On 7 Feb 2001, Jeff Trawick wrote: > Doesn't AC_TRY_COMPILE() succeed if there is a warning? I think your > patch only helps on rare systems where the compiler won't compile it > at all if the const-ness doesn't match the iconv() prototype. Yeah, > that is an improvement over the current situation but it would be nice > to get rid of the problem -- warning or error -- altogether.
We are testing for the error condition, that is why the #define is called HAVE_ERROR_CALL_ICONV_CONST. The error shows up on systems with the combo of a non const header file and a gcc newer than 2.95 (like Red Hat 7.0). > Mo DeJong <[EMAIL PROTECTED]> writes: > > > On Sun, 4 Feb 2001, Greg Stein wrote: > > > > > There was some discussion about iconv prototyes here recently, but I kind > > > of > > > missed it. > > > > > > Do we always need to live with a warning about a type mismatch, or is the > > > cast below appropriate? > > > > > > IOW, do some headers have "const" on them, and others not? > > > > Yup, you cannot just use a cast, you need to use a HAVE... > > test because headers differ and newer versions of > > gcc will generate an error on a plain cast. > > What does "plain cast" in this sense mean? A cast that does not happen using the ifdef HAVE_ERROR_CALL_ICONV_CONST conditional logic. The point was that just casting to char ** would fail on some systems. > > Here is the bit of code from the Jikes java compiler > > that deals with this issue. > > > > size_t n = iconv(_converter, > > #ifdef HAVE_ERROR_CALL_ICONV_CONST > > (char **) > > #endif > > &source_ptr, &srcl, > > (char **)&chp, &chl > > ); > > The code would be nicer if we define ICONV_INBUF_TYPE to "char **" or > "const char **" and then do Well, that would just be casting a const char** to a const char ** in the normal case, why put an extra cast in for no reason? I tend to like knowing about the exceptions and why they are in the code instead of having unexplained casts all over the place. > n = iconv(_converter, > (ICONV_INBUF_TYPE)&source_ptr, &srcl, > (char **)&chp, &chl); > > but that is a minor detail (particularly since we have so few calls to > iconv). > > Is it reasonable to test for a compile *warning* via autoconf? I am not sure why that matters. The point is that apr does not compile on some systems, this iconv #define code will fix that. Mo DeJong Red Hat Inc
