From: Zoran Zaric <Zoran.Zaric@amd.com>
To: gdb-patches@sourceware.org
Cc: Zoran Zaric <Zoran.Zaric@amd.com>
Subject: [PATCH 15/30] Add as_lval argument to expression evaluator
Date: Mon, 7 Dec 2020 19:00:16 +0000 [thread overview]
Message-ID: <20201207190031.13341-16-Zoran.Zaric@amd.com> (raw)
In-Reply-To: <20201207190031.13341-1-Zoran.Zaric@amd.com>
There are cases where the result of the expression evaluation is
expected to be in a form of a value and not location description.
One place that has this requirement is dwarf_entry_parameter_to_value
function, but more are expected in the future. Until now, this
requirement was fulfilled by extending the evaluated expression with
a DW_OP_stack_value operation at the end.
New implementation, introduces a new evaluation argument instead.
* dwarf2/expr.c (dwarf_expr_context::fetch_result): Add as_lval
argument.
(dwarf_expr_context::eval_exp): Add as_lval argument.
* dwarf2/expr.h (struct dwarf_expr_context): Add as_lval
argument to fetch_result and eval_exp methods.
* dwarf2/frame.c (execute_stack_op): Add as_lval argument.
* dwarf2/loc.c (dwarf_entry_parameter_to_value): Remove
DWARF expression extension.
(dwarf2_evaluate_loc_desc_full): Add as_lval argument support.
(dwarf2_evaluate_loc_desc): Add as_lval argument support.
(dwarf2_locexpr_baton_eval): Add as_lval argument support.
---
gdb/dwarf2/expr.c | 12 +++++++++---
gdb/dwarf2/expr.h | 19 ++++++++++++-------
gdb/dwarf2/frame.c | 2 +-
gdb/dwarf2/loc.c | 27 ++++++++++-----------------
gdb/dwarf2/loc.h | 6 ++++--
5 files changed, 36 insertions(+), 30 deletions(-)
diff --git a/gdb/dwarf2/expr.c b/gdb/dwarf2/expr.c
index 5e99a98e1e..b1283e70df 100644
--- a/gdb/dwarf2/expr.c
+++ b/gdb/dwarf2/expr.c
@@ -903,7 +903,8 @@ dwarf_expr_context::push_dwarf_reg_entry_value
struct value *
dwarf_expr_context::fetch_result (struct type *type,
struct type *subobj_type,
- LONGEST subobj_offset)
+ LONGEST subobj_offset,
+ bool as_lval)
{
struct value *retval = nullptr;
@@ -933,6 +934,11 @@ dwarf_expr_context::fetch_result (struct type *type,
}
else
{
+ /* If AS_LVAL is false, means that the implicit conversion
+ from a location description to value is expected. */
+ if (as_lval == false)
+ this->location = DWARF_VALUE_STACK;
+
switch (this->location)
{
case DWARF_VALUE_REGISTER:
@@ -1057,7 +1063,7 @@ dwarf_expr_context::fetch_result (struct type *type,
/* See expr.h. */
struct value *
-dwarf_expr_context::eval_exp (const gdb_byte *addr, size_t len,
+dwarf_expr_context::eval_exp (const gdb_byte *addr, size_t len, bool as_lval,
struct dwarf2_per_cu_data *per_cu,
struct frame_info *frame,
const struct property_addr_info *addr_info,
@@ -1073,7 +1079,7 @@ dwarf_expr_context::eval_exp (const gdb_byte *addr, size_t len,
this->ref_addr_size = per_cu->ref_addr_size ();
eval (addr, len);
- return fetch_result (type, subobj_type, subobj_offset);
+ return fetch_result (type, subobj_type, subobj_offset, as_lval);
}
/* Require that TYPE be an integral type; throw an exception if not. */
diff --git a/gdb/dwarf2/expr.h b/gdb/dwarf2/expr.h
index 69a043da50..1c06308f99 100644
--- a/gdb/dwarf2/expr.h
+++ b/gdb/dwarf2/expr.h
@@ -130,11 +130,13 @@ struct dwarf_expr_context
void push_address (CORE_ADDR value, bool in_stack_memory);
/* Evaluate the expression at ADDR (LEN bytes long) in a given PER_CU
- FRAME context. Where TYPE, SUBOBJ_TYPE and SUBOBJ_OFFSET describe
- expected struct value representation of the evaluation result.
- The ADDR_INFO property can be specified to override the range of
- memory addresses with the passed in buffer. */
- struct value *eval_exp (const gdb_byte *addr, size_t len,
+ FRAME context. AS_LVAL defines if the returned struct value is
+ expected to be a value or a location description. Where TYPE,
+ SUBOBJ_TYPE and SUBOBJ_OFFSET describe expected struct value
+ representation of the evaluation result. The ADDR_INFO property
+ can be specified to override the range of memory addresses with
+ the passed in buffer. */
+ struct value *eval_exp (const gdb_byte *addr, size_t len, bool as_lval,
struct dwarf2_per_cu_data *per_cu,
struct frame_info *frame,
const struct property_addr_info *addr_info = nullptr,
@@ -223,10 +225,13 @@ struct dwarf_expr_context
/* Fetch the result of the expression evaluation in a form of
a struct value, where TYPE, SUBOBJ_TYPE and SUBOBJ_OFFSET
- describe the source level representation of that result. */
+ describe the source level representation of that result.
+ AS_LVAL defines if the fetched struct value is expected to
+ be a value or a location description. */
struct value *fetch_result (struct type *type,
struct type *subobj_type,
- LONGEST subobj_offset);
+ LONGEST subobj_offset,
+ bool as_lval);
/* Return the location expression for the frame base attribute, in
START and LENGTH. The result must be live until the current
diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c
index 228c48f387..4037653106 100644
--- a/gdb/dwarf2/frame.c
+++ b/gdb/dwarf2/frame.c
@@ -232,7 +232,7 @@ execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size,
scoped_value_mark free_values;
ctx.push_address (initial, initial_in_stack_memory);
- struct value *result_val = ctx.eval_exp (exp, len, nullptr, this_frame);
+ struct value *result_val = ctx.eval_exp (exp, len, true, nullptr, this_frame);
if (VALUE_LVAL (result_val) == lval_memory)
return value_address (result_val);
diff --git a/gdb/dwarf2/loc.c b/gdb/dwarf2/loc.c
index fdf8385933..1a23e0b2da 100644
--- a/gdb/dwarf2/loc.c
+++ b/gdb/dwarf2/loc.c
@@ -50,7 +50,7 @@
static struct value *dwarf2_evaluate_loc_desc_full
(struct type *type, struct frame_info *frame, const gdb_byte *data,
size_t size, dwarf2_per_cu_data *per_cu, dwarf2_per_objfile *per_objfile,
- struct type *subobj_type, LONGEST subobj_byte_offset);
+ struct type *subobj_type, LONGEST subobj_byte_offset, bool as_lval = true);
/* Until these have formal names, we define these here.
ref: http://gcc.gnu.org/wiki/DebugFission
@@ -1183,7 +1183,6 @@ dwarf_entry_parameter_to_value (struct call_site_parameter *parameter,
dwarf2_per_objfile *per_objfile)
{
const gdb_byte *data_src;
- gdb_byte *data;
size_t size;
data_src = deref_size == -1 ? parameter->value : parameter->data_value;
@@ -1194,15 +1193,8 @@ dwarf_entry_parameter_to_value (struct call_site_parameter *parameter,
throw_error (NO_ENTRY_VALUE_ERROR,
_("Cannot resolve DW_AT_call_data_value"));
- /* DW_AT_call_value is a DWARF expression, not a DWARF
- location. Postprocessing of DWARF_VALUE_MEMORY would lose the type from
- DWARF block. */
- data = (gdb_byte *) alloca (size + 1);
- memcpy (data, data_src, size);
- data[size] = DW_OP_stack_value;
-
- return dwarf2_evaluate_loc_desc (type, caller_frame, data, size + 1, per_cu,
- per_objfile);
+ return dwarf2_evaluate_loc_desc (type, caller_frame, data_src, size, per_cu,
+ per_objfile, false);
}
/* VALUE must be of type lval_computed with entry_data_value_funcs. Perform
@@ -1428,7 +1420,8 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
dwarf2_per_cu_data *per_cu,
dwarf2_per_objfile *per_objfile,
struct type *subobj_type,
- LONGEST subobj_byte_offset)
+ LONGEST subobj_byte_offset,
+ bool as_lval)
{
if (subobj_type == NULL)
{
@@ -1448,8 +1441,8 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
try
{
- retval = ctx.eval_exp (data, size, per_cu, frame, nullptr, type,
- subobj_type, subobj_byte_offset);
+ retval = ctx.eval_exp (data, size, as_lval, per_cu, frame, nullptr,
+ type, subobj_type, subobj_byte_offset);
}
catch (const gdb_exception_error &ex)
{
@@ -1490,10 +1483,10 @@ struct value *
dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame,
const gdb_byte *data, size_t size,
dwarf2_per_cu_data *per_cu,
- dwarf2_per_objfile *per_objfile)
+ dwarf2_per_objfile *per_objfile, bool as_lval)
{
return dwarf2_evaluate_loc_desc_full (type, frame, data, size, per_cu,
- per_objfile, NULL, 0);
+ per_objfile, NULL, 0, as_lval);
}
/* Evaluates a dwarf expression and stores the result in VAL,
@@ -1536,7 +1529,7 @@ dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
try
{
result = ctx.eval_exp (dlbaton->data, dlbaton->size,
- per_cu, frame, addr_stack);
+ true, per_cu, frame, addr_stack);
}
catch (const gdb_exception_error &ex)
{
diff --git a/gdb/dwarf2/loc.h b/gdb/dwarf2/loc.h
index 1de3604194..c14ba8febd 100644
--- a/gdb/dwarf2/loc.h
+++ b/gdb/dwarf2/loc.h
@@ -69,14 +69,16 @@ struct call_site_parameter *dwarf_expr_reg_to_entry_parameter
/* Evaluate a location description, starting at DATA and with length
SIZE, to find the current location of variable of TYPE in the context
- of FRAME. */
+ of FRAME. AS_LVAL defines if the resulting struct value is expected to
+ be a value or a location description. */
struct value *dwarf2_evaluate_loc_desc (struct type *type,
struct frame_info *frame,
const gdb_byte *data,
size_t size,
dwarf2_per_cu_data *per_cu,
- dwarf2_per_objfile *per_objfile);
+ dwarf2_per_objfile *per_objfile,
+ bool as_lval = true);
/* A chain of addresses that might be needed to resolve a dynamic
property. */
--
2.17.1
next prev parent reply other threads:[~2020-12-07 19:01 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-07 19:00 [PATCH 00/30] Allow location description on the DWARF stack Zoran Zaric
2020-12-07 19:00 ` [PATCH 01/30] Replace the symbol needs evaluator with a parser Zoran Zaric
2021-01-21 21:16 ` Tom Tromey
2021-01-21 21:48 ` Zoran Zaric
2021-02-23 14:15 ` Zoran Zaric
2020-12-07 19:00 ` [PATCH 02/30] Move frame context info to dwarf_expr_context Zoran Zaric
2021-01-21 21:23 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 03/30] Remove get_frame_cfa from dwarf_expr_context Zoran Zaric
2021-01-21 21:23 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 04/30] Move compilation unit info to dwarf_expr_context Zoran Zaric
2021-01-21 21:28 ` Tom Tromey
2021-02-23 14:21 ` Zoran Zaric
2020-12-07 19:00 ` [PATCH 05/30] Move dwarf_call " Zoran Zaric
2021-01-21 21:30 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 06/30] Move get_object_address " Zoran Zaric
2021-01-21 21:31 ` Tom Tromey
2021-02-23 14:33 ` Zoran Zaric
2020-12-07 19:00 ` [PATCH 07/30] Move read_mem " Zoran Zaric
2021-01-21 21:34 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 08/30] Move push_dwarf_reg_entry_value to expr.c Zoran Zaric
2021-01-21 21:35 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 09/30] Inline get_reg_value method of dwarf_expr_context Zoran Zaric
2021-01-21 21:36 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 10/30] Remove empty frame and full evaluators Zoran Zaric
2021-01-21 21:37 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 11/30] Merge evaluate_for_locexpr_baton evaluator Zoran Zaric
2021-02-08 21:21 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 12/30] Move piece_closure and its support to expr.c Zoran Zaric
2021-02-08 21:32 ` Tom Tromey
2021-02-09 14:53 ` Zoran Zaric
2020-12-07 19:00 ` [PATCH 13/30] Make DWARF evaluator return a single struct value Zoran Zaric
2021-02-08 21:35 ` Tom Tromey
2021-02-09 14:55 ` Zoran Zaric
2021-02-09 17:13 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 14/30] Simplify dwarf_expr_context class interface Zoran Zaric
2021-02-08 21:38 ` Tom Tromey
2021-02-09 14:56 ` Zoran Zaric
2021-02-23 14:38 ` Zoran Zaric
2020-12-07 19:00 ` Zoran Zaric [this message]
2021-02-08 21:41 ` [PATCH 15/30] Add as_lval argument to expression evaluator Tom Tromey
2021-02-09 15:25 ` Zoran Zaric
2021-02-09 20:33 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 16/30] Add new register access interface to expr.c Zoran Zaric
2021-02-09 19:37 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 17/30] Add new memory " Zoran Zaric
2021-02-09 19:45 ` Tom Tromey
2021-02-23 15:35 ` Zoran Zaric
2020-12-07 19:00 ` [PATCH 18/30] Add new classes that model DWARF stack element Zoran Zaric
2021-02-08 21:54 ` Tom Tromey
2021-02-09 17:34 ` Zoran Zaric
2021-02-09 20:36 ` Tom Tromey
2021-02-09 21:07 ` Tom Tromey
2021-02-09 21:26 ` Zoran Zaric
2021-02-23 14:57 ` Zoran Zaric
2020-12-07 19:00 ` [PATCH 19/30] Add new location description access interface Zoran Zaric
2021-02-08 21:46 ` Tom Tromey
2021-02-09 16:00 ` Zoran Zaric
2021-02-09 17:30 ` Zoran Zaric
2021-02-23 14:49 ` Zoran Zaric
2020-12-07 19:00 ` [PATCH 20/30] Add dwarf_entry factory class to expr.c Zoran Zaric
2021-02-09 19:54 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 21/30] Change DWARF stack to use new dwarf_entry classes Zoran Zaric
2021-02-09 20:11 ` Tom Tromey
2020-12-07 19:00 ` [PATCH 22/30] Remove dwarf_expr_context from expr.h interface Zoran Zaric
2020-12-07 19:00 ` [PATCH 23/30] Rename and update the piece_closure structure Zoran Zaric
2020-12-07 19:00 ` [PATCH 24/30] Move read_addr_from_reg function to frame.c Zoran Zaric
2020-12-07 19:00 ` [PATCH 25/30] Add frame info check to DW_OP_reg operations Zoran Zaric
2020-12-07 19:00 ` [PATCH 26/30] Remove DWARF expression composition check Zoran Zaric
2020-12-07 19:00 ` [PATCH 27/30] Add support for any location description in CFI Zoran Zaric
2020-12-07 19:00 ` [PATCH 28/30] Add DWARF operations for byte and bit offset Zoran Zaric
2020-12-07 19:00 ` [PATCH 29/30] Add support for DW_OP_LLVM_undefined operation Zoran Zaric
2020-12-07 19:00 ` [PATCH 30/30] Add support for nested composite locations Zoran Zaric
2020-12-08 14:48 ` [PATCH 00/30] Allow location description on the DWARF stack Metzger, Markus T
2020-12-08 16:17 ` Simon Marchi
2020-12-09 0:30 ` Tye, Tony
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