(Severity::style).platform(Platform::Type::Unix64).build();
check("void f(unsigned char c) {\n"
" if (c == 256) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("[test.cpp:2]: (style) Comparing expression of type 'unsigned char' against value 256. Condition is always false.\n", errout.str());
check("void f(unsigned char* b, int i) {\n" // #6372
" if (b[i] == 256) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("[test.cpp:2]: (style) Comparing expression of type 'unsigned char' against value 256. Condition is always false.\n", errout.str());
check("void f(unsigned char c) {\n"
" if (c == 255) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("", errout.str());
check("void f(bool b) {\n"
" if (b == true) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("", errout.str());
// #10372
check("void f(signed char x) {\n"
" if (x == 0xff) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("[test.cpp:2]: (style) Comparing expression of type 'signed char' against value 255. Condition is always false.\n", errout.str());
check("void f(short x) {\n"
" if (x == 0xffff) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("[test.cpp:2]: (style) Comparing expression of type 'signed short' against value 65535. Condition is always false.\n", errout.str());
check("void f(int x) {\n"
" if (x == 0xffffffff) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("", errout.str());
check("void f(long x) {\n"
" if (x == ~0L) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("", errout.str());
check("void f(long long x) {\n"
" if (x == ~0LL) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("", errout.str());
check("int f(int x) {\n"
" const int i = 0xFFFFFFFF;\n"
" if (x == i) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("", errout.str());
check("void f() {\n"
" char c;\n"
" if ((c = foo()) != -1) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("", errout.str());
check("void f(int x) {\n"
" if (x < 3000000000) {}\n"
"}", settingsUnix64);
ASSERT_EQUALS("[test.cpp:2]: (style) Comparing expression of type 'signed int' against value 3000000000. Condition is always true.\n", errout.str());
check("void f(const signed char i) {\n" // #8545
" if (i > -129) {}\n" // warn
" if (i >= -128) {}\n" // warn
" if (i >= -127) {}\n"
" if (i < +128) {}\n" // warn
" if (i <= +127) {}\n" // warn
" if (i <= +126) {}\n"
"}\n", settingsUnix64);
ASSERT_EQUALS("[test.cpp:2]: (style) Comparing expression of type 'const signed char' against value -129. Condition is always true.\n"
"[test.cpp:3]: (style) Comparing expression of type 'const signed char' against value -128. Condition is always true.\n"
"[test.cpp:5]: (style) Comparing expression of type 'const signed char' against value 128. Condition is always true.\n"
"[test.cpp:6]: (style) Comparing expression of type 'const signed char' against value 127. Condition is always true.\n",
errout.str());
check("void f(const unsigned char u) {\n"
" if (u > 0) {}\n"
" if (u < 0) {}\n" // warn
" if (u >= 0) {}\n" // warn
" if (u <= 0) {}\n"
" if (u > 255) {}\n" // warn
" if (u < 255) {}\n"
" if (u >= 255) {}\n"
" if (u <= 255) {}\n" // warn
" if (0 < u) {}\n"
" if (0 > u) {}\n" // warn
" if (0 <= u) {}\n" // warn
" if (0 >= u) {}\n"
" if (255 < u) {}\n" // warn
" if (255 > u) {}\n"
" if (255 <= u) {}\n"
" if (255 >= u) {}\n" // warn
"}\n", settingsUnix64);
ASSERT_EQUALS("[test.cpp:3]: (style) Comparing expression of type 'const unsigned char' against value 0. Condition is always false.\n"
"[test.cpp:4]: (style) Comparing expression of type 'const unsigned char' against value 0. Condition is always true.\n"
"[test.cpp:6]: (style) Comparing expression of type 'const unsigned char' against value 255. Condition is always false.\n"
"[test.cpp:9]: (style) Comparing expression of type 'const unsigned char' against value 255. Condition is always true.\n"
"[test.cpp:11]: (style) Comparing expression of type 'const unsigned char' against value 0. Condition is always false.\n"
"[test.cpp:12]: (style) Comparing expression of type 'const unsigned char' against value 0. Condition is always true.\n"
"[test.cpp:14]: (style) Comparing expression of type 'const unsigned char' against value 255. Condition is always false.\n"
"[test.cpp:17]: (style) Comparing expression of type 'const unsigned char' against value 255. Condition is always true.\n",
errout.str());
}
void knownConditionCast() { // #9976
check("void f(int i) {\n"
" if (i < 0 || (unsigned)i > 5) {}\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void knownConditionIncrementLoop() { // #9808
check("void f() {\n"
" int a = 0;\n"
" while (++a < 5) {}\n"
" if (a == 1) {}\n"
" std::cout << a;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
};
REGISTER_TEST(TestCondition)