Decouple dllexport/dllimport from linkage

Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.

Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:

  define available_externally dllimport void @f() {}
  @Var = dllexport global i32 1, align 4

Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.

llvm-svn: 199204

1 files changed, 5 insertions, 2 deletions

diff --git a/llvm/lib/AsmParser/LLParser.h b/llvm/lib/AsmParser/LLParser.h
index ded776c3989..c62979e6f29 100644
--- a/llvm/lib/AsmParser/LLParser.h
+++ b/llvm/lib/AsmParser/LLParser.h
@@ -204,6 +204,7 @@ namespace llvm {
       bool HasLinkage; return ParseOptionalLinkage(Linkage, HasLinkage);
     }
     bool ParseOptionalVisibility(unsigned &Visibility);
+    bool ParseOptionalDLLStorageClass(unsigned &DLLStorageClass);
     bool ParseOptionalCallingConv(CallingConv::ID &CC);
     bool ParseOptionalAlignment(unsigned &Alignment);
     bool ParseScopeAndOrdering(bool isAtomic, SynchronizationScope &Scope,
@@ -234,8 +235,10 @@ namespace llvm {
     bool ParseUnnamedGlobal();
     bool ParseNamedGlobal();
     bool ParseGlobal(const std::string &Name, LocTy Loc, unsigned Linkage,
-                     bool HasLinkage, unsigned Visibility);
-    bool ParseAlias(const std::string &Name, LocTy Loc, unsigned Visibility);
+                     bool HasLinkage, unsigned Visibility,
+                     unsigned DLLStorageClass);
+    bool ParseAlias(const std::string &Name, LocTy Loc, unsigned Visibility,
+                    unsigned DLLStorageClass);
     bool ParseStandaloneMetadata();
     bool ParseNamedMetadata();
     bool ParseMDString(MDString *&Result);