cvs commit: src/bin/sh expand.c miscbltin.c trap.c

Ralf S. Engelschall rse at FreeBSD.org
Tue Sep 6 12:30:01 PDT 2005


rse         2005-09-06 19:30:00 UTC

  FreeBSD src repository

  Modified files:
    bin/sh               expand.c miscbltin.c trap.c 
  Log:
  Various small code cleanups resulting from a code reviewing
  and linting procedure:
  
  1. Remove useless sub-expression:
  
     - if (*start || (!ifsspc && start > string && (nulonly || 1))) {
     + if (*start || (!ifsspc && start > string)) {
  
     The sub-expression "(nulonly || 1)" always evaluates to true and
     according to CVS logs seems to be just a left-over from some
     debugging and introduced by accident. Removing the sub-expression
     doesn't change semantics and a code inspection showed that the
     variable "nulonly" is also not necessary here in any way (and the
     expression would require fixing instead of removing).
  
  2. Remove dead code:
  
     -                if (backslash && c == '\\') {
     -                        if (read(STDIN_FILENO, &c, 1) != 1) {
     -                                status = 1;
     -                                break;
     -                        }
     -                        STPUTC(c, p);
     -                } else if (ap[1] != NULL && strchr(ifs, c) != NULL) {
     +                if (ap[1] != NULL && strchr(ifs, c) != NULL) {
  
     Inspection of the control and data flow showed that variable
     "backslash" is always false (0) when the "if"-expression is
     evaluated, hence the whole block is effectively dead code.
     Additionally, the skipping of characters after a backslash is already
     performed correctly a few lines above, so this code is also not
     needed at all. According to the CVS logs and the ASH 0.2 sources,
     this code existed in this way already since its early days.
  
  3. Cleanup Style:
  
     - ! trap[signo][0] == '\0' &&
     + ! (trap[signo][0] == '\0') &&
  
     The expression wants to ensure the trap is not assigned the empty
     string. But the "!" operator has higher precedence than "==", so the
     comparison should be put into parenthesis to form the intended way of
     expression. Nevertheless the code was effectively not really broken
     as both particular NUL comparisons are semantically equal, of course.
     But the parenthesized version is a lot more intuitive.
  
  4. Remove shadowing variable declaration:
  
     - char *q;
  
     The declaration of symbol "q" hides another identical declaration of
     "q" in the same context. As the other "q" is already reused multiple
     times and also can be reused again without negative side-effects,
     just remove the shadowing declaration.
  
  5. Just small cosmetics:
  
     - if (ifsset() != 0)
     + if (ifsset())
  
     The ifsset() macro is already coded by returning the boolean result
     of a comparison operator, so no need to compare this boolean result
     again against a numerical value. This also aligns the macros usage to
     the remaining existing code.
  
  Reviewed by: stefanf@
  
  Revision  Changes    Path
  1.48      +2 -4      src/bin/sh/expand.c
  1.32      +1 -7      src/bin/sh/miscbltin.c
  1.30      +1 -1      src/bin/sh/trap.c


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