From 2f7dfeca0bab11b206d2ae9bc996a3c24cbeccbb Mon Sep 17 00:00:00 2001 From: Nikolai Nosov Date: Mon, 13 Jan 2020 22:13:08 +0400 Subject: [PATCH] small reformatting of the code --- framework/dwarf_operations.cpp | 73 ++++++++++++++++++---------------- framework/dwarf_operations.h | 2 - 2 files changed, 38 insertions(+), 37 deletions(-) diff --git a/framework/dwarf_operations.cpp b/framework/dwarf_operations.cpp index 34f3a5b..129181a 100644 --- a/framework/dwarf_operations.cpp +++ b/framework/dwarf_operations.cpp @@ -546,11 +546,10 @@ bool dw_op_mul(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwarf_ return false; } +// The DW_OP_neg operation pops the top stack entry, interprets it as a signed value and pushes its negation. +// If the negation cannot be represented, the result is undefined. bool dw_op_neg(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwarf_Word op2) { - // The DW_OP_neg operation pops the top stack entry, interprets it as a signed value and pushes its negation. - // If the negation cannot be represented, the result is undefined. - dwarf_value* value = ctx->stack.get(); if(value) { int64_t v = 0; @@ -710,8 +709,7 @@ bool dw_op_plus_uconst(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1 return false; } -// Register location descriptions. From DWARF 5, section 2.6.1.1.3: -// Register location descriptions describe an object (or a piece of an object) that resides in a register. +// Register location descriptions. Describe an object (or a piece of an object) that resides in a register. // A register location description must stand alone as the entire description of an object or a piece of an object. // The DW_OP_regx operation has a single unsigned LEB128 literal operand that encodes the name of a register bool dw_op_reg_x(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwarf_Word op2) @@ -732,13 +730,11 @@ bool dw_op_reg_x(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwar return true; } -// Register values. DWARF5, section 2.5.1.2 -// Register values are used to describe an object (or a piece of an object) that is located in memory at an address that is contained in -// a register (possibly offset by some constant) +// DWARF5, section 2.5.1.2 Register values are used to describe an object (or a piece of an object) that is located in memory at an address that is contained in a register (possibly offset by some constant) +// The DW_OP_bregx operation provides the sum of two values specified by its two operands. +// The first operand is a register number which is specified by an unsigned LEB128 number. The second operand is a signed LEB128 offset. bool dw_op_breg_x(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwarf_Word op2) { - // The DW_OP_bregx operation provides the sum of two values specified by its two operands. - // The first operand is a register number which is specified by an unsigned LEB128 number. The second operand is a signed LEB128 offset. if(map->op_num != DW_OP_bregx && (map->op_num < DW_OP_breg0 || map->op_num > DW_OP_breg31)) { return false; } @@ -763,10 +759,10 @@ bool dw_op_breg_x(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwa return true; } +// The DW_OP_lit operations encode the unsigned literal values from 0 through 31, inclusive. +// Operations other than DW_OP_const_type push a value with the generic type. bool dw_op_lit_x(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwarf_Word op2) { - // The DW_OP_lit operations encode the unsigned literal values from 0 through 31, inclusive. - // Operations other than DW_OP_const_type push a value with the generic type. if(map->op_num < DW_OP_lit0 || map->op_num > DW_OP_lit31) { return false; } @@ -777,12 +773,11 @@ bool dw_op_lit_x(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwar return true; } +// The DW_OP_stack_value operation specifies that the object does not exist in memory but its value is nonetheless known and is at the top of the DWARF +// expression stack. In this form of location description, the DWARF expression represents the actual value of the object, rather than its location. +// The DW_OP_stack_value operation terminates the expression. bool dw_op_stack_value(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwarf_Word op2) { - // DWARF5, Section 2.6.1.1.4: - // The DW_OP_stack_value operation specifies that the object does not exist in memory but its value is nonetheless known and is at the top of the DWARF - // expression stack. In this form of location description, the DWARF expression represents the actual value of the object, rather than its location. - // The DW_OP_stack_value operation terminates the expression. dwarf_value* v = ctx->stack.get(); if(v) { @@ -793,15 +788,10 @@ bool dw_op_stack_value(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1 return false; } +// The DW_OP_call_frame_cfa operation pushes the value of the CFA, obtained from the Call Frame Information (see Section 6.4 on page 171). bool dw_op_call_frame_cfa(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwarf_Word op2) { - // DWARF5, Section 2.6.1.1.4: - // The DW_OP_stack_value operation specifies that the object does not exist in memory but its value is nonetheless known and is at the top of the DWARF - // expression stack. In this form of location description, the DWARF expression represents the actual value of the object, rather than its location. - // The DW_OP_stack_value operation terminates the expression. - // since in signal handler we are know SP value, just push it to DWARF stack - unw_word_t sp; if(unw_get_reg(&ctx->cursor, UNW_REG_SP, &sp)) { return false; @@ -812,12 +802,11 @@ bool dw_op_call_frame_cfa(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word return true; } +// The DW_OP_fbreg operation provides a signed LEB128 offset from the address specified by the location description in the DW_AT_frame_base +// attribute of the current function. This is typically a stack pointer register plus or minus some offset +// since in signal handler we are know SP value, just use it as DW_AT_frame_base bool dw_op_fbreg(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwarf_Word op2) { - // The DW_OP_fbreg operation provides a signed LEB128 offset from the address specified by the location description in the DW_AT_frame_base - // attribute of the current function. This is typically a stack pointer register plus or minus some offset - // since in signal handler we are know SP value, just use it as DW_AT_frame_base - unw_word_t sp; if(unw_get_reg(&ctx->cursor, UNW_REG_SP, &sp)) { return false; @@ -831,7 +820,7 @@ bool dw_op_fbreg(pst_context* ctx, const dwarf_op_map* map, Dwarf_Word op1, Dwar return true; } - +// DWARF Operations to code & name mapping dwarf_op_map dw_op[] = { {DW_OP_addr, "DW_OP_addr", dw_op_addr}, {DW_OP_deref, "DW_OP_deref", dw_op_deref}, @@ -879,7 +868,7 @@ dwarf_op_map dw_op[] = { {DW_OP_lt, "DW_OP_lt", dw_op_notimpl}, {DW_OP_ne, "DW_OP_ne", dw_op_notimpl}, {DW_OP_skip, "DW_OP_skip", dw_op_notimpl}, - //DWARF5 2.5.1.1 Literal Encodings + // DWARF5 2.5.1.1 Literal Encodings {DW_OP_lit0, "DW_OP_lit0", dw_op_lit_x}, {DW_OP_lit1, "DW_OP_lit1", dw_op_lit_x}, {DW_OP_lit2, "DW_OP_lit2", dw_op_lit_x}, @@ -912,7 +901,7 @@ dwarf_op_map dw_op[] = { {DW_OP_lit29, "DW_OP_lit29", dw_op_lit_x}, {DW_OP_lit30, "DW_OP_lit30", dw_op_lit_x}, {DW_OP_lit31, "DW_OP_lit31", dw_op_lit_x}, - // Register location descriptions. + // Register location descriptions. I.e. register containing the value // GP Registers {DW_OP_reg0, "DW_OP_reg0", dw_op_reg_x}, {DW_OP_reg1, "DW_OP_reg1", dw_op_reg_x}, @@ -948,7 +937,7 @@ dwarf_op_map dw_op[] = { {DW_OP_reg29, "DW_OP_reg29", dw_op_reg_x}, {DW_OP_reg30, "DW_OP_reg30", dw_op_reg_x}, {DW_OP_reg31, "DW_OP_reg31", dw_op_reg_x}, - // Register values. + // Register values. I.e. appropriate register value + offset of operation is pushed onto the stack // GP Registers {DW_OP_breg0, "DW_OP_breg0", dw_op_breg_x}, {DW_OP_breg1, "DW_OP_breg1", dw_op_breg_x}, @@ -984,12 +973,26 @@ dwarf_op_map dw_op[] = { {DW_OP_breg29, "DW_OP_breg29", dw_op_breg_x}, {DW_OP_breg30, "DW_OP_breg30", dw_op_breg_x}, {DW_OP_breg31, "DW_OP_breg31", dw_op_breg_x}, + // special register-related commands + {DW_OP_regx, "DW_OP_regx", dw_op_reg_x}, // 1st operand register name + {DW_OP_fbreg, "DW_OP_fbreg", dw_op_fbreg}, // base is Frame base register there + {DW_OP_bregx, "DW_OP_bregx", dw_op_breg_x}, // base is value of 1st operand's register + + // not implemented + {DW_OP_piece, "DW_OP_piece", dw_op_notimpl}, + {DW_OP_deref_size, "DW_OP_deref_size", dw_op_notimpl}, + {DW_OP_xderef_size, "DW_OP_xderef_size", dw_op_notimpl}, + {DW_OP_nop, "DW_OP_nop", dw_op_notimpl}, + {DW_OP_push_object_address, "DW_OP_push_object_address",dw_op_notimpl}, + {DW_OP_call2, "DW_OP_call2", dw_op_notimpl}, + {DW_OP_call4, "DW_OP_call4", dw_op_notimpl}, + {DW_OP_call_ref, "DW_OP_call_ref", dw_op_notimpl}, + {DW_OP_form_tls_address, "DW_OP_form_tls_address", dw_op_notimpl}, + {DW_OP_call_frame_cfa, "DW_OP_call_frame_cfa", dw_op_call_frame_cfa}, + {DW_OP_bit_piece, "DW_OP_bit_piece", dw_op_notimpl}, + {DW_OP_implicit_value, "DW_OP_implicit_value", dw_op_notimpl}, + {DW_OP_stack_value, "DW_OP_stack_value", dw_op_stack_value}, - {DW_OP_regx, "DW_OP_regx", dw_op_reg_x}, - {DW_OP_fbreg, "DW_OP_fbreg", dw_op_fbreg}, - {DW_OP_bregx, "DW_OP_bregx", dw_op_breg_x}, - {DW_OP_call_frame_cfa, "DW_OP_call_frame_cfa", dw_op_call_frame_cfa}, - {DW_OP_stack_value, "DW_OP_stack_value", dw_op_stack_value}, // This opcode has two operands, the first one is uleb128 length and the second is block of that length, containing either a // simple register or DWARF expression {DW_OP_GNU_entry_value, "DW_OP_GNU_entry_value", dw_op_notimpl}, diff --git a/framework/dwarf_operations.h b/framework/dwarf_operations.h index 2af6d63..af53a41 100644 --- a/framework/dwarf_operations.h +++ b/framework/dwarf_operations.h @@ -10,8 +10,6 @@ typedef bool (*dwarf_operation)(pst_context* ctx, const dwarf_op_map* map, Dwarf typedef struct __dwarf_op_map { int op_num; // DWARF Operation DW_OP_XXX -// int regno; // platform-dependent register number if present -// const char* regname; // register name if 'regno' specified const char* op_name; // string representation of an operation dwarf_operation operation; // function which handles operation } dwarf_op_map;