Implemented "address selection entry" for DWARF 4 range lists.
This fixes a bug previously seen where Bloaty would die with
something like this when using "-d compileunits":
bloaty: Overflow in vm range, vmaddr=18446744073709551615, vmsize=4129
This especially occurred in Go binaries, as they appear to use this
DWARF feature by default, whereas other compiler toolchains usually
do not.
diff --git a/src/dwarf.cc b/src/dwarf.cc
index b1d0bec..3fc8446 100644
--- a/src/dwarf.cc
+++ b/src/dwarf.cc
@@ -184,6 +184,16 @@
}
}
+ uint64_t GetMaxAddress() const {
+ if (address_size_ == 8) {
+ return UINT64_MAX;
+ } else if (address_size_ == 4) {
+ return UINT32_MAX;
+ } else {
+ BLOATY_UNREACHABLE();
+ }
+ }
+
// Reads an "initial length" as specified in many DWARF headers. This
// contains either a 32-bit or a 64-bit length, and signals whether we are
// using the 32-bit or 64-bit DWARF format (so it sets dwarf64 appropriately).
@@ -1081,16 +1091,20 @@
void ReadRangeList(const DIEReader& die_reader, uint64_t low_pc,
string_view name, RangeSink* sink, string_view* data) {
std::string name_str(name);
+ uint64_t max_address = die_reader.unit_sizes().GetMaxAddress();
while (true) {
uint64_t start, end;
start = die_reader.unit_sizes().ReadAddress(data);
end = die_reader.unit_sizes().ReadAddress(data);
if (start == 0 && end == 0) {
return;
+ } else if (start == max_address) {
+ low_pc = end;
+ } else {
+ uint64_t size = end - start;
+ sink->AddVMRangeIgnoreDuplicate("dwarf_rangelist", low_pc + start, size,
+ name_str);
}
- uint64_t size = end - start;
- sink->AddVMRangeIgnoreDuplicate("dwarf_rangelist", low_pc + start, size,
- name_str);
}
}
