[PATCH 06/43] Move dwarf_call to dwarf_expr_context

Zoran Zaric via Gdb-patches
2021-03-01T14:47:00Z

From: Zoran Zaric <zoran.zaric@amd.com>

Following the idea of merging the evaluators, the dwarf_call and
get_frame_pc method can be moved from dwarf_expr_executor and
dwarf_evaluate_loc_desc classes to their base class dwarf_expr_context.
Once this is done, the get_frame_pc can be replace with lambda
function.

gdb/ChangeLog:

* dwarf2/expr.c (dwarf_expr_context::dwarf_call): Move from
dwarf_evaluate_loc_desc.
(dwarf_expr_context::get_frame_pc): Replace with lambda.
* dwarf2/expr.h (dwarf_expr_context::get_frame_pc): Remove
method.
* dwarf2/frame.c (dwarf_expr_executor::dwarf_call): Remove
method.
(dwarf_expr_executor::get_frame_pc): Remove method.
* dwarf2/loc.c (dwarf_evaluate_loc_desc::get_frame_pc): Remove
method.
(dwarf_evaluate_loc_desc::dwarf_call): Move to
dwarf_expr_context.
(per_cu_dwarf_call): Inline function.
---
gdb/dwarf2/expr.c | 28 +++++++++++++++++++++++++++-
gdb/dwarf2/expr.h | 22 ++++++----------------
gdb/dwarf2/frame.c | 10 ----------
gdb/dwarf2/loc.c | 43 -------------------------------------------
4 files changed, 33 insertions(+), 70 deletions(-)

diff --git a/gdb/dwarf2/expr.c b/gdb/dwarf2/expr.c
index 5a0a4a4299c..9b2c7485720 100644
--- a/gdb/dwarf2/expr.c
+++ b/gdb/dwarf2/expr.c
@@ -234,6 +234,31 @@ dwarf_expr_context::get_base_type (cu_offset die_cu_off, int size)
return result;
}

+/* See expr.h. */
+
+void
+dwarf_expr_context::dwarf_call (cu_offset die_cu_off)
+{
+ ensure_have_per_cu (per_cu, "DW_OP_call");
+
+ struct frame_info *frame = this->frame;
+
+ auto get_pc_from_frame = [frame] ()
+ {
+ ensure_have_frame (frame, "DW_OP_call");
+ return get_frame_address_in_block (frame);
+ };
+
+ struct dwarf2_locexpr_baton block
+ = dwarf2_fetch_die_loc_cu_off (die_cu_off, per_cu, per_objfile,
+ get_pc_from_frame);
+
+ /* DW_OP_call_ref is currently not supported. */
+ gdb_assert (block.per_cu == per_cu);
+
+ this->eval (block.data, block.size);
+}
+
/* Require that TYPE be an integral type; throw an exception if not. */

static void
@@ -1276,7 +1301,8 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
returned. */
result = value_as_long (fetch (0));
pop ();
- result = this->get_tls_address (result);
+ result = target_translate_tls_address (this->per_objfile->objfile,
+ result);
result_val = value_from_ulongest (address_type, result);
break;

diff --git a/gdb/dwarf2/expr.h b/gdb/dwarf2/expr.h
index 48dd37150db..9510dfe33d4 100644
--- a/gdb/dwarf2/expr.h
+++ b/gdb/dwarf2/expr.h
@@ -195,22 +195,6 @@ struct dwarf_expr_context
/* Read LENGTH bytes at ADDR into BUF. */
virtual void read_mem (gdb_byte *buf, CORE_ADDR addr, size_t length) = 0;

- /* Return the PC for the frame. */
- virtual CORE_ADDR get_frame_pc ()
- {
- error (_("%s is invalid in this context"), "DW_OP_implicit_pointer");
- }
-
- /* Return the thread-local storage address for
- DW_OP_GNU_push_tls_address or DW_OP_form_tls_address. */
- virtual CORE_ADDR get_tls_address (CORE_ADDR offset) = 0;
-
- /* Execute DW_AT_location expression for the DWARF expression
- subroutine in the DIE at DIE_CU_OFF in the CU. Do not touch
- STACK while it being passed to and returned from the called DWARF
- subroutine. */
- virtual void dwarf_call (cu_offset die_cu_off) = 0;
-
/* Push on DWARF stack an entry evaluated for DW_TAG_call_site's
parameter matching KIND and KIND_U at the caller of specified BATON.
If DEREF_SIZE is not -1 then use DW_AT_call_data_value instead of
@@ -247,6 +231,12 @@ struct dwarf_expr_context
represent a base type. SIZE is non-zero if this function should
verify that the resulting type has the correct size. */
struct type *get_base_type (cu_offset die_cu_off, int size);
+
+ /* Execute DW_AT_location expression for the DWARF expression
+ subroutine in the DIE at DIE_CU_OFF in the CU. Do not touch
+ STACK while it being passed to and returned from the called DWARF
+ subroutine. */
+ void dwarf_call (cu_offset die_cu_off);
};

/* Return the value of register number REG (a DWARF register number),
diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c
index 69a3e424c6e..f9f78f472cb 100644
--- a/gdb/dwarf2/frame.c
+++ b/gdb/dwarf2/frame.c
@@ -248,16 +248,6 @@ class dwarf_expr_executor : public dwarf_expr_context
invalid ("DW_OP_push_object_address");
}

- CORE_ADDR get_tls_address (CORE_ADDR offset) override
- {
- invalid ("DW_OP_form_tls_address");
- }
-
- void dwarf_call (cu_offset die_offset) override
- {
- invalid ("DW_OP_call*");
- }
-
private:

void invalid (const char *op) ATTRIBUTE_NORETURN
diff --git a/gdb/dwarf2/loc.c b/gdb/dwarf2/loc.c
index 1281a8a3d34..6b0fd4c8a02 100644
--- a/gdb/dwarf2/loc.c
+++ b/gdb/dwarf2/loc.c
@@ -600,26 +600,6 @@ func_get_frame_base_dwarf_block (struct symbol *framefunc, CORE_ADDR pc,
framefunc->natural_name ());
}

-static void
-per_cu_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset,
- dwarf2_per_cu_data *per_cu, dwarf2_per_objfile *per_objfile)
-{
- struct dwarf2_locexpr_baton block;
-
- auto get_frame_pc_from_ctx = [ctx] ()
- {
- return ctx->get_frame_pc ();
- };
-
- block = dwarf2_fetch_die_loc_cu_off (die_offset, per_cu, per_objfile,
- get_frame_pc_from_ctx);
-
- /* DW_OP_call_ref is currently not supported. */
- gdb_assert (block.per_cu == per_cu);
-
- ctx->eval (block.data, block.size);
-}
-
/* See loc.h. */

struct value *
@@ -654,29 +634,6 @@ class dwarf_evaluate_loc_desc : public dwarf_expr_context

CORE_ADDR obj_address;

- /* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for
- the frame in BATON. */
-
- CORE_ADDR get_frame_pc () override
- {
- return get_frame_address_in_block (frame);
- }
-
- /* Using the objfile specified in BATON, find the address for the
- current thread's thread-local storage with offset OFFSET. */
- CORE_ADDR get_tls_address (CORE_ADDR offset) override
- {
- return target_translate_tls_address (per_objfile->objfile, offset);
- }
-
- /* Helper interface of per_cu_dwarf_call for
- dwarf2_evaluate_loc_desc. */
-
- void dwarf_call (cu_offset die_offset) override
- {
- per_cu_dwarf_call (this, die_offset, per_cu, per_objfile);
- }
-
/* Callback function for get_object_address. Return the address of the VLA
object. */

--
2.17.1