DI: Reverse direction of subprogram -> function edge.
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.
For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.
This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.
Since this is an IR change, a bitcode upgrade has been provided.
Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.
Differential Revision: http://reviews.llvm.org/D14265
llvm-svn: 252219
diff --git a/llvm/test/DebugInfo/X86/missing-file-line.ll b/llvm/test/DebugInfo/X86/missing-file-line.ll
index 6fbfb94..1906457 100644
--- a/llvm/test/DebugInfo/X86/missing-file-line.ll
+++ b/llvm/test/DebugInfo/X86/missing-file-line.ll
@@ -11,7 +11,7 @@
%struct.S = type { %struct.S* }
-define void @f() {
+define void @f() !dbg !4 {
%x = alloca %struct.S, align 8
; CHECK: DW_TAG_typedef
; CHECK-NOT: DW_AT_decl_file
@@ -40,7 +40,7 @@
!1 = !DIFile(filename: "file.c", directory: "/dir")
!2 = !{}
!3 = !{!4}
-!4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 7, type: !5, isLocal: false, isDefinition: true, scopeLine: 7, isOptimized: false, function: void ()* @f, variables: !2)
+!4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 7, type: !5, isLocal: false, isDefinition: true, scopeLine: 7, isOptimized: false, variables: !2)
!5 = !DISubroutineType(types: !6)
!6 = !{null}
!7 = !{i32 2, !"Dwarf Version", i32 4}