tailieunhanh - HandBooks Professional Java-C-Scrip-SQL part 185

Tham khảo tài liệu 'handbooks professional java-c-scrip-sql part 185', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Common Object File Format COFF or Extended Linker Format ELF . If you ll be using more than one compiler . you ll be writing parts of your program in different source languages you need to make sure that each is capable of producing object files in the same format. Although many compilers particularly those that run on Unix platforms support standard object file formats like COFF and ELF gcc supports both there are also some others that produce object files only in proprietary formats. If you re using one of the compilers in the latter group you might find that you need to buy all of your other development tools from the same vendor. Most object files begin with a header that describes the sections that follow. Each of these sections contains one or more blocks of code or data that originated within the original source file. However these blocks have been regrouped by the compiler into related sections. For example all of the code blocks are collected into a section called text initialized global variables and their initial values into a section called data and uninitialized global variables into a section called bss. There is also usually a symbol table somewhere in the object file that contains the names and locations of all the variables and functions referenced within the source file. Parts of this table may be incomplete however because not all of the variables and functions are always defined in the same file. These are the symbols that refer to variables and functions defined in other source files. And it is up to the linker to resolve such unresolved references. Linking All of the object files resulting from step one must be combined in a special way before the program can be executed. The object files themselves are individually incomplete most notably in that some of the internal variable and function references have not yet been resolved. The job of the linker is to combine these object files and in the process to resolve all of the unresolved .