DebugInfo: Fix overwriting/loss of inlined arguments to recursively inlined functions.

Due to an unnecessary special case, inlined arguments that happened to
be from the same function as they were inlined into were misclassified
as non-inline arguments and would overwrite the non-inlined arguments.

Assert that we never overwrite a function's arguments, and stop
misclassifying inlined arguments as non-inline arguments to fix this
issue.

Excuse the rather crappy test case - handcrafted IR might do better, or
someone who understands better how to tickle the inliner to create a
recursive inlining situation like this (though it may also be necessary
to tickle the variable in a particular way to cause it to be recorded in
the MMI side table and go down this particular path for location
information).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215157 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index a0d58c6310ca91bd876982e9bd2d8ea1b9eb2d6f..7150a09cd4ca157b0813d95c7cb61881e1713079 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1144,6 +1144,7 @@ bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
   // arguments does the function have at source level.
   if (ArgNo > Size)
     CurrentFnArguments.resize(ArgNo * 2);
+  assert(!CurrentFnArguments[ArgNo - 1]);
   CurrentFnArguments[ArgNo - 1] = Var;
   return true;
 }
@@ -1309,10 +1310,7 @@ DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
       continue;
 
     LexicalScope *Scope = nullptr;
-    if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
-        DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
-      Scope = LScopes.getCurrentFunctionScope();
-    else if (MDNode *IA = DV.getInlinedAt()) {
+    if (MDNode *IA = DV.getInlinedAt()) {
       DebugLoc DL = DebugLoc::getFromDILocation(IA);
       Scope = LScopes.findInlinedScope(DebugLoc::get(
           DL.getLine(), DL.getCol(), DV.getContext(), IA));

diff --git a/test/DebugInfo/X86/recursive_inlining.ll b/test/DebugInfo/X86/recursive_inlining.ll
new file mode 100644 (file)
index 0000000..3949ad6
--- /dev/null
+++ b/test/DebugInfo/X86/recursive_inlining.ll
@@ -0,0 +1,275 @@
+; REQUIRES: object-emission
+
+; RUN: llc -filetype=obj -O0 < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+
+; This isn't a very pretty test case - I imagine there might be other ways to
+; tickle the optimizers into producing the desired code, but I haven't found
+; them.
+
+; The issue is when a function is inlined into itself, the inlined argument
+; accidentally overwrote the concrete argument and was lost.
+
+; IR generated from the following source compiled with clang -g:
+; void fn1(void *);
+; void fn2(int, int, int, int);
+; void fn3();
+; void fn8();
+; struct C {
+;   int b;
+;   void m_fn2() {
+;     fn8();
+;     if (b) fn2(0, 0, 0, 0);
+;     fn3();
+;   }
+; };
+; C *x;
+; inline void fn7() {}
+; void fn6() {
+;   fn8();
+;   x->m_fn2();
+;   fn7();
+; }
+; void fn3() { fn6(); }
+; void fn4() { x->m_fn2(); }
+; void fn5() { x->m_fn2(); }
+
+; The definition of C and declaration of C::m_fn2
+; CHECK: DW_TAG_structure_type
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK: DW_TAG_member
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK: [[M_FN2_DECL:.*]]:   DW_TAG_subprogram
+; CHECK-NOT: DW_TAG
+; CHECK:     DW_AT_name {{.*}} "m_fn2"
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK: [[M_FN2_THIS_DECL:.*]]:     DW_TAG_formal_parameter
+
+; The abstract definition of C::m_fn2
+; CHECK: [[M_FN2_ABS_DEF:.*]]: DW_TAG_subprogram
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_AT_specification {{.*}} {[[M_FN2_DECL]]}
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_AT_inline
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK: [[M_FN2_THIS_ABS_DEF:.*]]:   DW_TAG_formal_parameter
+; CHECK-NOT: DW_TAG
+; CHECK:     DW_AT_name {{.*}} "this"
+
+; Skip some other functions
+; CHECK: DW_TAG_subprogram
+; CHECK: DW_TAG_subprogram
+; CHECK: DW_TAG_subprogram
+
+; The concrete definition of C::m_fn2
+; CHECK: DW_TAG_subprogram
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_AT_abstract_origin {{.*}} {[[M_FN2_ABS_DEF]]}
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:   DW_TAG_formal_parameter
+; CHECK-NOT: DW_TAG
+; CHECK:     DW_AT_abstract_origin {{.*}} {[[M_FN2_THIS_ABS_DEF]]}
+; CHECK-NOT: {{DW_TAG|NULL}}
+; Inlined fn3:
+; CHECK:     DW_TAG_inlined_subroutine
+; CHECK-NOT: {{DW_TAG|NULL}}
+; Inlined fn6:
+; CHECK:       DW_TAG_inlined_subroutine
+; CHECK-NOT: {{DW_TAG|NULL}}
+; Inlined C::m_fn2:
+; CHECK:         DW_TAG_inlined_subroutine
+; CHECK-NOT: DW_TAG
+; CHECK:           DW_AT_abstract_origin {{.*}} {[[M_FN2_ABS_DEF]]}
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:           DW_TAG_formal_parameter
+; CHECK-NOT: DW_TAG
+; CHECK:              DW_AT_abstract_origin {{.*}} {[[M_FN2_THIS_ABS_DEF]]}
+
+
+
+%struct.C = type { i32 }
+
+@x = global %struct.C* null, align 8
+
+; Function Attrs: nounwind
+define void @_Z3fn6v() #0 {
+entry:
+  tail call void @_Z3fn8v() #3, !dbg !31
+  %0 = load %struct.C** @x, align 8, !dbg !32, !tbaa !33
+  tail call void @llvm.dbg.value(metadata !{%struct.C* %0}, i64 0, metadata !37) #3, !dbg !38
+  tail call void @_Z3fn8v() #3, !dbg !39
+  %b.i = getelementptr inbounds %struct.C* %0, i64 0, i32 0, !dbg !40
+  %1 = load i32* %b.i, align 4, !dbg !40, !tbaa !42
+  %tobool.i = icmp eq i32 %1, 0, !dbg !40
+  br i1 %tobool.i, label %_ZN1C5m_fn2Ev.exit, label %if.then.i, !dbg !40
+
+if.then.i:                                        ; preds = %entry
+  tail call void @_Z3fn2iiii(i32 0, i32 0, i32 0, i32 0) #3, !dbg !45
+  br label %_ZN1C5m_fn2Ev.exit, !dbg !45
+
+_ZN1C5m_fn2Ev.exit:                               ; preds = %entry, %if.then.i
+  tail call void @_Z3fn3v() #3, !dbg !47
+  ret void, !dbg !48
+}
+
+declare void @_Z3fn8v() #1
+
+; Function Attrs: nounwind
+define linkonce_odr void @_ZN1C5m_fn2Ev(%struct.C* nocapture readonly %this) #0 align 2 {
+entry:
+  tail call void @llvm.dbg.value(metadata !{%struct.C* %this}, i64 0, metadata !24), !dbg !49
+  tail call void @_Z3fn8v() #3, !dbg !50
+  %b = getelementptr inbounds %struct.C* %this, i64 0, i32 0, !dbg !51
+  %0 = load i32* %b, align 4, !dbg !51, !tbaa !42
+  %tobool = icmp eq i32 %0, 0, !dbg !51
+  br i1 %tobool, label %if.end, label %if.then, !dbg !51
+
+if.then:                                          ; preds = %entry
+  tail call void @_Z3fn2iiii(i32 0, i32 0, i32 0, i32 0) #3, !dbg !52
+  br label %if.end, !dbg !52
+
+if.end:                                           ; preds = %entry, %if.then
+  tail call void @_Z3fn8v() #3, !dbg !53
+  %1 = load %struct.C** @x, align 8, !dbg !56, !tbaa !33
+  tail call void @llvm.dbg.value(metadata !{%struct.C* %1}, i64 0, metadata !57) #3, !dbg !58
+  tail call void @_Z3fn8v() #3, !dbg !59
+  %b.i.i = getelementptr inbounds %struct.C* %1, i64 0, i32 0, !dbg !60
+  %2 = load i32* %b.i.i, align 4, !dbg !60, !tbaa !42
+  %tobool.i.i = icmp eq i32 %2, 0, !dbg !60
+  br i1 %tobool.i.i, label %_Z3fn6v.exit, label %if.then.i.i, !dbg !60
+
+if.then.i.i:                                      ; preds = %if.end
+  tail call void @_Z3fn2iiii(i32 0, i32 0, i32 0, i32 0) #3, !dbg !61
+  br label %_Z3fn6v.exit, !dbg !61
+
+_Z3fn6v.exit:                                     ; preds = %if.end, %if.then.i.i
+  tail call void @_Z3fn3v() #3, !dbg !62
+  ret void, !dbg !63
+}
+
+; Function Attrs: nounwind
+define void @_Z3fn3v() #0 {
+entry:
+  br label %tailrecurse
+
+tailrecurse:                                      ; preds = %tailrecurse.backedge, %entry
+  tail call void @_Z3fn8v() #3, !dbg !64
+  %0 = load %struct.C** @x, align 8, !dbg !66, !tbaa !33
+  tail call void @llvm.dbg.value(metadata !{%struct.C* %0}, i64 0, metadata !67) #3, !dbg !68
+  tail call void @_Z3fn8v() #3, !dbg !69
+  %b.i.i = getelementptr inbounds %struct.C* %0, i64 0, i32 0, !dbg !70
+  %1 = load i32* %b.i.i, align 4, !dbg !70, !tbaa !42
+  %tobool.i.i = icmp eq i32 %1, 0, !dbg !70
+  br i1 %tobool.i.i, label %tailrecurse.backedge, label %if.then.i.i, !dbg !70
+
+tailrecurse.backedge:                             ; preds = %tailrecurse, %if.then.i.i
+  br label %tailrecurse
+
+if.then.i.i:                                      ; preds = %tailrecurse
+  tail call void @_Z3fn2iiii(i32 0, i32 0, i32 0, i32 0) #3, !dbg !71
+  br label %tailrecurse.backedge, !dbg !71
+}
+
+; Function Attrs: nounwind
+define void @_Z3fn4v() #0 {
+entry:
+  %0 = load %struct.C** @x, align 8, !dbg !72, !tbaa !33
+  tail call void @_ZN1C5m_fn2Ev(%struct.C* %0), !dbg !72
+  ret void, !dbg !72
+}
+
+; Function Attrs: nounwind
+define void @_Z3fn5v() #0 {
+entry:
+  %0 = load %struct.C** @x, align 8, !dbg !73, !tbaa !33
+  tail call void @_ZN1C5m_fn2Ev(%struct.C* %0), !dbg !73
+  ret void, !dbg !73
+}
+
+declare void @_Z3fn2iiii(i32, i32, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata) #2
+
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { nounwind readnone }
+attributes #3 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!28, !29}
+!llvm.ident = !{!30}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.6.0 ", i1 true, metadata !"", i32 0, metadata !2, metadata !3, metadata !13, metadata !26, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/usr/local/google/home/blaikie/dev/scratch/missing_concrete_variable_on_darwin/reduce/<stdin>] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !"<stdin>", metadata !"/usr/local/google/home/blaikie/dev/scratch/missing_concrete_variable_on_darwin/reduce"}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786451, metadata !5, null, metadata !"C", i32 5, i64 32, i64 32, i32 0, i32 0, null, metadata !6, i32 0, null, null, metadata !"_ZTS1C"} ; [ DW_TAG_structure_type ] [C] [line 5, size 32, align 32, offset 0] [def] [from ]
+!5 = metadata !{metadata !"recursive_inlining.cpp", metadata !"/usr/local/google/home/blaikie/dev/scratch/missing_concrete_variable_on_darwin/reduce"}
+!6 = metadata !{metadata !7, metadata !9}
+!7 = metadata !{i32 786445, metadata !5, metadata !"_ZTS1C", metadata !"b", i32 6, i64 32, i64 32, i64 0, i32 0, metadata !8} ; [ DW_TAG_member ] [b] [line 6, size 32, align 32, offset 0] [from int]
+!8 = metadata !{i32 786468, null, null, 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]
+!9 = metadata !{i32 786478, metadata !5, metadata !"_ZTS1C", metadata !"m_fn2", metadata !"m_fn2", metadata !"_ZN1C5m_fn2Ev", i32 7, metadata !10, i1 false, i1 false, i32 0, i32 0, null, i32 256, i1 true, null, null, i32 0, null, i32 7} ; [ DW_TAG_subprogram ] [line 7] [m_fn2]
+!10 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !11, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!11 = metadata !{null, metadata !12}
+!12 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 64, i64 64, i64 0, i32 1088, metadata !"_ZTS1C"} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [artificial] [from _ZTS1C]
+!13 = metadata !{metadata !14, metadata !18, metadata !19, metadata !20, metadata !21, metadata !22}
+!14 = metadata !{i32 786478, metadata !5, metadata !15, metadata !"fn6", metadata !"fn6", metadata !"_Z3fn6v", i32 15, metadata !16, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void ()* @_Z3fn6v, null, null, metadata !2, i32 15} ; [ DW_TAG_subprogram ] [line 15] [def] [fn6]
+!15 = metadata !{i32 786473, metadata !5}         ; [ DW_TAG_file_type ] [/usr/local/google/home/blaikie/dev/scratch/missing_concrete_variable_on_darwin/reduce/recursive_inlining.cpp]
+!16 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !17, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!17 = metadata !{null}
+!18 = metadata !{i32 786478, metadata !5, metadata !15, metadata !"fn3", metadata !"fn3", metadata !"_Z3fn3v", i32 20, metadata !16, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void ()* @_Z3fn3v, null, null, metadata !2, i32 20} ; [ DW_TAG_subprogram ] [line 20] [def] [fn3]
+!19 = metadata !{i32 786478, metadata !5, metadata !15, metadata !"fn4", metadata !"fn4", metadata !"_Z3fn4v", i32 21, metadata !16, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void ()* @_Z3fn4v, null, null, metadata !2, i32 21} ; [ DW_TAG_subprogram ] [line 21] [def] [fn4]
+!20 = metadata !{i32 786478, metadata !5, metadata !15, metadata !"fn5", metadata !"fn5", metadata !"_Z3fn5v", i32 22, metadata !16, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void ()* @_Z3fn5v, null, null, metadata !2, i32 22} ; [ DW_TAG_subprogram ] [line 22] [def] [fn5]
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+!22 = metadata !{i32 786478, metadata !5, metadata !"_ZTS1C", metadata !"m_fn2", metadata !"m_fn2", metadata !"_ZN1C5m_fn2Ev", i32 7, metadata !10, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void (%struct.C*)* @_ZN1C5m_fn2Ev, null, metadata !9, metadata !23, i32 7} ; [ DW_TAG_subprogram ] [line 7] [def] [m_fn2]
+!23 = metadata !{metadata !24}
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+!28 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
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