/* 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 <cstdarg>
#include <dwarf.h>
#include <elfutils/libdw.h>
-#include "mc_object_info.h"
-#include "mc_private.h"
-#include "mc_location.h"
-#include "mc/AddressSpace.hpp"
-#include "mc/Frame.hpp"
-#include "mc/ObjectInformation.hpp"
-#include "mc/DwarfExpression.hpp"
+#include "src/mc/mc_private.h"
+#include "src/mc/LocationList.hpp"
+#include "src/mc/AddressSpace.hpp"
+#include "src/mc/Frame.hpp"
+#include "src/mc/ObjectInformation.hpp"
+#include "src/mc/DwarfExpression.hpp"
+#include "src/mc/mc_dwarf.hpp"
using simgrid::mc::remote;
namespace simgrid {
namespace dwarf {
-evaluation_error::~evaluation_error() {}
-
-}
-}
-
-extern "C" {
-
-/** Convert a DWARF register into a libunwind register
- *
- * DWARF and libunwind does not use the same convention for numbering the
- * registers on some architectures. The function makes the necessary
- * convertion.
- */
-static int mc_dwarf_register_to_libunwind(int dwarf_register)
-{
-#if defined(__x86_64__)
- // It seems for this arch, DWARF and libunwind agree in the numbering:
- return dwarf_register;
-#elif defined(__i386__)
- // Could't find the authoritative source of information for this.
- // This is inspired from http://source.winehq.org/source/dlls/dbghelp/cpu_i386.c#L517.
- switch (dwarf_register) {
- case 0:
- return UNW_X86_EAX;
- case 1:
- return UNW_X86_ECX;
- case 2:
- return UNW_X86_EDX;
- case 3:
- return UNW_X86_EBX;
- case 4:
- return UNW_X86_ESP;
- case 5:
- return UNW_X86_EBP;
- case 6:
- return UNW_X86_ESI;
- case 7:
- return UNW_X86_EDI;
- case 8:
- return UNW_X86_EIP;
- case 9:
- return UNW_X86_EFLAGS;
- case 10:
- return UNW_X86_CS;
- case 11:
- return UNW_X86_SS;
- case 12:
- return UNW_X86_DS;
- case 13:
- return UNW_X86_ES;
- case 14:
- return UNW_X86_FS;
- case 15:
- return UNW_X86_GS;
- case 16:
- return UNW_X86_ST0;
- case 17:
- return UNW_X86_ST1;
- case 18:
- return UNW_X86_ST2;
- case 19:
- return UNW_X86_ST3;
- case 20:
- return UNW_X86_ST4;
- case 21:
- return UNW_X86_ST5;
- case 22:
- return UNW_X86_ST6;
- case 23:
- return UNW_X86_ST7;
- default:
- xbt_die("Bad/unknown register number.");
- }
-#else
-#error This architecture is not supported yet for DWARF expression evaluation.
-#endif
-}
-
-}
-
-namespace simgrid {
-namespace dwarf {
+evaluation_error::~evaluation_error() noexcept(true) {}
void execute(
const Dwarf_Op* ops, std::size_t n,
case DW_OP_breg29:
case DW_OP_breg30:
case DW_OP_breg31:{
- int register_id =
- mc_dwarf_register_to_libunwind(op->atom - DW_OP_breg0);
+ // Push register + constant:
+ int register_id = simgrid::dwarf::dwarf_register_to_libunwind(
+ op->atom - DW_OP_breg0);
unw_word_t res;
if (!context.cursor)
- throw evaluation_error("Missin stack context");
+ 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 Addresse):
+ // Push the CFA (Canonical Frame Address):
case DW_OP_call_frame_cfa:
{
- // UNW_X86_64_CFA does not return the CFA DWARF expects
- // (it is a synonym for UNW_X86_64_RSP) so copy the cursor,
- // unwind it once in order to find the parent SP:
+ /* 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 (!context.cursor)
throw evaluation_error("Missint cursor");
// ***** Constants:
// Short constant literals:
- // DW_OP_lit15 pushed the 15 on the stack.
case DW_OP_lit0:
case DW_OP_lit1:
case DW_OP_lit2:
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;
stack.pop();
break;
- // Swap the two top-most value of the stack:
case DW_OP_swap:
- std::swap(stack.top(), stack.top(1));
+ stack.swap();
break;
// Duplicate the value under the top of the stack:
// and replace the top of the stack with the computed value
// (stack.top() += stack.before_top()).
- case DW_OP_plus:
- stack.push(stack.pop() + stack.pop());
+ case DW_OP_plus: {
+ intptr_t first = stack.pop();
+ intptr_t second = stack.pop();
+ stack.push(first + second);
break;
+ }
- case DW_OP_mul:
- stack.push(stack.pop() * stack.pop());
+ case DW_OP_mul: {
+ intptr_t first = stack.pop();
+ intptr_t second = stack.pop();
+ stack.push(first * second);
break;
+ }
case DW_OP_plus_uconst:
stack.top() += op->number;
stack.top() = - (intptr_t) stack.top();
break;
- case DW_OP_minus:
- stack.push(stack.pop() - stack.pop());
+ case DW_OP_minus: {
+ intptr_t first = stack.pop();
+ intptr_t second = stack.pop();
+ stack.push(second - first);
break;
+ }
- case DW_OP_and:
- stack.push(stack.pop() & stack.pop());
+ case DW_OP_and: {
+ intptr_t first = stack.pop();
+ intptr_t second = stack.pop();
+ stack.push(first & second);
break;
+ }
- case DW_OP_or:
- stack.push(stack.pop() | stack.pop());
+ case DW_OP_or: {
+ intptr_t first = stack.pop();
+ intptr_t second = stack.pop();
+ stack.push(first | second);
break;
+ }
- case DW_OP_xor:
- stack.push(stack.pop() ^ stack.pop());
+ case DW_OP_xor: {
+ intptr_t first = stack.pop();
+ intptr_t second = stack.pop();
+ stack.push(first ^ second);
break;
+ }
case DW_OP_nop:
break;
}
}
-// ***** Location
-
-/** \brief Resolve a location expression
- * \deprecated Use mc_dwarf_resolve_expression
- */
-void resolve_location(mc_location_t location,
- simgrid::dwarf::DwarfExpression const& expression,
- simgrid::mc::ObjectInformation* object_info,
- unw_cursor_t * c,
- void *frame_pointer_address,
- simgrid::mc::AddressSpace* address_space, int process_index)
-{
- simgrid::dwarf::ExpressionContext context;
- context.frame_base = frame_pointer_address;
- context.cursor = c;
- context.address_space = address_space;
- context.object_info = object_info;
- context.process_index = process_index;
-
- if (!expression.empty()
- && expression[0].atom >= DW_OP_reg0
- && expression[0].atom <= DW_OP_reg31) {
- int dwarf_register = expression[0].atom - DW_OP_reg0;
- xbt_assert(c,
- "Missing frame context for register operation DW_OP_reg%i",
- dwarf_register);
- location->memory_location = NULL;
- location->cursor = c;
- location->register_id = mc_dwarf_register_to_libunwind(dwarf_register);
- return;
- }
-
- simgrid::dwarf::ExpressionStack stack;
- simgrid::dwarf::execute(expression, context, stack);
-
- location->memory_location = (void*) stack.top();
- location->cursor = NULL;
- location->register_id = 0;
-}
-
}
}
-
-// TODO, move this in a method of LocationList
-static simgrid::dwarf::DwarfExpression* mc_find_expression(
- simgrid::mc::LocationList* locations, unw_word_t ip)
-{
- for (simgrid::mc::LocationListEntry& entry : *locations)
- if (entry.valid_for_ip(ip))
- return &entry.expression;
- return nullptr;
-}
-
-extern "C" {
-
-void mc_dwarf_resolve_locations(mc_location_t location,
- simgrid::mc::LocationList* locations,
- simgrid::mc::ObjectInformation* object_info,
- unw_cursor_t * c,
- void *frame_pointer_address,
- simgrid::mc::AddressSpace* address_space,
- int process_index)
-{
-
- unw_word_t ip = 0;
- if (c) {
- if (unw_get_reg(c, UNW_REG_IP, &ip))
- xbt_die("Could not resolve IP");
- }
-
- simgrid::dwarf::DwarfExpression* expression =
- mc_find_expression(locations, ip);
- if (expression) {
- simgrid::dwarf::resolve_location(location,
- *expression, object_info, c,
- frame_pointer_address, address_space, process_index);
- } else {
- xbt_die("Could not resolve location");
- }
-}
-
-/** \brief Find the frame base of a given frame
- *
- * \param frame
- * \param unw_cursor
- */
-void *mc_find_frame_base(simgrid::mc::Frame* frame, simgrid::mc::ObjectInformation* object_info,
- unw_cursor_t * unw_cursor)
-{
- s_mc_location_t location;
- mc_dwarf_resolve_locations(&location,
- &frame->frame_base, object_info,
- unw_cursor, NULL, NULL, -1);
- switch(mc_get_location_type(&location)) {
- case MC_LOCATION_TYPE_ADDRESS:
- return location.memory_location;
-
- case MC_LOCATION_TYPE_REGISTER: {
- // This is a special case.
- // The register if not the location of the frame base
- // (a frame base cannot be located in a register)
- // Instead, DWARF defines this to mean that the register
- // contains the address of the frame base.
- unw_word_t word;
- unw_get_reg(location.cursor, location.register_id, &word);
- return (void*) word;
- }
-
- default:
- xbt_die("Cannot handle non-address frame base");
- return NULL; // Unreachable
- }
-}
-
-void mc_dwarf_location_list_init(
- simgrid::mc::LocationList* list, simgrid::mc::ObjectInformation* info,
- Dwarf_Die * die, Dwarf_Attribute * attr)
-{
- list->clear();
-
- std::ptrdiff_t offset = 0;
- Dwarf_Addr base, start, end;
- Dwarf_Op *ops;
- std::size_t len;
-
- while (1) {
-
- offset = dwarf_getlocations(attr, offset, &base, &start, &end, &ops, &len);
- if (offset == 0)
- return;
- else if (offset == -1)
- xbt_die("Error while loading location list");
-
- simgrid::mc::LocationListEntry entry;
- entry.expression = simgrid::dwarf::DwarfExpression(ops, ops + len);
-
- void *base = info->base_address();
- // If start == 0, this is not a location list:
- entry.lowpc = start == 0 ? NULL : (char *) base + start;
- entry.highpc = start == 0 ? NULL : (char *) base + end;
-
- list->push_back(std::move(entry));
- }
-
-}
-
-}