[ELF] Print archive name when it fails to parse

[grimar]

ELF/Driver.cpp

119

This looks was not covered by testcase, just like 2 messages above btw,
also it has uppercase message while we usually do use lowercase always I believe.

[evgeny777]

ELF/Driver.cpp

119

Yep, but it wasn't covered originally as well and you have to use binary file to cover this.

[grimar]

ELF/Driver.cpp

119

I see now. I think anyways we want to cover that. (I am ok to take this task). Anyways I think we are in position where *all* errors should ideally be covered with testcases. LLD is pretty solid now and we might want to think about user frienly messages and so on.
Any objections ?

[evgeny777]

ELF/Driver.cpp

119

Any objections ?

I don't have any.

[ruiu]

LGTM

test/ELF/bad-archive.s

6–7

You can combine these two echos.

ELF/Driver.cpp

static std::tuple<ELFKind, uint16_t, uint8_t> parseEmulation(StringRef Emul) {
   return std::make_tuple(Ret.first, Ret.second, OSABI);
 }
 
 // Returns slices of MB by parsing MB as an archive file.
 // Each slice consists of a member file in the archive.
 std::vector<MemoryBufferRef>
 LinkerDriver::getArchiveMembers(MemoryBufferRef MB) {
   std::unique_ptr<Archive> File =
-      check(Archive::create(MB), "failed to parse archive");
+      check(Archive::create(MB),
+            MB.getBufferIdentifier() + ": failed to parse archive");
 
   std::vector<MemoryBufferRef> V;
   Error Err = Error::success();
   for (const ErrorOr<Archive::Child> &COrErr : File->children(Err)) {
-    Archive::Child C = check(COrErr, "could not get the child of the archive " +
-                                         File->getFileName());
+    Archive::Child C =
+        check(COrErr, MB.getBufferIdentifier() +
+                          ": could not get the child of the archive");
     MemoryBufferRef MBRef =
         check(C.getMemoryBufferRef(),
-              "could not get the buffer for a child of the archive " +
-                  File->getFileName());
+              MB.getBufferIdentifier() +
+                  ": could not get the buffer for a child of the archive");
     V.push_back(MBRef);
   }
   if (Err)
-    fatal("Archive::children failed: " + toString(std::move(Err)));
+    fatal(MB.getBufferIdentifier() + ": Archive::children failed: " +
+          toString(std::move(Err)));
 
   // Take ownership of memory buffers created for members of thin archives.
   for (std::unique_ptr<MemoryBuffer> &MB : File->takeThinBuffers())
     OwningMBs.push_back(std::move(MB));
 
   return V;
 }
 

ELF/InputFiles.cpp

if (Sec == &InputSection<ELFT>::Discarded)
                                                 /*CanOmitFromDynSym*/ false,
                                                 this)
           ->body();
     return elf::Symtab<ELFT>::X->addRegular(Name, *Sym, Sec, this)->body();
   }
 }
 
 template <class ELFT> void ArchiveFile::parse() {
-  File = check(Archive::create(MB), "failed to parse archive");
+  File = check(Archive::create(MB),
+               MB.getBufferIdentifier() + ": failed to parse archive");
 
   // Read the symbol table to construct Lazy objects.
   for (const Archive::Symbol &Sym : File->symbols())
     Symtab<ELFT>::X->addLazyArchive(this, Sym);
 }
 
 // Returns a buffer pointing to a member file containing a given symbol.
 std::pair<MemoryBufferRef, uint64_t>

test/ELF/bad-archive.s

+// REQUIRES: x86
+
+// Check bad archive error reporting with --whole-archive
+// and without it.
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
+// RUN: echo "!<arch>" > %t.bad.a
+// RUN: echo "bad archive" >> %t.bad.a
+// RUN: not ld.lld %t.o %t.bad.a -o %t 2>&1 | FileCheck %s
+// RUN: not ld.lld %t.o --whole-archive %t.bad.a -o %t 2>&1 | FileCheck %s
+// CHECK: {{.*}}.bad.a: failed to parse archive
+
+.globl _start
+_start: