534 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			534 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
| // RUN: %clang_cc1 -fsyntax-only -Wuninitialized -Wconditional-uninitialized -fsyntax-only -fblocks %s -verify
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| 
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| typedef __typeof(sizeof(int)) size_t;
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| void *malloc(size_t);
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| 
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| int test1() {
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|   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   return x; // expected-warning{{variable 'x' is uninitialized when used here}}
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| }
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| 
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| int test2() {
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|   int x = 0;
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|   return x; // no-warning
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| }
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| 
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| int test3() {
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|   int x;
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|   x = 0;
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|   return x; // no-warning
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| }
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| 
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| int test4() {
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|   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   ++x; // expected-warning{{variable 'x' is uninitialized when used here}}
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|   return x; 
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| }
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| 
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| int test5() {
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|   int x, y; // expected-note{{initialize the variable 'y' to silence this warning}}
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|   x = y; // expected-warning{{variable 'y' is uninitialized when used here}}
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|   return x;
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| }
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| 
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| int test6() {
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|   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   x += 2; // expected-warning{{variable 'x' is uninitialized when used here}}
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|   return x;
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| }
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| 
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| int test7(int y) {
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|   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   if (y) // expected-warning{{variable 'x' is used uninitialized whenever 'if' condition is false}} \
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|          // expected-note{{remove the 'if' if its condition is always true}}
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|     x = 1;
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|   return x; // expected-note{{uninitialized use occurs here}}
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| }
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| 
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| int test7b(int y) {
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|   int x = x; // expected-note{{variable 'x' is declared here}}
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|   if (y)
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|     x = 1;
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|   // Warn with "may be uninitialized" here (not "is sometimes uninitialized"),
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|   // since the self-initialization is intended to suppress a -Wuninitialized
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|   // warning.
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|   return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
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| }
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| 
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| int test8(int y) {
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|   int x;
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|   if (y)
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|     x = 1;
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|   else
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|     x = 0;
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|   return x;
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| }
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| 
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| int test9(int n) {
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|   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   for (unsigned i = 0 ; i < n; ++i) {
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|     if (i == n - 1)
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|       break;
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|     x = 1;
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|   }
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|   return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
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| }
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| 
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| int test10(unsigned n) {
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|   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   for (unsigned i = 0 ; i < n; ++i) {
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|     x = 1;
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|   }
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|   return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
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| }
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| 
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| int test11(unsigned n) {
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|   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   for (unsigned i = 0 ; i <= n; ++i) {
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|     x = 1;
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|   }
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|   return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
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| }
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| 
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| void test12(unsigned n) {
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|   for (unsigned i ; n ; ++i) ; // expected-warning{{variable 'i' is uninitialized when used here}} expected-note{{initialize the variable 'i' to silence this warning}}
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| }
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| 
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| int test13() {
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|   static int i;
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|   return i; // no-warning
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| }
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| 
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| // Simply don't crash on this test case.
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| void test14() {
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|   const char *p = 0;
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|   for (;;) {}
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| }
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| 
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| void test15() {
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|   int x = x; // no-warning: signals intended lack of initialization.
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| }
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| 
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| int test15b() {
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|   // Warn here with the self-init, since it does result in a use of
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|   // an unintialized variable and this is the root cause.
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|   int x = x; // expected-warning {{variable 'x' is uninitialized when used within its own initialization}}
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|   return x;
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| }
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| 
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| // Don't warn in the following example; shows dataflow confluence.
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| char *test16_aux();
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| void test16() {
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|   char *p = test16_aux();
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|   for (unsigned i = 0 ; i < 100 ; i++)
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|     p[i] = 'a'; // no-warning
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| }
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| 
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| void test17() {
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|   // Don't warn multiple times about the same uninitialized variable
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|   // along the same path.
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|   int *x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   *x = 1; // expected-warning{{variable 'x' is uninitialized when used here}}
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|   *x = 1; // no-warning
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| }
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| 
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| int test18(int x, int y) {
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|   int z;
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|   if (x && y && (z = 1)) {
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|     return z; // no-warning
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|   }
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|   return 0;
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| }
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| 
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| int test19_aux1();
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| int test19_aux2();
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| int test19_aux3(int *x);
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| int test19() {
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|   int z;
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|   if (test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z))
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|     return z; // no-warning
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|   return 0;
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| }
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| 
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| int test20() {
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|   int z; // expected-note{{initialize the variable 'z' to silence this warning}}
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|   if ((test19_aux1() + test19_aux2() && test19_aux1()) || test19_aux3(&z)) // expected-warning {{variable 'z' is used uninitialized whenever '||' condition is true}} expected-note {{remove the '||' if its condition is always false}}
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|     return z; // expected-note {{uninitialized use occurs here}}
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|   return 0;
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| }
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| 
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| int test21(int x, int y) {
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|   int z; // expected-note{{initialize the variable 'z' to silence this warning}}
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|   if ((x && y) || test19_aux3(&z) || test19_aux2()) // expected-warning {{variable 'z' is used uninitialized whenever '||' condition is true}} expected-note {{remove the '||' if its condition is always false}}
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|     return z; // expected-note {{uninitialized use occurs here}}
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|   return 0;
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| }
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| 
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| int test22() {
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|   int z;
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|   while (test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z))
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|     return z; // no-warning
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|   return 0;
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| }
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| 
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| int test23() {
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|   int z;
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|   for ( ; test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z) ; )
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|     return z; // no-warning
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|   return 0;
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| }
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| 
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| // The basic uninitialized value analysis doesn't have enough path-sensitivity
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| // to catch initializations relying on control-dependencies spanning multiple
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| // conditionals.  This possibly can be handled by making the CFG itself
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| // represent such control-dependencies, but it is a niche case.
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| int test24(int flag) {
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|   unsigned val; // expected-note{{initialize the variable 'val' to silence this warning}}
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|   if (flag)
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|     val = 1;
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|   if (!flag)
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|     val = 1;
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|   return val; // expected-warning{{variable 'val' may be uninitialized when used here}}
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| }
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| 
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| float test25() {
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|   float x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   return x; // expected-warning{{variable 'x' is uninitialized when used here}}
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| }
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| 
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| typedef int MyInt;
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| MyInt test26() {
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|   MyInt x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   return x; // expected-warning{{variable 'x' is uninitialized when used here}}
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| }
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| 
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| // Test handling of sizeof().
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| int test27() {
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|   struct test_27 { int x; } *y;
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|   return sizeof(y->x); // no-warning
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| }
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| 
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| int test28() {
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|   int len; // expected-note{{initialize the variable 'len' to silence this warning}}
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|   return sizeof(int[len]); // expected-warning{{variable 'len' is uninitialized when used here}}
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| }
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| 
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| void test29() {
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|   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   (void) ^{ (void) x; }; // expected-warning{{variable 'x' is uninitialized when captured by block}}
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| }
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| 
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| void test30() {
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|   static int x; // no-warning
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|   (void) ^{ (void) x; };
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| }
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| 
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| void test31() {
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|   __block int x; // no-warning
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|   (void) ^{ (void) x; };
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| }
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| 
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| int test32_x;
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| void test32() {
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|   (void) ^{ (void) test32_x; }; // no-warning
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| }
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| 
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| void test_33() {
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|   int x; // no-warning
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|   (void) x;
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| }
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| 
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| int test_34() {
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|   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   (void) x;
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|   return x; // expected-warning{{variable 'x' is uninitialized when used here}}
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| }
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| 
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| // Test that this case doesn't crash.
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| void test35(int x) {
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|   __block int y = 0;
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|   ^{ y = (x == 0); }();
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| }
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| 
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| // Test handling of indirect goto.
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| void test36()
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| {
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|   void **pc; // expected-note{{initialize the variable 'pc' to silence this warning}}
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|   void *dummy[] = { &&L1, &&L2 };
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|  L1:
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|     goto *pc; // expected-warning{{variable 'pc' is uninitialized when used here}}
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|  L2:
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|     goto *pc;
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| }
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| 
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| // Test && nested in ||.
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| int test37_a();
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| int test37_b();
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| int test37()
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| {
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|     int identifier;
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|     if ((test37_a() && (identifier = 1)) ||
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|         (test37_b() && (identifier = 2))) {
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|         return identifier; // no-warning
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|     }
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|     return 0;
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| }
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| 
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| // Test merging of path-specific dataflow values (without asserting).
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| int test38(int r, int x, int y)
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| {
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|   int z;
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|   return ((r < 0) || ((r == 0) && (x < y)));
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| }
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| 
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| int test39(int x) {
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|   int y; // expected-note{{initialize the variable 'y' to silence this warning}}
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|   int z = x + y; // expected-warning {{variable 'y' is uninitialized when used here}}
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|   return z;
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| }
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| 
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| 
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| int test40(int x) {
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|   int y; // expected-note{{initialize the variable 'y' to silence this warning}}
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|   return x ? 1 : y; // expected-warning {{variable 'y' is uninitialized when used here}}
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| }
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| 
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| int test41(int x) {
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|   int y; // expected-note{{initialize the variable 'y' to silence this warning}}
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|   if (x) y = 1; // expected-warning{{variable 'y' is used uninitialized whenever 'if' condition is false}} \
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|                 // expected-note{{remove the 'if' if its condition is always true}}
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|   return y; // expected-note{{uninitialized use occurs here}}
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| }
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| 
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| void test42() {
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|   int a;
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|   a = 30; // no-warning
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| }
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| 
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| void test43_aux(int x);
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| void test43(int i) {
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|   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
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|   for (i = 0 ; i < 10; i++)
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|     test43_aux(x++); // expected-warning {{variable 'x' is uninitialized when used here}}
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| }
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| 
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| void test44(int i) {
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|   int x = i;
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|   int y; // expected-note{{initialize the variable 'y' to silence this warning}}
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|   for (i = 0; i < 10; i++ ) {
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|     test43_aux(x++); // no-warning
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|     x += y; // expected-warning {{variable 'y' is uninitialized when used here}}
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|   }
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| }
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| 
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| int test45(int j) {
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|   int x = 1, y = x + 1;
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|   if (y) // no-warning
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|     return x;
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|   return y;
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| }
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| 
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| void test46()
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| {
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|   int i; // expected-note{{initialize the variable 'i' to silence this warning}}
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|   int j = i ? : 1; // expected-warning {{variable 'i' is uninitialized when used here}}
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| }
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| 
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| void *test47(int *i)
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| {
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|   return i ? : 0; // no-warning
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| }
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| 
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| void *test49(int *i)
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| {
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|   int a;
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|   return &a ? : i; // no-warning
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| }
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| 
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| void test50()
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| {
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|   char c[1 ? : 2]; // no-warning
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| }
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| 
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| int test51(void)
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| {
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|     __block int a;
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|     ^(void) {
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|       a = 42;
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|     }();
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|     return a; // no-warning
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| }
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| 
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| // FIXME: This is a false positive, but it tests logical operations in switch statements.
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| int test52(int a, int b) {
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|   int x;  // expected-note {{initialize the variable 'x' to silence this warning}}
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|   switch (a || b) { // expected-warning {{switch condition has boolean value}}
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|     case 0:
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|       x = 1;
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|       break;
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|     case 1:
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|       x = 2;
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|       break;
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|   }
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|   return x; // expected-warning {{variable 'x' may be uninitialized when used here}}
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| }
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| 
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| void test53() {
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|   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
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|   int y = (x);  // expected-warning {{variable 'x' is uninitialized when used here}}
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| }
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| 
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| // This CFG caused the uninitialized values warning to inf-loop.
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| extern int PR10379_g();
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| void PR10379_f(int *len) {
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|   int new_len; // expected-note{{initialize the variable 'new_len' to silence this warning}}
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|   for (int i = 0; i < 42 && PR10379_g() == 0; i++) {
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|     if (PR10379_g() == 1)
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|       continue;
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|     if (PR10379_g() == 2)
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|       PR10379_f(&new_len);
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|     else if (PR10379_g() == 3)
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|       PR10379_f(&new_len);
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|     *len += new_len; // expected-warning {{variable 'new_len' may be uninitialized when used here}}
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|   }
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| }
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| 
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| // Test that sizeof(VLA) doesn't trigger a warning.
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| void test_vla_sizeof(int x) {
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|   double (*memory)[2][x] = malloc(sizeof(*memory)); // no-warning
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| }
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| 
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| // Test absurd case of deadcode + use of blocks.  This previously was a false positive
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| // due to an analysis bug.
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| int test_block_and_dead_code() {
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|   __block int x;
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|   ^{ x = 1; }();
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|   if (0)
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|     return x;
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|   return x; // no-warning
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| }
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| 
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| // This previously triggered an infinite loop in the analysis.
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| void PR11069(int a, int b) {
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|   unsigned long flags;
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|   for (;;) {
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|     if (a && !b)
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|       break;
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|   }
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|   for (;;) {
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|     // This does not trigger a warning because it isn't a real use.
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|     (void)(flags); // no-warning
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|   }
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| }
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| 
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| // Test uninitialized value used in loop condition.
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| void rdar9432305(float *P) {
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|   int i; // expected-note {{initialize the variable 'i' to silence this warning}}
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|   for (; i < 10000; ++i) // expected-warning {{variable 'i' is uninitialized when used here}}
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|     P[i] = 0.0f;
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| }
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| 
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| // Test that fixits are not emitted inside macros.
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| #define UNINIT(T, x, y) T x; T y = x;
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| #define ASSIGN(T, x, y) T y = x;
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| void test54() {
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|   UNINIT(int, a, b);  // expected-warning {{variable 'a' is uninitialized when used here}} \
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|                       // expected-note {{variable 'a' is declared here}}
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|   int c;  // expected-note {{initialize the variable 'c' to silence this warning}}
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|   ASSIGN(int, c, d);  // expected-warning {{variable 'c' is uninitialized when used here}}
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| }
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| 
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| // Taking the address is fine
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| struct { struct { void *p; } a; } test55 = { { &test55.a }}; // no-warning
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| struct { struct { void *p; } a; } test56 = { { &(test56.a) }}; // no-warning
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| 
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| void uninit_in_loop() {
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|   int produce(void);
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|   void consume(int);
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|   for (int n = 0; n < 100; ++n) {
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|     int k; // expected-note {{initialize}}
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|     consume(k); // expected-warning {{variable 'k' is uninitialized}}
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|     k = produce();
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|   }
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| }
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| 
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| void uninit_in_loop_goto() {
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|   int produce(void);
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|   void consume(int);
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|   for (int n = 0; n < 100; ++n) {
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|     goto skip_decl;
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|     int k; // expected-note {{initialize}}
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| skip_decl:
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|     // FIXME: This should produce the 'is uninitialized' diagnostic, but we
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|     // don't have enough information in the CFG to easily tell that the
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|     // variable's scope has been left and re-entered.
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|     consume(k); // expected-warning {{variable 'k' may be uninitialized}}
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|     k = produce();
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|   }
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| }
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| 
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| typedef char jmp_buf[256];
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| extern int setjmp(jmp_buf env); // implicitly returns_twice
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| 
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| void do_stuff_and_longjmp(jmp_buf env, int *result) __attribute__((noreturn));
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| 
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| int returns_twice() {
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|   int a; // expected-note {{initialize}}
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|   if (!a) { // expected-warning {{variable 'a' is uninitialized}}
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|     jmp_buf env;
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|     int b;
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|     if (setjmp(env) == 0) {
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|       do_stuff_and_longjmp(env, &b);
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|     } else {
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|       a = b; // no warning
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|     }
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|   }
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|   return a;
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| }
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| 
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| int compound_assign(int *arr, int n) {
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|   int sum; // expected-note {{initialize}}
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|   for (int i = 0; i < n; ++i)
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|     sum += arr[i]; // expected-warning {{variable 'sum' is uninitialized}}
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|   return sum / n;
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| }
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| 
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| int compound_assign_2() {
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|   int x; // expected-note {{initialize}}
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|   return x += 1; // expected-warning {{variable 'x' is uninitialized}}
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| }
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| 
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| int compound_assign_3() {
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|   int x; // expected-note {{initialize}}
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|   x *= 0; // expected-warning {{variable 'x' is uninitialized}}
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|   return x;
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| }
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| 
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| int self_init_in_cond(int *p) {
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|   int n = ((p && (0 || 1)) && (n = *p)) ? n : -1; // ok
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|   return n;
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| }
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| 
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| void test_analyzer_noreturn_aux() __attribute__((analyzer_noreturn));
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| 
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| void test_analyzer_noreturn(int y) {
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|   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
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|   if (y) {
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|     test_analyzer_noreturn_aux();
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| 	++x; // no-warning
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|   }
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|   else {
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| 	++x; // expected-warning {{variable 'x' is uninitialized when used here}}
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|   }
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| }
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| void test_analyzer_noreturn_2(int y) {
 | |
|   int x;
 | |
|   if (y) {
 | |
|     test_analyzer_noreturn_aux();
 | |
|   }
 | |
|   else {
 | |
| 	x = 1;
 | |
|   }
 | |
|   ++x; // no-warning
 | |
| }
 |