Commit Graph

7 Commits

Author SHA1 Message Date
tom_at_work
9ce34c63c9 Fix shared library loading and unloading for Linux platforms. Shared library initialization and finalization are now called correctly at program startup for compile-time linked dynamic libraries on powerpc-/powerpc64-/arm-/i386- and x86_64-linux.
Every startup code must now provide an additional entry point called "_dynamic_start" that is set as new the entry point if the program links to a Pascal shared library. Its purpose is to set up an exit hook usually passed via a register, which should be called during program finalization if non-nil.

We use this additional entry point because this register only has meaningful content when there are any compile-time linked shared libraries, otherwise it often contains random garbage. The difference between the _dynamic_start and the original code is minimal; actually in all implementations the _dynamic_start code passes on control to the old startup code, so we use an additional entry point instead of an additional startup file.

Detailed changes and fixes list:
compiler:
  always link to the dynamic loader (ld.so) when compiling shared libraries. Fixes crashes in the loader during shared library finalization on some Linuxes
  remove additional ENTRY() section in arm linker script
  select either _dynamic_start or _start as entry point depending on whether this is a static or dynamic executable
powerpc*:
  do not set System.isLibrary in startup code, it will be set during library initialization anyway
  trap in case of reaching code locations that should not be reached instead of looping (possibly endlessly)
powerpc:
  register atexit() function pointer if supplied to the executable and call it during shutdown
  correctly set argc/argv/envp in shared library code and return correctly to the caller after initialization
  pass on exitcode in shared library haltproc
  use the more recent exit_group system call if available for shutdown
powerpc64
  fix .ptrgl stub, do not set the environment register to the value of the GOT entry in the function descriptor
arm
  do not set System.isLibrary in startup code, it will be set during library initialization anyway
  reload exitcode to pass to shutdown
mips,mipsel,sparc
  added stubs to allow correct linking

git-svn-id: trunk@19036 -
2011-09-08 21:17:35 +00:00
florian
00768bea47 * fix compilation of dllprt0.as for older arm assemblers without push support
git-svn-id: trunk@17254 -
2011-04-05 19:42:36 +00:00
tom_at_work
b0bd6a13ec Fixed argc/argv/envp for arm/linux shared libraries. They are by default in registers a1/a2/a3 as per ABI: the first arguments when calling a method (in this case the FPC_SHARED_LIB_START) are passed via registers, not on the stack.
git-svn-id: trunk@17033 -
2011-02-27 17:22:29 +00:00
tom_at_work
a8bf34d3fc Correctly return to caller in ARM/Linux shared library startup code instead of fall-through to system exit.
git-svn-id: trunk@16982 -
2011-02-23 09:41:19 +00:00
tom_at_work
56d30e7da0 Set up environment variables and call Pascal initialization in arm/linux shared library initialization
git-svn-id: trunk@16981 -
2011-02-22 22:32:44 +00:00
florian
3668be7ee4 * minimal implementation by Benjamin 'BeRo' Rosseaux
git-svn-id: trunk@15484 -
2010-06-27 11:07:35 +00:00
florian
f04bddec4a * initial revision of arm startup code 2003-08-27 13:07:07 +00:00