-/* Copyright (c) 2014-2019. The SimGrid Team. All rights reserved. */
-
-/* This program is free software; you can redistribute it and/or modify it
- * under the terms of the license (GNU LGPL) which comes with this package. */
-
-#include <cstddef>
-#include <cstdint>
-
-#include "src/mc/AddressSpace.hpp"
-#include "src/mc/DwarfExpression.hpp"
-#include "src/mc/Frame.hpp"
-#include "src/mc/LocationList.hpp"
-#include "src/mc/ObjectInformation.hpp"
-#include "src/mc/mc_dwarf.hpp"
-#include "src/mc/mc_private.hpp"
-
-using simgrid::mc::remote;
-
-namespace simgrid {
-namespace dwarf {
-
-void execute(
- const Dwarf_Op* ops, std::size_t n,
- const ExpressionContext& context, ExpressionStack& stack)
-{
- for (size_t i = 0; i != n; ++i) {
- const Dwarf_Op *op = ops + i;
- std::uint8_t atom = op->atom;
- intptr_t first;
- intptr_t second;
-
- switch (atom) {
-
- // Registers:
-
- case DW_OP_breg0:
- case DW_OP_breg1:
- case DW_OP_breg2:
- case DW_OP_breg3:
- case DW_OP_breg4:
- case DW_OP_breg5:
- case DW_OP_breg6:
- case DW_OP_breg7:
- case DW_OP_breg8:
- case DW_OP_breg9:
- case DW_OP_breg10:
- case DW_OP_breg11:
- case DW_OP_breg12:
- case DW_OP_breg13:
- case DW_OP_breg14:
- case DW_OP_breg15:
- case DW_OP_breg16:
- case DW_OP_breg17:
- case DW_OP_breg18:
- case DW_OP_breg19:
- case DW_OP_breg20:
- case DW_OP_breg21:
- case DW_OP_breg22:
- case DW_OP_breg23:
- case DW_OP_breg24:
- case DW_OP_breg25:
- case DW_OP_breg26:
- case DW_OP_breg27:
- case DW_OP_breg28:
- case DW_OP_breg29:
- case DW_OP_breg30:
- case DW_OP_breg31:{
- // Push register + constant:
- int register_id = simgrid::dwarf::dwarf_register_to_libunwind(
- op->atom - DW_OP_breg0);
- unw_word_t res;
- if (not context.cursor)
- throw evaluation_error("Missing stack context");
- unw_get_reg(context.cursor, register_id, &res);
- stack.push(res + op->number);
- break;
- }
-
- // Push the CFA (Canonical Frame Address):
- case DW_OP_call_frame_cfa:
- {
- /* See 6.4 of DWARF4 (http://dwarfstd.org/doc/DWARF4.pdf#page=140):
- *
- * > Typically, the CFA is defined to be the value of the stack
- * > pointer at the call site in the previous frame (which may be
- * > different from its value on entry to the current frame).
- *
- * We need to unwind the frame in order to get the SP of the parent
- * frame.
- *
- * Warning: the CFA returned by libunwind (UNW_X86_64_RSP, etc.)
- * is the SP of the *current* frame. */
-
- if (not context.cursor)
- throw evaluation_error("Missint cursor");
-
- // Get frame:
- unw_cursor_t cursor = *(context.cursor);
- unw_step(&cursor);
-
- unw_word_t res;
- unw_get_reg(&cursor, UNW_REG_SP, &res);
- stack.push(res);
- break;
- }
-
- // Frame base:
-
- case DW_OP_fbreg:
- stack.push((std::uintptr_t) context.frame_base + op->number);
- break;
-
- // ***** Constants:
-
- // Short constant literals:
- case DW_OP_lit0:
- case DW_OP_lit1:
- case DW_OP_lit2:
- case DW_OP_lit3:
- case DW_OP_lit4:
- case DW_OP_lit5:
- case DW_OP_lit6:
- case DW_OP_lit7:
- case DW_OP_lit8:
- case DW_OP_lit9:
- case DW_OP_lit10:
- case DW_OP_lit11:
- case DW_OP_lit12:
- case DW_OP_lit13:
- case DW_OP_lit14:
- case DW_OP_lit15:
- case DW_OP_lit16:
- case DW_OP_lit17:
- case DW_OP_lit18:
- case DW_OP_lit19:
- case DW_OP_lit20:
- case DW_OP_lit21:
- case DW_OP_lit22:
- case DW_OP_lit23:
- case DW_OP_lit24:
- case DW_OP_lit25:
- case DW_OP_lit26:
- case DW_OP_lit27:
- case DW_OP_lit28:
- case DW_OP_lit29:
- case DW_OP_lit30:
- case DW_OP_lit31:
- // Push a literal/constant on the stack:
- stack.push(atom - DW_OP_lit0);
- break;
-
- // Address from the base address of this ELF object.
- // Push the address on the stack (base_address + argument).
- case DW_OP_addr: {
- if (not context.object_info)
- throw evaluation_error("No base address");
- Dwarf_Off addr = (Dwarf_Off) (std::uintptr_t)
- context.object_info->base_address() + op->number;
- stack.push(addr);
- break;
- }
-
- // General constants:
- // Push the constant argument on the stack.
- case DW_OP_const1u:
- case DW_OP_const2u:
- case DW_OP_const4u:
- case DW_OP_const8u:
- case DW_OP_const1s:
- case DW_OP_const2s:
- case DW_OP_const4s:
- case DW_OP_const8s:
- case DW_OP_constu:
- case DW_OP_consts:
- stack.push(op->number);
- break;
-
- // ***** Stack manipulation:
-
- // Push another copy/duplicate the value at the top of the stack:
- case DW_OP_dup:
- stack.dup();
- break;
-
- // Pop/drop the top of the stack:
- case DW_OP_drop:
- stack.pop();
- break;
-
- case DW_OP_swap:
- stack.swap();
- break;
-
- // Duplicate the value under the top of the stack:
- case DW_OP_over:
- stack.push(stack.top(1));
- break;
-
- // ***** Operations:
- // Those usually take the top of the stack and the next value as argument
- // and replace the top of the stack with the computed value
- // (stack.top() += stack.before_top()).
-
- case DW_OP_plus:
- first = stack.pop();
- second = stack.pop();
- stack.push(first + second);
- break;
-
- case DW_OP_mul:
- first = stack.pop();
- second = stack.pop();
- stack.push(first * second);
- break;
-
- case DW_OP_plus_uconst:
- stack.top() += op->number;
- break;
-
- case DW_OP_not:
- stack.top() = ~stack.top();
- break;
-
- case DW_OP_neg:
- stack.top() = - (intptr_t) stack.top();
- break;
-
- case DW_OP_minus:
- first = stack.pop();
- second = stack.pop();
- stack.push(second - first);
- break;
-
- case DW_OP_and:
- first = stack.pop();
- second = stack.pop();
- stack.push(first & second);
- break;
-
- case DW_OP_or:
- first = stack.pop();
- second = stack.pop();
- stack.push(first | second);
- break;
-
- case DW_OP_xor:
- first = stack.pop();
- second = stack.pop();
- stack.push(first ^ second);
- break;
-
- case DW_OP_nop:
- break;
-
- // ***** Deference (memory fetch)
-
- case DW_OP_deref_size:
- throw evaluation_error("Unsupported operation");
-
- case DW_OP_deref:
- // Computed address:
- if (not context.address_space)
- throw evaluation_error("Missing address space");
- context.address_space->read_bytes(
- &stack.top(), sizeof(uintptr_t), remote(stack.top()),
- context.process_index);
- break;
-
- // Not handled:
- default:
- throw evaluation_error("Unsupported operation");
- }
-
- }
-}
-
-}
-}
