From dbe9fe588fc696a5d74b3a5c3208f2568b9fb7aa Mon Sep 17 00:00:00 2001 From: Andrew Cagney Date: Sun, 19 Jan 2003 17:39:16 +0000 Subject: [PATCH] 2003-01-19 Andrew Cagney * frame-unwind.h (frame_unwind_pop_ftype): Declare. (struct frame_unwind): Add field pop. * frame.h (frame_pop): Declare. * frame.c (frame_saved_regs_pop): New function. (trad_frame_unwinder): Add frame_saved_regs_pop. (frame_pop): New function. * dummy-frame.c (dummy_frame_pop): New function. (discard_innermost_dummy): New function. (generic_pop_dummy_frame): Use discard_innermost_dummy. (dummy_frame_unwind): Add dummy_frame_pop. * infrun.c (normal_stop): Call frame_pop instead of POP_FRAME. * valops.c (hand_function_call): Ditto. * stack.c (return_command): Ditto. --- gdb/ChangeLog | 16 ++++++++++++++++ gdb/dummy-frame.c | 49 ++++++++++++++++++++++++++++++++++++++++++++----- gdb/frame-unwind.h | 15 +++++++++++++++ gdb/frame.c | 20 ++++++++++++++++++++ gdb/frame.h | 4 ++++ gdb/infrun.c | 8 ++++---- gdb/stack.c | 15 ++++++++++++--- gdb/valops.c | 5 +++-- 8 files changed, 118 insertions(+), 14 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 4b116ae..b383e54 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,19 @@ +2003-01-19 Andrew Cagney + + * frame-unwind.h (frame_unwind_pop_ftype): Declare. + (struct frame_unwind): Add field pop. + * frame.h (frame_pop): Declare. + * frame.c (frame_saved_regs_pop): New function. + (trad_frame_unwinder): Add frame_saved_regs_pop. + (frame_pop): New function. + * dummy-frame.c (dummy_frame_pop): New function. + (discard_innermost_dummy): New function. + (generic_pop_dummy_frame): Use discard_innermost_dummy. + (dummy_frame_unwind): Add dummy_frame_pop. + * infrun.c (normal_stop): Call frame_pop instead of POP_FRAME. + * valops.c (hand_function_call): Ditto. + * stack.c (return_command): Ditto. + 2003-01-18 Andrew Cagney * cris-tdep.c: Fix function declaration indentation. diff --git a/gdb/dummy-frame.c b/gdb/dummy-frame.c index 0a3e35e..5b63830 100644 --- a/gdb/dummy-frame.c +++ b/gdb/dummy-frame.c @@ -270,8 +270,48 @@ generic_pop_current_frame (void (*popper) (struct frame_info * frame)) (*popper) (frame); } -/* Function: pop_dummy_frame - Restore the machine state from a saved dummy stack frame. */ +/* Discard the innermost dummy frame from the dummy frame stack + (passed in as a parameter). */ + +static void +discard_innermost_dummy (struct dummy_frame **stack) +{ + struct dummy_frame *tbd = (*stack); + (*stack) = (*stack)->next; + regcache_xfree (tbd->regcache); + xfree (tbd); +} + +/* Function: dummy_frame_pop. Restore the machine state from a saved + dummy stack frame. */ + +static void +dummy_frame_pop (struct frame_info *fi, void **cache, + struct regcache *regcache) +{ + struct dummy_frame *dummy = cached_find_dummy_frame (fi, cache); + + /* If it isn't, what are we even doing here? */ + gdb_assert (get_frame_type (fi) == DUMMY_FRAME); + + if (dummy == NULL) + error ("Can't pop dummy frame!"); + + /* Discard all dummy frames up-to but not including this one. */ + while (dummy_frame_stack != dummy) + discard_innermost_dummy (&dummy_frame_stack); + + /* Restore this one. */ + regcache_cpy (regcache, dummy->regcache); + flush_cached_frames (); + + /* Now discard it. */ + discard_innermost_dummy (&dummy_frame_stack); + + /* Note: target changed would be better. Registers, memory and + frame are all invalid. */ + flush_cached_frames (); +} void generic_pop_dummy_frame (void) @@ -283,12 +323,10 @@ generic_pop_dummy_frame (void) if (!dummy_frame) error ("Can't pop dummy frame!"); - dummy_frame_stack = dummy_frame->next; regcache_cpy (current_regcache, dummy_frame->regcache); flush_cached_frames (); - regcache_xfree (dummy_frame->regcache); - xfree (dummy_frame); + discard_innermost_dummy (&dummy_frame_stack); } /* Function: fix_call_dummy @@ -369,6 +407,7 @@ dummy_frame_id_unwind (struct frame_info *frame, static struct frame_unwind dummy_frame_unwind = { + dummy_frame_pop, dummy_frame_pc_unwind, dummy_frame_id_unwind, dummy_frame_register_unwind diff --git a/gdb/frame-unwind.h b/gdb/frame-unwind.h index 863f259..2c67c96 100644 --- a/gdb/frame-unwind.h +++ b/gdb/frame-unwind.h @@ -82,12 +82,27 @@ typedef void (frame_unwind_id_ftype) (struct frame_info * frame, void **unwind_cache, struct frame_id * id); +/* Discard the frame by restoring the registers (in regcache) back to + that of the caller. */ +/* NOTE: cagney/2003-01-19: While at present the callers all pop each + frame in turn, the implementor should try to code things so that + any frame can be popped directly. */ +/* FIXME: cagney/2003-01-19: Since both FRAME and REGCACHE refer to a + common register cache, care must be taken when restoring the + registers. The `correct fix' is to first first save the registers + in a scratch cache, and second write that scratch cache back to to + the real register cache. */ + +typedef void (frame_unwind_pop_ftype) (struct frame_info *frame, + void **unwind_cache, + struct regcache *regcache); struct frame_unwind { /* Should the frame's type go here? */ /* Should an attribute indicating the frame's address-in-block go here? */ + frame_unwind_pop_ftype *pop; frame_unwind_pc_ftype *pc; frame_unwind_id_ftype *id; frame_unwind_reg_ftype *reg; diff --git a/gdb/frame.c b/gdb/frame.c index f85b54a..9fb5e9b 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -145,6 +145,18 @@ frame_id_unwind (struct frame_info *frame) return frame->id_unwind_cache; } +void +frame_pop (struct frame_info *frame) +{ + /* FIXME: cagney/2003-01-18: There is probably a chicken-egg problem + with passing in current_regcache. The pop function needs to be + written carefully so as to not overwrite registers whose [old] + values are needed to restore other registers. Instead, this code + should pass in a scratch cache and, as a second step, restore the + registers using that. */ + frame->unwind->pop (frame, &frame->unwind_cache, current_regcache); + flush_cached_frames (); +} void frame_register_unwind (struct frame_info *frame, int regnum, @@ -715,7 +727,15 @@ frame_saved_regs_id_unwind (struct frame_info *next_frame, void **cache, id->base = base; } +static void +frame_saved_regs_pop (struct frame_info *fi, void **cache, + struct regcache *regcache) +{ + POP_FRAME; +} + const struct frame_unwind trad_frame_unwinder = { + frame_saved_regs_pop, frame_saved_regs_pc_unwind, frame_saved_regs_id_unwind, frame_saved_regs_register_unwind diff --git a/gdb/frame.h b/gdb/frame.h index 9cbdaa4..64f932a 100644 --- a/gdb/frame.h +++ b/gdb/frame.h @@ -306,6 +306,10 @@ extern CORE_ADDR frame_pc_unwind (struct frame_info *frame); caller's frame. */ extern struct frame_id frame_id_unwind (struct frame_info *frame); +/* Discard the specified frame. Restoring the registers to the state + of the caller. */ +extern void frame_pop (struct frame_info *frame); + /* Describe the saved registers of a frame. */ #if defined (EXTRA_FRAME_INFO) || defined (FRAME_FIND_SAVED_REGS) diff --git a/gdb/infrun.c b/gdb/infrun.c index 9f94aeb..29ebf44 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -3109,10 +3109,10 @@ normal_stop (void) if (stop_stack_dummy) { - /* Pop the empty frame that contains the stack dummy. - POP_FRAME ends with a setting of the current frame, so we - can use that next. */ - POP_FRAME; + /* Pop the empty frame that contains the stack dummy. POP_FRAME + ends with a setting of the current frame, so we can use that + next. */ + frame_pop (get_current_frame ()); /* Set stop_pc to what it was before we called the function. Can't rely on restore_inferior_status because that only gets called if we don't stop in the called function. */ diff --git a/gdb/stack.c b/gdb/stack.c index b48dec7..405a5e4 100644 --- a/gdb/stack.c +++ b/gdb/stack.c @@ -1625,6 +1625,10 @@ return_command (char *retval_exp, int from_tty) error ("Not confirmed."); } + /* FIXME: cagney/2003-01-18: Rather than pop each frame in turn, + this code should just go straight to the relevant frame and pop + that. */ + /* Do the real work. Pop until the specified frame is current. We use this method because the deprecated_selected_frame is not valid after a POP_FRAME. The pc comparison makes this work even if the @@ -1632,11 +1636,11 @@ return_command (char *retval_exp, int from_tty) while (selected_frame_addr != get_frame_base (frame = get_current_frame ()) || selected_frame_pc != get_frame_pc (frame)) - POP_FRAME; + frame_pop (get_current_frame ()); /* Then pop that frame. */ - POP_FRAME; + frame_pop (get_current_frame ()); /* Compute the return value (if any) and store in the place for return values. */ @@ -1646,9 +1650,14 @@ return_command (char *retval_exp, int from_tty) /* If we are at the end of a call dummy now, pop the dummy frame too. */ + /* FIXME: cagney/2003-01-18: This is silly. Instead of popping all + the frames except the dummy, and then, as an afterthought, + popping the dummy frame, this code should just pop through to the + dummy frame. */ + if (CALL_DUMMY_HAS_COMPLETED (read_pc(), read_sp (), get_frame_base (get_current_frame ()))) - POP_FRAME; + frame_pop (get_current_frame ()); /* If interactive, print the frame that is now current. */ diff --git a/gdb/valops.c b/gdb/valops.c index d3906f9..d1a1877 100644 --- a/gdb/valops.c +++ b/gdb/valops.c @@ -1711,8 +1711,9 @@ You must use a pointer to function type variable. Command ignored.", arg_name); { /* The user wants the context restored. */ - /* We must get back to the frame we were before the dummy call. */ - POP_FRAME; + /* We must get back to the frame we were before the dummy + call. */ + frame_pop (get_current_frame ()); /* FIXME: Insert a bunch of wrap_here; name can be very long if it's a C++ name with arguments and stuff. */ -- 2.7.4