gcc/testsuite/c-c++-common/analyzer/deref-before-check-pr112790.c

   1 /* Reproducer for false positive from -Wanalyzer-deref-before-check
   2    seen on Linux kernel's block/bdev.c due to -fanalyzer mishandling
   3    inlined functions.  */
   4
   5 /* { dg-additional-options "-O2 -g -fno-delete-null-pointer-checks" } */
   6
   7 typedef unsigned char u8;
   8 struct inode {
   9   void *i_mapping;
  10   u8 i_blkbits;
  11 };
  12 struct block_device {
  13   struct inode *bd_inode;
  14 };
  15 int sync_blockdev(struct block_device *bdev);
  16 int set_blocksize(struct block_device *bdev, u8 size) {
  17   if (bdev->bd_inode->i_blkbits != size) { /* { dg-bogus "pointer 'bdev' is dereferenced here" } */
  18     sync_blockdev(bdev);
  19   }
  20   return 0;
  21 }
  22 extern int filemap_write_and_wait(void *);
  23 int sync_blockdev(struct block_device *bdev) {
  24   if (!bdev) /* { dg-bogus "check of 'bdev' for NULL after already dereferencing it" } */
  25     return 0;
  26   return filemap_write_and_wait(bdev->bd_inode->i_mapping);
  27 }