HW6: Due Dec 8th 23:59

1. HW6: Due Dec 8th 23:59 • Describe test cases to reach full path coverage of the triangle program by completing the path condition table below. Also, draw the complete execution tree showing executed path conditions. • Assume that the initial test case is given as 1,1,1 • You should use the DFS algorithm. • You are required to get a concrete solutionby using Z3/Yices • Describe a SMTLIB spec for each next path condition and attach the snapshots of Z3/Yices results on the SMTLIB spec

2. 2. Test flash_read() by using CREST • Describe your environment model • You may use the similar environment model for HW#3-1 but need to modify • You have to specify an assert statement for checking correctness. • Enumerate all generated test cases through concolictesting and their result (i.e. assert pass/fail) • /* (pu_id, sect#) for the figure below */ Testcase 1: a (0,1), b (1,1), c (1,2) d (2,3) 3. Compare this concolic experiment with the CBMC experiments in HW#3-1 1. Covered cases/distributions 2. Performance SAM0~SAM3 PU0~PU3 Sector 0 Sector 1 Sector 2 Sector 3 A distribution of “abcd”

3. typedefstruct _SAM_type{ unsigned char offset[SECT_PER_U]; }SAM_type; typedefstruct _PU_type{ unsigned char sect[SECT_PER_U]; }PU_type; // Environment assumption // 0. Each unit contains 4 sectors. // 1. There is one logical unit containing "abcd" // 2. There are 4 physical units // 3. The value of SAM table is 255 if the corresponding // physical sector does not have a valid data void flash_read(char *buf, SAM_type *SAM, PU_type *pu ){ unsigned char nSamIdx = 0; unsigned char pu_id = 0; unsigned char n_scts = 4; // number of sectors to read unsigned char offset = 0; //offset of the physical sector to read unsigned char pBuf = 0; while(n_scts > 0){ pu_id=0; offset = 255; // read 1 character while(1) { if (SAM[pu_id].offset[nSamIdx] != 255){ offset = SAM[pu_id].offset[nSamIdx++]; buf[pBuf] = PU[pu_id].sect[offset]; break; } pu_id ++; } n_scts--; pBuf ++; } }

4. 3. Prove the correctness of copy2 by using WHY - You should write down requires/ensures annotation - You may also need loop invariant, variant, and assertion /* Contract: Return value should be same as input value x as long as x >= 0 */ int copy2(int x) { int y=0; while(y !=x) { y++; } return y; }