tools/dev/warn-ignored-err.sh

   1 #!/bin/sh
   2 HELP="\
   3 Usage: $0 [--remove] [FILE...]
   4
   5 Insert or remove the GCC attribute \"warn_unused_result\" on each function
   6 that returns a Subversion error, in the specified files or, by default,
   7 *.h and *.c in the ./subversion and ./tools trees.
   8 "
   9
  10 LC_ALL=C
  11
  12 # Parse options
  13 REMOVE=
  14 case "$1" in
  15 --remove) REMOVE=1; shift;;
  16 --help)   echo "$HELP"; exit 0;;
  17 --*)      echo "$0: unknown option \"$1\"; try \"--help\""; exit 1;;
  18 esac
  19
  20 # Set the positional parameters to the default files if none specified
  21 if [ $# = 0 ]; then
  22   set -- `find subversion/ tools/ -name '*.[ch]'`
  23 fi
  24
  25 # A line that declares a function return type of "svn_error_t *" looks like:
  26 # - Possibly leading whitespace, though not often.
  27 # - Possibly "static" or "typedef".
  28 # - The return type "svn_error_t *".
  29 # - Possibly a function or pointer-to-function declarator:
  30 #     - "identifier"
  31 #     - "(identifier)"  (used in some typedefs)
  32 #     - "(*identifier)"
  33 #   with either nothing more, or a "(" next (especially not "," or ";" or "="
  34 #   which all indicate a variable rather than a function).
  35
  36 # Regular expressions for "sed"
  37 # Note: take care in matching back-reference numbers to parentheses
  38 PREFIX="^\( *\| *static  *\| *typedef  *\)"
  39 RET_TYPE="\(svn_error_t *\* *\)"
  40 IDENT="[a-zA-Z_][a-zA-Z0-9_]*"
  41 DECLR="\($IDENT\|( *\(\*\|\) *$IDENT *)\)"
  42 SUFFIX="\($DECLR *\((.*\|\)\|\)$"
  43
  44 # The attribute string to be inserted or removed
  45 ATTRIB_RE="__attribute__((warn_unused_result))"  # regex version of it
  46 ATTRIB_STR="__attribute__((warn_unused_result))"  # plain text version of it
  47
  48 if [ $REMOVE ]; then
  49   SUBST="s/$PREFIX$ATTRIB_RE $RET_TYPE$SUFFIX/\1\2\3/"
  50 else
  51   SUBST="s/$PREFIX$RET_TYPE$SUFFIX/\1$ATTRIB_STR \2\3/"
  52 fi
  53
  54 for F do
  55   # Edit the file, leaving a backup suffixed with a tilde
  56   { sed -e "$SUBST" "$F" > "$F~1" &&
  57     { ! cmp -s "$F" "$F~1"; } &&
  58     mv "$F" "$F~" &&  # F is briefly absent now; a copy could avoid this
  59     mv "$F~1" "$F"
  60   } ||
  61   # If anything went wrong or no change was made, remove the temporary file
  62   rm "$F~1"
  63 done