Debug Info: Support DW_AT_calling_convention on composite types.

This implements the DWARF 5 feature described at
http://www.dwarfstd.org/ShowIssue.php?issue=141215.1

This allows a consumer to understand whether a composite data type is
trivially copyable and thus should be passed by value instead of by
reference. The canonical example is being able to distinguish the
following two types:

  // S is not trivially copyable because of the explicit destructor.
  struct S {
     ~S() {}
  };

  // T is a POD type.
  struct T {
     ~T() = default;
  };

This patch adds two new (DI)flags to LLVM metadata: TypePassByValue
and TypePassByReference.

<rdar://problem/36034922>
Differential Revision: https://reviews.llvm.org/D41743

llvm-svn: 321844

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/include/llvm-c/DebugInfo.h b/llvm/include/llvm-c/DebugInfo.h
index d17c690be4d..a5e5653630c 100644
--- a/llvm/include/llvm-c/DebugInfo.h
+++ b/llvm/include/llvm-c/DebugInfo.h
@@ -52,6 +52,8 @@ typedef enum {
   LLVMDIFlagBitField = 1 << 19,
   LLVMDIFlagNoReturn = 1 << 20,
   LLVMDIFlagMainSubprogram = 1 << 21,
+  LLVMDIFlagTypePassByValue = 1 << 22,
+  LLVMDIFlagTypePassByReference = 1 << 23,
   LLVMDIFlagIndirectVirtualBase = (1 << 2) | (1 << 5),
   LLVMDIFlagAccessibility = LLVMDIFlagPrivate | LLVMDIFlagProtected |
                             LLVMDIFlagPublic,