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initial implementation of DWARF Expression state machine parsing and

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it's usage for retrieve arguments/variables of function
This commit is contained in:
nnosov
2020-01-13 17:21:46 +04:00
parent 08ba87ce98
commit 50bebda6a1
5 changed files with 719 additions and 335 deletions
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framework/sysutils.cpp
+17 -31
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@@ -111,29 +111,6 @@ void print_framereg(int regno)
}
*/
bool __pst_handler::calc_expression(Dwarf_Op *exprs, int expr_len, dwarf_stack* stack, Dwarf_Attribute* attr)
{
for (int i = 0; i < expr_len; i++) {
const dwarf_op_map* map = find_op_map(exprs[i].atom);
if(!map) {
ctx.log(SEVERITY_ERROR, "Unknown operation type 0x%hhX(0x%lX, 0x%lX)", exprs[i].atom, exprs[i].number, exprs[i].number2);
return false;
}
if(map->op_num == DW_OP_stack_value && stack->Size() > 0) {
return true;
}
if(!map->operation(&ctx, map, exprs[i].number, exprs[i].number2)) {
ctx.log(SEVERITY_ERROR, "Failed to calculate %s(0x%lX, 0x%lX) operation", map->op_name, exprs[i].number, exprs[i].number2);
return false;
}
}
return true;
}
bool __pst_parameter::handle_type(Dwarf_Attribute* param, bool is_return)
{
Dwarf_Attribute attr_mem;
@@ -221,6 +198,10 @@ bool __pst_parameter::handle_dwarf(Dwarf_Die* result)
handle_type(attr);
}
Dwarf_Addr pc;
unw_get_reg(&ctx->cursor, UNW_REG_IP, &pc);
Dwarf_Addr offset = pc - ctx->base_addr;
// determine location of parameter in stack/heap or CPU registers
attr = dwarf_attr(result, DW_AT_location, &attr_mem);
if(attr) {
@@ -230,10 +211,8 @@ bool __pst_parameter::handle_dwarf(Dwarf_Die* result)
if (dwarf_getlocation(attr, &expr, &exprlen) == 0) {
char str[1024]; str[0] = 0;
ctx->print_expr_block (expr, exprlen, str, sizeof(str), attr);
ctx->log(SEVERITY_DEBUG, "Found DW_AT_location expression: %s", str);
// if(expr[0].atom >= DW_OP_reg0 && expr[0].atom <= DW_OP_bregx) {
// print_framereg(expr[0].atom);
// }
ctx->log(SEVERITY_DEBUG, "DW_AT_location expression: %s", str);
ctx->calc_expression(expr, exprlen, attr);
}
} else if(dwarf_hasform(attr, DW_FORM_sec_offset)) {
Dwarf_Addr base, start, end;
@@ -241,10 +220,17 @@ bool __pst_parameter::handle_dwarf(Dwarf_Die* result)
Dwarf_Op *expr;
size_t exprlen;
// handle list of possible locations of parameter
for(int i = 0; (off = dwarf_getlocations (attr, off, &base, &start, &end, &expr, &exprlen)) > 0; ++i) {
char str[1024]; str[0] = 0;
ctx->print_expr_block (expr, exprlen, str, sizeof(str), attr);
ctx->log(SEVERITY_DEBUG, "[%d] low_offset: 0x%" PRIx64 ", high_offset: 0x%" PRIx64 " ==> %s", i, start, end, str);
if(offset >= start && offset <= end) {
// actual location, try to calculate Location expression and retrieve value of parameter
char str[1024]; str[0] = 0;
ctx->print_expr_block (expr, exprlen, str, sizeof(str), attr);
ctx->log(SEVERITY_DEBUG, "Location list expression: [%d] low_offset: 0x%" PRIx64 ", high_offset: 0x%" PRIx64 " ==> %s", i, start, end, str);
ctx->calc_expression(expr, exprlen, attr);
} else {
// Location skipped due to don't match current PC offset
}
}
} else {
@@ -561,7 +547,7 @@ bool __pst_handler::unwind()
ctx.print("[%-2d] ", idx);
#endif
module = dwfl_addrmodule(dwfl, addr);
get_frame();
//get_frame();
pst_function fun(&ctx);
if(fun.unwind(dwfl, module, pc)) {
if(get_dwarf_function(fun)) {