John Maddock wrote:
When compiling the smart pointer tests with gcc 3.4.2 on Tru64, two tests fail with an error message. (See http://tinyurl.com/4jngu )
As far as I can see, the shared pointer implementation at some point includes the "pthread.h" system header file but gcc on Tru64 requires that -pthread must be specified on the command line when including this header file.
When running this test with gcc 3.4.2 on Linux the file "pthread.h" is also included but gcc doesn't require the addition of -pthread in the command line on this platform.
This leads to the question whether it is ok to include "pthread.h" without specifying -pthread on the command line. Does anyone know an answer to this?
I think on some platforms <pthread.h> doesn't compile unless _REENTRANT or some similar compiler-specific magic symbol is defined: in other words it's an assert that the compiler is indeed in thread safe mode.
Yes, it's true. _REENTRANT has to be defined, there is an explicit check in "pthread.h" for this.
It looks to me as though BOOST_HAS_THREADS is getting set unconditionally for gcc on this platform, and presumably we should only set it when _REENTRANT is defined (I'm assuming that's the symbol that gets defined when the -thread option is used - can you check?).
Hold on... checked the output from config_info and looks as though _REENTRANT *is* defined, so I'm mystified. I also note that the platform is detected as "generic unix". Do you know what macros gcc defines to identify this platform?
Attached is the output of "gcc -ansi -dM". I hope it contains enough information to answer your questions. Note also that _REENTRANT is not defined here, therefore its source must be somewhere outside of gcc. Markus #define __DBL_MIN_EXP__ (-1021) #define __FLT_MIN__ 1.17549435e-38F #define __CHAR_BIT__ 8 #define __WCHAR_MAX__ 4294967295U #define __DBL_DENORM_MIN__ 4.9406564584124654e-324 #define __FLT_EVAL_METHOD__ 0 #define __alpha_bwx__ 1 #define __DBL_MIN_10_EXP__ (-307) #define __FINITE_MATH_ONLY__ 0 #define __LP64__ 1 #define __GNUC_PATCHLEVEL__ 2 #define __SHRT_MAX__ 32767 #define __LDBL_MAX__ 1.18973149535723176508575932662800702e+4932L #define __SYSTYPE_BSD 1 #define __unix 1 #define __alpha_ev5__ 1 #define __LDBL_MAX_EXP__ 16384 #define __LANGUAGE_C_PLUS_PLUS 1 #define __SCHAR_MAX__ 127 #define __USER_LABEL_PREFIX__ #define __STDC_HOSTED__ 1 #define __osf__ 1 #define __LDBL_HAS_INFINITY__ 1 #define __DBL_DIG__ 15 #define __FLT_EPSILON__ 1.19209290e-7F #define __GXX_WEAK__ 0 #define __LDBL_MIN__ 3.36210314311209350626267781732175260e-4932L #define __digital__ 1 #define __unix__ 1 #define __DECIMAL_DIG__ 36 #define __LDBL_HAS_QUIET_NAN__ 1 #define _REENTRANT 1 #define __GNUC__ 3 #define __DBL_MAX__ 1.7976931348623157e+308 #define __DBL_HAS_INFINITY__ 1 #define __X_FLOAT 1 #define __STRICT_ANSI__ 1 #define __cplusplus 1 #define __DEPRECATED 1 #define __DBL_MAX_EXP__ 1024 #define __GNUG__ 3 #define __LANGUAGE_C_PLUS_PLUS__ 1 #define __LONG_LONG_MAX__ 9223372036854775807LL #define __GXX_ABI_VERSION 1002 #define __FLT_MIN_EXP__ (-125) #define __DBL_MIN__ 2.2250738585072014e-308 #define __FLT_MIN_10_EXP__ (-37) #define __DBL_HAS_QUIET_NAN__ 1 #define __REGISTER_PREFIX__ #define __NO_INLINE__ 1 #define __FLT_MANT_DIG__ 24 #define __VERSION__ "3.4.2" #define __PRAGMA_EXTERN_PREFIX 1 #define __alpha 1 #define __SIZE_TYPE__ long unsigned int #define __FLT_RADIX__ 2 #define __LDBL_EPSILON__ 1.92592994438723585305597794258492732e-34L #define __FLT_HAS_QUIET_NAN__ 1 #define __FLT_MAX_10_EXP__ 38 #define __LONG_MAX__ 9223372036854775807L #define __FLT_HAS_INFINITY__ 1 #define _SYSTYPE_BSD 1 #define __STDC_VERSION__ 199409L #define __EXCEPTIONS 1 #define __LDBL_MANT_DIG__ 113 #define _LONGLONG 1 #define __WCHAR_TYPE__ unsigned int #define __FLT_DIG__ 6 #define __INT_MAX__ 2147483647 #define __LONG_DOUBLE_128__ 1 #define __FLT_MAX_EXP__ 128 #define __DBL_MANT_DIG__ 53 #define __WINT_TYPE__ unsigned int #define __LDBL_MIN_EXP__ (-16381) #define __WCHAR_UNSIGNED__ 1 #define __LDBL_MAX_10_EXP__ 4932 #define __DBL_EPSILON__ 2.2204460492503131e-16 #define _LP64 1 #define __FLT_DENORM_MIN__ 1.40129846e-45F #define __FLT_MAX__ 3.40282347e+38F #define __GNUC_MINOR__ 4 #define __DBL_MAX_10_EXP__ 308 #define __LDBL_DENORM_MIN__ 6.47517511943802511092443895822764655e-4966L #define __SYSTYPE_BSD__ 1 #define __PTRDIFF_TYPE__ long int #define __arch64__ 1 #define __LDBL_MIN_10_EXP__ (-4931) #define __alpha__ 1 #define __LDBL_DIG__ 33