forked from OSchip/llvm-project
505 lines
13 KiB
C
505 lines
13 KiB
C
// RUN: %clang_cc1 %s -fsyntax-only -verify -fblocks -Wunreachable-code-aggressive -Wno-unused-value -Wno-covered-switch-default -I %S/Inputs
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// RUN: %clang_cc1 -fsyntax-only -fblocks -Wunreachable-code-aggressive -Wno-unused-value -Wno-covered-switch-default -fdiagnostics-parseable-fixits -I %S/Inputs %s 2>&1 | FileCheck %s
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#include "warn-unreachable.h"
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int halt() __attribute__((noreturn));
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int live();
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int dead();
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void test1() {
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goto c;
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d:
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goto e; // expected-warning {{will never be executed}}
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c: ;
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int i;
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return;
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goto b; // expected-warning {{will never be executed}}
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goto a; // expected-warning {{will never be executed}}
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b:
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i = 1;
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a:
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i = 2;
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goto f;
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e:
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goto d;
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f: ;
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}
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void test2() {
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int i;
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switch (live()) {
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case 1:
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halt(),
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dead(); // expected-warning {{will never be executed}}
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case 2:
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live(), halt(),
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dead(); // expected-warning {{will never be executed}}
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case 3:
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live()
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+ // expected-warning {{will never be executed}}
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halt();
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dead();
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case 4:
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a4:
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live(),
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halt();
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goto a4; // expected-warning {{will never be executed}}
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case 5:
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goto a5;
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c5:
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dead(); // expected-warning {{will never be executed}}
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goto b5;
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a5:
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live(),
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halt();
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b5:
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goto c5;
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case 6:
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if (live())
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goto e6;
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live(),
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halt();
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d6:
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dead(); // expected-warning {{will never be executed}}
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goto b6;
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c6:
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dead();
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goto b6;
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e6:
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live(),
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halt();
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b6:
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goto c6;
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case 7:
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halt()
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+
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dead(); // expected-warning {{will never be executed}}
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- // expected-warning {{will never be executed}}
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halt();
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case 8:
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i
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+= // expected-warning {{will never be executed}}
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halt();
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case 9:
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halt()
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? // expected-warning {{will never be executed}}
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dead() : dead();
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case 10:
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( // expected-warning {{will never be executed}}
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float)halt();
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case 11: {
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int a[5];
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live(),
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a[halt()
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]; // expected-warning {{will never be executed}}
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}
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}
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}
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enum Cases { C1, C2, C3 };
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int test_enum_cases(enum Cases C) {
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switch (C) {
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case C1:
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case C2:
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case C3:
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return 1;
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default: {
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int i = 0; // no-warning
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++i;
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return i;
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}
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}
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}
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// Handle unreachable code triggered by macro expansions.
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void __myassert_rtn(const char *, const char *, int, const char *) __attribute__((__noreturn__));
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#define myassert(e) \
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(__builtin_expect(!(e), 0) ? __myassert_rtn(__func__, __FILE__, __LINE__, #e) : (void)0)
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void test_assert() {
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myassert(0 && "unreachable");
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return; // no-warning
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}
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// Test case for PR 9774. Tests that dead code in macros aren't warned about.
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#define MY_MAX(a,b) ((a) >= (b) ? (a) : (b))
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void PR9774(int *s) {
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for (int i = 0; i < MY_MAX(2, 3); i++) // no-warning
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s[i] = 0;
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}
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// Test case for <rdar://problem/11005770>. We should treat code guarded
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// by 'x & 0' and 'x * 0' as unreachable.
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int calledFun();
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void test_mul_and_zero(int x) {
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if (x & 0) calledFun(); // expected-warning {{will never be executed}}
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if (0 & x) calledFun(); // expected-warning {{will never be executed}}
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if (x * 0) calledFun(); // expected-warning {{will never be executed}}
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if (0 * x) calledFun(); // expected-warning {{will never be executed}}
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}
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void raze() __attribute__((noreturn));
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void warn_here();
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int test_break_preceded_by_noreturn(int i) {
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switch (i) {
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case 1:
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raze();
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break; // expected-warning {{'break' will never be executed}}
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case 2:
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raze();
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break; // expected-warning {{'break' will never be executed}}
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warn_here(); // expected-warning {{will never be executed}}
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case 3:
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return 1;
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break; // expected-warning {{will never be executed}}
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default:
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break;
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break; // expected-warning {{will never be executed}}
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}
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return i;
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}
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// Don't warn about unreachable 'default' cases, as that is covered
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// by -Wcovered-switch-default.
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typedef enum { Value1 = 1 } MyEnum;
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void unreachable_default(MyEnum e) {
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switch (e) {
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case Value1:
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calledFun();
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break;
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case 2: // expected-warning {{case value not in enumerated type 'MyEnum'}}
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calledFun();
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break;
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default:
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calledFun(); // no-warning
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break;
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}
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}
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void unreachable_in_default(MyEnum e) {
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switch (e) {
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default:
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raze();
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calledFun(); // expected-warning {{will never be executed}}
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break;
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}
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}
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// Don't warn about trivial dead returns.
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int trivial_dead_return() {
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raze();
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return ((0)); // expected-warning {{'return' will never be executed}}
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}
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void trivial_dead_return_void() {
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raze();
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return; // expected-warning {{'return' will never be executed}}
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}
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MyEnum trivial_dead_return_enum() {
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raze();
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return Value1; // expected-warning {{'return' will never be executed}}
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}
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MyEnum trivial_dead_return_enum_2(int x) {
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switch (x) {
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case 1: return 1;
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case 2: return 2;
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case 3: return 3;
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default: return 4;
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}
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return 2; // expected-warning {{will never be executed}}
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}
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const char *trivial_dead_return_cstr() {
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raze();
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return ""; // expected-warning {{return' will never be executed}}
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}
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char trivial_dead_return_char() {
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raze();
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return ' '; // expected-warning {{return' will never be executed}}
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}
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MyEnum nontrivial_dead_return_enum_2(int x) {
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switch (x) {
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case 1: return 1;
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case 2: return 2;
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case 3: return 3;
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default: return 4;
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}
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return calledFun(); // expected-warning {{will never be executed}}
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}
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enum X { A, B, C };
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int covered_switch(enum X x) {
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switch (x) {
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case A: return 1;
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case B: return 2;
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case C: return 3;
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}
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return 4; // no-warning
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}
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// Test unreachable code depending on configuration values
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#define CONFIG_CONSTANT 1
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int test_config_constant(int x) {
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if (!CONFIG_CONSTANT) {
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calledFun(); // no-warning
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return 1;
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}
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if (!1) { // expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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calledFun(); // expected-warning {{will never be executed}}
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return 1;
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}
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if (sizeof(int) > sizeof(char)) {
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calledFun(); // no-warning
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return 1;
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}
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if (x > 10)
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return CONFIG_CONSTANT ? calledFun() : calledFun(); // no-warning
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else
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return 1 ? // expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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calledFun() :
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calledFun(); // expected-warning {{will never be executed}}
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}
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int sizeof_int(int x, int y) {
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if (sizeof(long) == sizeof(int))
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return 1; // no-warning
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if (sizeof(long) != sizeof(int))
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return 0; // no-warning
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if (x && y && sizeof(long) < sizeof(char))
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return 0; // no-warning
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return 2; // no-warning
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}
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enum MyEnum2 {
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ME_A = CONFIG_CONSTANT,
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ME_B = 1
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};
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int test_MyEnum() {
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if (!ME_A)
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return 1; // no-warning
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if (ME_A)
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return 2; // no-warning
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if (ME_B)
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return 3;
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if (!ME_B) // expected-warning {{will never be executed}}
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return 4; // expected-warning {{will never be executed}}
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return 5;
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}
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// Test for idiomatic do..while.
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int test_do_while(int x) {
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do {
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if (x == calledFun())
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break;
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++x;
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break;
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}
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while (0); // no-warning
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return x;
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}
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int test_do_while_nontrivial_cond(int x) {
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do {
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if (x == calledFun())
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break;
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++x;
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break;
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}
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while (calledFun()); // expected-warning {{will never be executed}}
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return x;
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}
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// Diagnostic control: -Wunreachable-code-return.
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#pragma clang diagnostic push
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#pragma clang diagnostic ignored "-Wunreachable-code-return"
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void trivial_dead_return_void_SUPPRESSED() {
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raze();
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return; // no-warning
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}
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MyEnum trivial_dead_return_enum_SUPPRESSED() {
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raze();
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return Value1; // no-warning
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}
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#pragma clang diagnostic pop
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// Diagnostic control: -Wunreachable-code-break.
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#pragma clang diagnostic push
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#pragma clang diagnostic ignored "-Wunreachable-code-break"
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int test_break_preceded_by_noreturn_SUPPRESSED(int i) {
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switch (i) {
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case 1:
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raze();
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break; // no-warning
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case 2:
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raze();
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break; // no-warning
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warn_here(); // expected-warning {{will never be executed}}
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case 3:
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return 1;
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break; // no-warning
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default:
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break;
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break; // no-warning
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}
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return i;
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}
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#pragma clang diagnostic pop
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// Test "silencing" with parentheses.
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void test_with_paren_silencing(int x) {
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if (0) calledFun(); // expected-warning {{will never be executed}} expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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if ((0)) calledFun(); // no-warning
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if (1) // expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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calledFun();
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else
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calledFun(); // expected-warning {{will never be executed}}
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if ((1))
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calledFun();
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else
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calledFun(); // no-warning
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if (!1) // expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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calledFun(); // expected-warning {{code will never be executed}}
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else
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calledFun();
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if ((!1))
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calledFun(); // no-warning
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else
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calledFun();
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if (!(1))
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calledFun(); // no-warning
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else
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calledFun();
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}
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// rdar://24570531
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struct StructWithPointer {
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void *p;
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};
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void emitJustOneWarningForOr(struct StructWithPointer *s) {
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if (1 || !s->p) // expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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return; // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:7-[[@LINE-1]]:7}:"/* DISABLES CODE */ ("
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// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:8-[[@LINE-2]]:8}:")"
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emitJustOneWarningForOr(s); // expected-warning {{code will never be executed}}
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}
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void emitJustOneWarningForOrSilenced(struct StructWithPointer *s) {
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if ((1) || !s->p)
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return;
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emitJustOneWarningForOrSilenced(s); // no warning
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}
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void emitJustOneWarningForOr2(struct StructWithPointer *s) {
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if (1 || !s->p) // expected-warning {{code will never be executed}}
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return; // expected-note@-1 {{silence by adding parentheses to mark code as explicitly dead}}
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// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:7-[[@LINE-2]]:7}:"/* DISABLES CODE */ ("
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// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:8-[[@LINE-3]]:8}:")"
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}
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void wrapOneInFixit(struct StructWithPointer *s) {
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if (!s->p || 1) // expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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return; // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:16-[[@LINE-1]]:16}:"/* DISABLES CODE */ ("
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// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:17-[[@LINE-2]]:17}:")"
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wrapOneInFixit(s); // expected-warning {{code will never be executed}}
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}
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void unaryOpNoFixit() {
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if (~ 1)
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return; // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]
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unaryOpNoFixit(); // expected-warning {{code will never be executed}}
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}
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void unaryOpStrictFixit(struct StructWithPointer *s) {
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if (!(s->p && 0)) // expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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return; // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:17-[[@LINE-1]]:17}:"/* DISABLES CODE */ ("
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// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:18-[[@LINE-2]]:18}:")"
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unaryOpStrictFixit(s); // expected-warning {{code will never be executed}}
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}
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void unaryOpFixitCastSubExpr(int x) {
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if (! (int)0) // expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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return; // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:7-[[@LINE-1]]:7}:"/* DISABLES CODE */ ("
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// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:15-[[@LINE-2]]:15}:")"
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unaryOpFixitCastSubExpr(x); // expected-warning {{code will never be executed}}
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}
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#define false 0
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#define true 1
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void testTrueFalseMacros() {
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if (false) // expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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testTrueFalseMacros(); // expected-warning {{code will never be executed}}
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if (!true) // expected-note {{silence by adding parentheses to mark code as explicitly dead}}
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testTrueFalseMacros(); // expected-warning {{code will never be executed}}
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}
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int pr13910_foo(int x) {
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if (x == 1)
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return 0;
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else
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return x;
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__builtin_unreachable(); // expected no warning
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__builtin_assume(0); // expected no warning
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}
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int pr13910_bar(int x) {
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switch (x) {
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default:
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return x + 1;
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}
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pr13910_foo(x); // expected-warning {{code will never be executed}}
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}
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int pr13910_bar2(int x) {
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if (x == 1)
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return 0;
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else
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return x;
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pr13910_foo(x); // expected-warning {{code will never be executed}}
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__builtin_unreachable(); // expected no warning
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__builtin_assume(0); // expected no warning
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pr13910_foo(x); // expected-warning {{code will never be executed}}
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}
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void pr13910_noreturn() {
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raze();
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__builtin_unreachable(); // expected no warning
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__builtin_assume(0); // expected no warning
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}
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void pr13910_assert() {
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myassert(0 && "unreachable");
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return;
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__builtin_unreachable(); // expected no warning
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__builtin_assume(0); // expected no warning
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}
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