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| // RUN: %clang_analyze_cc1 -analyzer-checker=core,deadcode.DeadStores,alpha.deadcode.UnreachableCode -verify -analyzer-opt-analyze-nested-blocks -Wno-unused-value %s
extern void foo(int a);
// The first few tests are non-path specific - we should be able to find them
void test(unsigned a) {
switch (a) {
a += 5; // expected-warning{{never executed}}
case 2:
a *= 10;
case 3:
a %= 2;
}
foo(a);
}
void test2(unsigned a) {
help:
if (a > 0)
return;
if (a == 0)
return;
foo(a); // expected-warning{{never executed}}
goto help;
}
void test3(unsigned a) {
while(1);
if (a > 5) { // expected-warning{{never executed}}
return;
}
}
// These next tests are path-sensitive
void test4() {
int a = 5;
while (a > 1)
a -= 2;
if (a > 1) {
a = a + 56; // expected-warning{{never executed}}
}
foo(a);
}
extern void bar(char c);
void test5(const char *c) {
foo(c[0]);
if (!c) {
bar(1); // expected-warning{{never executed}}
}
}
// These next tests are false positives and should not generate warnings
void test6(const char *c) {
if (c) return;
if (!c) return;
__builtin_unreachable(); // no-warning
__builtin_assume(0); // no-warning
}
// Compile-time constant false positives
#define CONSTANT 0
enum test_enum { Off, On };
void test7() {
if (CONSTANT)
return; // no-warning
if (sizeof(int))
return; // no-warning
if (Off)
return; // no-warning
}
void test8() {
static unsigned a = 0;
if (a)
a = 123; // no-warning
a = 5;
}
// Check for bugs where multiple statements are reported
void test9(unsigned a) {
switch (a) {
if (a) // expected-warning{{never executed}}
foo(a + 5); // no-warning
else // no-warning
foo(a); // no-warning
case 1:
case 2:
break;
default:
break;
}
}
// Tests from flow-sensitive version
void test10() {
goto c;
d:
goto e; // expected-warning {{never executed}}
c: ;
int i;
return;
goto b; // expected-warning {{never executed}}
goto a; // expected-warning {{never executed}}
b:
i = 1; // no-warning
a:
i = 2; // no-warning
goto f;
e:
goto d;
f: ;
}
// test11: we can actually end up in the default case, even if it is not
// obvious: there might be something wrong with the given argument.
enum foobar { FOO, BAR };
extern void error();
void test11(enum foobar fb) {
switch (fb) {
case FOO:
break;
case BAR:
break;
default:
error(); // no-warning
return;
error(); // expected-warning {{never executed}}
}
}
void inlined(int condition) {
if (condition) {
foo(5); // no-warning
} else {
foo(6);
}
}
void testInlined() {
extern int coin();
int cond = coin();
if (!cond) {
inlined(0);
if (cond) {
foo(5); // expected-warning {{never executed}}
}
}
}
// Don't warn about unreachable VarDecl.
void dostuff(int*A);
void varDecl1(int X) {
switch (X) {
int A; // No warning here.
case 1:
dostuff(&A);
break;
case 2:
dostuff(&A);
break;
}
}
void varDecl2(int X) {
switch (X) {
int A=1; // expected-warning {{never executed}}
case 1:
dostuff(&A);
break;
case 2:
dostuff(&A);
break;
}
}
// Ensure that ExplodedGraph and unoptimized CFG match.
void test12(int x) {
switch (x) {
case 1:
break; // not unreachable
case 2:
do { } while (0);
break;
}
}
// Don't merge return nodes in ExplodedGraph unless they are same.
extern int table[];
static int inlineFunction(const int i) {
if (table[i] != 0)
return 1;
return 0;
}
void test13(int i) {
int x = inlineFunction(i);
x && x < 10; // no-warning
}
// Don't warn in a macro
#define RETURN(X) do { return; } while (0)
void macro(void) {
RETURN(1); // no-warning
}
// Avoid FP when macro argument is known
void writeSomething(int *x);
#define MACRO(C) \
if (!C) { \
static int x; \
writeSomething(&x); \
}
void macro2(void) {
MACRO(1);
}
|