[lld] [ELF] Print a better error for an archive containing a non-ELF file.

[efriedma]

Summary

Hopefully gives a more readable error message for the most obvious mistake.

[grimar]

I am not fond of adding the precompiled binaries to inputs.
Is it possible to use echo to create such an archive?
Or maybe you could use llvm-ar + empty file maybe (or something like that)?

[ruiu]

test/ELF/invalid/invalid-elf.test

4 ↗

(On Diff #189971)

As George pointed out, I think it is better to avoid checking in an .ar file, even though the file does not contain any non-ASCII byte as it is header-only file. You could easily avoid it by creating a new archive file using llvm-ar.

[ruiu]

ELF/InputFiles.cpp

1197 ↗

(On Diff #189971)

Maybe "not an ELF file" is a better error message as it is more consistent with other error messages below?

[efriedma]

Rebased. Changed error message. Changed test to build archive with llvm-ar.

[ruiu]

ELF/InputFiles.cpp

1198 ↗

(On Diff #190192)

Perhaps this is a bit too complicated for this tiny utility function? I'd add "corrupted ELF file: " to the beginning of each existing error message instead.

[efriedma]

Addressed review comment.

[ruiu]

LGTM

[phosek]

This seems to be failing on our Mac bots for some reason:

-- Testing: 2004 tests, 24 threads --
Testing: 0 .. 10.. 20.. 30.. 40
FAIL: lld :: ELF/invalid/invalid-elf.test (852 of 2004)
******************** TEST 'lld :: ELF/invalid/invalid-elf.test' FAILED ********************
Script:
--
: 'RUN: at line 2';   rm -rf /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp && mkdir -p /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp
: 'RUN: at line 3';   /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/llvm-mc /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/invalid-elf.test -o /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp/simple.o -filetype=obj -triple x86_64-pc-linux
: 'RUN: at line 4';   echo > /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp/empty.o
: 'RUN: at line 5';   llvm-ar cr /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp/not-elf.a /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp/empty.o
: 'RUN: at line 7';   not /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/ld.lld /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp/simple.o /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp/not-elf.a -o /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp2 2>&1 |    /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/FileCheck --check-prefix=NOT-ELF /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/invalid-elf.test
: 'RUN: at line 11';   not /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/ld.lld /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp/simple.o /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/Inputs/data-encoding.a -o /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp2 2>&1 |    /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/FileCheck --check-prefix=INVALID-DATA-ENC /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/invalid-elf.test
: 'RUN: at line 15';   not /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/ld.lld /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp/simple.o /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/Inputs/file-class.a -o /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp2 2>&1 |    /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/FileCheck --check-prefix=INVALID-FILE-CLASS /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/invalid-elf.test
: 'RUN: at line 19';   not /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/ld.lld /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/Inputs/binding.elf -o /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp2 2>&1 |    /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/FileCheck --check-prefix=INVALID-BINDING /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/invalid-elf.test
: 'RUN: at line 23';   not /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/ld.lld /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/Inputs/section-index.elf -o /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp2 2>&1 |    /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/FileCheck --check-prefix=INVALID-SECTION-INDEX-LLD /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/invalid-elf.test
: 'RUN: at line 27';   not /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/ld.lld /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/Inputs/multiple-eh-relocs.elf -o /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/tools/lld/test/ELF/invalid/Output/invalid-elf.test.tmp2 2>&1 |    /b/s/w/ir/k/recipe_cleanup/clangWrfRL9/llvm_build_dir/bin/FileCheck --check-prefix=INVALID-EH-RELOCS /b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/invalid-elf.test
--
Exit Code: 1

Command Output (stderr):
--
/b/s/w/ir/k/llvm-project/lld/test/ELF/invalid/invalid-elf.test:9:12: error: NOT-ELF: expected string not found in input
# NOT-ELF: not-elf.a(empty.o): not an ELF file
           ^
<stdin>:1:1: note: scanning from here
ld.lld: error: undefined symbol: foo
^
<stdin>:1:17: note: possible intended match here
ld.lld: error: undefined symbol: foo
                ^

--

********************
Testing: 0 .. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. 
Testing Time: 21.57s
********************
Failing Tests (1):
    lld :: ELF/invalid/invalid-elf.test

  Expected Passes    : 1735
  Unsupported Tests  : 268
  Unexpected Failures: 1
[451/523] Building CXX object unittests/Transforms/Vectorize/CMakeFiles/VectorizeTests.dir/VPlanPredicatorTest.cpp.o
FAILED: tools/lld/test/CMakeFiles/check-lld

The full log is here: https://logs.chromium.org/logs/fuchsia/buildbucket/cr-buildbucket.appspot.com/8919231700097735408/+/steps/clang/0/steps/test/0/stdout

[efriedma]

Buildbot failure should be fixed by r355894.

lld/trunk/ELF/InputFiles.cpp

 static ELFKind getELFKind(MemoryBufferRef MB, StringRef ArchiveName) {
   unsigned char Size;
   unsigned char Endian;
   std::tie(Size, Endian) = getElfArchType(MB.getBuffer());
 
   auto Fatal = [&](StringRef Msg) {
     StringRef Filename = MB.getBufferIdentifier();
     if (ArchiveName.empty())
-      fatal(Filename + ": corrupted ELF file: " + Msg);
+      fatal(Filename + ": " + Msg);
     else
-      fatal(ArchiveName + "(" + Filename + "): corrupted ELF file: " + Msg);
+      fatal(ArchiveName + "(" + Filename + "): " + Msg);
   };
 
+  if (!MB.getBuffer().startswith(ElfMagic))
+    Fatal("not an ELF file");
   if (Endian != ELFDATA2LSB && Endian != ELFDATA2MSB)
-    Fatal("invalid data encoding");
+    Fatal("corrupted ELF file: invalid data encoding");
   if (Size != ELFCLASS32 && Size != ELFCLASS64)
-    Fatal("invalid file class");
+    Fatal("corrupted ELF file: invalid file class");
 
   size_t BufSize = MB.getBuffer().size();
   if ((Size == ELFCLASS32 && BufSize < sizeof(Elf32_Ehdr)) ||
       (Size == ELFCLASS64 && BufSize < sizeof(Elf64_Ehdr)))
-    Fatal("file is too short");
+    Fatal("corrupted ELF file: file is too short");
 
   if (Size == ELFCLASS32)
     return (Endian == ELFDATA2LSB) ? ELF32LEKind : ELF32BEKind;
   return (Endian == ELFDATA2LSB) ? ELF64LEKind : ELF64BEKind;
 }
 
 void BinaryFile::parse() {
   ArrayRef<uint8_t> Data = arrayRefFromStringRef(MB.getBuffer());

lld/trunk/test/ELF/invalid/invalid-elf.test

 # REQUIRES: x86
-# RUN: llvm-mc %s -o %t -filetype=obj -triple x86_64-pc-linux
+# RUN: rm -rf %t && mkdir -p %t
+# RUN: llvm-mc %s -o %t/simple.o -filetype=obj -triple x86_64-pc-linux
+# RUN: echo > %t/empty.o
+# RUN: llvm-ar cr %t/not-elf.a %t/empty.o
+
+# RUN: not ld.lld %t/simple.o %t/not-elf.a -o %t2 2>&1 | \
+# RUN:   FileCheck --check-prefix=NOT-ELF %s
+# NOT-ELF: not-elf.a(empty.o): not an ELF file
 
-# RUN: not ld.lld %t %p/Inputs/data-encoding.a -o %t2 2>&1 | \
+# RUN: not ld.lld %t/simple.o %p/Inputs/data-encoding.a -o %t2 2>&1 | \
 # RUN:   FileCheck --check-prefix=INVALID-DATA-ENC %s
 # INVALID-DATA-ENC: data-encoding.a(test.o): corrupted ELF file: invalid data encoding
 
-# RUN: not ld.lld %t %p/Inputs/file-class.a -o %t2 2>&1 | \
+# RUN: not ld.lld %t/simple.o %p/Inputs/file-class.a -o %t2 2>&1 | \
 # RUN:   FileCheck --check-prefix=INVALID-FILE-CLASS %s
 # INVALID-FILE-CLASS: file-class.a(test.o): corrupted ELF file: invalid file class
 
 # RUN: not ld.lld %p/Inputs/binding.elf -o %t2 2>&1 | \
 # RUN:   FileCheck --check-prefix=INVALID-BINDING %s
 # INVALID-BINDING: unexpected binding
 
 # RUN: not ld.lld %p/Inputs/section-index.elf -o %t2 2>&1 | \
 # RUN:   FileCheck --check-prefix=INVALID-SECTION-INDEX-LLD %s
 # INVALID-SECTION-INDEX-LLD: invalid section index
 
 # RUN: not ld.lld %p/Inputs/multiple-eh-relocs.elf -o %t2 2>&1 | \
 # RUN:   FileCheck --check-prefix=INVALID-EH-RELOCS %s
 # INVALID-EH-RELOCS: multiple relocation sections to one section are not supported
 
 .long foo