1 // RUN: %clang_analyze_cc1 -verify %s \ 2 // RUN: -analyzer-checker=core,alpha.unix.cstring \ 3 // RUN: -analyzer-output=text 4 5 #include "Inputs/system-header-simulator.h" 6 7 // Inspired by a report on ffmpeg, libavcodec/tiertexseqv.c, seq_decode_op1(). 8 int coin(); 9 10 void maybeWrite(const char *src, unsigned size, int *dst) { 11 if (coin()) // expected-note{{Assuming the condition is false}} 12 // expected-note@-1{{Taking false branch}} 13 memcpy(dst, src, size); 14 } // expected-note{{Returning without writing to '*dst'}} 15 16 void returning_without_writing_to_memcpy(const char *src, unsigned size) { 17 int block[8 * 8]; // expected-note{{'block' initialized here}} 18 // expected-note@+1{{Calling 'maybeWrite'}} 19 maybeWrite(src, size, block); // expected-note{{Returning from 'maybeWrite'}} 20 21 int buf[8 * 8]; 22 memcpy(buf, &block[0], 8); // expected-warning{{The first element of the 2nd argument is undefined [alpha.unix.cstring.UninitializedRead]}} 23 // expected-note@-1{{The first element of the 2nd argument is undefined}} 24 // expected-note@-2{{Other elements might also be undefined}} 25 } 26