[LLD][COFF] Add -build-id flag to generate .buildid section. (#71433)
[RFC](https://discourse.llvm.org/t/rfc-add-build-id-flag-to-lld-link/74661)
Before, lld-link only generate the debug directory containing guid when
generating PDB with the hash of PDB content.
With this change, lld-link can generate the debug directory when only
`/build-id` is given:
1. If generating PDB, `/build-id` is ignored. Same behaviour as before.
2. Not generating PDB, using hash of the binary.
- Not under MinGW, the debug directory is still in `.rdata` section.
- Under MinGW, place the debug directory into new `.buildid` section.
diff --git a/lld/COFF/Options.td b/lld/COFF/Options.td
index abee660..4dab4a2 100644
--- a/lld/COFF/Options.td
+++ b/lld/COFF/Options.td
@@ -302,6 +302,11 @@
def time_trace_granularity_eq: Joined<["--"], "time-trace-granularity=">,
HelpText<"Minimum time granularity (in microseconds) traced by time profiler">;
+defm build_id: B<
+ "build-id",
+ "Generate build ID (always on when generating PDB)",
+ "Do not Generate build ID">;
+
// Flags for debugging
def lldmap : F<"lldmap">;
def lldmap_file : P_priv<"lldmap">;
