diff options
Diffstat (limited to 'bfd/ctor.c')
| -rw-r--r-- | bfd/ctor.c | 146 |
1 files changed, 76 insertions, 70 deletions
@@ -21,62 +21,67 @@ You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -/*doc* -@section Constructors -Classes in C++ have 'constructors' and 'destructors'. These are -functions which are called automatically by the language whenever data -of a class is created or destroyed. Class data which is static data -may also be have a type which requires 'construction', the contructor -must be called before the data can be referenced, so the contructor -must be called before the program begins. - -The common solution to this problem is for the compiler to call a -magic function as the first statement @code{main}. This magic -function, (often called @code{__main}) runs around calling the -constructors for all the things needing it. - -With COFF the compile has a bargain with the linker et al. All -constructors are given strange names, for example -@code{__GLOBAL__$I$foo} might be the label of a contructor for the -class @var{foo}. The solution on unfortunate systems (most system V -machines) is to perform a partial link on all the .o files, do an -@code{nm} on the result, run @code{awk} or some such over the result -looking for strange @code{__GLOBAL__$} symbols, generate a C program -from this, compile it and link with the partially linked input. This -process is usually called @code{collect}. - -Some versions of @code{a.out} use something called the -@code{set_vector} mechanism. The constructor symbols are output from -the compiler with a special stab code saying that they are -constructors, and the linker can deal with them directly. - -BFD allows applications (ie the linker) to deal with constructor -information independently of their external implimentation by -providing a set of entry points for the indiviual object back ends to -call which maintains a database of the contructor information. The -application can interrogate the database to find out what it wants. - -The construction data essential for the linker to be able to perform -its job are: - -@itemize @bullet -@item asymbol -The asymbol of the contructor entry point contains all the information -necessary to call the function. -@item table id -The type of symbol, ie is it a contructor, a destructor or something -else someone dreamed up to make our lives difficult. -@end itemize - -This module takes this information and then builds extra sections -attached to the bfds which own the entry points. It creates these -sections as if they were tables of pointers to the entry points, and -builds relocation entries to go with them so that the tables can be -relocated along with the data they reference. - -These sections are marked with a special bit (@code{SEC_CONSTRUCTOR}) -which the linker notices and do with what it wants. - +/* +SECTION + Constructors + +DESCRIPTION + Classes in C++ have 'constructors' and 'destructors'. These + are functions which are called automatically by the language + whenever data of a class is created or destroyed. Class data + which is static data may also be have a type which requires + 'construction', the contructor must be called before the data + can be referenced, so the contructor must be called before the + program begins. + + The common solution to this problem is for the compiler to + call a magic function as the first statement <<main>>. + This magic function, (often called <<__main>>) runs around + calling the constructors for all the things needing it. + + With COFF the compile has a bargain with the linker et al. + All constructors are given strange names, for example + <<__GLOBAL__$I$foo>> might be the label of a contructor for + the class @var{foo}. The solution on unfortunate systems + (most system V machines) is to perform a partial link on all + the .o files, do an <<nm>> on the result, run <<awk>> or some + such over the result looking for strange <<__GLOBAL__$>> + symbols, generate a C program from this, compile it and link + with the partially linked input. This process is usually + called <<collect>>. + + Some versions of <<a.out>> use something called the + <<set_vector>> mechanism. The constructor symbols are output + from the compiler with a special stab code saying that they + are constructors, and the linker can deal with them directly. + + BFD allows applications (ie the linker) to deal with + constructor information independently of their external + implimentation by providing a set of entry points for the + indiviual object back ends to call which maintains a database + of the contructor information. The application can + interrogate the database to find out what it wants. The + construction data essential for the linker to be able to + perform its job are: + + o asymbol + The asymbol of the contructor entry point contains all the + information necessary to call the function. + + o table id + The type of symbol, ie is it a contructor, a destructor or + something else someone dreamed up to make our lives difficult. + + This module takes this information and then builds extra + sections attached to the bfds which own the entry points. It + creates these sections as if they were tables of pointers to + the entry points, and builds relocation entries to go with + them so that the tables can be relocated along with the data + they reference. + + These sections are marked with a special bit + (<<SEC_CONSTRUCTOR>>) which the linker notices and do with + what it wants. */ @@ -86,22 +91,23 @@ which the linker notices and do with what it wants. -/*proto-internal* bfd_constructor_entry - -This function is called with an a symbol describing the -function to be called, an string which descibes the xtor type, eg -something like "CTOR" or "DTOR" would be fine. And the bfd which owns -the function. - -It's duty is to create a section called "CTOR" or "DTOR" or whatever -if the bfd doesn't already have one, and grow a relocation table for -the entry points as they accumulate. +/* +INTERNAL FUNCTION + bfd_constructor_entry +DESCRIPTION + This function is called with an a symbol describing the + function to be called, an string which descibes the xtor type, + eg something like "CTOR" or "DTOR" would be fine. And the bfd + which owns the function. Its duty is to create a section + called "CTOR" or "DTOR" or whatever if the bfd doesn't already + have one, and grow a relocation table for the entry points as + they accumulate. -*; PROTO(void, bfd_constructor_entry, - (bfd *abfd, - asymbol **symbol_ptr_ptr, - CONST char*type)); +SYNOPSIS + void bfd_constructor_entry(bfd *abfd, + asymbol **symbol_ptr_ptr, + CONST char*type); */ |