llvm-mirror/test/Linker/subprogram-linkonce-weak.ll
Adrian Prantl fb3abba237 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

llvm-svn: 266446
2016-04-15 15:57:41 +00:00

161 lines
6.9 KiB
LLVM

; RUN: llvm-link %s %S/Inputs/subprogram-linkonce-weak.ll -S -o %t1
; RUN: FileCheck %s -check-prefix=LW -check-prefix=CHECK <%t1
; RUN: llvm-link %S/Inputs/subprogram-linkonce-weak.ll %s -S -o %t2
; RUN: FileCheck %s -check-prefix=WL -check-prefix=CHECK <%t2
; REQUIRES: default_triple
; This testcase tests the following flow:
; - File A defines a linkonce version of @foo which has inlined into @bar.
; - File B defines a weak version of @foo (different definition).
; - Linkage rules state File B version of @foo wins.
; - @bar still has inlined debug info related to the linkonce @foo.
;
; This should fix PR22792, although the testcase was hand-written. There's a
; RUN line with a crasher for llc at the end with checks for the DWARF output.
; The LW prefix means linkonce (this file) first, then weak (the other file).
; The WL prefix means weak (the other file) first, then linkonce (this file).
; We'll see @bar before @foo if this file is first.
; LW: define i32 @bar({{.*}} !dbg ![[BARSP:[0-9]+]]
; LW: %sum = add i32 %a, %b, !dbg ![[FOOINBAR:[0-9]+]]
; LW: ret i32 %sum, !dbg ![[BARRET:[0-9]+]]
; LW: define weak i32 @foo({{.*}} !dbg ![[WEAKFOOSP:[0-9]+]]
; LW: %sum = call i32 @fastadd(i32 %a, i32 %b), !dbg ![[FOOCALL:[0-9]+]]
; LW: ret i32 %sum, !dbg ![[FOORET:[0-9]+]]
; We'll see @foo before @bar if this file is second.
; WL: define weak i32 @foo({{.*}} !dbg ![[WEAKFOOSP:[0-9]+]]
; WL: %sum = call i32 @fastadd(i32 %a, i32 %b), !dbg ![[FOOCALL:[0-9]+]]
; WL: ret i32 %sum, !dbg ![[FOORET:[0-9]+]]
; WL: define i32 @bar({{.*}} !dbg ![[BARSP:[0-9]+]]
; WL: %sum = add i32 %a, %b, !dbg ![[FOOINBAR:[0-9]+]]
; WL: ret i32 %sum, !dbg ![[BARRET:[0-9]+]]
define i32 @bar(i32 %a, i32 %b) !dbg !3 {
entry:
%sum = add i32 %a, %b, !dbg !DILocation(line: 2, scope: !4,
inlinedAt: !DILocation(line: 12, scope: !3))
ret i32 %sum, !dbg !DILocation(line: 13, scope: !3)
}
define linkonce i32 @foo(i32 %a, i32 %b) !dbg !4 {
entry:
%sum = add i32 %a, %b, !dbg !DILocation(line: 2, scope: !4)
ret i32 %sum, !dbg !DILocation(line: 3, scope: !4)
}
!llvm.module.flags = !{!0}
!0 = !{i32 2, !"Debug Info Version", i32 3}
; CHECK-LABEL: !llvm.dbg.cu =
; LW-SAME: !{![[LCU:[0-9]+]], ![[WCU:[0-9]+]]}
; WL-SAME: !{![[WCU:[0-9]+]], ![[LCU:[0-9]+]]}
!llvm.dbg.cu = !{!1}
; LW: ![[LCU]] = distinct !DICompileUnit(
; LW: ![[WCU]] = distinct !DICompileUnit(
; LW: ![[BARSP]] = distinct !DISubprogram(name: "bar",{{.*}} unit: ![[LCU]]
; LW: ![[FOOINBAR]] = !DILocation(line: 2, scope: ![[FOOSP:.*]], inlinedAt: ![[BARIA:[0-9]+]])
; LW: ![[FOOSP]] = distinct !DISubprogram(name: "foo",{{.*}} unit: ![[LCU]]
; LW: ![[BARIA]] = !DILocation(line: 12, scope: ![[BARSP]])
; LW: ![[BARRET]] = !DILocation(line: 13, scope: ![[BARSP]])
; LW: ![[WEAKFOOSP]] = distinct !DISubprogram(name: "foo",{{.*}} unit: ![[WCU]]
; LW: ![[FOOCALL]] = !DILocation(line: 52, scope: ![[WEAKFOOSP]])
; LW: ![[FOORET]] = !DILocation(line: 53, scope: ![[WEAKFOOSP]])
; Same as above, but reordered.
; WL: ![[WCU]] = distinct !DICompileUnit(
; WL: ![[LCU]] = distinct !DICompileUnit(
; WL: ![[WEAKFOOSP]] = distinct !DISubprogram(name: "foo",{{.*}} unit: ![[WCU]]
; WL: ![[FOOCALL]] = !DILocation(line: 52, scope: ![[WEAKFOOSP]])
; WL: ![[FOORET]] = !DILocation(line: 53, scope: ![[WEAKFOOSP]])
; WL: ![[BARSP]] = distinct !DISubprogram(name: "bar",{{.*}} unit: ![[LCU]]
; WL: ![[FOOINBAR]] = !DILocation(line: 2, scope: ![[FOOSP:.*]], inlinedAt: ![[BARIA:[0-9]+]])
; WL: ![[FOOSP]] = distinct !DISubprogram(name: "foo",{{.*}} unit: ![[LCU]]
; WL: ![[BARIA]] = !DILocation(line: 12, scope: ![[BARSP]])
; WL: ![[BARRET]] = !DILocation(line: 13, scope: ![[BARSP]])
!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, emissionKind: FullDebug)
!2 = !DIFile(filename: "bar.c", directory: "/path/to/dir")
!3 = distinct !DISubprogram(file: !2, scope: !2, line: 11, name: "bar", type: !5, unit: !1)
!4 = distinct !DISubprogram(file: !2, scope: !2, line: 1, name: "foo", type: !5, unit: !1)
!5 = !DISubroutineType(types: !{})
; Crasher for llc.
; REQUIRES: object-emission
; RUN: %llc_dwarf -filetype=obj -O0 %t1 -o %t1.o
; RUN: llvm-dwarfdump %t1.o -debug-dump=all | FileCheck %s -check-prefix=DWLW -check-prefix=DW
; RUN: %llc_dwarf -filetype=obj -O0 %t2 -o %t2.o
; RUN: llvm-dwarfdump %t2.o -debug-dump=all | FileCheck %s -check-prefix=DWWL -check-prefix=DW
; Check that the debug info for the discarded linkonce version of @foo doesn't
; reference any code, and that the other subprograms look correct.
; DW-LABEL: .debug_info contents:
; DWLW: DW_TAG_compile_unit
; DWLW: DW_AT_name {{.*}}"bar.c"
; DWLW: DW_TAG_subprogram
; DWLW-NOT: DW_AT_low_pc
; DWLW-NOT: DW_AT_high_pc
; DWLW: DW_AT_name {{.*}}foo
; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}bar.c"
; DWLW: DW_AT_decl_line {{.*}}(1)
; DWLW: DW_TAG_subprogram
; DWLW: DW_AT_low_pc
; DWLW: DW_AT_high_pc
; DWLW: DW_AT_name {{.*}}bar
; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}bar.c"
; DWLW: DW_AT_decl_line {{.*}}(11)
; DWLW: DW_TAG_inlined_subroutine
; DWLW: DW_AT_abstract_origin
; DWLW: DW_TAG_compile_unit
; DWLW: DW_AT_name {{.*}}"foo.c"
; DWLW: DW_TAG_subprogram
; DWLW: DW_AT_low_pc
; DWLW: DW_AT_high_pc
; DWLW: DW_AT_name {{.*}}foo
; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}foo.c"
; DWLW: DW_AT_decl_line {{.*}}(51)
; The DWARF output is already symmetric (just reordered).
; DWWL: DW_TAG_compile_unit
; DWWL: DW_AT_name {{.*}}"foo.c"
; DWWL: DW_TAG_subprogram
; DWWL: DW_AT_low_pc
; DWWL: DW_AT_high_pc
; DWWL: DW_AT_name {{.*}}foo
; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}foo.c"
; DWWL: DW_AT_decl_line {{.*}}(51)
; DWWL: DW_TAG_compile_unit
; DWWL: DW_AT_name {{.*}}"bar.c"
; DWWL: DW_TAG_subprogram
; DWWL-NOT: DW_AT_low_pc
; DWWL-NOT: DW_AT_high_pc
; DWWL: DW_AT_name {{.*}}foo
; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}bar.c"
; DWWL: DW_AT_decl_line {{.*}}(1)
; DWWL: DW_TAG_subprogram
; DWWL: DW_AT_low_pc
; DWWL: DW_AT_high_pc
; DWWL: DW_AT_name {{.*}}bar
; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}bar.c"
; DWWL: DW_AT_decl_line {{.*}}(11)
; DWWL: DW_TAG_inlined_subroutine
; DWWL: DW_AT_abstract_origin
; DW-LABEL: .debug_line contents:
; Check that we have the right things in the line table as well.
; DWLW-LABEL: file_names[{{ *}}1]{{.*}} bar.c
; DWLW: 2 0 1 0 0 is_stmt prologue_end
; DWLW-LABEL: file_names[{{ *}}1]{{.*}} foo.c
; DWLW: 52 0 1 0 0 is_stmt prologue_end
; DWLW-NOT: prologue_end
; DWWL-LABEL: file_names[{{ *}}1]{{.*}} foo.c
; DWWL: 52 0 1 0 0 is_stmt prologue_end
; DWWL-LABEL: file_names[{{ *}}1]{{.*}} bar.c
; DWWL: 2 0 1 0 0 is_stmt prologue_end
; DWWL-NOT: prologue_end