From 3b3ac5a5fea4a80dfd0b0c71f3f01a4505b887f4 Mon Sep 17 00:00:00 2001 From: Zoran Zaric Date: Mon, 7 Dec 2020 19:00:05 +0000 Subject: [PATCH] Move compilation unit info to dwarf_expr_context 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. 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. Remove get_addr_index and dwarf_variable_value. * 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. Change-Id: Ib159fbbdffb25fa442cd6174d90e9522e8ccc9d1 --- gdb/dwarf2/expr.c | 54 ++++++++++++++++++++++++++++++++++++++-------- gdb/dwarf2/expr.h | 26 ++++++++-------------- gdb/dwarf2/frame.c | 10 --------- gdb/dwarf2/loc.c | 35 +++--------------------------- gdb/dwarf2/loc.h | 8 +++++++ 5 files changed, 65 insertions(+), 68 deletions(-) diff --git a/gdb/dwarf2/expr.c b/gdb/dwarf2/expr.c index 6ba8b90c584..29f5f977ace 100644 --- a/gdb/dwarf2/expr.c +++ b/gdb/dwarf2/expr.c @@ -68,6 +68,16 @@ 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. */ + +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 @@ -123,7 +133,8 @@ dwarf_expr_context::dwarf_expr_context (dwarf2_per_objfile *per_objfile) data (NULL), initialized (0), per_objfile (per_objfile), - frame (nullptr) + frame (nullptr), + per_cu (nullptr) { } @@ -207,6 +218,25 @@ 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, int size) +{ + if (per_cu == nullptr) + return builtin_type (this->gdbarch)->builtin_int; + + struct type *result = dwarf2_get_die_type (die_cu_off, 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; +} + /* Require that TYPE be an integral type; throw an exception if not. */ static void @@ -703,14 +733,20 @@ 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 (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; @@ -840,10 +876,7 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr, case DW_OP_GNU_implicit_pointer: { int64_t len; - - if (this->ref_addr_size == -1) - error (_("DWARF-2 expression error: DW_OP_implicit_pointer " - "is not allowed in frame context")); + ensure_have_per_cu (per_cu, "DW_OP_implicit_pointer"); /* The referred-to DIE of sect_offset kind. */ this->len = extract_unsigned_integer (op_ptr, this->ref_addr_size, @@ -1336,13 +1369,16 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr, case DW_OP_GNU_variable_value: { + ensure_have_per_cu (per_cu, "DW_OP_GNU_variable_value"); + sect_offset sect_off = (sect_offset) extract_unsigned_integer (op_ptr, this->ref_addr_size, byte_order); op_ptr += this->ref_addr_size; - result_val = value_cast (address_type, - this->dwarf_variable_value (sect_off)); + result_val = sect_variable_value (sect_off, this->per_cu, + this->per_objfile); + result_val = value_cast (address_type, result_val); } break; diff --git a/gdb/dwarf2/expr.h b/gdb/dwarf2/expr.h index 5abb870f883..e17cd99c256 100644 --- a/gdb/dwarf2/expr.h +++ b/gdb/dwarf2/expr.h @@ -189,6 +189,9 @@ struct dwarf_expr_context /* Frame information used for the evaluation. */ struct frame_info *frame; + /* Compilation unit used for the evaluation. */ + struct dwarf2_per_cu_data *per_cu; + /* Read LENGTH bytes at ADDR into BUF. */ virtual void read_mem (gdb_byte *buf, CORE_ADDR addr, size_t length) = 0; @@ -208,19 +211,6 @@ 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 +219,6 @@ 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 +241,12 @@ private: 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. 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); }; /* Return the value of register number REG (a DWARF register number), diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c index 4cc0ffe3c57..c93ec5d5a60 100644 --- a/gdb/dwarf2/frame.c +++ b/gdb/dwarf2/frame.c @@ -258,16 +258,6 @@ public: 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 diff --git a/gdb/dwarf2/loc.c b/gdb/dwarf2/loc.c index ecf1020b3b5..21e43e399c1 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 @@ public: : 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 @@ public: 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. */ diff --git a/gdb/dwarf2/loc.h b/gdb/dwarf2/loc.h index 907455b72c1..85700ea99d6 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. */ -- 2.47.2