Re: present but cannot be compiled (Was: OMVS unix configure error)

[Akim Demaille]

Thanks for the bug report!

Unfortunately, the problem comes from the package itself, not from
Autoconf.  The configure.ac script needs to be updated.  Please, send
all this message (which your output attached) to the bug list (or the
authors) of the package you were trying to configure.

Below two parts of the Autoconf documentation are included: 1. the
documentation of AC_CHECK_HEADER(S), and 2. what's to be done to
upgrade configure.ac.

If you have some knowledge in C compilation, then there is something
more you can do to help: find out what are the prerequisite headers on
your system.

For instance, if the error message is:

       sys/socket.h: present but cannot be compiled
       sys/socket.h: check for missing prerequisite headers?
       sys/socket.h: proceeding with the preprocessor's result

then try to compile the program sample.c:

       #include <sys/socket.h>

with `cc -c sample.c'.  It will fail.  Then try to understand what
other headers are needed.  For instance, on Darwin, one needs:

       #include <stdio.h>
       #include <stdlib.h>
       #include <sys/socket.h>
       #include <sys/socket.h>

to get a successful compilation.  Then, send this additional
information to the package maintainers, together with a description of
your machine.

Thanks!

----------------------------------------------------------------------

Generic Header Checks
---------------------

   These macros are used to find system header files not covered by the
"particular" test macros.  If you need to check the contents of a header
as well as find out whether it is present, you have to write your own
test for it (*note Writing Tests::).

 - Macro: AC_CHECK_HEADER (HEADER-FILE, [ACTION-IF-FOUND],
          [ACTION-IF-NOT-FOUND], [INCLUDES = `default-includes'])
     If the system header file HEADER-FILE is compilable, execute shell
     commands ACTION-IF-FOUND, otherwise execute ACTION-IF-NOT-FOUND.
     If you just want to define a symbol if the header file is
     available, consider using `AC_CHECK_HEADERS' instead.

     For compatibility issues with older versions of Autoconf, please
     read below.

 - Macro: AC_CHECK_HEADERS (HEADER-FILE..., [ACTION-IF-FOUND],
          [ACTION-IF-NOT-FOUND], [INCLUDES = `default-includes'])
     For each given system header file HEADER-FILE in the
     whitespace-separated argument list that exists, define
     `HAVE_HEADER-FILE' (in all capitals).  If ACTION-IF-FOUND is
     given, it is additional shell code to execute when one of the
     header files is found.  You can give it a value of `break' to
     break out of the loop on the first match.  If ACTION-IF-NOT-FOUND
     is given, it is executed when one of the header files is not found.

     For compatibility issues with older versions of Autoconf, please
     read below.

   Previous versions of Autoconf merely checked whether the header was
accepted by the preprocessor.  This was changed because the old test was
inappropriate for typical uses.  Headers are typically used to compile,
not merely to preprocess, and the old behavior sometimes accepted
headers that clashed at compile-time.  If you need to check whether a
header is preprocessable, you can use `AC_PREPROC_IFELSE' (*note
Running the Preprocessor::).

   This scheme, which improves the robustness of the test, also requires
that you make sure that headers that must be included before the
HEADER-FILE be part of the INCLUDES, (*note Default Includes::).  If
looking for `bar.h', which requires that `foo.h' be included before if
it exists, we suggest the following scheme:


AC_CHECK_HEADERS([foo.h])
AC_CHECK_HEADERS([bar.h], [], [],
[#if HAVE_FOO_H
# include <foo.h>
# endif
])

----------------------------------------------------------------------

Header Present But Cannot Be Compiled
=====================================

   The most important guideline to bear in mind when checking for
features is to mimic as much as possible the intended use.
Unfortunately, old versions of `AC_CHECK_HEADER' and `AC_CHECK_HEADERS'
failed to follow this idea, and called the preprocessor, instead of the
compiler, to check for headers.  As a result, incompatibilities between
headers went unnoticed during configuration, and maintainers finally
had to deal with this issue elsewhere.

   As of Autoconf 2.56 both checks are performed, and `configure'
complains loudly if the compiler and the preprocessor do not agree.
For the time being the result used is that of the preprocessor, to give
maintainers time to adjust their `configure.ac', but in the near
future, only the compiler will be considered.

   Consider the following example:

     $ cat number.h
     typedef int number;
     $ cat pi.h
     const number pi = 3;
     $ cat configure.ac
     AC_INIT
     AC_CHECK_HEADERS(pi.h)
     $ autoconf -Wall
     $ ./configure
     checking for gcc... gcc
     checking for C compiler default output... a.out
     checking whether the C compiler works... yes
     checking whether we are cross compiling... no
     checking for suffix of executables...
     checking for suffix of object files... o
     checking whether we are using the GNU C compiler... yes
     checking whether gcc accepts -g... yes
     checking for gcc option to accept ANSI C... none needed
     checking how to run the C preprocessor... gcc -E
     checking for egrep... grep -E
     checking for ANSI C header files... yes
     checking for sys/types.h... yes
     checking for sys/stat.h... yes
     checking for stdlib.h... yes
     checking for string.h... yes
     checking for memory.h... yes
     checking for strings.h... yes
     checking for inttypes.h... yes
     checking for stdint.h... yes
     checking for unistd.h... yes
     checking pi.h usability... no
     checking pi.h presence... yes
     configure: WARNING: pi.h: present but cannot be compiled
     configure: WARNING: pi.h: check for missing prerequisite headers?
     configure: WARNING: pi.h: proceeding with the preprocessor's result
     configure: WARNING:     ## ------------------------------------ ##
     configure: WARNING:     ## Report this to address@hidden ##
     configure: WARNING:     ## ------------------------------------ ##
     checking for pi.h... yes

The proper way the handle this case is using the fourth argument (*note
Generic Headers::):

     $ cat configure.ac
     AC_INIT
     AC_CHECK_HEADERS(number.h pi.h,,,
     [[#if HAVE_NUMBER_H
     # include <number.h>
     #endif
     ]])
     $ autoconf -Wall
     $ ./configure
     checking for gcc... gcc
     checking for C compiler default output... a.out
     checking whether the C compiler works... yes
     checking whether we are cross compiling... no
     checking for suffix of executables...
     checking for suffix of object files... o
     checking whether we are using the GNU C compiler... yes
     checking whether gcc accepts -g... yes
     checking for gcc option to accept ANSI C... none needed
     checking for number.h... yes
     checking for pi.h... yes

   See *Note Particular Headers::, for a list of headers with their
prerequisite.

----------------------------------------------------------------------

Portability of Headers
----------------------

This section tries to collect knowledge about common headers, and the
problems they cause.  By definition, this list will always require
additions.  Please help us keeping it as complete as possible.

`inttypes.h' vs. `stdint.h'
     Paul Eggert notes that: ISO C 1999 says that `inttypes.h' includes
     `stdint.h', so there's no need to include `stdint.h' separately in
     a standard environment.  Many implementations have `inttypes.h'
     but not `stdint.h' (e.g., Solaris 7), but I don't know of any
     implementation that has `stdint.h' but not `inttypes.h'.  Nor do I
     know of any free software that includes `stdint.h'; `stdint.h'
     seems to be a creation of the committee.

`linux/irda.h'
     It requires `linux/types.h' and `sys/socket.h'.

`net/if.h'
     On Darwin, this file requires that `sys/socket.h' be included
     beforehand.  One should run:

          AC_CHECK_HEADERS([sys/socket.h])
          AC_CHECK_HEADERS([net/if.h], [], [],
          [#include <stdio.h>
          #if STDC_HEADERS
          # include <stdlib.h>
          # include <stddef.h>
          #else
          # if HAVE_STDLIB_H
          #  include <stdlib.h>
          # endif
          #endif
          #if HAVE_SYS_SOCKET_H
          # include <sys/socket.h>
          #endif
          ])

`stdint.h'
     See above, item `inttypes.h' vs. `stdint.h'.

`stdlib.h'
     On many systems (e.g., Darwin), `stdio.h' is a prerequisite.

`sys/socket.h'
     On Darwin, `stdlib.h' is a prerequisite.

`X11/extensions/scrnsaver.h'
     Using XFree86, this header requires `X11/Xlib.h', which is probably
     so required that you might not even consider looking for it.

          AC_CHECK_HEADERS([X11/extensions/scrnsaver.h], [], [],
          [[#include <X11/Xlib.h>
          ]])
./configure --prefix=/usr/local --with-png=/usr/local
mvs with gnu make

Why I sent this email
checking for FT_Init_FreeType in -lfreetype...
no                              
configure: WARNING: not found - disabling freetype
support                     
checking freetype/freetype.h usability...
yes                                  
checking freetype/freetype.h presence...
no                                    
configure: WARNING: freetype/freetype.h: accepted by the compiler,
rejected by the
preprocessor!                                                               

configure: WARNING: freetype/freetype.h: proceeding with the
preprocessor's
result                                                                          
   

configure: WARNING:     ## ------------------------------------
##             
configure: WARNING:     ## Report this to address@hidden
##             
configure: WARNING:     ## ------------------------------------
##             
checking for freetype/freetype.h...
no                                         
checking for jpeg_set_defaults in -ljpeg...
no                                 
checking for XpmReadFileToXpmImage in -lXpm... no           

Full list of log                   
trap: ./configure 1311: FSUM7327 signal number 13 not conventional     
checking for a BSD-compatible install... config/install-sh -c          
checking whether build environment is sane... yes                      
checking for gawk... no                                                
checking for mawk... no                                                
checking for nawk... no                                                
checking for awk... awk                                                
checking whether make sets $(MAKE)... ac_maketemp="": eval: ./configure
no                                                                     
checking for gcc... no                                                 
checking for cc... cc                                                  
checking for C compiler default output... a.out                        
checking whether the C compiler works... yes                           
checking whether we are cross compiling... no                          
checking for suffix of executables...                                  
checking for suffix of object files... o                               
checking whether we are using the GNU C compiler... no                 
checking whether cc accepts -g... yes                                  
checking for cc option to accept ANSI C... none needed                 
checking for style of include used by make... GNU                      
checking dependency style of cc... none                                
checking for cc option to accept ANSI C... none needed                 
checking for a BSD-compatible install... config/install-sh -c          
checking build system type... i370-ibm-openedition                     
checking host system type... i370-ibm-openedition                      
checking for non-GNU ld... /usr/local/bin/ld                           
checking if the linker (/usr/local/bin/ld) is GNU ld... no             
checking for /usr/local/bin/ld option to reload object files... -r     
checking for BSD-compatible nm... /bin/nm -p                           
checking for a sed that does not truncate output... FSUM9199 input line
/bin/sed                                                               
checking whether ln -s works... yes                                    
checking how to recognise dependent libraries... unknown               
checking command to parse /bin/nm -p output... failed                  
checking how to run the C preprocessor... cc -E                        
checking for egrep... grep -E                                          
checking for ANSI C header files... yes                                
checking for sys/types.h... yes                                        
checking for sys/stat.h... yes                                         
checking for stdlib.h... yes                                           
checking for string.h... yes                                           
checking for memory.h... yes                                           
checking for strings.h... yes                                          
checking for inttypes.h... yes                                         
checking for stdint.h... yes                                           
checking for unistd.h... yes                                           
checking dlfcn.h usability... yes                                      
checking dlfcn.h presence... no                                        
configure: WARNING: dlfcn.h: accepted by the compiler, rejected by the p
configure: WARNING: dlfcn.h: proceeding with the preprocessor's result 
configure: WARNING:     ## ------------------------------------ ##     
configure: WARNING:     ## Report this to address@hidden ##     
configure: WARNING:     ## ------------------------------------ ##     
checking for dlfcn.h... no                                             
checking for ranlib... :                                               
checking for strip... strip                                            
checking for objdir... .libs                                           
checking for cc option to produce PIC... none                          
checking if cc static flag  works... yes                               
checking if cc supports -c -o file.o... yes                            
checking if cc supports -c -o file.lo... yes                           
checking whether the linker (/usr/local/bin/ld) supports shared librarie
checking how to hardcode library paths into programs... unsupported    
checking whether stripping libraries is possible... no                 
checking dynamic linker characteristics... no                          
checking if libtool supports shared libraries... no                    
checking whether to build shared libraries... no                       
checking whether to build static libraries... yes                      
creating libtool                                                       
checking whether ln -s works... yes                                    
checking whether make sets $(MAKE)... (cached) no                      
checking for ranlib... (cached) :                                      
checking for X... libraries /usr/lib, headers                          
checking for ANSI C header files... (cached) yes                       
checking errno.h usability... yes                                      
checking errno.h presence... yes                                       
checking for errno.h... yes                                            
checking limits.h usability... yes                                     
checking limits.h presence... yes                                      
checking for limits.h... yes                                           
checking stddef.h usability... yes                                     
checking stddef.h presence... yes                                      
checking for stddef.h... yes                                           
checking for stdlib.h... (cached) yes                                  
checking for string.h... (cached) yes                                  
checking for unistd.h... (cached) yes                                  
checking for non-GNU ld... /usr/local/bin/ld                           
checking if the linker (/usr/local/bin/ld) is GNU ld... no             
checking for shared library run path origin... done                    
checking for iconv... yes                                              
checking for iconv declaration...                                      
extern size_t iconv (iconv_t cd, char * *inbuf, size_t *inbytes
checking iconv.h usability... yes                                      
checking iconv.h presence... yes                                       
checking for iconv.h... yes                                            
checking whether iconv.h defines iconv_t... yes                        
checking for sin... yes                                                
checking for deflate in -lz... no                                      
configure: WARNING: zlib is required - see http://www.gzip.org/zlib/   
checking for libpng-config... no                                       
checking png.h usability... yes                                        
checking png.h presence... yes                                         
checking for png.h... yes                                              
checking for png_create_read_struct in -lpng... no                     
configure: WARNING: libpng is required - see http://www.libpng.org/pub/p
checking for freetype-config... no                                     
checking for FT_Init_FreeType in -lfreetype... no                      
configure: WARNING: not found - disabling freetype support             
checking freetype/freetype.h usability... yes                          
checking freetype/freetype.h presence... no                            
configure: WARNING: freetype/freetype.h: accepted by the compiler, rejec
configure: WARNING: freetype/freetype.h: proceeding with the preprocesso
configure: WARNING:     ## ------------------------------------ ##     
configure: WARNING:     ## Report this to address@hidden ##     
configure: WARNING:     ## ------------------------------------ ##     
checking for freetype/freetype.h... no                                 
checking for jpeg_set_defaults in -ljpeg... no                       
checking for XpmReadFileToXpmImage in -lXpm... no                    

** Configuration summary for gd 2.0.12:                              

Support for PNG library:          no                              
Support for JPEG library:         no                              
Support for Freetype 2.x library: no                              
Support for Xpm library:          no                              

configure: creating ./config.status                                  
trap: ./config.status 428: FSUM7327 signal number 13 not conventional
config.status: creating Makefile                                     
config.status: creating config/Makefile                              
config.status: creating config/gdlib-config                          
config.status: creating test/Makefile                                
config.status: creating config.h                                     
config.status: config.h is unchanged                                 
config.status: executing depfiles commands