Add support for DW_TAG_thrown_type.

For Swift we would like to be able to encode the error types that a
function may throw, so the debugger can display them alongside the
function's return value when finish-ing a function.

DWARF defines DW_TAG_thrown_type (intended to be used for C++ throw()
declarations) that is a perfect fit for this purpose. This patch wires
up support for DW_TAG_thrown_type in LLVM by adding a list of thrown
types to DISubprogram.

To offset the cost of the extra pointer, there is a follow-up patch
that turns DISubprogram into a variable-length node.

rdar://problem/29481673

Differential Revision: https://reviews.llvm.org/D32559

llvm-svn: 301489

1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/test/Verifier/DISubprogram.ll b/llvm/test/Verifier/DISubprogram.ll
new file mode 100644
index 00000000000..e78220c8bd7
--- /dev/null
+++ b/llvm/test/Verifier/DISubprogram.ll
@@ -0,0 +1,22 @@
+; RUN: not opt -S <%s 2>&1| FileCheck %s
+
+define void @f() !dbg !14 {
+  ret void
+}
+
+!0 = !{null}
+!1 = distinct !DICompositeType(tag: DW_TAG_structure_type)
+!2 = !DIFile(filename: "path/to/file", directory: "/path/to/dir")
+!3 = !DISubroutineType(types: !0)
+!4 = distinct !DICompositeType(tag: DW_TAG_structure_type)
+!8 = distinct !DICompileUnit(language: DW_LANG_Swift, producer: "clang",
+                             file: !2, emissionKind: 2)
+; CHECK: invalid thrown type
+!13 = !{!14}
+!14 = distinct !DISubprogram(name: "f", scope: !1,
+                            file: !2, line: 1, type: !3, isLocal: true,
+                            isDefinition: true, scopeLine: 2,
+                            unit: !8, thrownTypes: !13)
+!15 = !{i32 1, !"Debug Info Version", i32 3}
+!llvm.module.flags = !{!15}
+!llvm.dbg.cu = !{!8}