[lld] [LLD] [COFF] Print a warning when using /dependentloadflag without load config (PR #117400)

[Mateusz Mikuła via llvm-commits]

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@@ -2307,8 +2307,11 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
 
   // Handle /dependentloadflag
   for (auto *arg :
-       args.filtered(OPT_dependentloadflag, OPT_dependentloadflag_opt))
+       args.filtered(OPT_dependentloadflag, OPT_dependentloadflag_opt)) {
     parseDependentLoadFlags(arg);
+    if (!ctx.symtab.findUnderscore("_load_config_used"))
+      warn("_load_config_used not found, /delayloadflag will have no effect");
+  }
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mati865 wrote:

I had started there, but judging by other uses of `ctx.symtab` I figured the driver might be the right place to put it.

https://github.com/llvm/llvm-project/pull/117400