MSP430 IAR C/C++ Compiler reference guide - Rice University

The DLIB runtime environmentSITUATIONS THAT REQUIRE LIBRARY BUILDINGBuilding a customized library is complex. You should therefore carefully considerwhether it is really necessary.You must build your own library when:● There is no prebuilt library for the required combination of compiler options orhardware support● You want to define your own library configuration with support for locale, filedescriptors, multibyte characters, et cetera.For information about how to build a customized library, see Building and using acustomized library, page 55.LIBRARY CONFIGURATIONSIt is possible to configure the level of support for, for example, locale, file descriptors,multibyte characters. The runtime library configuration is defined in the libraryconfiguration file. It contains information about what functionality is part of the runtimeenvironment. The configuration file is used for tailoring a build of a runtime library, aswell as tailoring the system header files used when compiling your application. The lessfunctionality you need in the runtime environment, the smaller it is.The following DLIB library configurations are available:Library configurationNormal DLIBFull DLIBTable 9: Library configurationsDescriptionNo locale interface, C locale, no file descriptor support, no multibytecharacters in printf and scanf, and no hex floats in strtod.Full locale interface, C locale, file descriptor support, multibytecharacters in printf and scanf, and hex floats in strtod.In addition to these configurations, you can define your own configurations, whichmeans that you must modify the configuration file. Note that the library configurationfile describes how a library was built and thus cannot be changed unless you rebuild thelibrary. For further information, see Building and using a customized library, page 55.The prebuilt libraries are based on the default configurations, see Table 11, Prebuiltlibraries, page 49. There is also a ready-made library project template that you can useif you want to rebuild the runtime library.DEBUG SUPPORT IN THE RUNTIME LIBRARYYou can make the library provide different levels of debugging support—basic, runtime,and I/O debugging.Part 1. Using the compiler47