C/C++ Programmer's Guide (G06.27+, H06.08+, J06.03+)

Usage Guidelines
• As of G06.20, the default for native mode C++ compilation is VERSION3 (not VERSION1).
If you are going to recompile an application that used the previous default (VERSION1), you
must specify the VERSION1 pragma. See also VERSION2 (page 254) and VERSION3 (page 255).
• You can enter the VERSION1 directive on the compiler RUN command line when specifying
NMCPLUS on Guardian environment, or using the -Wversion1 flag when specifying c89
On OSS environment. You cannot enter the VERSION1 directive in the source file.
• All modules of an application must be built using the same version of the Standard C++ Library.
For example, you must compile all modules using the same version directive (VERSION1,
VERSION2, or VERSION3). Mixing versions within an application can cause unpredictable
results. Additionally, the linkers and the NonStop OS perform version checking. Attempting
to mix VERSION3 with either of the other versions will yield an error (for link files) or a warning
(for load files) from the linker, and a run-time error at load time from the NonStop OS.
• Using the VERSION1 directive with the D45 (or later) native C++ compiler produces an object
file that is compatible with an object file produced by the D40 native C++ compiler but not
compatible with an object file produced by the D45 (or later) native C++ compiler using the
VERSION2 or VERSION3 directives.
New C++ features introduced at the D45 RVU mean that objects compiled to take advantage
of these features are incompatible with objects produced using earlier versions of the compiler.
Moreover, object files produced by the D45 C++ compiler using the default at D45 (VERSION1)
are not binary compatible with object files produced by the D45 C++ compiler using the
VERSION2 directive or with object files produced by the G06.20 C++ compiler using the
default, VERSION3.
• The nld linker issues an error or warning if you attempt to link several C++ modules that were
compiled with different version directives. You can use the eld or ld linker only with
VERSION2 or VERSION3.
• VERSION1 does not support the IEEE floating-point format for performing floating-point
arithmetic.
• VERSION1 does not support Position-Independent Code (PIC) or the use of DLLs.
• In the G06.20 RVU, all the native C++ header files have been combined into one product
number (T2824). These headers have been modified to identify the version used in the compile
and to redirect calls to the correct library.
• If you include the RUNNABLE option when compiling VERSION1 on Guardian environment
(or if you do not include -c On OSS environment), the compiler automatically links:
◦ ZCPLGSRL (Guardian C++ library) or ZCPLOSRL (OSS C++ library)
◦ LIBCOBEY for a TNS/R program (an OBEY file that links the C run-time library and the
Common Run-Time Environment [CRE])
• VERSION1 supports version 6.1 of Tools.h++.
• To use the Tools.h++ library (version 6.1) when using VERSION1, you need to link ZTLHGSRL
(the Guardian Tools.h++ library) or ZTLHOSRL (the OSS Tools.h++ library). If you are compiling
a loadfile (using RUNNABLE in Guardian), you can link to Tools.h++ by specifying the correct
SRL in a LINKFILE pragma or by using the -Wnld_obey option to c89 in OSS.
For more details about SRLs, see Shared Run-Time Libraries (SRLs) (page 294).
VERSION1 253