lambdas.cpp
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// RUN: %clang_analyze_cc1 -std=c++11 -analyzer-checker=core,deadcode,debug.ExprInspection -analyzer-config inline-lambdas=true -verify %s
// RUN: %clang_analyze_cc1 -std=c++11 -analyzer-checker=core -analyzer-config inline-lambdas=false -DNO_INLINING=1 -verify %s
// RUN: %clang_analyze_cc1 -std=c++11 -analyzer-checker=core,debug.DumpCFG -analyzer-config inline-lambdas=true %s > %t 2>&1
// RUN: FileCheck --input-file=%t %s
void clang_analyzer_warnIfReached();
void clang_analyzer_eval(int);
#ifdef NO_INLINING
// expected-no-diagnostics
int& invalidate_static_on_unknown_lambda() {
static int* z;
auto f = [] {
z = nullptr;
}; // should invalidate "z" when inlining is disabled.
f();
return *z; // no-warning
}
#else
struct X { X(const X&); };
void f(X x) { (void) [x]{}; }
// Lambda semantics tests.
void basicCapture() {
int i = 5;
[i]() mutable {
// clang_analyzer_eval does nothing in inlined functions.
if (i != 5)
clang_analyzer_warnIfReached();
++i;
}();
[&i] {
if (i != 5)
clang_analyzer_warnIfReached();
}();
[&i] {
if (i != 5)
clang_analyzer_warnIfReached();
i++;
}();
clang_analyzer_eval(i == 6); // expected-warning{{TRUE}}
}
void deferredLambdaCall() {
int i = 5;
auto l1 = [i]() mutable {
if (i != 5)
clang_analyzer_warnIfReached();
++i;
};
auto l2 = [&i] {
if (i != 5)
clang_analyzer_warnIfReached();
};
auto l3 = [&i] {
if (i != 5)
clang_analyzer_warnIfReached();
i++;
};
l1();
l2();
l3();
clang_analyzer_eval(i == 6); // expected-warning{{TRUE}}
}
void multipleCaptures() {
int i = 5, j = 5;
[i, &j]() mutable {
if (i != 5 && j != 5)
clang_analyzer_warnIfReached();
++i;
++j;
}();
clang_analyzer_eval(i == 5); // expected-warning{{TRUE}}
clang_analyzer_eval(j == 6); // expected-warning{{TRUE}}
[=]() mutable {
if (i != 5 && j != 6)
clang_analyzer_warnIfReached();
++i;
++j;
}();
clang_analyzer_eval(i == 5); // expected-warning{{TRUE}}
clang_analyzer_eval(j == 6); // expected-warning{{TRUE}}
[&]() mutable {
if (i != 5 && j != 6)
clang_analyzer_warnIfReached();
++i;
++j;
}();
clang_analyzer_eval(i == 6); // expected-warning{{TRUE}}
clang_analyzer_eval(j == 7); // expected-warning{{TRUE}}
}
void testReturnValue() {
int i = 5;
auto l = [i] (int a) {
return i + a;
};
int b = l(3);
clang_analyzer_eval(b == 8); // expected-warning{{TRUE}}
}
void testAliasingBetweenParameterAndCapture() {
int i = 5;
auto l = [&i](int &p) {
i++;
p++;
};
l(i);
clang_analyzer_eval(i == 7); // expected-warning{{TRUE}}
}
// Nested lambdas.
void testNestedLambdas() {
int i = 5;
auto l = [i]() mutable {
[&i]() {
++i;
}();
if (i != 6)
clang_analyzer_warnIfReached();
};
l();
clang_analyzer_eval(i == 5); // expected-warning{{TRUE}}
}
// Captured this.
class RandomClass {
int i;
void captureFields() {
i = 5;
[this]() {
// clang_analyzer_eval does nothing in inlined functions.
if (i != 5)
clang_analyzer_warnIfReached();
++i;
}();
clang_analyzer_eval(i == 6); // expected-warning{{TRUE}}
}
};
// Nested this capture.
class RandomClass2 {
int i;
void captureFields() {
i = 5;
[this]() {
// clang_analyzer_eval does nothing in inlined functions.
if (i != 5)
clang_analyzer_warnIfReached();
++i;
[this]() {
// clang_analyzer_eval does nothing in inlined functions.
if (i != 6)
clang_analyzer_warnIfReached();
++i;
}();
}();
clang_analyzer_eval(i == 7); // expected-warning{{TRUE}}
}
};
// Captured function pointers.
void inc(int &x) {
++x;
}
void testFunctionPointerCapture() {
void (*func)(int &) = inc;
int i = 5;
[&i, func] {
func(i);
}();
clang_analyzer_eval(i == 6); // expected-warning{{TRUE}}
}
// Captured variable-length array.
void testVariableLengthArrayCaptured() {
int n = 2;
int array[n];
array[0] = 7;
int i = [&]{
return array[0];
}();
clang_analyzer_eval(i == 7); // expected-warning{{TRUE}}
}
// Test inline defensive checks
int getNum();
void inlineDefensiveChecks() {
int i = getNum();
[=]() {
if (i == 0)
;
}();
int p = 5/i;
(void)p;
}
template<typename T>
void callLambda(T t) {
t();
}
struct DontCrash {
int x;
void f() {
callLambda([&](){ ++x; });
callLambdaFromStatic([&](){ ++x; });
}
template<typename T>
static void callLambdaFromStatic(T t) {
t();
}
};
// Capture constants
void captureConstants() {
const int i = 5;
[=]() {
if (i != 5)
clang_analyzer_warnIfReached();
}();
[&] {
if (i != 5)
clang_analyzer_warnIfReached();
}();
}
void captureReferenceByCopy(int &p) {
int v = 7;
p = 8;
// p is a reference captured by copy
[&v,p]() mutable {
v = p;
p = 22;
}();
clang_analyzer_eval(v == 8); // expected-warning{{TRUE}}
clang_analyzer_eval(p == 8); // expected-warning{{TRUE}}
}
void captureReferenceByReference(int &p) {
int v = 7;
p = 8;
// p is a reference captured by reference
[&v,&p]() {
v = p;
p = 22;
}();
clang_analyzer_eval(v == 8); // expected-warning{{TRUE}}
clang_analyzer_eval(p == 22); // expected-warning{{TRUE}}
}
void callMutableLambdaMultipleTimes(int &p) {
int v = 0;
p = 8;
auto l = [&v, p]() mutable {
v = p;
p++;
};
l();
clang_analyzer_eval(v == 8); // expected-warning{{TRUE}}
clang_analyzer_eval(p == 8); // expected-warning{{TRUE}}
l();
clang_analyzer_eval(v == 9); // expected-warning{{TRUE}}
clang_analyzer_eval(p == 8); // expected-warning{{TRUE}}
}
// PR 24914
struct StructPR24914{
int x;
};
void takesConstStructArgument(const StructPR24914&);
void captureStructReference(const StructPR24914& s) {
[s]() {
takesConstStructArgument(s);
}();
}
// Lambda capture counts as use for dead-store checking.
int returnsValue();
void captureByCopyCausesUse() {
int local1 = returnsValue(); // no-warning
int local2 = returnsValue(); // no-warning
int local3 = returnsValue(); // expected-warning{{Value stored to 'local3' during its initialization is never read}}
(void)[local1, local2]() { }; // Explicit capture by copy counts as use.
int local4 = returnsValue(); // no-warning
int local5 = returnsValue(); // expected-warning{{Value stored to 'local5' during its initialization is never read}}
(void)[=]() {
(void)local4; // Implicit capture by copy counts as use
};
}
void captureByReference() {
int local1 = returnsValue(); // no-warning
auto lambda1 = [&local1]() { // Explicit capture by reference
local1++;
};
// Don't treat as a dead store because local1 was was captured by reference.
local1 = 7; // no-warning
lambda1();
int local2 = returnsValue(); // no-warning
auto lambda2 = [&]() {
local2++; // Implicit capture by reference
};
// Don't treat as a dead store because local2 was was captured by reference.
local2 = 7; // no-warning
lambda2();
}
void testCapturedConstExprFloat() {
constexpr float localConstant = 4.0;
auto lambda = []{
// Don't treat localConstant as containing a garbage value
float copy = localConstant; // no-warning
(void)copy;
};
lambda();
}
void escape(void*);
int& invalidate_static_on_unknown_lambda() {
static int* z;
auto lambda = [] {
static float zz;
z = new int(120);
};
escape(&lambda);
return *z; // no-warning
}
static int b = 0;
int f() {
b = 0;
auto &bm = b;
[&] {
bm++;
bm++;
}();
if (bm != 2) {
int *y = 0;
return *y; // no-warning
}
return 0;
}
#endif
// CHECK: [B2 (ENTRY)]
// CHECK: Succs (1): B1
// CHECK: [B1]
// CHECK: 1: x
// CHECK: 2: [B1.1] (ImplicitCastExpr, NoOp, const struct X)
// CHECK: 3: [B1.2] (CXXConstructExpr, struct X)
// CHECK: 4: [x] {
// CHECK: }
// CHECK: 5: (void)[B1.4] (CStyleCastExpr, ToVoid, void)
// CHECK: Preds (1): B2
// CHECK: Succs (1): B0
// CHECK: [B0 (EXIT)]
// CHECK: Preds (1): B1