std.debug.SelfInfo: thread safety

This has been a TODO for ages, but in the past it didn't really matter
because stack traces are typically printed to stderr for which a mutex
is held so in practice there was a mutex guarding usage of `SelfInfo`.

However, now that `SelfInfo` is also used for simply capturing traces,
thread safety is needed. Instead of just a single mutex, though, there
are a couple of different mutexes involved; this helps make critical
sections smaller, particularly when unwinding the stack as `unwindFrame`
doesn't typically need to hold any lock at all.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/std/debug/Dwarf.zig b/lib/std/debug/Dwarf.zig
index 655a65b709..3934777ea5 100644
--- a/lib/std/debug/Dwarf.zig
+++ b/lib/std/debug/Dwarf.zig
@@ -346,7 +346,7 @@ pub fn deinit(di: *Dwarf, gpa: Allocator) void {
     di.* = undefined;
 }
 
-pub fn getSymbolName(di: *Dwarf, address: u64) ?[]const u8 {
+pub fn getSymbolName(di: *const Dwarf, address: u64) ?[]const u8 {
     // Iterate the function list backwards so that we see child DIEs before their parents. This is
     // important because `DW_TAG_inlined_subroutine` DIEs will have a range which is a sub-range of
     // their caller, and we want to return the callee's name, not the caller's.