[PATCH] D157300: [lld-macho]Rework error-checking in peeking at first-member in archive to avoid segfault.

[Vy Nguyen via Phabricator via llvm-commits]

oontvoo added inline comments.


================
Comment at: lld/MachO/InputFiles.cpp:2113
   // Ignore the I/O error here - will be reported later.
-  if (!mbOrErr) {
-    llvm::consumeError(mbOrErr.takeError());
-  } else if (!err) {
-    if (identify_magic(mbOrErr->getBuffer()) == file_magic::macho_object) {
-      if (target->wordSize == 8)
-        compatArch = compatWithTargetArch(
-            this, reinterpret_cast<const LP64::mach_header *>(
-                      mbOrErr->getBufferStart()));
-      else
-        compatArch = compatWithTargetArch(
-            this, reinterpret_cast<const ILP32::mach_header *>(
-                      mbOrErr->getBufferStart()));
-
-      if (!compatArch)
-        return;
+  // Also avoid calling getMemoryBUfferRef() on zero-symbol archive
+  // since that crashes.
----------------
smeenai wrote:
> Typo: BUffer -> Buffer
> 
> I think this would be cleaner as an early return, instead of nesting everything else inside it, since zero symbols should mean the loop below is a no-op as well.
Thanks! 
Fixed typo and moved the numberOfSymbols check to beginning.
(Still need the nested if,unfortunately, because we dont want to access the `child` if there was error )


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D157300/new/

https://reviews.llvm.org/D157300