From a71f8c301ed74646c78414ae45f551848443db5c Mon Sep 17 00:00:00 2001 From: Randolph Chung Date: Fri, 12 Nov 2004 00:51:23 +0000 Subject: [PATCH] 2004-11-11 Randolph Chung * hppa-tdep.c (skip_prologue_hard_way): Make static, add stop_after_branch parameter and use it to determine if we should look at the delay slot of the first branch insn to find prologue insns. (hppa_skip_prologue): Update comment and call to skip_prologue_hard_way. (hppa_frame_cache): Likewise. --- gdb/ChangeLog | 8 ++++++++ gdb/hppa-tdep.c | 43 ++++++++++++++++++++++++++++++------------- 2 files changed, 38 insertions(+), 13 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 986318a1fd..dcd83bfd1f 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,11 @@ +2004-11-11 Randolph Chung + + * hppa-tdep.c (skip_prologue_hard_way): Make static, add + stop_after_branch parameter and use it to determine if we should look + at the delay slot of the first branch insn to find prologue insns. + (hppa_skip_prologue): Update comment and call to skip_prologue_hard_way. + (hppa_frame_cache): Likewise. + 2004-11-11 Randolph Chung * hppa-tdep.c (hppa_frame_cache): Properly handle the frame pointer diff --git a/gdb/hppa-tdep.c b/gdb/hppa-tdep.c index c48ca8609a..8e863678c7 100644 --- a/gdb/hppa-tdep.c +++ b/gdb/hppa-tdep.c @@ -1247,14 +1247,15 @@ inst_saves_fr (unsigned long inst) be in the prologue. */ -CORE_ADDR -skip_prologue_hard_way (CORE_ADDR pc) +static CORE_ADDR +skip_prologue_hard_way (CORE_ADDR pc, int stop_before_branch) { char buf[4]; CORE_ADDR orig_pc = pc; unsigned long inst, stack_remaining, save_gr, save_fr, save_rp, save_sp; unsigned long args_stored, status, i, restart_gr, restart_fr; struct unwind_table_entry *u; + int final_iteration; restart_gr = 0; restart_fr = 0; @@ -1298,6 +1299,8 @@ restart: save_fr |= (1 << i); save_fr &= ~restart_fr; + final_iteration = 0; + /* Loop until we find everything of interest or hit a branch. For unoptimized GCC code and for any HP CC code this will never ever @@ -1434,7 +1437,7 @@ restart: /* Quit if we hit any kind of branch. This can happen if a prologue instruction is in the delay slot of the first call/branch. */ - if (is_branch (inst)) + if (is_branch (inst) && stop_before_branch) break; /* What a crock. The HP compilers set args_stored even if no @@ -1455,6 +1458,13 @@ restart: /* Bump the PC. */ pc += 4; + + /* !stop_before_branch, so also look at the insn in the delay slot + of the branch. */ + if (final_iteration) + break; + if (is_branch (inst)) + final_iteration = 1; } /* We've got a tenative location for the end of the prologue. However @@ -1513,12 +1523,13 @@ after_prologue (CORE_ADDR pc) /* To skip prologues, I use this predicate. Returns either PC itself if the code at PC does not look like a function prologue; otherwise - returns an address that (if we're lucky) follows the prologue. If - LENIENT, then we must skip everything which is involved in setting - up the frame (it's OK to skip more, just so long as we don't skip - anything which might clobber the registers which are being saved. - Currently we must not skip more on the alpha, but we might the lenient - stuff some day. */ + returns an address that (if we're lucky) follows the prologue. + + hppa_skip_prologue is called by gdb to place a breakpoint in a function. + It doesn't necessarily skips all the insns in the prologue. In fact + we might not want to skip all the insns because a prologue insn may + appear in the delay slot of the first branch, and we don't want to + skip over the branch in that case. */ static CORE_ADDR hppa_skip_prologue (CORE_ADDR pc) @@ -1543,7 +1554,7 @@ hppa_skip_prologue (CORE_ADDR pc) if (post_prologue_pc != 0) return max (pc, post_prologue_pc); else - return (skip_prologue_hard_way (pc)); + return (skip_prologue_hard_way (pc, 1)); } struct hppa_frame_cache @@ -1626,18 +1637,24 @@ hppa_frame_cache (struct frame_info *next_frame, void **this_cache) int looking_for_rp = u->Save_RP; int fp_loc = -1; - /* We have to use hppa_skip_prologue instead of just + /* We have to use skip_prologue_hard_way instead of just skip_prologue_using_sal, in case we stepped into a function without symbol information. hppa_skip_prologue also bounds the returned pc by the passed in pc, so it will not return a pc in the next - function. */ + function. + + We used to call hppa_skip_prologue to find the end of the prologue, + but if some non-prologue instructions get scheduled into the prologue, + and the program is compiled with debug information, the "easy" way + in hppa_skip_prologue will return a prologue end that is too early + for us to notice any potential frame adjustments. */ /* We used to use frame_func_unwind () to locate the beginning of the function to pass to skip_prologue (). However, when objects are compiled without debug symbols, frame_func_unwind can return the wrong function (or 0). We can do better than that by using unwind records. */ - prologue_end = hppa_skip_prologue (u->region_start); + prologue_end = skip_prologue_hard_way (u->region_start, 0); end_pc = frame_pc_unwind (next_frame); if (prologue_end != 0 && end_pc > prologue_end)