638 lines
14 KiB
C
638 lines
14 KiB
C
// RUN: %check_analyzer_fixit %s %t \
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// RUN: -Wunused-variable -fblocks -Wno-unreachable-code \
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// RUN: -analyzer-checker=core,deadcode.DeadStores \
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// RUN: -analyzer-config deadcode.DeadStores:ShowFixIts=true \
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// RUN: -analyzer-config \
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// RUN: deadcode.DeadStores:WarnForDeadNestedAssignments=false \
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// RUN: -verify=non-nested
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// RUN: %check_analyzer_fixit %s %t \
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// RUN: -Wunused-variable -fblocks -Wno-unreachable-code \
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// RUN: -analyzer-checker=core,deadcode.DeadStores \
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// RUN: -analyzer-config deadcode.DeadStores:ShowFixIts=true \
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// RUN: -verify=non-nested,nested
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void f1() {
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int k, y; // non-nested-warning {{unused variable 'k'}}
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// non-nested-warning@-1 {{unused variable 'y'}}
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int abc = 1;
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long idx = abc + 3 * 5; // non-nested-warning {{never read}}
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// non-nested-warning@-1 {{unused variable 'idx'}}
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// CHECK-FIXES: int abc = 1;
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// CHECK-FIXES-NEXT: long 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; // non-nested-warning {{never read}}
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// non-nested-warning@-1 {{unused variable 'd'}}
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// CHECK-FIXES: char *c = (char *)b;
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// CHECK-FIXES-NEXT: char *d;
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printf("%s", c);
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// non-nested-warning@-1 {{implicitly declaring library function 'printf' with type 'int (const char *, ...)'}}
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// non-nested-note@-2 {{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; // non-nested-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; // non-nested-warning {{never read}}
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// non-nested-warning@-1 {{unused variable 'p'}}
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// CHECK-FIXES: int x = 4;
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// CHECK-FIXES-NEXT: int *p;
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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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// Warn for dead stores in nested expressions.
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int f8(int *p) {
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extern int *baz();
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if ((p = baz())) // nested-warning {{Although the value stored}}
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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; // non-nested-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; // non-nested-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++; // non-nested-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; // non-nested-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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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]; // non-nested-warning {{unused variable 'z'}}
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}
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// Warn for dead stores in nested expressions.
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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]) ? 5 : 8;
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// nested-warning@-1 {{Although the value stored}}
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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; // non-nested-warning {{Value stored to 'x' is never read}}
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while (1)
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x = 10; // non-nested-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); // nested-warning {{Although the value stored}}
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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; // non-nested-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; // non-nested-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; // non-nested-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; // non-nested-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; // non-nested-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));
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// non-nested-warning@-1 {{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));
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// non-nested-warning@-1 {{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:
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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;
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} 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:
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for (; 1;) {
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(void)y17;
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}
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(void)x;
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break;
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case 16:
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for (; 0;) {
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(void)x;
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}
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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)
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f23_aux("I did too use it!\n");
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else
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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);
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// non-nested-warning@-1 {{Value stored to 'shouldLog' during its initialization is never read}}
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// non-nested-warning@-2 {{unused variable 'shouldLog'}}
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// CHECK-FIXES: void f23_pos(int argc, char **argv) {
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// CHECK-FIXES-NEXT: int 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;
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// non-nested-warning@-1 {{Value stored to 'z' during its initialization is never read}}
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// non-nested-warning@-2 {{unused variable 'z'}}
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// CHECK-FIXES: void f24_A(int y) {
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// CHECK-FIXES-NEXT: //
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// CHECK-FIXES-NEXT: int x = (y > 2);
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// CHECK-FIXES-NEXT: ^{
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// CHECK-FIXES-NEXT: int 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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// This example shows that writing to a variable captured by a block means that
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// it might 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)() = ^{
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z = x + y;
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};
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x = 4; // no-warning
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foo();
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return z;
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}
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// This test is mostly the same as 'f25', but shows that the heuristic of
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// pruning out dead stores for variables that are just marked '__block' is
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// 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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}
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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; // non-nested-warning {{Value stored to 'k' is never read}}
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^{
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y = z + 1;
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}();
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}();
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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
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// placed within the increment code of for loops.
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void rdar8014335() {
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for (int i = 0 ; i != 10 ; ({ break; })) {
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for (;; ({ ++i; break; }))
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;
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// non-nested-warning@-2 {{'break' is bound to current loop, GCC binds it to the enclosing loop}}
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// Note that the next value stored to 'i' is never executed
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// because the next statement to be executed is the 'break'
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// in the increment code of the first loop.
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i = i * 3; // non-nested-warning {{Value stored to 'i' is never read}}
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}
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}
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// <rdar://problem/8320674> NullStmts followed by do...while() can lead to disconnected CFG
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//
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// This previously caused bogus dead-stores warnings because the body of the first do...while was
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// disconnected from the entry of the function.
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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)
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{
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s_rdar8320674 * z2;
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s_rdar8320674 * tw1 = st->x;
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s_rdar8320674 t;
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z2 = z + m;
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do{
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; ;
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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);
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++z2;
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++z;
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}while (--m);
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}
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// Avoid dead stores resulting from an assignment (and use) being unreachable.
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void rdar8405222_aux(int i);
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void rdar8405222() {
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const int show = 0;
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int i = 0;
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if (show)
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i = 5; // no-warning
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if (show)
|
|
rdar8405222_aux(i);
|
|
}
|
|
|
|
// Look through chains of assignments, e.g.: int x = y = 0, when employing
|
|
// silencing heuristics.
|
|
int radar11185138_foo() {
|
|
int x, y;
|
|
x = y = 0; // non-nested-warning {{never read}}
|
|
return y;
|
|
}
|
|
|
|
int rdar11185138_bar() {
|
|
int y;
|
|
int x = y = 0; // nested-warning {{Although the value stored}}
|
|
x = 2;
|
|
y = 2;
|
|
return x + y;
|
|
}
|
|
|
|
int *radar11185138_baz() {
|
|
int *x, *y;
|
|
x = y = 0; // no-warning
|
|
return y;
|
|
}
|
|
|
|
int getInt();
|
|
int *getPtr();
|
|
void testBOComma() {
|
|
int x0 = (getInt(), 0); // non-nested-warning {{unused variable 'x0'}}
|
|
int x1 = (getInt(), getInt());
|
|
// non-nested-warning@-1 {{Value stored to 'x1' during its initialization is never read}}
|
|
// non-nested-warning@-2 {{unused variable 'x1'}}
|
|
|
|
int x2 = (getInt(), getInt(), getInt());
|
|
// non-nested-warning@-1 {{Value stored to 'x2' during its initialization is never read}}
|
|
// non-nested-warning@-2 {{unused variable 'x2'}}
|
|
|
|
int x3;
|
|
x3 = (getInt(), getInt(), 0);
|
|
// non-nested-warning@-1 {{Value stored to 'x3' is never read}}
|
|
|
|
int x4 = (getInt(), (getInt(), 0));
|
|
// non-nested-warning@-1 {{unused variable 'x4'}}
|
|
|
|
int y;
|
|
int x5 = (getInt(), (y = 0));
|
|
// non-nested-warning@-1 {{unused variable 'x5'}}
|
|
// nested-warning@-2 {{Although the value stored}}
|
|
|
|
int x6 = (getInt(), (y = getInt()));
|
|
// non-nested-warning@-1 {{Value stored to 'x6' during its initialization is never read}}
|
|
// non-nested-warning@-2 {{unused variable 'x6'}}
|
|
// nested-warning@-3 {{Although the value stored}}
|
|
|
|
int x7 = 0, x8 = getInt();
|
|
// non-nested-warning@-1 {{Value stored to 'x8' during its initialization is never read}}
|
|
// non-nested-warning@-2 {{unused variable 'x8'}}
|
|
// non-nested-warning@-3 {{unused variable 'x7'}}
|
|
|
|
int x9 = getInt(), x10 = 0;
|
|
// non-nested-warning@-1 {{Value stored to 'x9' during its initialization is never read}}
|
|
// non-nested-warning@-2 {{unused variable 'x9'}}
|
|
// non-nested-warning@-3 {{unused variable 'x10'}}
|
|
|
|
int m = getInt(), mm, mmm;
|
|
// non-nested-warning@-1 {{Value stored to 'm' during its initialization is never read}}
|
|
// non-nested-warning@-2 {{unused variable 'm'}}
|
|
// non-nested-warning@-3 {{unused variable 'mm'}}
|
|
// non-nested-warning@-4 {{unused variable 'mmm'}}
|
|
|
|
int n, nn = getInt();
|
|
// non-nested-warning@-1 {{Value stored to 'nn' during its initialization is never read}}
|
|
// non-nested-warning@-2 {{unused variable 'n'}}
|
|
// non-nested-warning@-3 {{unused variable 'nn'}}
|
|
|
|
int *p;
|
|
p = (getPtr(), (int *)0); // no warning
|
|
}
|
|
|
|
void testVolatile() {
|
|
volatile int v;
|
|
v = 0; // no warning
|
|
}
|