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

   1 // RUN: %clang_analyze_cc1 -analyzer-checker=core \
   2 // RUN:   -analyzer-checker=unix.Stream \
   3 // RUN:   -analyzer-config unix.Stream:Pedantic=true \
   4 // RUN:   -analyzer-checker=unix.Errno \
   5 // RUN:   -analyzer-checker=unix.StdCLibraryFunctions \
   6 // RUN:   -analyzer-config unix.StdCLibraryFunctions:ModelPOSIX=true \
   7 // RUN:   -analyzer-output text -verify %s
   8
   9 #include "Inputs/system-header-simulator.h"
  10 #include "Inputs/errno_func.h"
  11
  12 void check_fopen(void) {
  13   FILE *F = fopen("xxx", "r");
  14   // expected-note@-1{{Assuming that 'fopen' is successful; 'errno' becomes undefined after the call}}
  15   // expected-note@+2{{'F' is non-null}}
  16   // expected-note@+1{{Taking false branch}}
  17   if (!F)
  18     return;
  19   if (errno) {} // expected-warning{{An undefined value may be read from 'errno' [unix.Errno]}}
  20   // expected-note@-1{{An undefined value may be read from 'errno'}}
  21   fclose(F);
  22 }
  23
  24 void check_tmpfile(void) {
  25   FILE *F = tmpfile();
  26   // expected-note@-1{{Assuming that 'tmpfile' is successful; 'errno' becomes undefined after the call}}
  27   // expected-note@+2{{'F' is non-null}}
  28   // expected-note@+1{{Taking false branch}}
  29   if (!F)
  30     return;
  31   if (errno) {} // expected-warning{{An undefined value may be read from 'errno' [unix.Errno]}}
  32   // expected-note@-1{{An undefined value may be read from 'errno'}}
  33   fclose(F);
  34 }
  35
  36 void check_freopen(void) {
  37   FILE *F = tmpfile();
  38   // expected-note@+2{{'F' is non-null}}
  39   // expected-note@+1{{Taking false branch}}
  40   if (!F)
  41     return;
  42   F = freopen("xxx", "w", F);
  43   // expected-note@-1{{Assuming that 'freopen' is successful; 'errno' becomes undefined after the call}}
  44   // expected-note@+2{{'F' is non-null}}
  45   // expected-note@+1{{Taking false branch}}
  46   if (!F)
  47     return;
  48   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
  49   // expected-note@-1{{An undefined value may be read from 'errno'}}
  50   fclose(F);
  51 }
  52
  53 void check_fclose(void) {
  54   FILE *F = tmpfile();
  55   // expected-note@+2{{'F' is non-null}}
  56   // expected-note@+1{{Taking false branch}}
  57   if (!F)
  58     return;
  59   (void)fclose(F);
  60   // expected-note@-1{{Assuming that 'fclose' is successful; 'errno' becomes undefined after the call}}
  61   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
  62   // expected-note@-1{{An undefined value may be read from 'errno'}}
  63 }
  64
  65 void check_fread(void) {
  66   char Buf[10];
  67   FILE *F = tmpfile();
  68   // expected-note@+2{{'F' is non-null}}
  69   // expected-note@+1{{Taking false branch}}
  70   if (!F)
  71     return;
  72   (void)fread(Buf, 1, 10, F);
  73   // expected-note@-1{{Assuming that 'fread' is successful; 'errno' becomes undefined after the call}}
  74   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
  75   // expected-note@-1{{An undefined value may be read from 'errno'}}
  76   (void)fclose(F);
  77 }
  78
  79 void check_fread_size0(void) {
  80   char Buf[10];
  81   FILE *F = tmpfile();
  82   // expected-note@+2{{'F' is non-null}}
  83   // expected-note@+1{{Taking false branch}}
  84   if (!F)
  85     return;
  86   fread(Buf, 0, 1, F);
  87   // expected-note@-1{{Assuming that argument 'size' to 'fread' is 0; 'errno' becomes undefined after the call}}
  88   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
  89   // expected-note@-1{{An undefined value may be read from 'errno'}}
  90 }
  91
  92 void check_fread_nmemb0(void) {
  93   char Buf[10];
  94   FILE *F = tmpfile();
  95   // expected-note@+2{{'F' is non-null}}
  96   // expected-note@+1{{Taking false branch}}
  97   if (!F)
  98     return;
  99   fread(Buf, 1, 0, F);
 100   // expected-note@-1{{Assuming that 'fread' is successful; 'errno' becomes undefined after the call}}
 101   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
 102   // expected-note@-1{{An undefined value may be read from 'errno'}}
 103 }
 104
 105 void check_fwrite(void) {
 106   char Buf[] = "0123456789";
 107   FILE *F = tmpfile();
 108   // expected-note@+2{{'F' is non-null}}
 109   // expected-note@+1{{Taking false branch}}
 110   if (!F)
 111     return;
 112   int R = fwrite(Buf, 1, 10, F);
 113   // expected-note@-1{{Assuming that 'fwrite' is successful; 'errno' becomes undefined after the call}}
 114   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
 115   // expected-note@-1{{An undefined value may be read from 'errno'}}
 116   (void)fclose(F);
 117 }
 118
 119 void check_fseek(void) {
 120   FILE *F = tmpfile();
 121   // expected-note@+2{{'F' is non-null}}
 122   // expected-note@+1{{Taking false branch}}
 123   if (!F)
 124     return;
 125   (void)fseek(F, 11, SEEK_SET);
 126   // expected-note@-1{{Assuming that 'fseek' is successful; 'errno' becomes undefined after the call}}
 127   if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
 128   // expected-note@-1{{An undefined value may be read from 'errno'}}
 129   (void)fclose(F);
 130 }
 131
 132 void check_rewind_errnocheck(void) {
 133   FILE *F = tmpfile();
 134   // expected-note@+2{{'F' is non-null}}
 135   // expected-note@+1{{Taking false branch}}
 136   if (!F)
 137     return;
 138   errno = 0;
 139   rewind(F); // expected-note{{After calling 'rewind' reading 'errno' is required to find out if the call has failed}}
 140   fclose(F); // expected-warning{{Value of 'errno' was not checked and may be overwritten by function 'fclose' [unix.Errno]}}
 141   // expected-note@-1{{Value of 'errno' was not checked and may be overwritten by function 'fclose'}}
 142 }
 143
 144 void check_fileno(void) {
 145   // nothing to check: checker assumes that 'fileno' is always successful
 146   // (and does not change 'errno')
 147 }
 148
 149 void check_fwrite_zeroarg(size_t Siz) {
 150   char Buf[] = "0123456789";
 151   FILE *F = tmpfile();
 152   // expected-note@+2{{'F' is non-null}}
 153   // expected-note@+1{{Taking false branch}}
 154   if (!F)
 155     return;
 156   errno = 0;
 157   int R = fwrite(Buf, Siz, 1, F);
 158   // expected-note@-1{{Assuming that argument 'size' to 'fwrite' is 0; 'errno' becomes undefined after the call}}
 159   // expected-note@+2{{'R' is <= 0}}
 160   // expected-note@+1{{Taking true branch}}
 161   if (R <= 0) {
 162     if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}
 163     // expected-note@-1{{An undefined value may be read from 'errno'}}
 164   }
 165   (void)fclose(F);
 166 }