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* config/rs6000/tm-rs6000.h (INIT_EXTRA_FRAME_INFO):

Browse source 
Don't test for zero backchain pointer to recognize a signal
	handler frame, if read() gets interrupted by a signal, the
	backchain will be non zero.
	(SIG_FRAME_FP_OFFSET):  Move to here from rs6000-tdep.c,
	improve comment.
	(SIG_FRAME_PC_OFFSET):  New definition.
	(FRAME_SAVED_PC):  Return saved pc from sigcontext if this
	is a signal handler frame.
	* rs6000-tdep.c (function_frame_info):  Do not error out
	if we can't access the instructions.

	* config/rs6000/tm-rs6000.h (CONVERT_FROM_FUNC_PTR_ADDR):
	New definition to get the function address from a function pointer.
	* valops.c (find_function_addr):  Use it when calling a user
	function through a function pointer.
This commit is contained in:
Peter Schauer 1994-10-29 09:56:38 +00:00
parent 9ed8604f38
commit 44761ac746
1 changed files with 31 additions and 29 deletions
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60
gdb/config/rs6000/tm-rs6000.h
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@ -98,15 +98,6 @@ function_frame_info PARAMS ((CORE_ADDR, struct aix_framedata *));
#define SKIP_TRAMPOLINE_CODE(pc) skip_trampoline_code (pc)
/* When a child process is just starting, we sneak in and relocate
the symbol table (and other stuff) after the dynamic linker has
figured out where they go. */
#define SOLIB_CREATE_INFERIOR_HOOK(PID) \
do { \
xcoff_relocate_symtab (PID); \
} while (0)
/* Number of trap signals we need to skip over, once the inferior process
starts running. */
@ -132,18 +123,6 @@ function_frame_info PARAMS ((CORE_ADDR, struct aix_framedata *));
#define PROCESS_LINENUMBER_HOOK() aix_process_linenos ()
/* When a target process or core-file has been attached, we sneak in
and figure out where the shared libraries have got to. */
#define SOLIB_ADD(a, b, c) \
if (inferior_pid) \
/* Attach to process. */ \
xcoff_relocate_symtab (inferior_pid); \
else \
/* Core file. */ \
xcoff_relocate_core ();
extern void xcoff_relocate_core PARAMS ((void));
/* Immediately after a function call, return the saved pc.
Can't go through the frames for this because on some machines
the new frame is not set up until the new function executes
@ -189,10 +168,6 @@ extern void xcoff_relocate_core PARAMS ((void));
#define ABOUT_TO_RETURN(pc) \
((read_memory_integer (pc, 4) & 0xfe8007ff) == 0x4e800020)
/* Return 1 if P points to an invalid floating point value. */
#define INVALID_FLOAT(p, len) 0 /* Just a first guess; not checked */
/* Say how long (ordinary) registers are. This is a piece of bogosity
used in push_word and a few other places; REGISTER_RAW_SIZE is the
real way to know how big a register is. */
@ -345,7 +320,7 @@ extern CORE_ADDR rs6000_struct_return_address;
#define STORE_STRUCT_RETURN(ADDR, SP) \
{ write_register (3, (ADDR)); \
rs6000_struct_return_address = (unsigned int)(ADDR); }
rs6000_struct_return_address = (ADDR); }
/* Extract from an array REGBUF containing the (raw) register state
a function return value of type TYPE, and copy that, in virtual format,
@ -426,13 +401,23 @@ CORE_ADDR rs6000_frame_chain PARAMS ((struct frame_info *));
fi->initial_sp = 0; \
fi->cache_fsr = 0; \
if (fi->next != (CORE_ADDR)0 \
&& read_memory_integer (fi->frame, 4) == 0 \
&& fi->pc < TEXT_SEGMENT_BASE) \
/* We're in get_prev_frame_info */ \
/* and this is a special signal frame. */ \
/* (fi->pc will be something like 0x3f88 or 0x2790). */ \
/* (fi->pc will be some low address in the kernel, */ \
/* to which the signal handler returns). */
fi->signal_handler_caller = 1;
/* If the kernel has to deliver a signal, it pushes a sigcontext
structure on the stack and then calls the signal handler, passing
the address of the sigcontext in an argument register. Usually
the signal handler doesn't save this register, so we have to
access the sigcontext structure via an offset from the signal handler
frame.
The following constants were determined by experimentation on AIX 3.2. */
#define SIG_FRAME_PC_OFFSET 96
#define SIG_FRAME_FP_OFFSET 284
/* Frameless function invocation in IBM RS/6000 is sometimes
half-done. It perfectly sets up a new frame, e.g. a new frame (in
fact stack) pointer, etc, but it doesn't save the %pc. We call
@ -441,7 +426,9 @@ CORE_ADDR rs6000_frame_chain PARAMS ((struct frame_info *));
#define FRAME_SAVED_PC(FRAME) \
(frameless_function_invocation (FRAME, 1) \
? SAVED_PC_AFTER_CALL (FRAME) \
: read_memory_integer (rs6000_frame_chain (FRAME)+8, 4))
: (FRAME)->signal_handler_caller \
? read_memory_integer ((FRAME)->frame + SIG_FRAME_PC_OFFSET, 4) \
: read_memory_integer (rs6000_frame_chain (FRAME) + 8, 4))
#define FRAME_ARGS_ADDRESS(FI) \
(((struct frame_info*)(FI))->initial_sp ? \
@ -579,6 +566,21 @@ CORE_ADDR rs6000_frame_chain PARAMS ((struct frame_info *));
#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, using_gcc) \
fix_call_dummy(dummyname, pc, fun, nargs, type)
/* Usually a function pointer's representation is simply the address of
the function. On the RS/6000 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 macro to
get the function address from a function pointer. */
#define CONVERT_FROM_FUNC_PTR_ADDR(ADDR) read_memory_integer (ADDR, 4)
/* Flag for machine-specific stuff in shared files. FIXME */
#define IBM6000_TARGET