llvm/lib/Transforms
Gor Nishanov d73686e841 [cloning] Do not duplicate types when cloning functions
Summary:
This is an addon to the change rl304488 cloning fixes. (Originally rl304226 reverted rl304228 and reapplied rl304488 https://reviews.llvm.org/D33655)

rl304488 works great when DILocalVariables that comes from the inlined function has a 'unique-ed' type, but,
in the case when the variable type is distinct we will create a second DILocalVariable in the scope of the original function that was inlined.

Consider cloning of the following function:
```
define private void @f() !dbg !5 {
  %1 = alloca i32, !dbg !11
  call void @llvm.dbg.declare(metadata i32* %1, metadata !14, metadata !12), !dbg !18
  ret void, !dbg !18
}

!14 = !DILocalVariable(name: "inlined", scope: !15, file: !6, line: 5, type: !17) ; came from an inlined function
!15 = distinct !DISubprogram(name: "inlined", linkageName: "inlined", scope: null, file: !6, line: 8, type: !7, isLocal: true, isDefinition: true, scopeLine: 9, isOptimized: false, unit: !0, variables: !16)
!16 = !{!14}
!17 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "some_struct", size: 32, align: 32)
```

Without this fix, when function 'f' is cloned, we will create another DILocalVariable for "inlined", due to its type being distinct.

```
define private void @f.1() !dbg !23 {
  %1 = alloca i32, !dbg !26
  call void @llvm.dbg.declare(metadata i32* %1, metadata !28, metadata !12), !dbg !30
  ret void, !dbg !30
}

!14 = !DILocalVariable(name: "inlined", scope: !15, file: !6, line: 5, type: !17)
!15 = distinct !DISubprogram(name: "inlined", linkageName: "inlined", scope: null, file: !6, line: 8, type: !7, isLocal: true, isDefinition: true, scopeLine: 9, isOptimized: false, unit: !0, variables: !16)
!16 = !{!14}
!17 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "some_struct", size: 32, align: 32)
 ;
!28 = !DILocalVariable(name: "inlined", scope: !15, file: !6, line: 5, type: !29) ; OOPS second DILocalVariable
!29 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "some_struct", size: 32, align: 32)
```

Now we have two DILocalVariable for "inlined" within the same scope. This result in assert in AsmPrinter/DwarfDebug.h:131: void llvm::DbgVariable::addMMIEntry(const llvm::DbgVariable &): Assertion `V.Var == Var && "conflicting variable"' failed.
(Full example: See: https://bugs.llvm.org/show_bug.cgi?id=33492)

In this change we prevent duplication of types so that when a metadata for DILocalVariable is cloned it will get uniqued to the same metadate node as an original variable.

Reviewers: loladiro, dblaikie, aprantl, echristo

Reviewed By: loladiro

Subscribers: EricWF, llvm-commits

Differential Revision: https://reviews.llvm.org/D35106

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307418 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-07 18:24:20 +00:00
..
Coroutines Remove inline keyword from inline classof methods 2017-06-29 19:35:17 +00:00
Hello Add auto-exporting of symbols from tools so that plugins work on Windows 2016-05-26 11:16:43 +00:00
InstCombine [InstCombine] No need to pass DataLayout to helper functions if we're passing the InstCombiner object. We can just ask it for the DataLayout. NFC 2017-07-06 23:18:43 +00:00
Instrumentation Revert r307342, r307343. 2017-07-07 01:31:23 +00:00
IPO [lib/LTO] Add a comment to explain where we set the linkage in the summary. 2017-07-06 20:04:20 +00:00
ObjCARC Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
Scalar [InferAddressSpaces] Fix assertion about null pointer 2017-07-07 02:40:13 +00:00
Utils [cloning] Do not duplicate types when cloning functions 2017-07-07 18:24:20 +00:00
Vectorize [SLPVectorizer] Add an extra parameter to cancelScheduling function, NFCI. 2017-07-05 13:53:03 +00:00
CMakeLists.txt [coroutines] Part 3 of N: Adding Boilerplate for Coroutine Passes 2016-07-28 21:04:31 +00:00
LLVMBuild.txt [coroutines] Part 3 of N: Adding Boilerplate for Coroutine Passes 2016-07-28 21:04:31 +00:00