[ELF][MIPS] Prevent substitution of _gp_disp symbol
On MIPS O32 ABI, _gp_disp is a magic symbol designates offset between
start of function and gp pointer into GOT. To make seal with such symbol
we add new method addIgnoredStrong(). It adds ignored symbol with global
binding to prevent the symbol substitution. The addIgnored call is not
enough here because this call adds a weak symbol which might be
substituted by symbol from shared library.
Differential Revision: http://reviews.llvm.org/D16084
llvm-svn: 257449
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index ea1a51c..f00d978 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -304,8 +304,9 @@
if (Config->EMachine == EM_MIPS) {
// On MIPS O32 ABI, _gp_disp is a magic symbol designates offset between
- // start of function and gp pointer into GOT.
- Config->MipsGpDisp = Symtab.addIgnored("_gp_disp");
+ // start of function and gp pointer into GOT. Use 'strong' variant of
+ // the addIgnored to prevent '_gp_disp' substitution.
+ Config->MipsGpDisp = Symtab.addIgnoredStrong("_gp_disp");
// Define _gp for MIPS. st_value of _gp symbol will be updated by Writer
// so that it points to an absolute address which is relative to GOT.