Changes between Version 9 and Version 10 of TBR/UserManual/Using_C_Plus_Plus

Timestamp:

06/26/07 21:23:49 (17 years ago)

Author:

Rsg

Comment:

/* C++ .init Linker Magic */

TBR/UserManual/Using_C_Plus_Plus

@@ -110 +110 @@
  * Note''', '''_init()''' is not an ordinary function but 'compiler/linker magic' which uses the special '''.init''' section. An object file's '''.init* section must be composed of small snippets of code like
 
- 
         do_something ();
         do_something_else ();
 
-
 that should eventually go into the '''_init()''' routine. Any object may contain such code. The linker finally gathers all these snippets (in the order the objects are linked together) and that's where the '''ecrti.o/ecrtn.o''' files come into play. These two files bracket the '''.init''' snippets with a proper function prologue (from ecrti.o) and epilogue (ecrtn.o), i.e., if you link (ecrti/ecrtn implicitely provided by gcc specs) :
 
- 
       ecrti.o  my_object.o ecrtn.o
 
-   you end up with something like ('translated into C'):
-
+you end up with something like ('translated into C'):
  
       _init ()
@@ -131 +127 @@
       } /* from ecrtn.o */
 
-
 Hence, the rtems_crti.S file does the following :
 
- 
       /* from ecrti.o: */
       __init()
@@ -151 +145 @@
       }
 
-
 GCC uses this feature to call C++ static constructors by sticking a call to :
-
  
       __do_global_ctors_aux()
 
-
 into the '''.init''' section of '''crtend.o''' hence if you don't link against '''crtbegin/crtend''' (bsp_specs) your constructors are not called.
 
-  <big><strong>Your gcc configuration, linkcmds and bsp_specs must harmonize</strong></big>
+<big><strong>Your gcc configuration, linkcmds and bsp_specs must harmonize</strong></big>