[sql] Import SQLite 3.17.0.

third_party/sqlite/src/tool/srcck1.c

Index: third_party/sqlite/src/tool/srcck1.c
diff --git a/third_party/sqlite/src/tool/srcck1.c b/third_party/sqlite/src/tool/srcck1.c
new file mode 100644
index 0000000000000000000000000000000000000000..20084ac47f1a0793c2bd9f6c511ab7da0e34e544
--- /dev/null
+++ b/third_party/sqlite/src/tool/srcck1.c
@@ -0,0 +1,158 @@
+/*
+** The program does some simple static analysis of the sqlite3.c source
+** file looking for mistakes.
+**
+** Usage:
+**
+**      ./srcck1 sqlite3.c
+**
+** This program looks for instances of assert(), ALWAYS(), NEVER() or
+** testcase() that contain side-effects and reports errors if any such
+** instances are found.
+**
+** The aim of this utility is to prevent recurrences of errors such
+** as the one fixed at:
+**
+**   https://www.sqlite.org/src/info/a2952231ac7abe16
+**
+** Note that another similar error was found by this utility when it was
+** first written.  That other error was fixed by the same check-in that
+** committed the first version of this utility program.
+*/
+#include <stdlib.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+
+/* Read the complete text of a file into memory.  Return a pointer to
+** the result.  Panic if unable to read the file or allocate memory.
+*/
+static char *readFile(const char *zFilename){
+  FILE *in;
+  char *z;
+  long n;
+  size_t got;
+
+  in = fopen(zFilename, "rb");
+  if( in==0 ){
+    fprintf(stderr, "unable to open '%s' for reading\n", zFilename);
+    exit(1);
+  }
+  fseek(in, 0, SEEK_END);
+  n = ftell(in);
+  rewind(in);
+  z = malloc( n+1 );
+  if( z==0 ){
+    fprintf(stderr, "cannot allocate %d bytes to store '%s'\n", 
+            (int)(n+1), zFilename);
+    exit(1);
+  }
+  got = fread(z, 1, n, in);
+  fclose(in);
+  if( got!=(size_t)n ){
+    fprintf(stderr, "only read %d of %d bytes from '%s'\n",
+           (int)got, (int)n, zFilename);
+    exit(1);
+  }
+  z[n] = 0;
+  return z;
+}
+
+/* Check the C code in the argument to see if it might have
+** side effects.  The only accurate way to know this is to do a full
+** parse of the C code, which this routine does not do.  This routine
+** uses a simple heuristic of looking for:
+**
+**    *  '=' not immediately after '>', '<', '!', or '='.
+**    *  '++'
+**    *  '--'
+**
+** If the code contains the phrase "side-effects-ok" is inside a 
+** comment, then always return false.  This is used to disable checking
+** for assert()s with deliberate side-effects, such as used by
+** SQLITE_TESTCTRL_ASSERT - a facility that allows applications to
+** determine at runtime whether or not assert()s are enabled.  
+** Obviously, that determination cannot be made unless the assert()
+** has some side-effect.
+**
+** Return true if a side effect is seen.  Return false if not.
+*/
+static int hasSideEffect(const char *z, unsigned int n){
+  unsigned int i;
+  for(i=0; i<n; i++){
+    if( z[i]=='/' && strncmp(&z[i], "/*side-effects-ok*/", 19)==0 ) return 0;
+    if( z[i]=='=' && i>0 && z[i-1]!='=' && z[i-1]!='>'
+           && z[i-1]!='<' && z[i-1]!='!' && z[i+1]!='=' ) return 1;
+    if( z[i]=='+' && z[i+1]=='+' ) return 1;
+    if( z[i]=='-' && z[i+1]=='-' ) return 1;
+  }
+  return 0;
+}
+
+/* Return the number of bytes in string z[] prior to the first unmatched ')'
+** character.
+*/
+static unsigned int findCloseParen(const char *z){
+  unsigned int nOpen = 0;
+  unsigned i;
+  for(i=0; z[i]; i++){
+    if( z[i]=='(' ) nOpen++;
+    if( z[i]==')' ){
+      if( nOpen==0 ) break;
+      nOpen--;
+    }
+  }
+  return i;
+}
+
+/* Search for instances of assert(...), ALWAYS(...), NEVER(...), and/or
+** testcase(...) where the argument contains side effects.
+**
+** Print error messages whenever a side effect is found.  Return the number
+** of problems seen.
+*/
+static unsigned int findAllSideEffects(const char *z){
+  unsigned int lineno = 1;   /* Line number */
+  unsigned int i;
+  unsigned int nErr = 0;
+  char c, prevC = 0;
+  for(i=0; (c = z[i])!=0; prevC=c, i++){
+    if( c=='\n' ){ lineno++; continue; }
+    if( isalpha(c) && !isalpha(prevC) ){
+      if( strncmp(&z[i],"assert(",7)==0
+       || strncmp(&z[i],"ALWAYS(",7)==0
+       || strncmp(&z[i],"NEVER(",6)==0
+       || strncmp(&z[i],"testcase(",9)==0
+      ){
+        unsigned int n;
+        const char *z2 = &z[i+5];
+        while( z2[0]!='(' ){ z2++; }
+        z2++;
+        n = findCloseParen(z2);
+        if( hasSideEffect(z2, n) ){
+          nErr++;
+          fprintf(stderr, "side-effect line %u: %.*s\n", lineno,
+                  (int)(&z2[n+1] - &z[i]), &z[i]);
+        }
+      }
+    }
+  }
+  return nErr;
+}
+
+int main(int argc, char **argv){
+  char *z;
+  unsigned int nErr = 0;
+  if( argc!=2 ){
+    fprintf(stderr, "Usage: %s FILENAME\n", argv[0]);
+    return 1;
+  }
+  z = readFile(argv[1]);
+  nErr = findAllSideEffects(z);
+  free(z);
+  if( nErr ){
+    fprintf(stderr, "Found %u undesirable side-effects\n", nErr);
+    return 1;
+  }
+  return 0; 
+}