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authorK. Richard Pixley <rich@cygnus>1991-03-28 16:26:26 +0000
committerK. Richard Pixley <rich@cygnus>1991-03-28 16:26:26 +0000
commitbd5635a1e2b38ee8432fcdaa6456079191375277 (patch)
treeffc4c35618c4b6af001f38247ed0d1c05c7a35ad /gdb/blockframe.c
parent5a131cc7f0469e0375872605593e4a9c5d1eaefb (diff)
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Initial revision
Diffstat (limited to 'gdb/blockframe.c')
-rw-r--r--gdb/blockframe.c650
1 files changed, 650 insertions, 0 deletions
diff --git a/gdb/blockframe.c b/gdb/blockframe.c
new file mode 100644
index 0000000..7971166
--- /dev/null
+++ b/gdb/blockframe.c
@@ -0,0 +1,650 @@
+/* Get info from stack frames;
+ convert between frames, blocks, functions and pc values.
+ Copyright (C) 1986, 1987, 1988, 1989 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+GDB is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 1, or (at your option)
+any later version.
+
+GDB is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GDB; see the file COPYING. If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "defs.h"
+#include "param.h"
+#include "symtab.h"
+#include "frame.h"
+#include "gdbcore.h"
+#include "value.h" /* for read_register */
+#include "target.h" /* for target_has_stack */
+
+/* Required by INIT_EXTRA_FRAME_INFO on 88k. */
+#include <setjmp.h>
+#include <obstack.h>
+
+CORE_ADDR read_pc (); /* In infcmd.c */
+
+/* Start and end of object file containing the entry point.
+ STARTUP_FILE_END is the first address of the next file.
+ This file is assumed to be a startup file
+ and frames with pc's inside it
+ are treated as nonexistent.
+
+ Setting these variables is necessary so that backtraces do not fly off
+ the bottom of the stack. */
+CORE_ADDR startup_file_start;
+CORE_ADDR startup_file_end;
+
+/* Is ADDR outside the startup file? Note that if your machine
+ has a way to detect the bottom of the stack, there is no need
+ to call this function from FRAME_CHAIN_VALID; the reason for
+ doing so is that some machines have no way of detecting bottom
+ of stack. */
+int
+outside_startup_file (addr)
+ CORE_ADDR addr;
+{
+ return !(addr >= startup_file_start && addr < startup_file_end);
+}
+
+/* Address of innermost stack frame (contents of FP register) */
+
+static FRAME current_frame;
+
+/*
+ * Cache for frame addresses already read by gdb. Valid only while
+ * inferior is stopped. Control variables for the frame cache should
+ * be local to this module.
+ */
+struct obstack frame_cache_obstack;
+
+/* Return the innermost (currently executing) stack frame. */
+
+FRAME
+get_current_frame ()
+{
+ /* We assume its address is kept in a general register;
+ param.h says which register. */
+
+ return current_frame;
+}
+
+void
+set_current_frame (frame)
+ FRAME frame;
+{
+ current_frame = frame;
+}
+
+FRAME
+create_new_frame (addr, pc)
+ FRAME_ADDR addr;
+ CORE_ADDR pc;
+{
+ struct frame_info *fci; /* Same type as FRAME */
+
+ fci = (struct frame_info *)
+ obstack_alloc (&frame_cache_obstack,
+ sizeof (struct frame_info));
+
+ /* Arbitrary frame */
+ fci->next = (struct frame_info *) 0;
+ fci->prev = (struct frame_info *) 0;
+ fci->frame = addr;
+ fci->next_frame = 0; /* Since arbitrary */
+ fci->pc = pc;
+
+#ifdef INIT_EXTRA_FRAME_INFO
+ INIT_EXTRA_FRAME_INFO (fci);
+#endif
+
+ return fci;
+}
+
+/* Return the frame that called FRAME.
+ If FRAME is the original frame (it has no caller), return 0. */
+
+FRAME
+get_prev_frame (frame)
+ FRAME frame;
+{
+ /* We're allowed to know that FRAME and "struct frame_info *" are
+ the same */
+ return get_prev_frame_info (frame);
+}
+
+/* Return the frame that FRAME calls (0 if FRAME is the innermost
+ frame). */
+
+FRAME
+get_next_frame (frame)
+ FRAME frame;
+{
+ /* We're allowed to know that FRAME and "struct frame_info *" are
+ the same */
+ return frame->next;
+}
+
+/*
+ * Flush the entire frame cache.
+ */
+void
+flush_cached_frames ()
+{
+ /* Since we can't really be sure what the first object allocated was */
+ obstack_free (&frame_cache_obstack, 0);
+ obstack_init (&frame_cache_obstack);
+
+ current_frame = (struct frame_info *) 0; /* Invalidate cache */
+}
+
+/* Return a structure containing various interesting information
+ about a specified stack frame. */
+/* How do I justify including this function? Well, the FRAME
+ identifier format has gone through several changes recently, and
+ it's not completely inconceivable that it could happen again. If
+ it does, have this routine around will help */
+
+struct frame_info *
+get_frame_info (frame)
+ FRAME frame;
+{
+ return frame;
+}
+
+/* If a machine allows frameless functions, it should define a macro
+ FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) in param.h. FI is the struct
+ frame_info for the frame, and FRAMELESS should be set to nonzero
+ if it represents a frameless function invocation. */
+
+/* Return nonzero if the function for this frame has a prologue. Many
+ machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
+ function. */
+
+int
+frameless_look_for_prologue (frame)
+ FRAME frame;
+{
+ CORE_ADDR func_start, after_prologue;
+ func_start = (get_pc_function_start (frame->pc) +
+ FUNCTION_START_OFFSET);
+ if (func_start)
+ {
+ after_prologue = func_start;
+ SKIP_PROLOGUE (after_prologue);
+ return after_prologue == func_start;
+ }
+ else
+ /* If we can't find the start of the function, we don't really
+ know whether the function is frameless, but we should be able
+ to get a reasonable (i.e. best we can do under the
+ circumstances) backtrace by saying that it isn't. */
+ return 0;
+}
+
+#if !defined (INIT_FRAME_PC)
+#define INIT_FRAME_PC(fromleaf, prev) \
+ prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
+ prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
+#endif
+
+/* Return a structure containing various interesting information
+ about the frame that called NEXT_FRAME. Returns NULL
+ if there is no such frame. */
+
+struct frame_info *
+get_prev_frame_info (next_frame)
+ FRAME next_frame;
+{
+ FRAME_ADDR address;
+ struct frame_info *prev;
+ int fromleaf = 0;
+
+ /* If the requested entry is in the cache, return it.
+ Otherwise, figure out what the address should be for the entry
+ we're about to add to the cache. */
+
+ if (!next_frame)
+ {
+ if (!current_frame)
+ {
+ error ("You haven't set up a process's stack to examine.");
+ }
+
+ return current_frame;
+ }
+
+ /* If we have the prev one, return it */
+ if (next_frame->prev)
+ return next_frame->prev;
+
+ /* On some machines it is possible to call a function without
+ setting up a stack frame for it. On these machines, we
+ define this macro to take two args; a frameinfo pointer
+ identifying a frame and a variable to set or clear if it is
+ or isn't leafless. */
+#ifdef FRAMELESS_FUNCTION_INVOCATION
+ /* Still don't want to worry about this except on the innermost
+ frame. This macro will set FROMLEAF if NEXT_FRAME is a
+ frameless function invocation. */
+ if (!(next_frame->next))
+ {
+ FRAMELESS_FUNCTION_INVOCATION (next_frame, fromleaf);
+ if (fromleaf)
+ address = next_frame->frame;
+ }
+#endif
+
+ if (!fromleaf)
+ {
+ /* Two macros defined in tm.h specify the machine-dependent
+ actions to be performed here.
+ First, get the frame's chain-pointer.
+ If that is zero, the frame is the outermost frame or a leaf
+ called by the outermost frame. This means that if start
+ calls main without a frame, we'll return 0 (which is fine
+ anyway).
+
+ Nope; there's a problem. This also returns when the current
+ routine is a leaf of main. This is unacceptable. We move
+ this to after the ffi test; I'd rather have backtraces from
+ start go curfluy than have an abort called from main not show
+ main. */
+ address = FRAME_CHAIN (next_frame);
+ if (!FRAME_CHAIN_VALID (address, next_frame))
+ return 0;
+ address = FRAME_CHAIN_COMBINE (address, next_frame);
+ }
+
+ prev = (struct frame_info *)
+ obstack_alloc (&frame_cache_obstack,
+ sizeof (struct frame_info));
+
+ if (next_frame)
+ next_frame->prev = prev;
+ prev->next = next_frame;
+ prev->prev = (struct frame_info *) 0;
+ prev->frame = address;
+ prev->next_frame = prev->next ? prev->next->frame : 0;
+
+#ifdef INIT_EXTRA_FRAME_INFO
+ INIT_EXTRA_FRAME_INFO(prev);
+#endif
+
+ /* This entry is in the frame queue now, which is good since
+ FRAME_SAVED_PC may use that queue to figure out it's value
+ (see m-sparc.h). We want the pc saved in the inferior frame. */
+ INIT_FRAME_PC(fromleaf, prev);
+
+ return prev;
+}
+
+CORE_ADDR
+get_frame_pc (frame)
+ FRAME frame;
+{
+ struct frame_info *fi;
+ fi = get_frame_info (frame);
+ return fi->pc;
+}
+
+#if defined (FRAME_FIND_SAVED_REGS)
+/* Find the addresses in which registers are saved in FRAME. */
+
+void
+get_frame_saved_regs (frame_info_addr, saved_regs_addr)
+ struct frame_info *frame_info_addr;
+ struct frame_saved_regs *saved_regs_addr;
+{
+ FRAME_FIND_SAVED_REGS (frame_info_addr, *saved_regs_addr);
+}
+#endif
+
+/* Return the innermost lexical block in execution
+ in a specified stack frame. The frame address is assumed valid. */
+
+struct block *
+get_frame_block (frame)
+ FRAME frame;
+{
+ struct frame_info *fi;
+ CORE_ADDR pc;
+
+ fi = get_frame_info (frame);
+
+ pc = fi->pc;
+ if (fi->next_frame != 0)
+ /* We are not in the innermost frame. We need to subtract one to
+ get the correct block, in case the call instruction was the
+ last instruction of the block. If there are any machines on
+ which the saved pc does not point to after the call insn, we
+ probably want to make fi->pc point after the call insn anyway. */
+ --pc;
+ return block_for_pc (pc);
+}
+
+struct block *
+get_current_block ()
+{
+ return block_for_pc (read_pc ());
+}
+
+CORE_ADDR
+get_pc_function_start (pc)
+ CORE_ADDR pc;
+{
+ register struct block *bl = block_for_pc (pc);
+ register struct symbol *symbol;
+ if (bl == 0 || (symbol = block_function (bl)) == 0)
+ {
+ register int misc_index = find_pc_misc_function (pc);
+ if (misc_index >= 0)
+ return misc_function_vector[misc_index].address;
+ return 0;
+ }
+ bl = SYMBOL_BLOCK_VALUE (symbol);
+ return BLOCK_START (bl);
+}
+
+/* Return the symbol for the function executing in frame FRAME. */
+
+struct symbol *
+get_frame_function (frame)
+ FRAME frame;
+{
+ register struct block *bl = get_frame_block (frame);
+ if (bl == 0)
+ return 0;
+ return block_function (bl);
+}
+
+/* Return the blockvector immediately containing the innermost lexical block
+ containing the specified pc value, or 0 if there is none.
+ PINDEX is a pointer to the index value of the block. If PINDEX
+ is NULL, we don't pass this information back to the caller. */
+
+struct blockvector *
+blockvector_for_pc (pc, pindex)
+ register CORE_ADDR pc;
+ int *pindex;
+{
+ register struct block *b;
+ register int bot, top, half;
+ register struct symtab *s;
+ struct blockvector *bl;
+
+ /* First search all symtabs for one whose file contains our pc */
+ s = find_pc_symtab (pc);
+ if (s == 0)
+ return 0;
+
+ bl = BLOCKVECTOR (s);
+ b = BLOCKVECTOR_BLOCK (bl, 0);
+
+ /* Then search that symtab for the smallest block that wins. */
+ /* Use binary search to find the last block that starts before PC. */
+
+ bot = 0;
+ top = BLOCKVECTOR_NBLOCKS (bl);
+
+ while (top - bot > 1)
+ {
+ half = (top - bot + 1) >> 1;
+ b = BLOCKVECTOR_BLOCK (bl, bot + half);
+ if (BLOCK_START (b) <= pc)
+ bot += half;
+ else
+ top = bot + half;
+ }
+
+ /* Now search backward for a block that ends after PC. */
+
+ while (bot >= 0)
+ {
+ b = BLOCKVECTOR_BLOCK (bl, bot);
+ if (BLOCK_END (b) > pc)
+ {
+ if (pindex)
+ *pindex = bot;
+ return bl;
+ }
+ bot--;
+ }
+
+ return 0;
+}
+
+/* Return the innermost lexical block containing the specified pc value,
+ or 0 if there is none. */
+
+struct block *
+block_for_pc (pc)
+ register CORE_ADDR pc;
+{
+ register struct blockvector *bl;
+ int index;
+
+ bl = blockvector_for_pc (pc, &index);
+ if (bl)
+ return BLOCKVECTOR_BLOCK (bl, index);
+ return 0;
+}
+
+/* Return the function containing pc value PC.
+ Returns 0 if function is not known. */
+
+struct symbol *
+find_pc_function (pc)
+ CORE_ADDR pc;
+{
+ register struct block *b = block_for_pc (pc);
+ if (b == 0)
+ return 0;
+ return block_function (b);
+}
+
+/* These variables are used to cache the most recent result
+ * of find_pc_partial_function. */
+
+static CORE_ADDR cache_pc_function_low = 0;
+static CORE_ADDR cache_pc_function_high = 0;
+static char *cache_pc_function_name = 0;
+
+/* Clear cache, e.g. when symbol table is discarded. */
+
+void
+clear_pc_function_cache()
+{
+ cache_pc_function_low = 0;
+ cache_pc_function_high = 0;
+ cache_pc_function_name = (char *)0;
+}
+
+/* Finds the "function" (text symbol) that is smaller than PC
+ but greatest of all of the potential text symbols. Sets
+ *NAME and/or *ADDRESS conditionally if that pointer is non-zero.
+ Returns 0 if it couldn't find anything, 1 if it did. On a zero
+ return, *NAME and *ADDRESS are always set to zero. On a 1 return,
+ *NAME and *ADDRESS contain real information. */
+
+int
+find_pc_partial_function (pc, name, address)
+ CORE_ADDR pc;
+ char **name;
+ CORE_ADDR *address;
+{
+ struct partial_symtab *pst;
+ struct symbol *f;
+ int miscfunc;
+ struct partial_symbol *psb;
+
+ if (pc >= cache_pc_function_low && pc < cache_pc_function_high)
+ {
+ if (address)
+ *address = cache_pc_function_low;
+ if (name)
+ *name = cache_pc_function_name;
+ return 1;
+ }
+
+ pst = find_pc_psymtab (pc);
+ if (pst)
+ {
+ if (pst->readin)
+ {
+ /* The information we want has already been read in.
+ We can go to the already readin symbols and we'll get
+ the best possible answer. */
+ f = find_pc_function (pc);
+ if (!f)
+ {
+ return_error:
+ /* No available symbol. */
+ if (name != 0)
+ *name = 0;
+ if (address != 0)
+ *address = 0;
+ return 0;
+ }
+
+ cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f));
+ cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f));
+ cache_pc_function_name = SYMBOL_NAME (f);
+ if (name)
+ *name = cache_pc_function_name;
+ if (address)
+ *address = cache_pc_function_low;
+ return 1;
+ }
+
+ /* Get the information from a combination of the pst
+ (static symbols), and the misc function vector (extern
+ symbols). */
+ miscfunc = find_pc_misc_function (pc);
+ psb = find_pc_psymbol (pst, pc);
+
+ if (!psb && miscfunc == -1)
+ {
+ goto return_error;
+ }
+ if (psb
+ && (miscfunc == -1
+ || (SYMBOL_VALUE_ADDRESS (psb)
+ >= misc_function_vector[miscfunc].address)))
+ {
+ /* This case isn't being cached currently. */
+ if (address)
+ *address = SYMBOL_VALUE_ADDRESS (psb);
+ if (name)
+ *name = SYMBOL_NAME (psb);
+ return 1;
+ }
+ }
+ else
+ /* Must be in the misc function stuff. */
+ {
+ miscfunc = find_pc_misc_function (pc);
+ if (miscfunc == -1)
+ goto return_error;
+ }
+
+ {
+ if (misc_function_vector[miscfunc].type == mf_text)
+ cache_pc_function_low = misc_function_vector[miscfunc].address;
+ else
+ /* It is a transfer table for Sun shared libraries. */
+ cache_pc_function_low = pc - FUNCTION_START_OFFSET;
+ }
+ cache_pc_function_name = misc_function_vector[miscfunc].name;
+ if (miscfunc < misc_function_count && 1 /* FIXME mf_text again? */ )
+ cache_pc_function_high = misc_function_vector[miscfunc+1].address;
+ else
+ cache_pc_function_high = cache_pc_function_low + 1;
+ if (address)
+ *address = cache_pc_function_low;
+ if (name)
+ *name = cache_pc_function_name;
+ return 1;
+}
+
+/* Find the misc function whose address is the largest
+ while being less than PC. Return its index in misc_function_vector.
+ Returns -1 if PC is not in suitable range. */
+
+int
+find_pc_misc_function (pc)
+ register CORE_ADDR pc;
+{
+ register int lo = 0;
+ register int hi = misc_function_count-1;
+ register int new;
+
+ /* Note that the last thing in the vector is always _etext. */
+ /* Actually, "end", now that non-functions
+ go on the misc_function_vector. */
+
+ /* Above statement is not *always* true - fix for case where there are */
+ /* no misc functions at all (ie no symbol table has been read). */
+ if (hi < 0) return -1; /* no misc functions recorded */
+
+ /* trivial reject range test */
+ if (pc < misc_function_vector[0].address ||
+ pc > misc_function_vector[hi].address)
+ return -1;
+
+ /* Note that the following search will not return hi if
+ pc == misc_function_vector[hi].address. If "end" points to the
+ first unused location, this is correct and the above test
+ simply needs to be changed to
+ "pc >= misc_function_vector[hi].address". */
+ do {
+ new = (lo + hi) >> 1;
+ if (misc_function_vector[new].address == pc)
+ return new; /* an exact match */
+ else if (misc_function_vector[new].address > pc)
+ hi = new;
+ else
+ lo = new;
+ } while (hi-lo != 1);
+
+ /* if here, we had no exact match, so return the lower choice */
+ return lo;
+}
+
+/* Return the innermost stack frame executing inside of the specified block,
+ or zero if there is no such frame. */
+
+FRAME
+block_innermost_frame (block)
+ struct block *block;
+{
+ struct frame_info *fi;
+ register FRAME frame;
+ register CORE_ADDR start = BLOCK_START (block);
+ register CORE_ADDR end = BLOCK_END (block);
+
+ frame = 0;
+ while (1)
+ {
+ frame = get_prev_frame (frame);
+ if (frame == 0)
+ return 0;
+ fi = get_frame_info (frame);
+ if (fi->pc >= start && fi->pc < end)
+ return frame;
+ }
+}
+
+void
+_initialize_blockframe ()
+{
+ obstack_init (&frame_cache_obstack);
+}