Improve ArchiveWriter diagnostics

[kongyi]

Summary

Print out the archive member that failed, to make debugging easier.

Before:

error: failed to build archive: Not an int attribute (Producer: 'LLVM15.0.1git' Reader: 'LLVM 14.0.5-rust-dev')

After:

error: failed to build archive: 'fake_bt_keystore.o': Not an int attribute (Producer: 'LLVM15.0.1git' Reader: 'LLVM 14.0.5-rust-dev')

[MaskRay]

error: failed to build archive: 'fake_bt_keystore.o': Not an int attribute (Producer: 'LLVM15.0.1git' Reader: 'LLVM 14.0.5-rust-dev')

No existing test uses this diagnostic. Do we need more coverage? Personally I think build archive: can be build archive (i.e. remove one colon).

llvm/test/Object/archive-malformed-object.test

13

Archive members are often described with xxx(yyy) syntax, i.e.

# ERR1: error: bad.a(input.bc): Invalid bitcode signature

[kongyi]

In D133607#3781588, @MaskRay wrote:

error: failed to build archive: 'fake_bt_keystore.o': Not an int attribute (Producer: 'LLVM15.0.1git' Reader: 'LLVM 14.0.5-rust-dev')

No existing test uses this diagnostic. Do we need more coverage? Personally I think build archive: can be build archive (i.e. remove one colon).

This diagnostic came from rustc.

[kongyi]

llvm/test/Object/archive-malformed-object.test

13

These are added at different points. Rustc uses the ArchiveWriter API, it only gets the member part. If we switch to your suggested syntax, the printout from Rustc would become

error: failed to build archive: ('fake_bt_keystore.o') Not an int attribute (Producer: 'LLVM15.0.1git' Reader: 'LLVM 14.0.5-rust-dev')

llvm/lib/Object/ArchiveWriter.cpp

if (isAIXBigArchive(Kind)) {
                         ModTime, Size);
     }
     Out.flush();
 
     std::vector<unsigned> Symbols;
     if (NeedSymbols) {
       Expected<std::vector<unsigned>> SymbolsOrErr =
           getSymbols(Buf, SymNames, HasObject);
-      if (auto E = SymbolsOrErr.takeError())
-        return std::move(E);
+      if (!SymbolsOrErr)
+        return createFileError(M.MemberName, SymbolsOrErr.takeError());
       Symbols = std::move(*SymbolsOrErr);
     }
 
     Pos += Header.size() + Data.size() + Padding.size();
     Ret.push_back({std::move(Symbols), std::move(Header), Data, Padding});
   }
   // If there are no symbols, emit an empty symbol table, to satisfy Solaris
   // tools, older versions of which expect a symbol table in a non-empty

llvm/test/Object/archive-malformed-object.test

 ## Show that the archive library emits error messages when adding malformed
 ## objects.
 
 # RUN: rm -rf %t.dir
 # RUN: split-file %s %t.dir
 # RUN: cd %t.dir
 
 ## Malformed bitcode object.
 # RUN: llvm-as input.ll -o input.bc
 # RUN: %python -c "with open('input.bc', 'a') as f: f.truncate(10)"
 # RUN: not llvm-ar rc bad.a input.bc 2>&1 | FileCheck %s --check-prefix=ERR1
 
-# ERR1: error: bad.a: Invalid bitcode signature
+# ERR1: error: bad.a: 'input.bc': Invalid bitcode signature
 
 ## Non-bitcode malformed file.
 # RUN: yaml2obj input.yaml -o input.o
 # RUN: not llvm-ar rc bad.a input.o 2>&1 | FileCheck %s --check-prefix=ERR2
 
-# ERR2: error: bad.a: section header table goes past the end of the file: e_shoff = 0x9999
+# ERR2: error: bad.a: 'input.o': section header table goes past the end of the file: e_shoff = 0x9999
 
 ## Don't emit an error if the symbol table is not required.
 # RUN: llvm-ar rcS good.a input.o input.bc
 # RUN: llvm-ar t good.a | FileCheck %s --check-prefix=CONTENTS
 
 # CONTENTS:      input.o
 # CONTENTS-NEXT: input.bc