Use LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN instead of the "dso list".

There are two ways one could implement hiding of linkonce_odr symbols in LTO:
* LLVM tells the linker which symbols can be hidden if not used from native
  files.
* The linker tells LLVM which symbols are not used from other object files,
  but will be put in the dso symbol table if present.

GOLD's API is the second option. It was implemented almost 1:1 in llvm by
passing the list down to internalize.

LLVM already had partial support for the first option. It is also very similar
to how ld64 handles hiding these symbols when *not* doing LTO.

This patch then
* removes the APIs for the DSO list.
* marks LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN all linkonce_odr unnamed_addr
  global values and other linkonce_odr whose address is not used.
* makes the gold plugin responsible for handling the API mismatch.

llvm-svn: 193800

1 files changed, 0 insertions, 9 deletions

diff --git a/llvm/include/llvm-c/lto.h b/llvm/include/llvm-c/lto.h
index a09db24f983..89f54b7a7b7 100644
--- a/llvm/include/llvm-c/lto.h
+++ b/llvm/include/llvm-c/lto.h
@@ -270,15 +270,6 @@ lto_codegen_set_assembler_args(lto_code_gen_t cg, const char **args,
 extern void
 lto_codegen_add_must_preserve_symbol(lto_code_gen_t cg, const char* symbol);
 
-
-/**
- * Tells LTO optimization passes that a dynamic shared library is being
- * built and this symbol may be exported. Unless IR semantics allow the symbol
- * to be made local to the library, it should remain so it can be exported by
- * the shared library.
- */
-extern void lto_codegen_add_dso_symbol(lto_code_gen_t cg, const char *symbol);
-
 /**
  * Writes a new object file at the specified path that contains the
  * merged contents of all modules added so far.