From: Zoran Zaric <zoran.zaric@amd.com>
To: <gdb-patches@sourceware.org>
Subject: [PATCH v3 05/17] Move compilation unit info to dwarf_expr_context
Date: Fri, 28 May 2021 16:46:36 +0100 [thread overview]
Message-ID: <20210528154648.60881-6-zoran.zaric@amd.com> (raw)
In-Reply-To: <20210528154648.60881-1-zoran.zaric@amd.com>
This patch moves the compilation unit context information and support
from dwarf_expr_executor and dwarf_evaluate_loc_desc to
dwarf_expr_context evaluator. The idea is to report an error when a
given operation requires a compilation unit information to be resolved,
which is not available.
With this change, it also makes sense to always acquire ref_addr_size
information from the compilation unit context, considering that all
DWARF operations that refer to that information require a compilation
unit context to be present during their evaluation.
gdb/ChangeLog:
* dwarf2/expr.c (ensure_have_per_cu): New function.
(dwarf_expr_context::dwarf_expr_context): Add compilation unit
context information.
(dwarf_expr_context::get_base_type): Move from
dwarf_evaluate_loc_desc.
(dwarf_expr_context::get_addr_index): Remove method.
(dwarf_expr_context::dwarf_variable_value): Remove method.
(dwarf_expr_context::execute_stack_op): Call compilation unit
context info check. Inline get_addr_index and
dwarf_variable_value methods.
* dwarf2/expr.h (struct dwarf_expr_context): Add compilation
context info.
(dwarf_expr_context::get_addr_index): Remove method.
(dwarf_expr_context::dwarf_variable_value): Remove method.
(dwarf_expr_context::ref_addr_size): Remove member.
* dwarf2/frame.c (dwarf_expr_executor::get_addr_index): Remove
method.
(dwarf_expr_executor::dwarf_variable_value): Remove method.
* dwarf2/loc.c (sect_variable_value): Expose function.
(dwarf_evaluate_loc_desc::get_addr_index): Remove method.
(dwarf_evaluate_loc_desc::dwarf_variable_value): Remove method.
(class dwarf_evaluate_loc_desc): Move compilation unit context
information to dwarf_expr_context class.
* dwarf2/loc.h (sect_variable_value): Expose function.
---
gdb/dwarf2/expr.c | 76 ++++++++++++++++++++++++++++++++++++----------
gdb/dwarf2/expr.h | 29 +++++-------------
gdb/dwarf2/frame.c | 11 -------
gdb/dwarf2/loc.c | 37 ++--------------------
gdb/dwarf2/loc.h | 8 +++++
5 files changed, 79 insertions(+), 82 deletions(-)
diff --git a/gdb/dwarf2/expr.c b/gdb/dwarf2/expr.c
index ced78034fdf..d70f92f27bc 100644
--- a/gdb/dwarf2/expr.c
+++ b/gdb/dwarf2/expr.c
@@ -72,6 +72,20 @@ ensure_have_frame (struct frame_info *frame, const char *op_name)
_("%s evaluation requires a frame."), op_name);
}
+/* Ensure that a PER_CU is defined and throw an exception otherwise.
+
+ Throwing NOT_AVAILABLE_ERROR error so that a client can chose
+ to react differently if the evaluation ended because there
+ was a missing context information. */
+
+static void
+ensure_have_per_cu (struct dwarf2_per_cu_data *per_cu, const char* op_name)
+{
+ if (per_cu == nullptr)
+ throw_error (GENERIC_ERROR,
+ _("%s evaluation requires a compilation unit."), op_name);
+}
+
/* See expr.h. */
CORE_ADDR
@@ -201,6 +215,23 @@ dwarf_expr_context::get_frame_base (const gdb_byte **start,
start, length);
}
+/* See expr.h. */
+
+struct type *
+dwarf_expr_context::get_base_type (cu_offset die_cu_off)
+{
+ if (per_cu == nullptr)
+ return builtin_type (this->gdbarch)->builtin_int;
+
+ struct type *result = dwarf2_get_die_type (die_cu_off, this->per_cu,
+ this->per_objfile);
+
+ if (result == nullptr)
+ error (_("Could not find type for operation"));
+
+ return result;
+}
+
/* Require that TYPE be an integral type; throw an exception if not. */
static void
@@ -697,14 +728,20 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
case DW_OP_addrx:
case DW_OP_GNU_addr_index:
+ ensure_have_per_cu (this->per_cu, "DW_OP_addrx");
+
op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
- result = this->get_addr_index (uoffset);
+ result = dwarf2_read_addr_index (this->per_cu, this->per_objfile,
+ uoffset);
result += this->per_objfile->objfile->text_section_offset ();
result_val = value_from_ulongest (address_type, result);
break;
case DW_OP_GNU_const_index:
+ ensure_have_per_cu (this->per_cu, "DW_OP_GNU_const_index");
+
op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
- result = this->get_addr_index (uoffset);
+ result = dwarf2_read_addr_index (this->per_cu, this->per_objfile,
+ uoffset);
result_val = value_from_ulongest (address_type, result);
break;
@@ -834,15 +871,14 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
case DW_OP_GNU_implicit_pointer:
{
int64_t len;
+ ensure_have_per_cu (this->per_cu, "DW_OP_implicit_pointer");
- if (this->ref_addr_size == -1)
- error (_("DWARF-2 expression error: DW_OP_implicit_pointer "
- "is not allowed in frame context"));
+ int ref_addr_size = this->per_cu->ref_addr_size ();
/* The referred-to DIE of sect_offset kind. */
- this->len = extract_unsigned_integer (op_ptr, this->ref_addr_size,
- byte_order);
- op_ptr += this->ref_addr_size;
+ this->len = extract_unsigned_integer (op_ptr, ref_addr_size,
+ byte_order);
+ op_ptr += ref_addr_size;
/* The byte offset into the data. */
op_ptr = safe_read_sleb128 (op_ptr, op_end, &len);
@@ -1008,7 +1044,7 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
{
op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
cu_offset type_die_cu_off = (cu_offset) uoffset;
- type = get_base_type (type_die_cu_off, 0);
+ type = get_base_type (type_die_cu_off);
}
else
type = address_type;
@@ -1331,13 +1367,17 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
case DW_OP_GNU_variable_value:
{
+ ensure_have_per_cu (this->per_cu, "DW_OP_GNU_variable_value");
+ int ref_addr_size = this->per_cu->ref_addr_size ();
+
sect_offset sect_off
= (sect_offset) extract_unsigned_integer (op_ptr,
- this->ref_addr_size,
+ ref_addr_size,
byte_order);
- op_ptr += this->ref_addr_size;
- result_val = value_cast (address_type,
- this->dwarf_variable_value (sect_off));
+ op_ptr += ref_addr_size;
+ result_val = sect_variable_value (sect_off, this->per_cu,
+ this->per_objfile);
+ result_val = value_cast (address_type, result_val);
}
break;
@@ -1407,7 +1447,11 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
data = op_ptr;
op_ptr += n;
- type = get_base_type (type_die_cu_off, n);
+ type = get_base_type (type_die_cu_off);
+
+ if (TYPE_LENGTH (type) != n)
+ error (_("DW_OP_const_type has different sizes for type and data"));
+
result_val = value_from_contents (type, data);
}
break;
@@ -1421,7 +1465,7 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
cu_offset type_die_cu_off = (cu_offset) uoffset;
- type = get_base_type (type_die_cu_off, 0);
+ type = get_base_type (type_die_cu_off);
result_val = this->get_reg_value (type, reg);
}
break;
@@ -1439,7 +1483,7 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
if (to_underlying (type_die_cu_off) == 0)
type = address_type;
else
- type = get_base_type (type_die_cu_off, 0);
+ type = get_base_type (type_die_cu_off);
result_val = fetch (0);
pop ();
diff --git a/gdb/dwarf2/expr.h b/gdb/dwarf2/expr.h
index ba17dc40165..f14070de522 100644
--- a/gdb/dwarf2/expr.h
+++ b/gdb/dwarf2/expr.h
@@ -137,10 +137,6 @@ struct dwarf_expr_context
/* Target address size in bytes. */
int addr_size = 0;
- /* DW_FORM_ref_addr size in bytes. If -1 DWARF is executed from a frame
- context and operations depending on DW_FORM_ref_addr are not allowed. */
- int ref_addr_size = 0;
-
/* The current depth of dwarf expression recursion, via DW_OP_call*,
DW_OP_fbreg, DW_OP_push_object_address, etc., and the maximum
depth we'll tolerate before raising an error. */
@@ -189,6 +185,9 @@ struct dwarf_expr_context
/* Frame information used for the evaluation. */
struct frame_info *frame = nullptr;
+ /* Compilation unit used for the evaluation. */
+ struct dwarf2_per_cu_data *per_cu = nullptr;
+
/* Read LENGTH bytes at ADDR into BUF. */
virtual void read_mem (gdb_byte *buf, CORE_ADDR addr, size_t length) = 0;
@@ -208,19 +207,6 @@ struct dwarf_expr_context
subroutine. */
virtual void dwarf_call (cu_offset die_cu_off) = 0;
- /* Execute "variable value" operation on the DIE at SECT_OFF. */
- virtual struct value *dwarf_variable_value (sect_offset sect_off) = 0;
-
- /* Return the base type given by the indicated DIE at DIE_CU_OFF.
- This can throw an exception if the DIE is invalid or does not
- represent a base type. SIZE is non-zero if this function should
- verify that the resulting type has the correct size. */
- virtual struct type *get_base_type (cu_offset die_cu_off, int size)
- {
- /* Anything will do. */
- return builtin_type (this->gdbarch)->builtin_int;
- }
-
/* 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
@@ -229,10 +215,6 @@ struct dwarf_expr_context
union call_site_parameter_u kind_u,
int deref_size) = 0;
- /* Return the address indexed by DW_OP_addrx or DW_OP_GNU_addr_index.
- This can throw an exception if the index is out of range. */
- virtual CORE_ADDR get_addr_index (unsigned int index) = 0;
-
/* Return the `object address' for DW_OP_push_object_address. */
virtual CORE_ADDR get_object_address () = 0;
@@ -255,6 +237,11 @@ struct dwarf_expr_context
START and LENGTH. The result must be live until the current
expression evaluation is complete. */
void get_frame_base (const gdb_byte **start, size_t *length);
+
+ /* Return the base type given by the indicated DIE at DIE_CU_OFF.
+ This can throw an exception if the DIE is invalid or does not
+ represent a base type. */
+ struct type *get_base_type (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 c543848cda6..492c1ec9d7c 100644
--- a/gdb/dwarf2/frame.c
+++ b/gdb/dwarf2/frame.c
@@ -259,16 +259,6 @@ class dwarf_expr_executor : public dwarf_expr_context
invalid ("DW_OP_call*");
}
- struct value *dwarf_variable_value (sect_offset sect_off) override
- {
- invalid ("DW_OP_GNU_variable_value");
- }
-
- CORE_ADDR get_addr_index (unsigned int index) override
- {
- invalid ("DW_OP_addrx or DW_OP_GNU_addr_index");
- }
-
private:
void invalid (const char *op) ATTRIBUTE_NORETURN
@@ -290,7 +280,6 @@ execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size,
ctx.frame = this_frame;
ctx.gdbarch = get_frame_arch (this_frame);
ctx.addr_size = addr_size;
- ctx.ref_addr_size = -1;
ctx.push_address (initial, initial_in_stack_memory);
ctx.eval (exp, len);
diff --git a/gdb/dwarf2/loc.c b/gdb/dwarf2/loc.c
index 7b9f06bd5a9..f5bd5c57c61 100644
--- a/gdb/dwarf2/loc.c
+++ b/gdb/dwarf2/loc.c
@@ -620,12 +620,10 @@ per_cu_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset,
ctx->eval (block.data, block.size);
}
-/* Given context CTX, section offset SECT_OFF, and compilation unit
- data PER_CU, execute the "variable value" operation on the DIE
- found at SECT_OFF. */
+/* See loc.h. */
-static struct value *
-sect_variable_value (struct dwarf_expr_context *ctx, sect_offset sect_off,
+struct value *
+sect_variable_value (sect_offset sect_off,
dwarf2_per_cu_data *per_cu,
dwarf2_per_objfile *per_objfile)
{
@@ -654,7 +652,6 @@ class dwarf_evaluate_loc_desc : public dwarf_expr_context
: dwarf_expr_context (per_objfile)
{}
- struct dwarf2_per_cu_data *per_cu;
CORE_ADDR obj_address;
/* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for
@@ -680,32 +677,6 @@ class dwarf_evaluate_loc_desc : public dwarf_expr_context
per_cu_dwarf_call (this, die_offset, per_cu, per_objfile);
}
- /* Helper interface of sect_variable_value for
- dwarf2_evaluate_loc_desc. */
-
- struct value *dwarf_variable_value (sect_offset sect_off) override
- {
- return sect_variable_value (this, sect_off, per_cu, per_objfile);
- }
-
- struct type *get_base_type (cu_offset die_offset, int size) override
- {
- struct type *result = dwarf2_get_die_type (die_offset, per_cu, per_objfile);
- if (result == NULL)
- error (_("Could not find type for DW_OP_const_type"));
- if (size != 0 && TYPE_LENGTH (result) != size)
- error (_("DW_OP_const_type has different sizes for type and data"));
- return result;
- }
-
- /* Callback function for dwarf2_evaluate_loc_desc.
- Fetch the address indexed by DW_OP_addrx or DW_OP_GNU_addr_index. */
-
- CORE_ADDR get_addr_index (unsigned int index) override
- {
- return dwarf2_read_addr_index (per_cu, per_objfile, index);
- }
-
/* Callback function for get_object_address. Return the address of the VLA
object. */
@@ -2195,7 +2166,6 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
ctx.gdbarch = per_objfile->objfile->arch ();
ctx.addr_size = per_cu->addr_size ();
- ctx.ref_addr_size = per_cu->ref_addr_size ();
try
{
@@ -2462,7 +2432,6 @@ dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
ctx.gdbarch = per_objfile->objfile->arch ();
ctx.addr_size = dlbaton->per_cu->addr_size ();
- ctx.ref_addr_size = dlbaton->per_cu->ref_addr_size ();
if (push_initial_value)
ctx.push_address (ctx.obj_address, false);
diff --git a/gdb/dwarf2/loc.h b/gdb/dwarf2/loc.h
index 2943baf91d2..a729b370e2e 100644
--- a/gdb/dwarf2/loc.h
+++ b/gdb/dwarf2/loc.h
@@ -53,6 +53,14 @@ extern void func_get_frame_base_dwarf_block (struct symbol *framefunc,
const gdb_byte **start,
size_t *length);
+/* Given section offset SECT_OFF, and compilation unit data
+ PER_CU, execute the "variable value" operation on the DIE
+ found at SECT_OFF. */
+
+struct value *sect_variable_value (sect_offset sect_off,
+ dwarf2_per_cu_data *per_cu,
+ dwarf2_per_objfile *per_objfile);
+
/* 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. */
--
2.17.1
next prev parent reply other threads:[~2021-05-28 15:47 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-28 15:46 [PATCH v3 00/17] DWARF expression evaluator design cleanup Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 01/17] Replace the symbol needs evaluator with a parser Zoran Zaric
2021-06-07 21:48 ` Simon Marchi
2021-06-11 17:22 ` Zaric, Zoran (Zare)
2021-05-28 15:46 ` [PATCH v3 02/17] Cleanup of the dwarf_expr_context constructor Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 03/17] Move frame context info to dwarf_expr_context Zoran Zaric
2021-06-09 0:45 ` Simon Marchi
2021-06-11 17:16 ` Zaric, Zoran (Zare)
2021-05-28 15:46 ` [PATCH v3 04/17] Remove get_frame_cfa from dwarf_expr_context Zoran Zaric
2021-05-28 15:46 ` Zoran Zaric [this message]
2021-06-09 0:50 ` [PATCH v3 05/17] Move compilation unit info to dwarf_expr_context Simon Marchi
2021-06-11 17:19 ` Zaric, Zoran (Zare)
2021-05-28 15:46 ` [PATCH v3 06/17] Move dwarf_call " Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 07/17] Move get_object_address " Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 08/17] Move read_mem " Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 09/17] Move push_dwarf_reg_entry_value to expr.c Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 10/17] Inline get_reg_value method of dwarf_expr_context Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 11/17] Remove empty frame and full evaluators Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 12/17] Merge evaluate_for_locexpr_baton evaluator Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 13/17] Move piece_closure and its support to expr.c Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 14/17] Make value_copy also copy the stack data member Zoran Zaric
2021-05-28 15:46 ` [PATCH v3 15/17] Make DWARF evaluator return a single struct value Zoran Zaric
2021-08-11 17:00 ` Tom Tromey
2021-08-12 18:03 ` Tom Tromey
2021-08-13 9:57 ` Zoran Zaric
2021-08-13 16:59 ` Tom Tromey
2021-08-13 17:57 ` Zoran Zaric
2021-08-16 15:37 ` Tom Tromey
2021-08-16 16:05 ` Zoran Zaric
2021-08-16 17:32 ` Tom Tromey
2021-05-28 15:46 ` [PATCH v3 16/17] Simplify dwarf_expr_context class interface Zoran Zaric
2021-06-09 1:01 ` Simon Marchi
2021-06-11 17:20 ` Zaric, Zoran (Zare)
2021-05-28 15:46 ` [PATCH v3 17/17] Add as_lval argument to expression evaluator Zoran Zaric
2021-06-09 1:04 ` [PATCH v3 00/17] DWARF expression evaluator design cleanup Simon Marchi
2021-08-05 16:38 ` Zaric, Zoran (Zare)
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