Hello,
As discussed on
<https://gcc.gnu.org/ml/gcc-patches/2016-02/msg01708.html>, this change
removes a field in the dw_loc_descr_node structure so we can get rid of
the CHECKING_P macro usage.
This field was used to perform consistency checks for frame offset in
DWARF procedures. As a replacement, this commit turns the "visited
nodes" set in resolve_args_picking_1 into a map that remembers for each
dw_loc_descr_node the frame offset associated to it, so that the
consistency check is still operational.
Boostrapped and regtested on x86_64-linux. Ok to commit? Thank you in
advance!
---
gcc/dwarf2out.c | 37 +++++++++++++++++++------------------
gcc/dwarf2out.h | 6 ------
2 files changed, 19 insertions(+), 24 deletions(-)
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 0bbff87..463863d 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -1325,9 +1325,6 @@ new_loc_descr (enum dwarf_location_atom op, unsigned
HOST_WIDE_INT oprnd1,
dw_loc_descr_ref descr = ggc_cleared_alloc<dw_loc_descr_node> ();
descr->dw_loc_opc = op;
-#if CHECKING_P
- descr->dw_loc_frame_offset = -1;
-#endif
descr->dw_loc_oprnd1.val_class = dw_val_class_unsigned_const;
descr->dw_loc_oprnd1.val_entry = NULL;
descr->dw_loc_oprnd1.v.val_unsigned = oprnd1;
@@ -15353,12 +15350,14 @@ is_handled_procedure_type (tree type)
&& int_size_in_bytes (type) <= DWARF2_ADDR_SIZE);
}
-/* Helper for resolve_args_picking. Stop when coming across VISITED nodes. */
+/* Helper for resolve_args_picking: do the same but stop when coming across
+ visited nodes. For each node we visit, register in FRAME_OFFSETS the frame
+ offset *before* evaluating the corresponding operation. */
static bool
resolve_args_picking_1 (dw_loc_descr_ref loc, unsigned initial_frame_offset,
struct dwarf_procedure_info *dpi,
- hash_set<dw_loc_descr_ref> &visited)
+ hash_map<dw_loc_descr_ref, unsigned> &frame_offsets)
{
/* The "frame_offset" identifier is already used to name a macro... */
unsigned frame_offset_ = initial_frame_offset;
@@ -15366,19 +15365,18 @@ resolve_args_picking_1 (dw_loc_descr_ref loc,
unsigned initial_frame_offset,
for (l = loc; l != NULL;)
{
+ bool existed;
+ unsigned &l_frame_offset = frame_offsets.get_or_insert (l, &existed);
+
/* If we already met this node, there is nothing to compute anymore. */
- if (visited.add (l))
+ if (existed)
{
-#if CHECKING_P
/* Make sure that the stack size is consistent wherever the execution
flow comes from. */
- gcc_assert ((unsigned) l->dw_loc_frame_offset == frame_offset_);
-#endif
+ gcc_assert ((unsigned) l_frame_offset == frame_offset_);
break;
}
-#if CHECKING_P
- l->dw_loc_frame_offset = frame_offset_;
-#endif
+ l_frame_offset = frame_offset_;
/* If needed, relocate the picking offset with respect to the frame
offset. */
@@ -15601,7 +15599,7 @@ resolve_args_picking_1 (dw_loc_descr_ref loc, unsigned
initial_frame_offset,
{
case DW_OP_bra:
if (!resolve_args_picking_1 (l->dw_loc_next, frame_offset_, dpi,
- visited))
+ frame_offsets))
return false;
/* Fall through... */
@@ -15623,17 +15621,20 @@ resolve_args_picking_1 (dw_loc_descr_ref loc,
unsigned initial_frame_offset,
/* Make a DFS over operations reachable through LOC (i.e. follow branch
operations) in order to resolve the operand of DW_OP_pick operations that
- target DWARF procedure arguments (DPI). Stop at already visited nodes.
- INITIAL_FRAME_OFFSET is the frame offset *before* LOC is executed. Return
- if all relocations were successful. */
+ target DWARF procedure arguments (DPI). INITIAL_FRAME_OFFSET is the frame
+ offset *before* LOC is executed. Return if all relocations were
+ successful. */
static bool
resolve_args_picking (dw_loc_descr_ref loc, unsigned initial_frame_offset,
struct dwarf_procedure_info *dpi)
{
- hash_set<dw_loc_descr_ref> visited;
+ /* Associate to all visited operations the frame offset *before* evaluating
+ this operation. */
+ hash_map<dw_loc_descr_ref, unsigned> frame_offsets;
- return resolve_args_picking_1 (loc, initial_frame_offset, dpi, visited);
+ return resolve_args_picking_1 (loc, initial_frame_offset, dpi,
+ frame_offsets);
}
/* Try to generate a DWARF procedure that computes the same result as FNDECL.
diff --git a/gcc/dwarf2out.h b/gcc/dwarf2out.h
index 91b3d6b..abf0550 100644
--- a/gcc/dwarf2out.h
+++ b/gcc/dwarf2out.h
@@ -239,12 +239,6 @@ struct GTY((chain_next ("%h.dw_loc_next")))
dw_loc_descr_node {
frame offset. */
unsigned int frame_offset_rel : 1;
int dw_loc_addr;
-#if CHECKING_P
- /* When translating a function into a DWARF procedure, contains the frame
- offset *before* evaluating this operation. It is -1 when not yet
- initialized. */
- int dw_loc_frame_offset;
-#endif
dw_val_node dw_loc_oprnd1;
dw_val_node dw_loc_oprnd2;
};
--
2.7.4
