1 2 /* This test case was originally written by Nicholas Nethercote. */ 3 4 5 6 7 /* For 'x', we get an uninitialised error for every addition to it. For 8 each one we get one origin identified, even though most of them involve 9 more than one undefined value. */ 10 11 /* For 'y', we get a single uninitialised value error, on the value handed 12 to the exit() system call. Fair enough. 13 14 An important question is: which of the origins is reported in the 15 error? Well, considering that (1) m_execontext allocates ECUs 16 (origin tags, basically) in increasing order, and (2) memcheck's 17 instrumentation for dealing with two uninitialised sources simply 18 involves 'max'-ing the otags, we expect the origin to be attributed 19 to the last of the 8 mallocs, that is, to p_ui8. 20 */ 21 22 #include <stdlib.h> 23 #include <stdio.h> 24 25 static int x = 0; 26 static int y = 0; 27 28 int main(void) 29 { 30 // Do them separately rather than all in one array so they all have 31 // different origins. 32 int* p_ui1 = malloc(sizeof(int)); 33 int* p_ui2 = malloc(sizeof(int)); 34 int* p_ui3 = malloc(sizeof(int)); 35 int* p_ui4 = malloc(sizeof(int)); 36 int* p_ui5 = malloc(sizeof(int)); 37 int* p_ui6 = malloc(sizeof(int)); 38 int* p_ui7 = malloc(sizeof(int)); 39 int* p_ui8 = malloc(sizeof(int)); 40 int ui1 = *p_ui1; 41 int ui2 = *p_ui2; 42 int ui3 = *p_ui3; 43 int ui4 = *p_ui4; 44 int ui5 = *p_ui5; 45 int ui6 = *p_ui6; 46 int ui7 = *p_ui7; 47 int ui8 = *p_ui8; 48 49 #define P printf("huh?") 50 51 x += (ui1 == 0x12345678 ? P : 23); 52 x += (ui1 +ui2 == 0x12345678 ? P : 24); 53 x += (ui1 +ui2 +ui3 == 0x12345678 ? P : 25); 54 x += (ui1 +ui2 +ui3 +ui4 == 0x12345678 ? P : 26); 55 x += (ui1 +ui2 +ui3 +ui4 +ui5 == 0x12345678 ? P : 27); 56 x += (ui1 +ui2 +ui3 +ui4 +ui5 +ui6 == 0x12345678 ? P : 28); 57 x += (ui1 +ui2 +ui3 +ui4 +ui5 +ui6 +ui7 == 0x12345678 ? P : 29); 58 x += (ui1 +ui2 +ui3 +ui4 +ui5 +ui6 +ui7 +ui8 == 0x12345678 ? P : 30); 59 60 y += (ui1 ); 61 y += (ui1 +ui2 ); 62 y += (ui1 +ui2 +ui3 ); 63 y += (ui1 +ui2 +ui3 +ui4 ); 64 y += (ui1 +ui2 +ui3 +ui4 +ui5 ); 65 y += (ui1 +ui2 +ui3 +ui4 +ui5 +ui6 ); 66 y += (ui1 +ui2 +ui3 +ui4 +ui5 +ui6 +ui7 ); 67 y += (ui1 +ui2 +ui3 +ui4 +ui5 +ui6 +ui7 +ui8); 68 69 return y & 1; 70 } 71
