531 lines
12 KiB
C
531 lines
12 KiB
C
// RUN: %clang_cc1 -Wunused-variable -analyze -analyzer-checker=core.DeadStores,core.experimental.IdempotentOps -analyzer-check-objc-mem -fblocks -verify -Wno-unreachable-code -analyzer-opt-analyze-nested-blocks %s
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// RUN: %clang_cc1 -Wunused-variable -analyze -analyzer-checker=core.DeadStores,core.experimental.IdempotentOps -analyzer-check-objc-mem -analyzer-store=basic -analyzer-constraints=basic -fblocks -verify -Wno-unreachable-code -analyzer-opt-analyze-nested-blocks %s
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// RUN: %clang_cc1 -Wunused-variable -analyze -analyzer-checker=core.DeadStores,core.experimental.IdempotentOps -analyzer-check-objc-mem -analyzer-store=basic -analyzer-constraints=range -fblocks -verify -Wno-unreachable-code -analyzer-opt-analyze-nested-blocks %s
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// RUN: %clang_cc1 -Wunused-variable -analyze -analyzer-checker=core.DeadStores,core.experimental.IdempotentOps -analyzer-check-objc-mem -analyzer-store=region -analyzer-constraints=basic -fblocks -verify -Wno-unreachable-code -analyzer-opt-analyze-nested-blocks %s
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// RUN: %clang_cc1 -Wunused-variable -analyze -analyzer-checker=core.DeadStores,core.experimental.IdempotentOps -analyzer-check-objc-mem -analyzer-store=region -analyzer-constraints=range -fblocks -verify -Wno-unreachable-code -analyzer-opt-analyze-nested-blocks %s
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void f1() {
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int k, y; // expected-warning{{unused variable 'k'}} expected-warning{{unused variable 'y'}}
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int abc=1;
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long idx=abc+3*5; // expected-warning {{never read}} expected-warning{{unused variable 'idx'}}
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}
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void f2(void *b) {
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char *c = (char*)b; // no-warning
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char *d = b+1; // expected-warning {{never read}} expected-warning{{unused variable 'd'}}
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printf("%s", c); // expected-warning{{implicitly declaring C library function 'printf' with type 'int (const char *, ...)'}} \
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// expected-note{{please include the header <stdio.h> or explicitly provide a declaration for 'printf'}}
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}
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int f();
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void f3() {
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int r;
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if ((r = f()) != 0) { // no-warning
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int y = r; // no-warning
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printf("the error is: %d\n", y);
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}
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}
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void f4(int k) {
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k = 1;
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if (k)
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f1();
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k = 2; // expected-warning {{never read}}
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}
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void f5() {
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int x = 4; // no-warning
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int *p = &x; // expected-warning{{never read}} expected-warning{{unused variable 'p'}}
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}
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//
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int f6() {
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int x = 4;
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++x; // no-warning
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return 1;
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}
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int f7(int *p) {
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// This is allowed for defensive programming.
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p = 0; // no-warning
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return 1;
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}
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int f7b(int *p) {
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// This is allowed for defensive programming.
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p = (0); // no-warning
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return 1;
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}
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int f7c(int *p) {
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// This is allowed for defensive programming.
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p = (void*) 0; // no-warning
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return 1;
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}
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int f7d(int *p) {
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// This is allowed for defensive programming.
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p = (void*) (0); // no-warning
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return 1;
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}
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// Don't warn for dead stores in nested expressions. We have yet
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// to see a real bug in this scenario.
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int f8(int *p) {
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extern int *baz();
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if ((p = baz())) // no-warning
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return 1;
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return 0;
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}
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int f9() {
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int x = 4;
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x = x + 10; // expected-warning{{never read}}
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return 1;
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}
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int f10() {
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int x = 4;
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x = 10 + x; // expected-warning{{never read}}
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return 1;
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}
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int f11() {
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int x = 4;
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return x++; // expected-warning{{never read}}
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}
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int f11b() {
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int x = 4;
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return ((((++x)))); // no-warning
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}
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int f12a(int y) {
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int x = y; // expected-warning{{unused variable 'x'}}
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return 1;
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}
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int f12b(int y) {
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int x __attribute__((unused)) = y; // no-warning
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return 1;
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}
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int f12c(int y) {
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// Allow initialiation of scalar variables by parameters as a form of
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// defensive programming.
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int x = y; // no-warning
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x = 1;
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return x;
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}
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// Filed with PR 2630. This code should produce no warnings.
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int f13(void)
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{
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int a = 1;
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int b, c = b = a + a;
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if (b > 0)
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return (0);
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return (a + b + c);
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}
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// Filed with PR 2763.
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int f14(int count) {
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int index, nextLineIndex;
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for (index = 0; index < count; index = nextLineIndex+1) {
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nextLineIndex = index+1; // no-warning
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continue;
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}
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return index;
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}
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// Test case for <rdar://problem/6248086>
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void f15(unsigned x, unsigned y) {
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int count = x * y; // no-warning
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int z[count]; // expected-warning{{unused variable 'z'}}
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}
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// Don't warn for dead stores in nested expressions. We have yet
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// to see a real bug in this scenario.
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int f16(int x) {
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x = x * 2;
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x = sizeof(int [x = (x || x + 1) * 2]) // expected-warning{{The left operand to '+' is always 0}} expected-warning{{The left operand to '*' is always 1}}
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? 5 : 8;
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return x;
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}
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// Self-assignments should not be flagged as dead stores.
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void f17() {
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int x = 1;
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x = x;
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}
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// <rdar://problem/6506065>
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// The values of dead stores are only "consumed" in an enclosing expression
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// what that value is actually used. In other words, don't say "Although the
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// value stored to 'x' is used...".
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int f18() {
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int x = 0; // no-warning
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if (1)
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x = 10; // expected-warning{{Value stored to 'x' is never read}}
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while (1)
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x = 10; // expected-warning{{Value stored to 'x' is never read}}
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// unreachable.
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do
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x = 10; // no-warning
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while (1);
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return (x = 10); // no-warning
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}
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int f18_a() {
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int x = 0; // no-warning
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return (x = 10); // no-warning
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}
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void f18_b() {
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int x = 0; // no-warning
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if (1)
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x = 10; // expected-warning{{Value stored to 'x' is never read}}
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}
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void f18_c() {
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int x = 0;
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while (1)
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x = 10; // expected-warning{{Value stored to 'x' is never read}}
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}
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void f18_d() {
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int x = 0; // no-warning
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do
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x = 10; // expected-warning{{Value stored to 'x' is never read}}
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while (1);
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}
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// PR 3514: false positive `dead initialization` warning for init to global
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// http://llvm.org/bugs/show_bug.cgi?id=3514
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extern const int MyConstant;
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int f19(void) {
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int x = MyConstant; // no-warning
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x = 1;
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return x;
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}
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int f19b(void) { // This case is the same as f19.
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const int MyConstant = 0;
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int x = MyConstant; // no-warning
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x = 1;
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return x;
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}
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void f20(void) {
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int x = 1; // no-warning
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#pragma unused(x)
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}
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void halt() __attribute__((noreturn));
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int f21() {
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int x = 4;
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x = x + 1; // expected-warning{{never read}}
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if (1) {
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halt();
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(void)x;
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}
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return 1;
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}
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int j;
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void f22() {
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int x = 4;
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int y1 = 4;
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int y2 = 4;
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int y3 = 4;
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int y4 = 4;
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int y5 = 4;
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int y6 = 4;
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int y7 = 4;
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int y8 = 4;
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int y9 = 4;
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int y10 = 4;
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int y11 = 4;
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int y12 = 4;
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int y13 = 4;
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int y14 = 4;
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int y15 = 4;
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int y16 = 4;
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int y17 = 4;
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int y18 = 4;
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int y19 = 4;
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int y20 = 4;
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x = x + 1; // expected-warning{{never read}}
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++y1;
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++y2;
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++y3;
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++y4;
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++y5;
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++y6;
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++y7;
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++y8;
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++y9;
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++y10;
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++y11;
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++y12;
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++y13;
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++y14;
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++y15;
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++y16;
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++y17;
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++y18;
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++y19;
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++y20;
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switch (j) {
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case 1:
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if (0)
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|
(void)x;
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if (1) {
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(void)y1;
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return;
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}
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(void)x;
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break;
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case 2:
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if (0)
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(void)x;
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else {
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|
(void)y2;
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return;
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|
}
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(void)x;
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|
break;
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case 3:
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if (1) {
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(void)y3;
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return;
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} else
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(void)x;
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(void)x;
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break;
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case 4:
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0 ? : ((void)y4, ({ return; }));
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(void)x;
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break;
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case 5:
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1 ? : (void)x;
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0 ? (void)x : ((void)y5, ({ return; }));
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(void)x;
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break;
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case 6:
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1 ? ((void)y6, ({ return; })) : (void)x;
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|
(void)x;
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break;
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|
case 7:
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|
(void)(0 && x);
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|
(void)y7;
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(void)(0 || (y8, ({ return; }), 1)); // expected-warning {{expression result unused}}
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(void)x;
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break;
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case 8:
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(void)(1 && (y9, ({ return; }), 1)); // expected-warning {{expression result unused}}
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(void)x;
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|
break;
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case 9:
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|
(void)(1 || x);
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|
(void)y10;
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|
break;
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|
case 10:
|
|
while (0) {
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|
(void)x;
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|
}
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|
(void)y11;
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|
break;
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|
case 11:
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|
while (1) {
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|
(void)y12;
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}
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(void)x;
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break;
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case 12:
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do {
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(void)y13;
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|
} while (0);
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(void)y14;
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|
break;
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|
case 13:
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|
do {
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|
(void)y15;
|
|
} while (1);
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|
(void)x;
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break;
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|
case 14:
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|
for (;;) {
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|
(void)y16;
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|
}
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|
(void)x;
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|
break;
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|
case 15:
|
|
for (;1;) {
|
|
(void)y17;
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|
}
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|
(void)x;
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|
break;
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|
case 16:
|
|
for (;0;) {
|
|
(void)x;
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|
}
|
|
(void)y18;
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|
break;
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|
case 17:
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|
__builtin_choose_expr(0, (void)x, ((void)y19, ({ return; })));
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|
(void)x;
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|
break;
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|
case 19:
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__builtin_choose_expr(1, ((void)y20, ({ return; })), (void)x);
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(void)x;
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|
break;
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|
}
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|
}
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void f23_aux(const char* s);
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void f23(int argc, char **argv) {
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int shouldLog = (argc > 1); // no-warning
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^{
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if (shouldLog) f23_aux("I did too use it!\n");
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else f23_aux("I shouldn't log. Wait.. d'oh!\n");
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}();
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}
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void f23_pos(int argc, char **argv) {
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int shouldLog = (argc > 1); // expected-warning{{Value stored to 'shouldLog' during its initialization is never read}} expected-warning{{unused variable 'shouldLog'}}
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^{
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f23_aux("I did too use it!\n");
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}();
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}
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void f24_A(int y) {
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// FIXME: One day this should be reported as dead since 'z = x + y' is dead.
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int x = (y > 2); // no-warning
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^ {
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int z = x + y; // expected-warning{{Value stored to 'z' during its initialization is never read}} expected-warning{{unused variable 'z'}}
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}();
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}
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void f24_B(int y) {
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// FIXME: One day this should be reported as dead since 'x' is just overwritten.
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__block int x = (y > 2); // no-warning
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^{
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// FIXME: This should eventually be a dead store since it is never read either.
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x = 5; // no-warning
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}();
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}
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int f24_C(int y) {
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// FIXME: One day this should be reported as dead since 'x' is just overwritten.
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__block int x = (y > 2); // no-warning
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^{
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x = 5; // no-warning
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}();
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return x;
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}
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int f24_D(int y) {
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__block int x = (y > 2); // no-warning
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^{
|
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if (y > 4)
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x = 5; // no-warning
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}();
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return x;
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}
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|
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// This example shows that writing to a variable captured by a block means that it might
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// not be dead.
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int f25(int y) {
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__block int x = (y > 2);
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__block int z = 0;
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void (^foo)() = ^{ z = x + y; };
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x = 4; // no-warning
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foo();
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return z;
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|
}
|
|
|
|
// This test is mostly the same as 'f25', but shows that the heuristic of pruning out dead
|
|
// stores for variables that are just marked '__block' is overly conservative.
|
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int f25_b(int y) {
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// FIXME: we should eventually report a dead store here.
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__block int x = (y > 2);
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__block int z = 0;
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x = 4; // no-warning
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return z;
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}
|
|
|
|
int f26_nestedblocks() {
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int z;
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z = 1;
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__block int y = 0;
|
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^{
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|
int k;
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k = 1; // expected-warning{{Value stored to 'k' is never read}}
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^{
|
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y = z + 1;
|
|
}();
|
|
}();
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return y;
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}
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|
|
// The FOREACH macro in QT uses 'break' statements within statement expressions
|
|
// placed within the increment code of for loops.
|
|
void rdar8014335() {
|
|
for (int i = 0 ; i != 10 ; ({ break; })) {
|
|
for ( ; ; ({ ++i; break; })) ;
|
|
// Note that the next value stored to 'i' is never executed
|
|
// because the next statement to be executed is the 'break'
|
|
// in the increment code of the first loop.
|
|
i = i * 3; // expected-warning{{Value stored to 'i' is never read}} expected-warning{{The left operand to '*' is always 1}}
|
|
}
|
|
}
|
|
|
|
// <rdar://problem/8320674> NullStmts followed by do...while() can lead to disconnected CFG
|
|
//
|
|
// This previously caused bogus dead-stores warnings because the body of the first do...while was
|
|
// disconnected from the entry of the function.
|
|
typedef struct { float r; float i; } s_rdar8320674;
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|
typedef struct { s_rdar8320674 x[1]; } s2_rdar8320674;
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|
|
void rdar8320674(s_rdar8320674 *z, unsigned y, s2_rdar8320674 *st, int m)
|
|
{
|
|
s_rdar8320674 * z2;
|
|
s_rdar8320674 * tw1 = st->x;
|
|
s_rdar8320674 t;
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|
z2 = z + m;
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|
do{
|
|
; ;
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|
do{ (t).r = (*z2).r*(*tw1).r - (*z2).i*(*tw1).i; (t).i = (*z2).r*(*tw1).i + (*z2).i*(*tw1).r; }while(0);
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tw1 += y;
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|
do { (*z2).r=(*z).r-(t).r; (*z2).i=(*z).i-(t).i; }while(0);
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|
do { (*z).r += (t).r; (*z).i += (t).i; }while(0);
|
|
++z2;
|
|
++z;
|
|
}while (--m);
|
|
}
|
|
|
|
// Avoid dead stores resulting from an assignment (and use) being unreachable.
|
|
void rdar8405222_aux(int i);
|
|
void rdar8405222() {
|
|
const int show = 0;
|
|
int i = 0;
|
|
|
|
if (show)
|
|
i = 5; // no-warning
|
|
|
|
if (show)
|
|
rdar8405222_aux(i);
|
|
}
|
|
|