Check that COFF .obj files have sections with zero virtual address spaces.

When talking about the virtual address of sections the coff spec says:
  ... for simplicity, compilers should set this to zero. Otherwise, it is an
  arbitrary value that is subtracted from offsets during relocation.

We don't currently subtract it, so check that it is zero.

If some producer does create such files, we can change getRelocationOffset
instead.

llvm-svn: 241447

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/tools/llvm-readobj/COFFDumper.cpp b/llvm/tools/llvm-readobj/COFFDumper.cpp
index f5effe29244..91a4435d848 100644
--- a/llvm/tools/llvm-readobj/COFFDumper.cpp
+++ b/llvm/tools/llvm-readobj/COFFDumper.cpp
@@ -48,7 +48,6 @@ public:
   COFFDumper(const llvm::object::COFFObjectFile *Obj, StreamWriter& Writer)
     : ObjDumper(Writer)
     , Obj(Obj) {
-    cacheRelocations();
   }
 
   void printFileHeaders() override;
@@ -92,6 +91,7 @@ private:
   typedef DenseMap<const coff_section*, std::vector<RelocationRef> > RelocMapTy;
 
   const llvm::object::COFFObjectFile *Obj;
+  bool RelocCached = false;
   RelocMapTy RelocMap;
   StringRef CVFileIndexToStringOffsetTable;
   StringRef CVStringTable;
@@ -119,6 +119,7 @@ std::error_code createCOFFDumper(const object::ObjectFile *Obj,
 // symbol used for the relocation at the offset.
 std::error_code COFFDumper::resolveSymbol(const coff_section *Section,
                                           uint64_t Offset, SymbolRef &Sym) {
+  cacheRelocations();
   const auto &Relocations = RelocMap[Section];
   for (const auto &Relocation : Relocations) {
     uint64_t RelocationOffset = Relocation.getOffset();
@@ -339,6 +340,10 @@ static std::error_code getSymbolAuxData(const COFFObjectFile *Obj,
 }
 
 void COFFDumper::cacheRelocations() {
+  if (RelocCached)
+    return;
+  RelocCached = true;
+
   for (const SectionRef &S : Obj->sections()) {
     const coff_section *Section = Obj->getCOFFSection(S);