diff options
| -rw-r--r-- | gdb/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/ppc-linux-tdep.c | 40 |
2 files changed, 45 insertions, 0 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index f544f57..7c0b6c9 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,10 @@ 2003-06-24 Jim Blandy <jimb@redhat.com> + * ppc-linux-tdep.c (ppc64_linux_convert_from_func_ptr_addr): New + function. + (ppc_linux_init_abi): Register it as the + CONVERT_FROM_FUNC_PTR_ADDR method under the PPC64 Linux ABI. + * ppc-linux-tdep.c (ppc64_call_dummy_address): New function. (ppc_linux_init_abi): Set it as the gdbarch's call_dummy_address method. diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c index 5b82a91..269e16d 100644 --- a/gdb/ppc-linux-tdep.c +++ b/gdb/ppc-linux-tdep.c @@ -894,6 +894,41 @@ ppc64_skip_trampoline_code (CORE_ADDR pc) } +/* Support for CONVERT_FROM_FUNC_PTR_ADDR(ADDR) on PPC64 Linux. + + Usually a function pointer's representation is simply the address + of the function. On Linux on the 64-bit PowerPC however, a function + pointer is represented by a pointer to a TOC entry. This TOC entry + contains three words, the first word is the address of the + function, the second word is the TOC pointer (r2), and the third + word is the static chain value. Throughout GDB it is currently + assumed that a function pointer contains the address of the + function, which is not easy to fix. In addition, the conversion of + a function address to a function pointer would require allocation + of a TOC entry in the inferior's memory space, with all its + drawbacks. To be able to call C++ virtual methods in the inferior + (which are called via function pointers), find_function_addr uses + this function to get the function address from a function + pointer. */ + +/* Return real function address if ADDR (a function pointer) is in the data + space and is therefore a special function pointer. */ + +static CORE_ADDR +ppc64_linux_convert_from_func_ptr_addr (CORE_ADDR addr) +{ + struct obj_section *s; + + s = find_pc_section (addr); + if (s && s->the_bfd_section->flags & SEC_CODE) + return addr; + + /* ADDR is in the data space, so it's a pointer to a descriptor, not + the entry point. */ + return ppc64_desc_entry_point (addr); +} + + /* On 64-bit PowerPC Linux, the ELF header's e_entry field is the address of a function descriptor for the entry point function, not the actual entry point itself. So to find the actual address at @@ -1027,6 +1062,11 @@ ppc_linux_init_abi (struct gdbarch_info info, if (tdep->wordsize == 8) { + /* Handle PPC64 Linux function pointers (which are really + function descriptors). */ + set_gdbarch_convert_from_func_ptr_addr + (gdbarch, ppc64_linux_convert_from_func_ptr_addr); + set_gdbarch_call_dummy_address (gdbarch, ppc64_call_dummy_address); set_gdbarch_in_solib_call_trampoline |