fix handling of '#pragma pack(pop [, id])'

[Mike Coleman]

"Zack Weinberg" <zackw@Stanford.EDU> writes:
> On Sat, Sep 30, 2000 at 12:06:50AM -0500, Mike Coleman wrote:
> > "Zack Weinberg" <zackw@stanford.edu> writes:
> > > You must not use a variable to hold an error message, or message
> > > translation will break.  You have to do it like this:
> > 
> > Ok, I didn't know about this.
> >
> > > Better you should set align to zero at the beginning of the function
> > > and leave the switch alone.
> > 
> > That would also work.  I put the 'action != pop' check in to make it clearer
> > to the reader that the switch didn't apply in the 'pop' case.  Personal
> > taste--your way is fine with me.
> 
> Your way is fine with me, too.
> 
> > Do I need to submit a revised patch?
> 
> Please.  And maybe some test cases?


Okay, here's another try.  I wrote a macro to avoid repeating the same verbose
if-else error statement, but it's still kind of ugly.

As for test cases, not unless someone can point me to a good test case to ape.
I wandered around in the test tree for a while and realized there's too much
stuff there for me to try to comprehend right now (time is short).

--Mike



  2000-09-29  Mike Coleman  <mkc@users.sourceforge.net>
  
  	* c-pragma.c (handle_pragma_pack): fixed handling of '#pragma
  	pack(pop [, id])' and improved error messages.


Index: gcc/c-pragma.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/c-pragma.c,v
retrieving revision 1.37
diff -c -3 -p -r1.37 c-pragma.c
*** c-pragma.c	2000/09/11 04:29:58	1.37
--- c-pragma.c	2000/10/13 10:17:51
*************** handle_pragma_pack (dummy)
*** 186,192 ****
       cpp_reader *dummy ATTRIBUTE_UNUSED;
  {
    tree x, id = 0;
!   int align;
    enum cpp_ttype token;
    enum { set, push, pop } action;
  
--- 186,192 ----
       cpp_reader *dummy ATTRIBUTE_UNUSED;
  {
    tree x, id = 0;
!   int align = -1;
    enum cpp_ttype token;
    enum { set, push, pop } action;
  
*************** handle_pragma_pack (dummy)
*** 208,213 ****
--- 208,219 ----
      }
    else if (token == CPP_NAME)
      {
+ #define BAD_ACTION do { if (action == push) \
+ 	  BAD ("malformed '#pragma pack(push[, id], <n>)' - ignored"); \
+ 	else \
+ 	  BAD ("malformed '#pragma pack(pop[, id])' - ignored"); \
+ 	} while (0)
+ 
        const char *op = IDENTIFIER_POINTER (x);
        if (!strcmp (op, "push"))
  	action = push;
*************** handle_pragma_pack (dummy)
*** 217,240 ****
  	BAD2 ("unknown action '%s' for '#pragma pack' - ignored", op);
  
        if (c_lex (&x) != CPP_COMMA)
! 	BAD2 ("malformed '#pragma pack(%s[, id], <n>)' - ignored", op);
  
        token = c_lex (&x);
        if (token == CPP_NAME)
  	{
  	  id = x;
! 	  if (c_lex (&x) != CPP_COMMA)
! 	    BAD2 ("malformed '#pragma pack(%s[, id], <n>)' - ignored", op);
  	  token = c_lex (&x);
  	}
- 
-       if (token == CPP_NUMBER)
- 	align = TREE_INT_CST_LOW (x);
-       else
- 	BAD2 ("malformed '#pragma pack(%s[, id], <n>)' - ignored", op);
  
!       if (c_lex (&x) != CPP_CLOSE_PAREN)
! 	BAD ("malformed '#pragma pack' - ignored");
      }
    else
      BAD ("malformed '#pragma pack' - ignored");
--- 223,251 ----
  	BAD2 ("unknown action '%s' for '#pragma pack' - ignored", op);
  
        if (c_lex (&x) != CPP_COMMA)
! 	BAD_ACTION;
  
        token = c_lex (&x);
        if (token == CPP_NAME)
  	{
  	  id = x;
! 	  if (action == push && c_lex (&x) != CPP_COMMA)
! 	    BAD_ACTION;
  	  token = c_lex (&x);
  	}
  
!       if (action == push)
! 	if (token == CPP_NUMBER)
! 	  {
! 	    align = TREE_INT_CST_LOW (x);
! 	    token = c_lex (&x);
! 	  }
! 	else
! 	  BAD_ACTION;
! 
!       if (token != CPP_CLOSE_PAREN)
! 	BAD_ACTION;
! #undef BAD_ACTION
      }
    else
      BAD ("malformed '#pragma pack' - ignored");
*************** handle_pragma_pack (dummy)
*** 242,260 ****
    if (c_lex (&x) != CPP_EOF)
      warning ("junk at end of '#pragma pack'");
  
!   switch (align)
!     {
!     case 0:
!     case 1:
!     case 2:
!     case 4:
!     case 8:
!     case 16:
!       align *= BITS_PER_UNIT;
!       break;
!     default:
!       BAD2 ("alignment must be a small power of two, not %d", align);
!     }
  
    switch (action)
      {
--- 253,272 ----
    if (c_lex (&x) != CPP_EOF)
      warning ("junk at end of '#pragma pack'");
  
!   if (action != pop)
!     switch (align)
!       {
!       case 0:
!       case 1:
!       case 2:
!       case 4:
!       case 8:
!       case 16:
! 	align *= BITS_PER_UNIT;
! 	break;
!       default:
! 	BAD2 ("alignment must be a small power of two, not %d", align);
!       }
  
    switch (action)
      {



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