Linker: correctly link in dbg.declare

Given source IR:
call void @llvm.dbg.declare(metadata !{i32* %argc.addr}, metadata !14), !dbg !15
we used to generate 
call void @llvm.dbg.declare(metadata !27, metadata !28), !dbg !29
!27 = metadata !{null}

With this patch, we will correctly generate
call void @llvm.dbg.declare(metadata !{i32* %argc.addr}, metadata !27), !dbg !28

Looking up %argc.addr in ValueMap will return null, since %argc.addr is already
correctly set up, we can use identity mapping.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173946 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 145 insertions, 2 deletions

diff --git a/lib/Transforms/Utils/ValueMapper.cpp b/lib/Transforms/Utils/ValueMapper.cpp
index a5e164374f..b9e4ddf349 100644
--- a/lib/Transforms/Utils/ValueMapper.cpp
+++ b/lib/Transforms/Utils/ValueMapper.cpp
@@ -63,14 +63,23 @@ Value *llvm::MapValue(const Value *V, ValueToValueMapTy &VM, RemapFlags Flags,
     // Check all operands to see if any need to be remapped.
     for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i) {
       Value *OP = MD->getOperand(i);
-      if (OP == 0 || MapValue(OP, VM, Flags, TypeMapper) == OP) continue;
+      if (OP == 0) continue;
+      Value *Mapped_OP = MapValue(OP, VM, Flags, TypeMapper);
+      // If Mapped_Op is null, we should use indentity map.
+      if (Mapped_OP == OP || Mapped_OP == 0) continue;
 
       // Ok, at least one operand needs remapping.  
       SmallVector<Value*, 4> Elts;
       Elts.reserve(MD->getNumOperands());
       for (i = 0; i != e; ++i) {
         Value *Op = MD->getOperand(i);
-        Elts.push_back(Op ? MapValue(Op, VM, Flags, TypeMapper) : 0);
+        if (Op == 0)
+          Elts.push_back(0);
+        else {
+          Value *Mapped_Op = MapValue(Op, VM, Flags, TypeMapper);
+          // If Mapped_Op is null, we should use indentity map.
+          Elts.push_back(Mapped_Op ? Mapped_Op : Op);
+        }
       }
       MDNode *NewMD = MDNode::get(V->getContext(), Elts);
       Dummy->replaceAllUsesWith(NewMD);
diff --git a/test/Linker/DbgDeclare.ll b/test/Linker/DbgDeclare.ll
new file mode 100644
index 0000000000..7f64f95c3a
--- /dev/null
+++ b/test/Linker/DbgDeclare.ll
@@ -0,0 +1,58 @@
+; RUN: llvm-link %s %p/DbgDeclare2.ll -o %t.bc
+; RUN: llvm-dis < %t.bc | FileCheck %s
+; Test if metadata in dbg.declare is mapped properly or not.
+
+; rdar://13089880
+; CHECK: define i32 @main(i32 %argc, i8** %argv)
+; CHECK: call void @llvm.dbg.declare(metadata !{i32* %argc.addr}, metadata !{{[0-9]+}})
+; CHECK: call void @llvm.dbg.declare(metadata !{i8*** %argv.addr}, metadata !{{[0-9]+}})
+; CHECK: define void @test(i32 %argc, i8** %argv)
+; CHECK: call void @llvm.dbg.declare(metadata !{i32* %argc.addr}, metadata !{{[0-9]+}})
+; CHECK: call void @llvm.dbg.declare(metadata !{i8*** %argv.addr}, metadata !{{[0-9]+}})
+; CHECK: call void @llvm.dbg.declare(metadata !{i32* %i}, metadata !{{[0-9]+}})
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.9.0"
+
+define i32 @main(i32 %argc, i8** %argv) uwtable ssp {
+entry:
+  %retval = alloca i32, align 4
+  %argc.addr = alloca i32, align 4
+  %argv.addr = alloca i8**, align 8
+  store i32 0, i32* %retval
+  store i32 %argc, i32* %argc.addr, align 4
+  call void @llvm.dbg.declare(metadata !{i32* %argc.addr}, metadata !14), !dbg !15
+  store i8** %argv, i8*** %argv.addr, align 8
+  call void @llvm.dbg.declare(metadata !{i8*** %argv.addr}, metadata !16), !dbg !15
+  %0 = load i32* %argc.addr, align 4, !dbg !17
+  %1 = load i8*** %argv.addr, align 8, !dbg !17
+  call void @test(i32 %0, i8** %1), !dbg !17
+  ret i32 0, !dbg !19
+}
+
+declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
+
+declare void @test(i32, i8**)
+
+!llvm.dbg.cu = !{!0}
+
+!0 = metadata !{i32 786449, i32 0, i32 4, metadata !"main.cpp", metadata !"/private/tmp", metadata !"clang version 3.3 (trunk 173515)", i1 true, i1 false, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !1} ; [ DW_TAG_compile_unit ]
+!1 = metadata !{metadata !2}
+!2 = metadata !{i32 0}
+!3 = metadata !{metadata !4}
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 786478, i32 0, metadata !6, metadata !"main", metadata !"main", metadata !"", metadata !6, i32 3, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (i32, i8**)* @main, null, null, metadata !1, i32 4} ; [ DW_TAG_subprogram ]
+!6 = metadata !{i32 786473, metadata !"main.cpp", metadata !"/private/tmp", null} ; [ DW_TAG_file_type ]
+!7 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
+!8 = metadata !{metadata !9, metadata !9, metadata !10}
+!9 = metadata !{i32 786468, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
+!10 = metadata !{i32 786447, null, metadata !"", null, i32 0, i64 64, i64 64, i64 0, i32 0, metadata !11} ; [ DW_TAG_pointer_type ]
+!11 = metadata !{i32 786447, null, metadata !"", null, i32 0, i64 64, i64 64, i64 0, i32 0, metadata !12} ; [ DW_TAG_pointer_type ]
+!12 = metadata !{i32 786470, null, metadata !"", null, i32 0, i64 0, i64 0, i64 0, i32 0, metadata !13} ; [ DW_TAG_const_type ]
+!13 = metadata !{i32 786468, null, metadata !"char", null, i32 0, i64 8, i64 8, i64 0, i32 0, i32 6} ; [ DW_TAG_base_type ]
+!14 = metadata !{i32 786689, metadata !5, metadata !"argc", metadata !6, i32 16777219, metadata !9, i32 0, i32 0} ; [ DW_TAG_arg_variable ]
+!15 = metadata !{i32 3, i32 0, metadata !5, null}
+!16 = metadata !{i32 786689, metadata !5, metadata !"argv", metadata !6, i32 33554435, metadata !10, i32 0, i32 0} ; [ DW_TAG_arg_variable ]
+!17 = metadata !{i32 5, i32 0, metadata !18, null}
+!18 = metadata !{i32 786443, metadata !5, i32 4, i32 0, metadata !6, i32 0} ; [ DW_TAG_lexical_block ]
+!19 = metadata !{i32 6, i32 0, metadata !18, null}
diff --git a/test/Linker/DbgDeclare2.ll b/test/Linker/DbgDeclare2.ll
new file mode 100644
index 0000000000..e2e56b2893
--- /dev/null
+++ b/test/Linker/DbgDeclare2.ll
@@ -0,0 +1,76 @@
+; This file is used by 2011-08-04-DebugLoc.ll, so it doesn't actually do anything itself
+;
+; RUN: true
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.9.0"
+
+define void @test(i32 %argc, i8** %argv) uwtable ssp {
+entry:
+  %argc.addr = alloca i32, align 4
+  %argv.addr = alloca i8**, align 8
+  %i = alloca i32, align 4
+  store i32 %argc, i32* %argc.addr, align 4
+  call void @llvm.dbg.declare(metadata !{i32* %argc.addr}, metadata !14), !dbg !15
+  store i8** %argv, i8*** %argv.addr, align 8
+  call void @llvm.dbg.declare(metadata !{i8*** %argv.addr}, metadata !16), !dbg !15
+  call void @llvm.dbg.declare(metadata !{i32* %i}, metadata !17), !dbg !20
+  store i32 0, i32* %i, align 4, !dbg !20
+  br label %for.cond, !dbg !20
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4, !dbg !20
+  %1 = load i32* %argc.addr, align 4, !dbg !20
+  %cmp = icmp slt i32 %0, %1, !dbg !20
+  br i1 %cmp, label %for.body, label %for.end, !dbg !20
+
+for.body:                                         ; preds = %for.cond
+  %2 = load i32* %i, align 4, !dbg !21
+  %idxprom = sext i32 %2 to i64, !dbg !21
+  %3 = load i8*** %argv.addr, align 8, !dbg !21
+  %arrayidx = getelementptr inbounds i8** %3, i64 %idxprom, !dbg !21
+  %4 = load i8** %arrayidx, align 8, !dbg !21
+  %call = call i32 @puts(i8* %4), !dbg !21
+  br label %for.inc, !dbg !23
+
+for.inc:                                          ; preds = %for.body
+  %5 = load i32* %i, align 4, !dbg !20
+  %inc = add nsw i32 %5, 1, !dbg !20
+  store i32 %inc, i32* %i, align 4, !dbg !20
+  br label %for.cond, !dbg !20
+
+for.end:                                          ; preds = %for.cond
+  ret void, !dbg !24
+}
+
+declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
+
+declare i32 @puts(i8*)
+
+!llvm.dbg.cu = !{!0}
+
+!0 = metadata !{i32 786449, i32 0, i32 4, metadata !"main.cpp", metadata !"/private/tmp", metadata !"clang version 3.3 (trunk 173515)", i1 true, i1 false, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !1} ; [ DW_TAG_compile_unit ]
+!1 = metadata !{metadata !2}
+!2 = metadata !{i32 0}
+!3 = metadata !{metadata !4}
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 786478, i32 0, metadata !6, metadata !"print_args", metadata !"print_args", metadata !"test", metadata !6, i32 4, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, void (i32, i8**)* @test, null, null, metadata !1, i32 5} ; [ DW_TAG_subprogram ]
+!6 = metadata !{i32 786473, metadata !"test.cpp", metadata !"/private/tmp", null} ; [ DW_TAG_file_type ]
+!7 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
+!8 = metadata !{null, metadata !9, metadata !10}
+!9 = metadata !{i32 786468, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
+!10 = metadata !{i32 786447, null, metadata !"", null, i32 0, i64 64, i64 64, i64 0, i32 0, metadata !11} ; [ DW_TAG_pointer_type ]
+!11 = metadata !{i32 786447, null, metadata !"", null, i32 0, i64 64, i64 64, i64 0, i32 0, metadata !12} ; [ DW_TAG_pointer_type ]
+!12 = metadata !{i32 786470, null, metadata !"", null, i32 0, i64 0, i64 0, i64 0, i32 0, metadata !13} ; [ DW_TAG_const_type ]
+!13 = metadata !{i32 786468, null, metadata !"char", null, i32 0, i64 8, i64 8, i64 0, i32 0, i32 6} ; [ DW_TAG_base_type ]
+!14 = metadata !{i32 786689, metadata !5, metadata !"argc", metadata !6, i32 16777220, metadata !9, i32 0, i32 0} ; [ DW_TAG_arg_variable ]
+!15 = metadata !{i32 4, i32 0, metadata !5, null}
+!16 = metadata !{i32 786689, metadata !5, metadata !"argv", metadata !6, i32 33554436, metadata !10, i32 0, i32 0} ; [ DW_TAG_arg_variable ]
+!17 = metadata !{i32 786688, metadata !18, metadata !"i", metadata !6, i32 6, metadata !9, i32 0, i32 0} ; [ DW_TAG_auto_variable ]
+!18 = metadata !{i32 786443, metadata !19, i32 6, i32 0, metadata !6, i32 1} ; [ DW_TAG_lexical_block ]
+!19 = metadata !{i32 786443, metadata !5, i32 5, i32 0, metadata !6, i32 0} ; [ DW_TAG_lexical_block ]
+!20 = metadata !{i32 6, i32 0, metadata !18, null}
+!21 = metadata !{i32 8, i32 0, metadata !22, null}
+!22 = metadata !{i32 786443, metadata !18, i32 7, i32 0, metadata !6, i32 2} ; [ DW_TAG_lexical_block ]
+!23 = metadata !{i32 9, i32 0, metadata !22, null}
+!24 = metadata !{i32 10, i32 0, metadata !19, null}