[IR] Remove the DIExpression field from DIGlobalVariable.

This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

This reapplies r289902 with additional testcase upgrades and a change
to the Bitcode record for DIGlobalVariable, that makes upgrading the
old format unambiguous also for variables without DIExpressions.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 290153

5 files changed, 6 insertions, 6 deletions

diff --git a/llvm/test/CodeGen/X86/2010-05-26-DotDebugLoc.ll b/llvm/test/CodeGen/X86/2010-05-26-DotDebugLoc.ll
index 30e5e346d29..ae8214b4bb6 100644
--- a/llvm/test/CodeGen/X86/2010-05-26-DotDebugLoc.ll
+++ b/llvm/test/CodeGen/X86/2010-05-26-DotDebugLoc.ll
@@ -24,7 +24,7 @@ declare void @llvm.dbg.value(metadata, i64, metadata, metadata) nounwind readnon
 !llvm.dbg.cu = !{!2}
 !llvm.module.flags = !{!38}
 
-!0 = !DIGlobalVariable(name: "ret", line: 7, isLocal: false, isDefinition: true, scope: !1, file: !1, type: !3)
+!0 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "ret", line: 7, isLocal: false, isDefinition: true, scope: !1, file: !1, type: !3))
 !1 = !DIFile(filename: "foo.c", directory: "/tmp/")
 !2 = distinct !DICompileUnit(language: DW_LANG_C89, producer: "4.2.1 (Based on Apple Inc. build 5658) (LLVM build)", isOptimized: true, emissionKind: FullDebug, file: !36, enums: !37, retainedTypes: !37, globals: !31, imports:  !37)
 !3 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
diff --git a/llvm/test/CodeGen/X86/fp128-g.ll b/llvm/test/CodeGen/X86/fp128-g.ll
index 129695dbe20..aede7e55f4b 100644
--- a/llvm/test/CodeGen/X86/fp128-g.ll
+++ b/llvm/test/CodeGen/X86/fp128-g.ll
@@ -116,7 +116,7 @@ attributes #2 = { nounwind readnone }
 !llvm.module.flags = !{!7, !8, !9}
 !llvm.ident = !{!10}
 
-!0 = distinct !DIGlobalVariable(name: "ld_ptr", scope: !1, file: !2, line: 17, type: !5, isLocal: false, isDefinition: true)
+!0 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "ld_ptr", scope: !1, file: !2, line: 17, type: !5, isLocal: false, isDefinition: true))
 !1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, producer: "clang version 4.0.0 (trunk 281495)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !3, globals: !4)
 !2 = !DIFile(filename: "fp128-g.c", directory: "/disk5/chh/Debug/ld.loop")
 !3 = !{}
diff --git a/llvm/test/CodeGen/X86/fpstack-debuginstr-kill.ll b/llvm/test/CodeGen/X86/fpstack-debuginstr-kill.ll
index 60d335dd48d..208a893c82c 100644
--- a/llvm/test/CodeGen/X86/fpstack-debuginstr-kill.ll
+++ b/llvm/test/CodeGen/X86/fpstack-debuginstr-kill.ll
@@ -64,7 +64,7 @@ declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
 !19 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
 !20 = !DILocalVariable(name: "value", line: 16, scope: !4, file: !6, type: !14)
 !21 = !{!22, !23}
-!22 = !DIGlobalVariable(name: "g1", line: 5, isLocal: false, isDefinition: true, scope: null, file: !6, type: !14)
-!23 = !DIGlobalVariable(name: "g2", line: 6, isLocal: false, isDefinition: true, scope: null, file: !6, type: !19)
+!22 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "g1", line: 5, isLocal: false, isDefinition: true, scope: null, file: !6, type: !14))
+!23 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "g2", line: 6, isLocal: false, isDefinition: true, scope: null, file: !6, type: !19))
 !24 = !{i32 2, !"Dwarf Version", i32 2}
 !25 = !{i32 2, !"Debug Info Version", i32 3}
diff --git a/llvm/test/CodeGen/X86/misched-code-difference-with-debug.ll b/llvm/test/CodeGen/X86/misched-code-difference-with-debug.ll
index 1f91e3ad0b8..5737ffd6374 100644
--- a/llvm/test/CodeGen/X86/misched-code-difference-with-debug.ll
+++ b/llvm/test/CodeGen/X86/misched-code-difference-with-debug.ll
@@ -82,7 +82,7 @@ declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
 !18 = !DILocalVariable(name: "c", line: 7, scope: !13, file: !14, type: !4)
 !19 = !DILocalVariable(name: "lc", line: 8, scope: !13, file: !14, type: !11)
 !20 = !{!21}
-!21 = !DIGlobalVariable(name: "argc", line: 1, isLocal: false, isDefinition: true, scope: null, file: !14, type: !11)
+!21 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "argc", line: 1, isLocal: false, isDefinition: true, scope: null, file: !14, type: !11))
 !22 = !{i32 2, !"Dwarf Version", i32 4}
 !23 = !{i32 2, !"Debug Info Version", i32 3}
 !25 = !DILocation(line: 8, column: 3, scope: !13)
diff --git a/llvm/test/CodeGen/X86/null-streamer.ll b/llvm/test/CodeGen/X86/null-streamer.ll
index b331b92868f..30dfade356b 100644
--- a/llvm/test/CodeGen/X86/null-streamer.ll
+++ b/llvm/test/CodeGen/X86/null-streamer.ll
@@ -22,6 +22,6 @@ define void @f1() {
 !7 = !{!8}
 !8 = !DIBasicType(tag: DW_TAG_base_type, size: 32, align: 32, encoding: DW_ATE_signed)
 !9 = !{!10}
-!10 = !DIGlobalVariable(name: "i", linkageName: "_ZL1i", line: 1, isLocal: true, isDefinition: true, scope: null, file: !1, type: !8)
+!10 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "i", linkageName: "_ZL1i", line: 1, isLocal: true, isDefinition: true, scope: null, file: !1, type: !8))
 !11 = !{i32 2, !"Dwarf Version", i32 3}
 !13 = !{i32 1, !"Debug Info Version", i32 3}