[COFF] more informative "broken object file" diagnostics

Summary:
When a symbol refers to a special section or a section that doesn't
exist, lld would fatal with "broken object file". This change gives a
different message for each scenario, and includes the name of the
file, name of the symbol, and the section being referred to.

Reviewers: pcc, ruiu

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46090

llvm-svn: 330883

1 files changed, 4 insertions, 5 deletions

diff --git a/lld/COFF/InputFiles.cpp b/lld/COFF/InputFiles.cpp
index b310fce5fd4..8f18910617b 100644
--- a/lld/COFF/InputFiles.cpp
+++ b/lld/COFF/InputFiles.cpp
@@ -326,14 +326,13 @@ Optional<Symbol *> ObjFile::createDefined(
   if (SectionNumber == llvm::COFF::IMAGE_SYM_DEBUG)
     return nullptr;
 
-  // Reserved sections numbers don't have contents.
   if (llvm::COFF::isReservedSectionNumber(SectionNumber))
-    fatal("broken object file: " + toString(this));
+    fatal(toString(this) + ": " + Name +
+          " should not refer to special section " + Twine(SectionNumber));
 
-  // This symbol references a section which is not present in the section
-  // header.
   if ((uint32_t)SectionNumber >= SparseChunks.size())
-    fatal("broken object file: " + toString(this));
+    fatal(toString(this) + ": " + Name +
+          " should not refer to non-existent section " + Twine(SectionNumber));
 
   // Handle comdat leader symbols.
   if (const coff_aux_section_definition *Def = ComdatDefs[SectionNumber]) {