clang/test/Analysis/stream-errno-note.c

   1 // RUN: %clang_analyze_cc1 -analyzer-checker=core \
   2 // RUN:   -analyzer-checker=alpha.unix.Stream \
   3 // RUN:   -analyzer-checker=alpha.unix.Errno \
   4 // RUN:   -analyzer-checker=alpha.unix.StdCLibraryFunctions \
   5 // RUN:   -analyzer-config alpha.unix.StdCLibraryFunctions:ModelPOSIX=true \
   6 // RUN:   -analyzer-output text -verify %s
   7
   8 #include "Inputs/system-header-simulator.h"
   9 #include "Inputs/errno_func.h"
  10
  11 void check_fopen(void) {
  12   FILE *F = fopen("xxx", "r");
  13   // expected-note@-1{{Assuming that function 'fopen' is successful, in this case the value 'errno' may be undefined after the call and should not be used}}
  14   // expected-note@+2{{'F' is non-null}}
  15   // expected-note@+1{{Taking false branch}}
  16   if (!F)
  17     return;
  18   if (errno) {} // expected-warning{{An undefined value may be read from 'errno' [alpha.unix.Errno]}}
  19   // expected-note@-1{{An undefined value may be read from 'errno'}}
  20   fclose(F);
  21 }
  22
  23 void check_tmpfile(void) {
  24   FILE *F = tmpfile();
  25   // expected-note@-1{{Assuming that function 'tmpfile' is successful, in this case the value 'errno' may be undefined after the call and should not be used}}
  26   // expected-note@+2{{'F' is non-null}}
  27   // expected-note@+1{{Taking false branch}}
  28   if (!F)
  29     return;
  30   if (errno) {} // expected-warning{{An undefined value may be read from 'errno' [alpha.unix.Errno]}}
  31   // expected-note@-1{{An undefined value may be read from 'errno'}}
  32   fclose(F);
  33 }
  34
  35 void check_freopen(void) {
  36   FILE *F = tmpfile();
  37   // expected-note@+2{{'F' is non-null}}
  38   // expected-note@+1{{Taking false branch}}
  39   if (!F)
  40     return;
  41   F = freopen("xxx", "w", F);
  42   // expected-note@-1{{Assuming that function 'freopen' is successful}}
  43   // expected-note@+2{{'F' is non-null}}
  44   // expected-note@+1{{Taking false branch}}
  45   if (!F)
  46     return;
  47   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
  48   // expected-note@-1{{An undefined value may be read from 'errno'}}
  49   fclose(F);
  50 }
  51
  52 void check_fclose(void) {
  53   FILE *F = tmpfile();
  54   // expected-note@+2{{'F' is non-null}}
  55   // expected-note@+1{{Taking false branch}}
  56   if (!F)
  57     return;
  58   (void)fclose(F);
  59   // expected-note@-1{{Assuming that function 'fclose' is successful}}
  60   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
  61   // expected-note@-1{{An undefined value may be read from 'errno'}}
  62 }
  63
  64 void check_fread(void) {
  65   char Buf[10];
  66   FILE *F = tmpfile();
  67   // expected-note@+2{{'F' is non-null}}
  68   // expected-note@+1{{Taking false branch}}
  69   if (!F)
  70     return;
  71   (void)fread(Buf, 1, 10, F);
  72   // expected-note@-1{{Assuming that function 'fread' is successful}}
  73   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
  74   // expected-note@-1{{An undefined value may be read from 'errno'}}
  75   (void)fclose(F);
  76 }
  77
  78 void check_fwrite(void) {
  79   char Buf[] = "0123456789";
  80   FILE *F = tmpfile();
  81   // expected-note@+2{{'F' is non-null}}
  82   // expected-note@+1{{Taking false branch}}
  83   if (!F)
  84     return;
  85   int R = fwrite(Buf, 1, 10, F);
  86   // expected-note@-1{{Assuming that function 'fwrite' is successful}}
  87   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
  88   // expected-note@-1{{An undefined value may be read from 'errno'}}
  89   (void)fclose(F);
  90 }
  91
  92 void check_fseek(void) {
  93   FILE *F = tmpfile();
  94   // expected-note@+2{{'F' is non-null}}
  95   // expected-note@+1{{Taking false branch}}
  96   if (!F)
  97     return;
  98   (void)fseek(F, 11, SEEK_SET);
  99   // expected-note@-1{{Assuming that function 'fseek' is successful}}
 100   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
 101   // expected-note@-1{{An undefined value may be read from 'errno'}}
 102   (void)fclose(F);
 103 }
 104
 105 void check_rewind_errnocheck(void) {
 106   FILE *F = tmpfile();
 107   // expected-note@+2{{'F' is non-null}}
 108   // expected-note@+1{{Taking false branch}}
 109   if (!F)
 110     return;
 111   errno = 0;
 112   rewind(F); // expected-note{{Function 'rewind' indicates failure only by setting of 'errno'}}
 113   fclose(F); // expected-warning{{Value of 'errno' was not checked and may be overwritten by function 'fclose' [alpha.unix.Errno]}}
 114   // expected-note@-1{{Value of 'errno' was not checked and may be overwritten by function 'fclose'}}
 115 }
 116
 117 void check_fileno(void) {
 118   FILE *F = tmpfile();
 119   // expected-note@+2{{'F' is non-null}}
 120   // expected-note@+1{{Taking false branch}}
 121   if (!F)
 122     return;
 123   fileno(F);
 124   // expected-note@-1{{Assuming that function 'fileno' is successful}}
 125   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
 126   // expected-note@-1{{An undefined value may be read from 'errno'}}
 127   (void)fclose(F);
 128 }