137736 - configure does not detect pthreads using CC on IRIX 6.5

Status: RESOLVED FIXED

(NSPR :: NSPR, defect, P2)

Description

[Simon Julier]

The ./configure script does not detect pthreads on an SGI IRIX 6.5 platform
using CC  7.3.1.3m. Browsing through config.log indicates that the problem is
not due to lack of thread support but is caused by the fact that the header file
which defines 'exit' is not included in the test program:

========================================================================

configure:4889: checking for pthread_create in -lpthreads
CC -o dummy dummy.c  -fullwarn -xansi -multigot -n32 -woff 1209 -mips3  -lpthreads  
cc-1116 CC: WARNING File = dummy.c, Line = 3
  Non-void function "foo" (declared at line 3) should return a value.

      void *foo(void *v) { int a = 1;  } 
                                       ^

cc-3201 CC: REMARK File = dummy.c, Line = 3
  The parameter "v" was never referenced.

      void *foo(void *v) { int a = 1;  } 
                      ^

cc-1174 CC: WARNING File = dummy.c, Line = 3
  The variable "a" was declared but never referenced.

      void *foo(void *v) { int a = 1;  } 
                               ^

cc-1020 CC: ERROR File = dummy.c, Line = 9
  The identifier "exit" is undefined.

          exit(0);
          ^

1 error detected in the compilation of "dummy.c".

========================================================================

This can be rectified by adding

#include <stdlib.h>

Comment 1

[Wan-Teh Chang]

Assigned the bug to Chris.

Comment 2

[Nick Blievers]

On IRIX the pthread library is libpthread not libpthreads. eg
% find $TOOLROOT/* $ROOT/* -name libpthrea\*
/projects/sise/roots/latest_root/usr/lib/libpthread.so
/projects/sise/roots/latest_root/usr/lib32/libpthread.so
/projects/sise/roots/latest_root/usr/lib64/libpthread.so

or 
% find /usr/lib /usr/lib32 /usr/lib64 -name libpthre\*
/usr/lib/libpthread.so
/usr/lib32/libpthread.so
/usr/lib64/libpthread.so

% cc -version
MIPSpro Compilers: Version 7.3.1.3m

Further, this works for me:
configure:7329: checking for pthread_create in -lpthread
cc -o dummy dummy.c  -woff 3201 -woff 1506 -mips3 -n32 -woff 3262 -G 4 -n32  
-lpthread -mips3 -n32 -n32 -lsocket -ldl -lm 
cc-1116 cc: WARNING File = dummy.c, Line = 3
  Non-void function "foo" (declared at line 3) should return a value.

      void *foo(void *v) { int a = 1;  } 
                                       ^       

cc-1174 cc: WARNING File = dummy.c, Line = 3
  The variable "a" was declared but never referenced.

      void *foo(void *v) { int a = 1;  }
                               ^

ld32: WARNING 84 : /usr/lib32/libsocket.so is not used for resolving any symbol.
ld32: WARNING 84 : /usr/lib32/libdl.so is not used for resolving any symbol.
ld32: WARNING 84 : /usr/lib32/mips3/libm.so is not used for resolving any symbol.

To cut a long story short... you should be using cc not CC. If you use cc
you will not have this problem.
eg:
% cc -o dummy dummy.c -woff 3201 -woff 1506 -mips3 -n32 -woff 3262 -G 4 -n32
-lpthread -mips3 -n32 -n32 -lsocket -ldl -lm
cc-1116 cc: WARNING File = dummy.c, Line = 2
  Non-void function "foo" (declared at line 2) should return a value.

  void *foo(void *v) { int a = 1;  } 
                                   ^

cc-1174 cc: WARNING File = dummy.c, Line = 2
  The variable "a" was declared but never referenced.

  void *foo(void *v) { int a = 1;  } 
                           ^

ld32: WARNING 84 : /usr/lib32/libsocket.so is not used for resolving any symbol.
ld32: WARNING 84 : /usr/lib32/libdl.so is not used for resolving any symbol.
ld32: WARNING 84 : /usr/lib32/mips3/libm.so is not used for resolving any symbol.

% CC -o dummy dummy.c -woff 3201 -woff 1506 -mips3 -n32 -woff 3262 -G 4 -n32
-lpthread -mips3 -n32 -n32 -lsocket -ldl -lm
cc-1116 CC: WARNING File = dummy.c, Line = 2
  Non-void function "foo" (declared at line 2) should return a value.

  void *foo(void *v) { int a = 1;  } 
                                   ^

cc-1174 CC: WARNING File = dummy.c, Line = 2
  The variable "a" was declared but never referenced.

  void *foo(void *v) { int a = 1;  } 
                           ^

cc-1020 CC: ERROR File = dummy.c, Line = 8
  The identifier "exit" is undefined.

        exit(0);
        ^

1 error detected in the compilation of "dummy.c".
 

Comment 3

[Simon Julier]

Thanks! I'll try that.

Is there any way to get the configure script to default to the correct choice of
compiler? Conversely, can anything be added to the build FAQ? The reason for the
configuration error is not at all obvious (I dug around the website for a while
and couldn't find anything relevant). The only mention of I've found of setting
CC/CXX was on the SGI Mozilla FAQ webpage and, even then, there was no
explanation as to why this had to be done.

Comment 4

[Wan-Teh Chang]

Attachment: Proposed patch

Replace exit(0) by "return 0".	These are equivalent for the
main() function.

I also modified the foo() function to eliminate the compiler
warnings and remark.

Comment 5

[Wan-Teh Chang]

Attachment: Proposed patch

Changed another exit(0) to "return 0".	Explicitly declare
the main() function to return int.

Comment 6

[Wan-Teh Chang]

I checked in my fix on the tip and NSPRPUB_PRE_4_2_CLIENT_BRANCH
of NSPR.  Chris, I'd appreciate it if you could still review my
patch.

Mr. Julier, configure scripts typically choose g++ and gcc by
default.  Whether you want to use the GNU compilers or the OS
vendor's compilers (CC and cc) is a personal choice.  It is
possible for the configure script to detect that $CC is actually
a C++ compiler, but as I point out in bug 136344, some people
do that on purpose, so it's not clear whether we should flag
that as an error.

Lowered the severity to minor because the bug reporter specified
CC (the IRIX MIPSpro C++ compiler) as the C compiler unintentionally.