[lld] [llvm] [LLD][COFF] Make unresolved symbol search behavior compliant with MSVC link.exe (PR #85290)

[Jacek Caban via llvm-commits]

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@@ -93,10 +94,40 @@ static bool ignoredSymbolName(StringRef name) {
   return name == "@feat.00" || name == "@comp.id";
 }
 
+static bool compatibleMachineType(COFFLinkerContext &ctx, MachineTypes mt) {
+  if (mt == IMAGE_FILE_MACHINE_UNKNOWN)
+    return true;
+  switch (ctx.config.machine) {
+  case ARM64:
+    return mt == ARM64 || mt == ARM64X;
+  case ARM64EC:
+    return COFF::isArm64EC(mt) || mt == AMD64;
+  case ARM64X:
+    return COFF::isAnyArm64(mt) || mt == AMD64;
+  default:
+    return ctx.config.machine == mt;
+  }
+}
+
+static void setMachine(InputFile *file, COFFLinkerContext &ctx) {
+  MachineTypes mt = file->getMachineType();
+  if (ctx.config.machine == IMAGE_FILE_MACHINE_UNKNOWN) {
+    ctx.config.machine = mt;
+    ctx.driver.addWinSysRootLibSearchPaths();
+  } else if (!compatibleMachineType(ctx, mt)) {
+    error(toString(file) + ": machine type " + machineToStr(mt) +
+          " conflicts with " + machineToStr(ctx.config.machine));
+    return;
+  }
+}
+
 ArchiveFile::ArchiveFile(COFFLinkerContext &ctx, MemoryBufferRef m)
-    : InputFile(ctx, ArchiveKind, m) {}
+    : InputFile(ctx, ArchiveKind, m, /*lazy=*/true) {
+  static unsigned Order = 0;
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cjacek wrote:

It could be a member of `COFFLinkerContext`.

https://github.com/llvm/llvm-project/pull/85290