llvm-project/llvm/test/Linker/replaced-function-matches-f...

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; RUN: llvm-link %s %S/Inputs/replaced-function-matches-first-subprogram.ll -S | FileCheck %s
; Generated from C++ source:
;
; // repro/t.h
; template <class T> struct Class {
; int foo() { return 0; }
; };
; // repro/d1/t1.cpp
; #include "t.h"
; int foo() { return Class<int>().foo(); }
; // repro/d2/t2.cpp
; #include "t.h"
; template struct Class<int>;
%struct.Class = type { i8 }
; CHECK: define i32 @_Z3foov(){{.*}} !dbg ![[SP1:[0-9]+]]
define i32 @_Z3foov() !dbg !4 {
entry:
%tmp = alloca %struct.Class, align 1
%call = call i32 @_ZN5ClassIiE3fooEv(%struct.Class* %tmp), !dbg !14
ret i32 %call, !dbg !14
}
; CHECK: define weak_odr i32 @_ZN5ClassIiE3fooEv(%struct.Class* %this){{.*}} !dbg ![[SP2:[0-9]+]] {
; CHECK-NOT: }
; CHECK: !dbg ![[LOC:[0-9]+]]
define linkonce_odr i32 @_ZN5ClassIiE3fooEv(%struct.Class* %this) align 2 !dbg !7 {
entry:
%this.addr = alloca %struct.Class*, align 8
store %struct.Class* %this, %struct.Class** %this.addr, align 8
%this1 = load %struct.Class*, %struct.Class** %this.addr
ret i32 0, !dbg !15
}
; CHECK: !llvm.dbg.cu = !{![[CU1:[0-9]+]], ![[CU2:[0-9]+]]}
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!10, !11, !12}
!llvm.ident = !{!13}
; Extract out the list of subprograms from each compile unit.
; CHECK: ![[CU1:[0-9]+]] = distinct !DICompileUnit(
; CHECK: ![[CU2:[0-9]+]] = distinct !DICompileUnit(
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.6.0 (trunk 224193) (llvm/trunk 224197)", isOptimized: false, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
!1 = !DIFile(filename: "t1.cpp", directory: "/Users/dexonsmith/data/llvm/staging/test/Linker/repro/d1")
!2 = !{}
!4 = distinct !DISubprogram(name: "foo", line: 2, isLocal: false, isDefinition: true, flags: DIFlagPrototyped, isOptimized: false, unit: !0, scopeLine: 2, file: !1, scope: !5, type: !6, retainedNodes: !2)
!5 = !DIFile(filename: "t1.cpp", directory: "/Users/dexonsmith/data/llvm/staging/test/Linker/repro/d1")
!6 = !DISubroutineType(types: !2)
; Extract out the file from the replaced subprogram.
; CHECK-DAG: ![[SP2:.*]] = distinct !DISubprogram({{.*}} file: ![[FILE:[0-9]+]],{{.*}}, unit: ![[CU2]]
Reapply "Linker: Drop function pointers for overridden subprograms" This reverts commit r233254, effectively reapplying r233164 (and its successors), with an additional testcase for when subprograms match exactly. This fixes PR22792 (again). I'm using the same approach, but I've moved up the call to `stripReplacedSubprograms()`. The function pointers need to be dropped before mapping any metadata from the source module, or else this can drop the function from new subprograms that have merged (via Metadata uniquing) with the old ones. Dropping the pointers first prevents them from merging. **** The original commit message follows. **** Linker: Drop function pointers for overridden subprograms Instead of dropping subprograms that have been overridden, just set their function pointers to `nullptr`. This is a minor adjustment to the stop-gap fix for PR21910 committed in r224487, and fixes the crasher from PR22792. The problem that r224487 put a band-aid on: how do we find the canonical subprogram for a `Function`? Since the backend currently relies on `DebugInfoFinder` (which does a naive in-order traversal of compile units and picks the first subprogram) for this, r224487 tried dropping non-canonical subprograms. Dropping subprograms fails because the backend *also* builds up a map from subprogram to compile unit (`DwarfDebug::SPMap`) based on the subprogram lists. A missing subprogram causes segfaults later when an inlined reference (such as in this testcase) is created. Instead, just drop the `Function` pointer to `nullptr`, which nicely mirrors what happens when an already-inlined `Function` is optimized out. We can't really be sure that it's the same definition anyway, as the testcase demonstrates. This still isn't completely satisfactory. Two flaws at least that I can think of: - I still haven't found a straightforward way to make this symmetric in the IR. (Interestingly, the DWARF output is already symmetric, and I've tested for that to be sure we don't regress.) - Using `DebugInfoFinder` to find the canonical subprogram for a function is kind of crazy. We should just attach metadata to the function, like this: define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) { llvm-svn: 233302
2015-03-27 02:35:30 +08:00
; We can't use CHECK-NOT/CHECK-SAME with a CHECK-DAG, so rely on field order to
; prove that there's no function: here.
; CHECK-DAG: ![[SP2r:.*]] = {{.*}}!DISubprogram({{.*}} isOptimized: false, unit: ![[CU1]], retainedNodes:
!7 = distinct !DISubprogram(name: "foo", line: 2, isLocal: false, isDefinition: true, flags: DIFlagPrototyped, isOptimized: false, unit: !0, scopeLine: 2, file: !8, scope: !9, type: !6, retainedNodes: !2)
; The new subprogram should be pointing at the new directory.
; CHECK-DAG: ![[FILE]] = !DIFile(filename: "../t.h", directory: "/Users/dexonsmith/data/llvm/staging/test/Linker/repro/d2")
!8 = !DIFile(filename: "../t.h", directory: "/Users/dexonsmith/data/llvm/staging/test/Linker/repro/d1")
!9 = !DIFile(filename: "../t.h", directory: "/Users/dexonsmith/data/llvm/staging/test/Linker/repro/d1")
!10 = !{i32 2, !"Dwarf Version", i32 2}
DebugInfo: Move new hierarchy into place Move the specialized metadata nodes for the new debug info hierarchy into place, finishing off PR22464. I've done bootstraps (and all that) and I'm confident this commit is NFC as far as DWARF output is concerned. Let me know if I'm wrong :). The code changes are fairly mechanical: - Bumped the "Debug Info Version". - `DIBuilder` now creates the appropriate subclass of `MDNode`. - Subclasses of DIDescriptor now expect to hold their "MD" counterparts (e.g., `DIBasicType` expects `MDBasicType`). - Deleted a ton of dead code in `AsmWriter.cpp` and `DebugInfo.cpp` for printing comments. - Big update to LangRef to describe the nodes in the new hierarchy. Feel free to make it better. Testcase changes are enormous. There's an accompanying clang commit on its way. If you have out-of-tree debug info testcases, I just broke your build. - `upgrade-specialized-nodes.sh` is attached to PR22564. I used it to update all the IR testcases. - Unfortunately I failed to find way to script the updates to CHECK lines, so I updated all of these by hand. This was fairly painful, since the old CHECKs are difficult to reason about. That's one of the benefits of the new hierarchy. This work isn't quite finished, BTW. The `DIDescriptor` subclasses are almost empty wrappers, but not quite: they still have loose casting checks (see the `RETURN_FROM_RAW()` macro). Once they're completely gutted, I'll rename the "MD" classes to "DI" and kill the wrappers. I also expect to make a few schema changes now that it's easier to reason about everything. llvm-svn: 231082
2015-03-04 01:24:31 +08:00
!11 = !{i32 2, !"Debug Info Version", i32 3}
!12 = !{i32 1, !"PIC Level", i32 2}
!13 = !{!"clang version 3.6.0 (trunk 224193) (llvm/trunk 224197)"}
!14 = !DILocation(line: 2, column: 20, scope: !4)
; The same subprogram should be pointed to by inside the !dbg reference.
; CHECK: ![[LOC]] = !DILocation(line: 2, column: 15, scope: ![[SP2]])
!15 = !DILocation(line: 2, column: 15, scope: !7)