llvm-6502/test/DebugInfo/inline-debug-info-multiret.ll
David Blaikie f93662d3d5 DebugInfo: Use distinct inlinedAt MDLocations to avoid separate inlined calls being coalesced
When two calls from the same MDLocation are inlined they currently get
treated as one inlined function call (creating difficulty debugging,
duplicate variables, etc).

Clang worked around this by including column information on inline calls
which doesn't address LTO inlining or calls to the same function from
the same line and column (such as through a macro). It also didn't
address ctor and member function calls.

By making the inlinedAt locations distinct, every call site has an
explicitly distinct location that cannot be coalesced with any other
call.

This can produce linearly (2x in the worst case where every call is
inlined and the call instruction has a non-call instruction at the same
location) more debug locations. Any increase beyond that are in cases
where the Clang workaround was insufficient and the new scheme is
creating necessary distinct nodes that were being erroneously coalesced
previously.

After this change to LLVM the incomplete workarounds in Clang. That
should reduce the number of debug locations (in a build without column
info, the default on Darwin, not the default on Linux) by not creating
pseudo-distinct locations for every call to an inline function.

(oh, and I made the inlined-at chain rebuilding iterative instead of
recursive because I was having trouble wrapping my head around it the
way it was - open to discussion on the right design for that function
(including going back to a recursive solution))

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226736 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-21 22:57:29 +00:00

157 lines
6.8 KiB
LLVM

; RUN: opt -inline -S < %s | FileCheck %s
;
; A hand-edited version of inline-debug-info.ll to test inlining of a
; function with multiple returns.
;
; Make sure the branch instructions created during inlining has a debug location,
; so the range of the inlined function is correct.
; CHECK: br label %_Z4testi.exit, !dbg ![[MD:[0-9]+]]
; CHECK: br label %_Z4testi.exit, !dbg ![[MD]]
; CHECK: br label %invoke.cont, !dbg ![[MD]]
; The branch instruction has the source location of line 9 and its inlined location
; has the source location of line 14.
; CHECK: ![[INL:[0-9]+]] = distinct !MDLocation(line: 14, scope: {{.*}})
; CHECK: ![[MD]] = !MDLocation(line: 9, scope: {{.*}}, inlinedAt: ![[INL]])
; ModuleID = 'test.cpp'
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-darwin12.0.0"
@_ZTIi = external constant i8*
@global_var = external global i32
; copy of above function with multiple returns
define i32 @_Z4testi(i32 %k) {
entry:
%retval = alloca i32, align 4
%k.addr = alloca i32, align 4
%k2 = alloca i32, align 4
store i32 %k, i32* %k.addr, align 4
call void @llvm.dbg.declare(metadata i32* %k.addr, metadata !13, metadata !{!"0x102"}), !dbg !14
call void @llvm.dbg.declare(metadata i32* %k2, metadata !15, metadata !{!"0x102"}), !dbg !16
%0 = load i32* %k.addr, align 4, !dbg !16
%call = call i32 @_Z8test_exti(i32 %0), !dbg !16
store i32 %call, i32* %k2, align 4, !dbg !16
%1 = load i32* %k2, align 4, !dbg !17
%cmp = icmp sgt i32 %1, 100, !dbg !17
br i1 %cmp, label %if.then, label %if.end, !dbg !17
if.then: ; preds = %entry
%2 = load i32* %k2, align 4, !dbg !18
store i32 %2, i32* %retval, !dbg !18
br label %return, !dbg !18
if.end: ; preds = %entry
store i32 0, i32* %retval, !dbg !19
%3 = load i32* %retval, !dbg !20 ; hand-edited
ret i32 %3, !dbg !20 ; hand-edited
return: ; preds = %if.end, %if.then
%4 = load i32* %retval, !dbg !20
ret i32 %4, !dbg !20
}
; Function Attrs: nounwind readnone
declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
declare i32 @_Z8test_exti(i32)
define i32 @_Z5test2v() {
entry:
%exn.slot = alloca i8*
%ehselector.slot = alloca i32
%e = alloca i32, align 4
%0 = load i32* @global_var, align 4, !dbg !21
%call = invoke i32 @_Z4testi(i32 %0)
to label %invoke.cont unwind label %lpad, !dbg !21
invoke.cont: ; preds = %entry
br label %try.cont, !dbg !23
lpad: ; preds = %entry
%1 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
catch i8* bitcast (i8** @_ZTIi to i8*), !dbg !21
%2 = extractvalue { i8*, i32 } %1, 0, !dbg !21
store i8* %2, i8** %exn.slot, !dbg !21
%3 = extractvalue { i8*, i32 } %1, 1, !dbg !21
store i32 %3, i32* %ehselector.slot, !dbg !21
br label %catch.dispatch, !dbg !21
catch.dispatch: ; preds = %lpad
%sel = load i32* %ehselector.slot, !dbg !23
%4 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) #2, !dbg !23
%matches = icmp eq i32 %sel, %4, !dbg !23
br i1 %matches, label %catch, label %eh.resume, !dbg !23
catch: ; preds = %catch.dispatch
call void @llvm.dbg.declare(metadata i32* %e, metadata !24, metadata !{!"0x102"}), !dbg !25
%exn = load i8** %exn.slot, !dbg !23
%5 = call i8* @__cxa_begin_catch(i8* %exn) #2, !dbg !23
%6 = bitcast i8* %5 to i32*, !dbg !23
%7 = load i32* %6, align 4, !dbg !23
store i32 %7, i32* %e, align 4, !dbg !23
store i32 0, i32* @global_var, align 4, !dbg !26
call void @__cxa_end_catch() #2, !dbg !28
br label %try.cont, !dbg !28
try.cont: ; preds = %catch, %invoke.cont
store i32 1, i32* @global_var, align 4, !dbg !29
ret i32 0, !dbg !30
eh.resume: ; preds = %catch.dispatch
%exn1 = load i8** %exn.slot, !dbg !23
%sel2 = load i32* %ehselector.slot, !dbg !23
%lpad.val = insertvalue { i8*, i32 } undef, i8* %exn1, 0, !dbg !23
%lpad.val3 = insertvalue { i8*, i32 } %lpad.val, i32 %sel2, 1, !dbg !23
resume { i8*, i32 } %lpad.val3, !dbg !23
}
declare i32 @__gxx_personality_v0(...)
; Function Attrs: nounwind readnone
declare i32 @llvm.eh.typeid.for(i8*) #1
declare i8* @__cxa_begin_catch(i8*)
declare void @__cxa_end_catch()
attributes #1 = { nounwind readnone }
attributes #2 = { nounwind }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!31}
!0 = !{!"0x11\004\00clang version 3.3 \000\00\000\00\000", !1, !2, !2, !3, !2, !2} ; [ DW_TAG_compile_unit ] [<unknown>] [DW_LANG_C_plus_plus]
!1 = !{!"<unknown>", !""}
!2 = !{i32 0}
!3 = !{!4, !10}
!4 = !{!"0x2e\00test\00test\00_Z4testi\004\000\001\000\006\00256\000\004", !5, !6, !7, null, i32 (i32)* @_Z4testi, null, null, !2} ; [ DW_TAG_subprogram ] [line 4] [def] [test]
!5 = !{!"test.cpp", !""}
!6 = !{!"0x29", !5} ; [ DW_TAG_file_type ] [test.cpp]
!7 = !{!"0x15\00\000\000\000\000\000\000", i32 0, null, null, !8, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
!8 = !{!9, !9}
!9 = !{!"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
!10 = !{!"0x2e\00test2\00test2\00_Z5test2v\0011\000\001\000\006\00256\000\0011", !5, !6, !11, null, i32 ()* @_Z5test2v, null, null, !2} ; [ DW_TAG_subprogram ] [line 11] [def] [test2]
!11 = !{!"0x15\00\000\000\000\000\000\000", i32 0, null, null, !12, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
!12 = !{!9}
!13 = !{!"0x101\00k\0016777220\000", !4, !6, !9} ; [ DW_TAG_arg_variable ] [k] [line 4]
!14 = !MDLocation(line: 4, scope: !4)
!15 = !{!"0x100\00k2\005\000", !4, !6, !9} ; [ DW_TAG_auto_variable ] [k2] [line 5]
!16 = !MDLocation(line: 5, scope: !4)
!17 = !MDLocation(line: 6, scope: !4)
!18 = !MDLocation(line: 7, scope: !4)
!19 = !MDLocation(line: 8, scope: !4)
!20 = !MDLocation(line: 9, scope: !4)
!21 = !MDLocation(line: 14, scope: !22)
!22 = !{!"0xb\0013\000\000", !5, !10} ; [ DW_TAG_lexical_block ] [test.cpp]
!23 = !MDLocation(line: 15, scope: !22)
!24 = !{!"0x100\00e\0016\000", !10, !6, !9} ; [ DW_TAG_auto_variable ] [e] [line 16]
!25 = !MDLocation(line: 16, scope: !10)
!26 = !MDLocation(line: 17, scope: !27)
!27 = !{!"0xb\0016\000\001", !5, !10} ; [ DW_TAG_lexical_block ] [test.cpp]
!28 = !MDLocation(line: 18, scope: !27)
!29 = !MDLocation(line: 19, scope: !10)
!30 = !MDLocation(line: 20, scope: !10)
!31 = !{i32 1, !"Debug Info Version", i32 2}