Update StripDeadDebugInfo to use DebugInfoFinder so that it is no longer stale to the point of not working and more resilient to debug info changes.

The current version of StripDeadDebugInfo became stale and no longer actually
worked since it was expecting an older version of debug info.

This patch updates it to use DebugInfoFinder and the modern DebugInfo classes as
much as possible to make it more redundent to such changes. Additionally, the
only place where that was avoided (the code where we replace the old sets with
the new), I call verify on the DIContextUnit implying that if the format changes
and my live set changes no longer make sense an assert will be hit. In order to
ensure that that occurs I have included a test case.

The actual stripping of the dead debug info follows the same strategy as was
used before in this class: find the live set and replace the old set in the
given compile unit (which may contain dead global variables/functions) with the
new live one.

llvm-svn: 189078

3 files changed, 59 insertions, 53 deletions

diff --git a/llvm/test/Transforms/StripSymbols/2010-07-01-DeadDbgInfo.ll b/llvm/test/Transforms/StripSymbols/2010-07-01-DeadDbgInfo.ll
deleted file mode 100644
index b893410503e..00000000000
--- a/llvm/test/Transforms/StripSymbols/2010-07-01-DeadDbgInfo.ll
+++ /dev/null
@@ -1,49 +0,0 @@
-; RUN: opt -strip-dead-debug-info < %s | llvm-dis -o %t.ll
-; RUN: grep -v bar %t.ll
-; RUN: grep -v abcd %t.ll
-
-@xyz = global i32 2                               ; <i32*> [#uses=1]
-
-declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
-
-define i32 @fn() nounwind readnone ssp {
-entry:
-  ret i32 0, !dbg !17
-}
-
-define i32 @foo(i32 %i) nounwind readonly ssp {
-entry:
-  tail call void @llvm.dbg.value(metadata !{i32 %i}, i64 0, metadata !14), !dbg !19
-  %.0 = load i32* @xyz, align 4                   ; <i32> [#uses=1]
-  ret i32 %.0, !dbg !20
-}
-
-!llvm.dbg.cu = !{!2}
-!llvm.dbg.sp = !{!0, !5, !9}
-!llvm.dbg.lv.bar = !{!12}
-!llvm.dbg.lv.foo = !{!14}
-!llvm.dbg.gv = !{!15, !16}
-
-!0 = metadata !{i32 524334, metadata !22, null, metadata !"bar", metadata !"bar", metadata !"", i32 5, metadata !3, i1 true, i1 true, i32 0, i32 0, null, i1 false, i1 true, null, null, null, null, i32 0} ; [ DW_TAG_subprogram ]
-!1 = metadata !{i32 524329, metadata !22} ; [ DW_TAG_file_type ]
-!2 = metadata !{i32 524305, metadata !22, i32 1, metadata !"4.2.1 (Based on Apple Inc. build 5658) (LLVM build)", i1 true, metadata !"", i32 0, metadata !4, metadata !4, null, null, null, metadata !""} ; [ DW_TAG_compile_unit ]
-!3 = metadata !{i32 524309, metadata !22, metadata !1, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !4, i32 0, null} ; [ DW_TAG_subroutine_type ]
-!4 = metadata !{null}
-!5 = metadata !{i32 524334, metadata !22, null, metadata !"fn", metadata !"fn", metadata !"fn", i32 6, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i1 false, i1 true, i32 ()* @fn, null, null, null, i32 0} ; [ DW_TAG_subprogram ]
-!6 = metadata !{i32 524309, metadata !22, metadata !1, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !7, i32 0, null} ; [ DW_TAG_subroutine_type ]
-!7 = metadata !{metadata !8}
-!8 = metadata !{i32 524324, metadata !22, metadata !1, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
-!9 = metadata !{i32 524334, metadata !22, null, metadata !"foo", metadata !"foo", metadata !"foo", i32 7, metadata !10, i1 false, i1 true, i32 0, i32 0, null, i1 false, i1 true, i32 (i32)* @foo, null, null, null, i32 0} ; [ DW_TAG_subprogram ]
-!10 = metadata !{i32 524309, metadata !22, metadata !1, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !11, i32 0, null} ; [ DW_TAG_subroutine_type ]
-!11 = metadata !{metadata !8, metadata !8}
-!12 = metadata !{i32 524544, metadata !13, metadata !"bb", metadata !1, i32 5, metadata !8} ; [ DW_TAG_auto_variable ]
-!13 = metadata !{i32 524299, metadata !22, metadata !0, i32 5, i32 0, i32 0} ; [ DW_TAG_lexical_block ]
-!14 = metadata !{i32 524545, metadata !9, metadata !"i", metadata !1, i32 7, metadata !8} ; [ DW_TAG_arg_variable ]
-!15 = metadata !{i32 524340, i32 0, metadata !1, metadata !"abcd", metadata !"abcd", metadata !"", metadata !1, i32 2, metadata !8, i1 true, i1 true, null} ; [ DW_TAG_variable ]
-!16 = metadata !{i32 524340, i32 0, metadata !1, metadata !"xyz", metadata !"xyz", metadata !"", metadata !1, i32 3, metadata !8, i1 false, i1 true, i32* @xyz} ; [ DW_TAG_variable ]
-!17 = metadata !{i32 6, i32 0, metadata !18, null}
-!18 = metadata !{i32 524299, metadata !22, metadata !5, i32 6, i32 0, i32 0} ; [ DW_TAG_lexical_block ]
-!19 = metadata !{i32 7, i32 0, metadata !9, null}
-!20 = metadata !{i32 10, i32 0, metadata !21, null}
-!21 = metadata !{i32 524299, metadata !22, metadata !9, i32 7, i32 0, i32 0} ; [ DW_TAG_lexical_block ]
-!22 = metadata !{metadata !"g.c", metadata !"/tmp/"}
diff --git a/llvm/test/Transforms/StripSymbols/2010-08-25-crash.ll b/llvm/test/Transforms/StripSymbols/2010-08-25-crash.ll
index e480f43e67c..570681a7213 100644
--- a/llvm/test/Transforms/StripSymbols/2010-08-25-crash.ll
+++ b/llvm/test/Transforms/StripSymbols/2010-08-25-crash.ll
@@ -5,18 +5,18 @@ entry:
 }
 
 !llvm.dbg.cu = !{!2}
-!llvm.dbg.sp = !{!0}
-!llvm.dbg.gv = !{!6}
 
 !0 = metadata !{i32 524334, metadata !10, metadata !1, metadata !"foo", metadata !"foo", metadata !"foo", i32 3, metadata !3, i1 false, i1 true, i32 0, i32 0, null, i1 false, i1 false, i32 ()* @foo, null, null, null, i32 0} ; [ DW_TAG_subprogram ]
 !1 = metadata !{i32 524329, metadata !10} ; [ DW_TAG_file_type ]
-!2 = metadata !{i32 524305, metadata !10, i32 12, metadata !"clang version 2.8 (trunk 112062)", i1 true, metadata !"", i32 0, metadata !11, metadata !11, null, null, null, metadata !""} ; [ DW_TAG_compile_unit ]
+!2 = metadata !{i32 524305, metadata !10, i32 12, metadata !"clang version 2.8 (trunk 112062)", i1 true, metadata !"", i32 0, metadata !11, metadata !11, metadata !12, metadata !13, null, metadata !""} ; [ DW_TAG_compile_unit ]
 !3 = metadata !{i32 524309, metadata !10, metadata !1, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !4, i32 0, null} ; [ DW_TAG_subroutine_type ]
 !4 = metadata !{metadata !5}
 !5 = metadata !{i32 524324, metadata !10, metadata !1, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
-!6 = metadata !{i32 524340, i32 0, metadata !1, metadata !"i", metadata !"i", metadata !"i", metadata !1, i32 2, metadata !7, i1 true, i1 true, i32 0} ; [ DW_TAG_variable ]
+!6 = metadata !{i32 524340, i32 0, metadata !1, metadata !"i", metadata !"i", metadata !"i", metadata !1, i32 2, metadata !7, i1 true, i1 true, i32 0, null} ; [ DW_TAG_variable ]
 !7 = metadata !{i32 524326, metadata !10, metadata !1, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, metadata !5} ; [ DW_TAG_const_type ]
 !8 = metadata !{i32 3, i32 13, metadata !9, null}
 !9 = metadata !{i32 524299, metadata !10, metadata !0, i32 3, i32 11, i32 0} ; [ DW_TAG_lexical_block ]
 !10 = metadata !{metadata !"/tmp/a.c", metadata !"/Volumes/Lalgate/clean/D.CW"}
 !11 = metadata !{i32 0}
+!12 = metadata !{metadata !0}
+!13 = metadata !{metadata !6}
diff --git a/llvm/test/Transforms/StripSymbols/strip-dead-debug-info.ll b/llvm/test/Transforms/StripSymbols/strip-dead-debug-info.ll
new file mode 100644
index 00000000000..99b3fb61abc
--- /dev/null
+++ b/llvm/test/Transforms/StripSymbols/strip-dead-debug-info.ll
@@ -0,0 +1,55 @@
+; RUN: opt -strip-dead-debug-info -verify %s -S | FileCheck %s
+
+; CHECK-NOT: bar
+; CHECK-NOT: abcd
+
+@xyz = global i32 2
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata) #0
+
+; Function Attrs: nounwind readnone ssp
+define i32 @fn() #1 {
+entry:
+  ret i32 0, !dbg !18
+}
+
+; Function Attrs: nounwind readonly ssp
+define i32 @foo(i32 %i) #2 {
+entry:
+  tail call void @llvm.dbg.value(metadata !{i32 %i}, i64 0, metadata !15), !dbg !20
+  %.0 = load i32* @xyz, align 4
+  ret i32 %.0, !dbg !21
+}
+
+attributes #0 = { nounwind readnone }
+attributes #1 = { nounwind readnone ssp }
+attributes #2 = { nounwind readonly ssp }
+
+!llvm.dbg.cu = !{!0}
+
+!0 = metadata !{i32 524305, metadata !1, i32 1, metadata !"4.2.1 (Based on Apple Inc. build 5658) (LLVM build)", i1 true, metadata !"", i32 0, metadata !2, metadata !2, metadata !23, metadata !24, null, metadata !""} ; [ DW_TAG_compile_unit ] [/tmp//g.c] [DW_LANG_C89]
+!1 = metadata !{metadata !"g.c", metadata !"/tmp/"}
+!2 = metadata !{null}
+!3 = metadata !{i32 524334, metadata !1, null, metadata !"bar", metadata !"bar", metadata !"", i32 5, metadata !4, i1 true, i1 true, i32 0, i32 0, null, i1 false, i1 true, null, null, null, null, i32 0} ; [ DW_TAG_subprogram ] [line 5] [local] [def] [scope 0] [bar]
+!4 = metadata !{i32 524309, metadata !1, metadata !5, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !2, i32 0, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!5 = metadata !{i32 524329, metadata !1}          ; [ DW_TAG_file_type ] [/tmp//g.c]
+!6 = metadata !{i32 524334, metadata !1, null, metadata !"fn", metadata !"fn", metadata !"fn", i32 6, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i1 false, i1 true, i32 ()* @fn, null, null, null, i32 0} ; [ DW_TAG_subprogram ] [line 6] [def] [scope 0] [fn]
+!7 = metadata !{i32 524309, metadata !1, metadata !5, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!8 = metadata !{metadata !9}
+!9 = metadata !{i32 524324, metadata !1, metadata !5, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!10 = metadata !{i32 524334, metadata !1, null, metadata !"foo", metadata !"foo", metadata !"foo", i32 7, metadata !11, i1 false, i1 true, i32 0, i32 0, null, i1 false, i1 true, i32 (i32)* @foo, null, null, null, i32 0} ; [ DW_TAG_subprogram ] [line 7] [def] [scope 0] [foo]
+!11 = metadata !{i32 524309, metadata !1, metadata !5, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !12, i32 0, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!12 = metadata !{metadata !9, metadata !9}
+!13 = metadata !{i32 524544, metadata !14, metadata !"bb", metadata !5, i32 5, metadata !9}
+!14 = metadata !{i32 524299, metadata !1, metadata !3, i32 5, i32 0, i32 0} ; [ DW_TAG_lexical_block ] [/tmp//g.c]
+!15 = metadata !{i32 524545, metadata !10, metadata !"i", metadata !5, i32 7, metadata !9}
+!16 = metadata !{i32 524340, i32 0, metadata !5, metadata !"abcd", metadata !"abcd", metadata !"", metadata !5, i32 2, metadata !9, i1 true, i1 true, null, null}
+!17 = metadata !{i32 524340, i32 0, metadata !5, metadata !"xyz", metadata !"xyz", metadata !"", metadata !5, i32 3, metadata !9, i1 false, i1 true, i32* @xyz, null}
+!18 = metadata !{i32 6, i32 0, metadata !19, null}
+!19 = metadata !{i32 524299, metadata !1, metadata !6, i32 6, i32 0, i32 0} ; [ DW_TAG_lexical_block ] [/tmp//g.c]
+!20 = metadata !{i32 7, i32 0, metadata !10, null}
+!21 = metadata !{i32 10, i32 0, metadata !22, null}
+!22 = metadata !{i32 524299, metadata !1, metadata !10, i32 7, i32 0, i32 0} ; [ DW_TAG_lexical_block ] [/tmp//g.c]
+!23 = metadata !{metadata !3, metadata !6, metadata !10}
+!24 = metadata !{metadata !16, metadata !17}