diff options
Diffstat (limited to 'gdb/ppc-sysv-tdep.c')
| -rw-r--r-- | gdb/ppc-sysv-tdep.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/gdb/ppc-sysv-tdep.c b/gdb/ppc-sysv-tdep.c index 450162d..1cbaaf2 100644 --- a/gdb/ppc-sysv-tdep.c +++ b/gdb/ppc-sysv-tdep.c @@ -28,6 +28,7 @@ #include "objfiles.h" #include "infcall.h" #include "dwarf2.h" +#include "dwarf2/loc.h" #include "target-float.h" #include <algorithm> @@ -2156,3 +2157,43 @@ ppc64_sysv_abi_return_value (struct gdbarch *gdbarch, struct value *function, return RETURN_VALUE_STRUCT_CONVENTION; } +CORE_ADDR ppc64_sysv_get_return_buf_addr (struct type *val_type, + frame_info_ptr cur_frame) +{ + /* The PowerPC ABI specifies aggregates that are not returned by value + are returned in a storage buffer provided by the caller. The + address of the storage buffer is provided as a hidden first input + arguement in register r3. The PowerPC ABI does not guarantee that + register r3 will not be changed while executing the function. Hence, it + cannot be assumed that r3 will still contain the address of the storage + buffer when execution reaches the end of the function. + + This function attempts to determine the value of r3 on entry to the + function using the DW_OP_entry_value DWARF entries. This requires + compiling the user program with -fvar-tracking to resolve the + DW_TAG_call_sites in the binary file. */ + + union call_site_parameter_u kind_u; + enum call_site_parameter_kind kind; + CORE_ADDR return_val = 0; + + kind_u.dwarf_reg = 3; /* First passed arg/return value is in r3. */ + kind = CALL_SITE_PARAMETER_DWARF_REG; + + /* val_type is the type of the return value. Need the pointer type + to the return value. */ + val_type = lookup_pointer_type (val_type); + + try + { + return_val = value_as_address (value_of_dwarf_reg_entry (val_type, + cur_frame, + kind, kind_u)); + } + catch (const gdb_exception_error &e) + { + warning ("Cannot determine the function return value.\n" + "Try compiling with -fvar-tracking."); + } + return return_val; +} |