Object/COFF: Support large relocation table.

NumberOfRelocations field in COFF section table is only 16-bit wide. If an
object has more than 65535 relocations, the number of relocations is stored
to VirtualAddress field in the first relocation field, and a special flag
(IMAGE_SCN_LNK_NRELOC_OVFL) is set to Characteristics field.

In test we cheated a bit. I made up a test file so that it has
IMAGE_SCN_LNK_NRELOC_OVFL flag but the number of relocations is much smaller
than 65535. This is to avoid checking in a large test file just to test a
file with many relocations.

Differential Revision: http://llvm-reviews.chandlerc.com/D3139

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204418 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 0 deletions

diff --git a/include/llvm/Object/COFF.h b/include/llvm/Object/COFF.h
index 31b7d6ea17..c2e7d52b91 100644
--- a/include/llvm/Object/COFF.h
+++ b/include/llvm/Object/COFF.h
@@ -250,6 +250,13 @@ struct coff_section {
   support::ulittle16_t NumberOfRelocations;
   support::ulittle16_t NumberOfLinenumbers;
   support::ulittle32_t Characteristics;
+
+  // Returns true if the actual number of relocations is stored in
+  // VirtualAddress field of the first relocation table entry.
+  bool hasExtendedRelocations() const {
+    return Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL &&
+        NumberOfRelocations == UINT16_MAX;
+  };
 };
 
 struct coff_relocation {