COFF: Fix __ImageBase symbol relocation.

__ImageBase is a special symbol whose value is the image base address.
Previously, we handled __ImageBase symbol as an absolute symbol.

Absolute symbols point to specific locations in memory and the locations
never change even if an image is base-relocated. That means that we
don't have base relocation entries for absolute symbols.

This is not a case for __ImageBase. If an image is base-relocated, its
base address changes, and __ImageBase needs to be shifted as well.
So we have to have base relocations for __ImageBase. That means that
__ImageBase is not really an absolute symbol but a different kind of
symbol.

In this patch, I introduced a new type of symbol -- DefinedRelative.
DefinedRelative is similar to DefinedAbsolute, but it has not a VA but RVA
and is a subject of base relocation. Currently only __ImageBase is of
the new symbol type.

llvm-svn: 243176

1 files changed, 2 insertions, 2 deletions

diff --git a/lld/COFF/DLL.cpp b/lld/COFF/DLL.cpp
index 6a0e70a8750..68d35fc1d6f 100644
--- a/lld/COFF/DLL.cpp
+++ b/lld/COFF/DLL.cpp
@@ -319,7 +319,7 @@ public:
     write32le(Buf + FileOff + 13, Helper->getRVA() - RVA - 17);
   }
 
-  void getBaserels(std::vector<uint32_t> *Res, Defined *ImageBase) override {
+  void getBaserels(std::vector<uint32_t> *Res) override {
     Res->push_back(RVA + 3);
     Res->push_back(RVA + 8);
   }
@@ -367,7 +367,7 @@ public:
     write64le(Buf + FileOff, Thunk->getRVA() + Config->ImageBase);
   }
 
-  void getBaserels(std::vector<uint32_t> *Res, Defined *ImageBase) override {
+  void getBaserels(std::vector<uint32_t> *Res) override {
     Res->push_back(RVA);
   }