Finding Information About Procedures And Subprocedures In Linkfiles; The Dwarf Symbol Table - HP eld Manual

TNS/E Native Object Files
Finding Information About Procedures and Subprocedures in
Linkfiles
The linker obtains information about procedures and subprocedures from the .procinfo
and .procnames sections of linkfiles. These sections tell the linker what all the
procedures and subprocedures are, giving the following information about each one:
•
its name
•
its location
•
its attributes
•
how it is nested in other procedures
In addition, the .procinfo and .procnames sections tell the linker about alternate entry
points that have the CALLABLE or KERNEL_CALLABLE attribute.
When creating a linkfile, the linker creates the .procinfo and .procnames sections of
that linkfile from the sections of the same names in its input files. This is mostly done
by concatenation, in the same order as the linker saw those linkfiles, except that the
pointers from the .procinfo section to the .procnames section need the appropriate
updating, and entries for unneeded copies of procedures are omitted. (This ordering is
potentially important. For example, it can affect which procedure is chosen as the main
entry point, when the -allow_multiple_mains option tells the linker that it is okay to have
more than one procedure with the MAIN attribute.)

The DWARF Symbol Table

The DWARF symbol table contains information used by debuggers and by the COBOL
compiler, whereas the .symtab, .dynsym, and .dynsym.gblzd sections contain
information used by the linker and runtime loader.
The DWARF symbol table information in an import library that represents a single DLL
is the same as the DWARF symbol table information that is present in the
corresponding DLL. There is no DWARF symbol table information in the import library
that represents the implicit libraries.
A file may be "stripped", meaning that it doesn't have debugging information in it. This
means that the DWARF symbol table is not present. Note that it is even possible for a
linkfile to be stripped. In other words, even after being stripped, a linkfile can still be
processed by the linker, because the DWARF symbol table does not contain any
information that is required by the linker. An import library can be stripped even if the
corresponding DLL is not stripped.
DWARF Object File Sections
Here is a summary of the purposes of the DWARF sections that the HP NonStop
operating system uses:
.debug_info
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Finding Information About Procedures and
Subprocedures in Linkfiles