Restore lit feature object-emission

[nigelp-xmos]

Summary

D73568 removed the lit feature object-emission, because it was introduced for a
target which did not support the integrated assembler, and that target no longer
required the feature. XCore still does not support the integrated assembler,
so a build with XCore as the default target fails tests requiring
object-emission. This issue was not publicly visible because there was not a
buildbot for XCore as the default target. We fixed the failures downstream. We
now have builder clang-xcore-ubuntu-20-x64 on the staging buildmaster, which
shows the failures. We would like to fix them upstream.

[nigelp-xmos]

Invite reviewers around lit.cfg.py changes.

[MaskRay]

For test/DebugInfo/Generic/, can you exclude xcore in lit.cfg.py instead of patching nearly every file?

[nigelp-xmos]

@MaskRay Thanks for the comment. I will look at that. But DebugInfo/Generic has 78 files requiring object-emission and 60 not requiring it - isn't it worth still running the 60? (I looked at some to see what they were doing: running llvm-as, llvm-dis, and checking assembly output.)

[nigelp-xmos]

DebugInfo/Generic can be handled by two lines in lit.local.cfg:

elif 'xcore' in config.target_triple:
config.unsupported = True

If that is better than qualifying the individual tests, I'll rebase and upload the patch.

[MaskRay]

There are other targets which don't support/use integrated assembler but they are not host targets, so that is fine.
Now you want to run XCore as something similar like a host target and exercise these tests, I think it is reasonable to add more requirement like supporting integrated assembler.
(IIRC we requested the same for M68k.)
Otherwise new tests may be developed with subsequent fixups that add REQUIRES: object-emission. That is certainly a maintenance burden.

This is a phase ordering issue. If an integrated assembler is planned, adding REQUIRES: object-emission and then removing REQUIRES: object-emission is just churn.
If there are few tests in some directory which needs REQUIRES: object-emission, I think adding the annotation is fine if that conveniences you.

[nigelp-xmos]

Thanks, I see what you mean about churn and maintenance. The integrated assembler is planned. I will rework the patch.

Do you mean that a build for a host would normally have that host as its default target, and the generic tests only need to pass for that target?

[nigelp-xmos]

Omit DebugInfo/Generic on XCore to avoid annotating 70 separate files.

[nigelp-xmos]

Tidy up.

[nigelp-xmos]

As suggested, excluded xcore from DebugInfo/Generic rather than patching each file.

We previously found a code issue by running default-target tests as xcore (D92108), so it was worth doing. Is it not right to run like this? @MaskRay I must admit I don't understand how this is running like a host target.

[nigelp-xmos]

Invite debug info code owner to review.

[JDevlieghere]

LGTM if @MaskRay is happy.

[echristo]

SGTM. :)

-eric

[nigelp-xmos]

Thank you for the reviews, I appreciate people taking time on something that is only for this target.

llvm/test/CodeGen/Generic/dwarf-md5.ll

 ; MD5 checksums provided by IR should be passed through to asm.
 ; They'll be emitted to an object file only for DWARF 5 or later.
 
+; REQUIRES: object-emission
 ; RUN: %llc_dwarf -dwarf-version 4 -filetype=asm -o - %s | FileCheck %s --check-prefix=ASM-4
 ; RUN: %llc_dwarf -dwarf-version 5 -filetype=asm -o - %s | FileCheck %s --check-prefix=ASM-5
 ; RUN: %llc_dwarf -dwarf-version 4 -filetype=obj -o %t4.o %s
 ; RUN: llvm-dwarfdump -debug-line %t4.o | FileCheck %s --check-prefix=OBJ
 ; RUN: %llc_dwarf -dwarf-version 5 -filetype=obj -o %t5.o %s
 ; RUN: llvm-dwarfdump -debug-line %t5.o | FileCheck %s --check-prefixes=OBJ,OBJ-5
 
 ; ASM-4-NOT: .file 0

llvm/test/CodeGen/Generic/dwarf-source.ll

 ; Source text provided by IR should be passed through to asm.
 ; It is emitted to an object file only for DWARF 5 or later.
 
+; REQUIRES: object-emission
 ; RUN: %llc_dwarf -dwarf-version 4 -filetype=asm -o - %s | FileCheck %s --check-prefix=ASM-4
 ; RUN: %llc_dwarf -dwarf-version 5 -filetype=asm -o - %s | FileCheck %s --check-prefix=ASM-5
 ; RUN: %llc_dwarf -dwarf-version 4 -filetype=obj -o %t4.o %s
 ; RUN: llvm-dwarfdump -debug-line %t4.o | FileCheck %s --check-prefixes=OBJ,OBJ-4
 ; RUN: %llc_dwarf -dwarf-version 5 -filetype=obj -o %t5.o %s
 ; RUN: llvm-dwarfdump -debug-line %t5.o | FileCheck %s --check-prefixes=OBJ,OBJ-5
 
 ; ASM-4: .file 1 "/test{{.*[/\\]}}t1.h" source "11111111111111111111111111111111"

llvm/test/DebugInfo/Generic/lit.local.cfg

 if not config.target_triple:
     config.unsupported = True
+elif 'xcore' in config.target_triple:
+    config.unsupported = True

llvm/test/DebugInfo/cross-cu-scope.ll

 ; RUN: %llc_dwarf %s -filetype=obj -o %t
 ; RUN: llvm-dwarfdump -debug-info %t | FileCheck %s
-; REQUIRES: default_triple
+; REQUIRES: default_triple, object-emission
 
 ; Reduced test case from PR35212. Two DISubprogram belong to a different CU but
 ; share a scope. Both are declarations and end up in the scope's CU. We want to
 ; check that the CU from the context DIE is used (rather than from the IR).
 ; This manifests itself by the DW_base_type ending up in the second CU, rather
 ; than in the first one as specified in the IR.
 
 ; CHECK: DW_TAG_compile_unit

llvm/test/DebugInfo/debuglineinfo-path.ll

 ; Make sure that absolute source dir is detected correctly regardless of the platform.
 
 ; On powerpc llvm-nm describes win_func as a global variable, not a function. It breaks the test.
 ; It is not essential to DWARF path handling code we're testing here.
 ; UNSUPPORTED: powerpc
-; REQUIRES: default_triple
+; REQUIRES: default_triple, object-emission
 ; RUN: %llc_dwarf -O0 -filetype=obj -o %t < %s
 ; RUN: llvm-nm --radix=o %t | grep posix_absolute_func > %t.posix_absolute_func
 ; RUN: llvm-nm --radix=o %t | grep posix_relative_func > %t.posix_relative_func
 ; RUN: llvm-nm --radix=o %t | grep win_func > %t.win_func
 ; RUN: llvm-symbolizer --functions=linkage --inlining --no-demangle --obj %t < %t.posix_absolute_func | FileCheck %s --check-prefix=POSIX_A
 ; RUN: llvm-symbolizer --functions=linkage --inlining --no-demangle --obj %t < %t.posix_relative_func | FileCheck %s --check-prefix=POSIX_R
 ; RUN: llvm-symbolizer --functions=linkage --inlining --no-demangle --obj %t < %t.win_func | FileCheck %s --check-prefix=WIN
 

llvm/test/DebugInfo/dwo.ll

 ; RUN: %llc_dwarf %s -filetype=obj -o %t
 ; RUN: llvm-dwarfdump -debug-info %t | FileCheck %s
-; REQUIRES: default_triple
+; REQUIRES: default_triple, object-emission
 ;
 ; CHECK: DW_TAG_compile_unit
 ; CHECK-NOT: dwo_id
 ;
 ; The skeleton must come second or LLDB may get confused.
 ; CHECK: DW_TAG_compile_unit
 ; CHECK: DW_AT_GNU_dwo_id {{.*}}abcd
 ; CHECK: DW_AT_GNU_dwo_name {{.*}}"my.dwo"

llvm/test/DebugInfo/omit-empty.ll

 ; RUN: %llc_dwarf %s -filetype=obj -o - | llvm-objdump -h - | FileCheck %s
-; REQUIRES: default_triple
+; REQUIRES: default_triple, object-emission
 
 ; CHECK-NOT: .debug_
 
 !llvm.dbg.cu = !{!0, !5}
 !llvm.module.flags = !{!3, !4}
 
 !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: false, runtimeVersion: 2, emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
 !1 = !DIFile(filename: "<stdin>", directory: "/")

llvm/test/DebugInfo/skeletoncu.ll

 ; RUN: %llc_dwarf %s -filetype=obj -o %t
 ; RUN: llvm-dwarfdump -debug-info %t | FileCheck %s
 ; CHECK: DW_TAG_compile_unit
 ; CHECK: DW_AT_GNU_dwo_id {{.*}}abcd
 ; CHECK: DW_AT_GNU_dwo_name {{.*}}"my.dwo"
-; REQUIRES: default_triple
+; REQUIRES: default_triple, object-emission
  
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!3, !4}
 
 !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: false, runtimeVersion: 2, splitDebugFilename: "my.dwo", emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2, imports: !2, dwoId: 43981)
 !1 = !DIFile(filename: "<stdin>", directory: "/")
 !2 = !{}
 !3 = !{i32 2, !"Dwarf Version", i32 4}
 !4 = !{i32 2, !"Debug Info Version", i32 3}
 

llvm/test/Linker/subprogram-linkonce-weak.ll

 
 !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 --all | FileCheck %s -check-prefix=DWLW -check-prefix=DW
 ; RUN: %llc_dwarf -filetype=obj -O0 %t2 -o %t2.o
 ; RUN: llvm-dwarfdump %t2.o --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:

llvm/test/Linker/type-unique-odr-a.ll

-; REQUIRES: default_triple
+; REQUIRES: default_triple, object-emission
 ;
 ; RUN: llvm-link %s %p/type-unique-odr-b.ll -S -o - \
 ; RUN:   | %llc_dwarf -dwarf-linkage-names=All -filetype=obj -O0 \
 ; RUN:   | llvm-dwarfdump -v -debug-info - \
 ; RUN:   | FileCheck %s
 ; RUN: llvm-link %p/type-unique-odr-b.ll %s -S -o - \
 ; RUN:   | %llc_dwarf -dwarf-linkage-names=All -filetype=obj -O0 \
 ; RUN:   | llvm-dwarfdump -v -debug-info - \

llvm/test/Linker/type-unique-simple-a.ll

-; REQUIRES: default_triple
+; REQUIRES: default_triple, object-emission
 
 ; RUN: llvm-link %s %p/type-unique-simple-b.ll -S -o %t
 ; RUN: cat %t | FileCheck %s -check-prefix=LINK
 ; RUN: %llc_dwarf -filetype=obj -O0 < %t > %t2
 ; RUN: llvm-dwarfdump -v -debug-info %t2 | FileCheck %s
 
 ; Make sure the backend generates a single DIE and uses ref_addr.
 ; CHECK: 0x[[BASE:.*]]: DW_TAG_structure_type

llvm/test/Linker/type-unique-simple2-a.ll

-; REQUIRES: default_triple
+; REQUIRES: default_triple, object-emission
 ;
 ; RUN: llvm-link %s %p/type-unique-simple2-b.ll -S -o - | %llc_dwarf -filetype=obj -O0 | llvm-dwarfdump -v -debug-info - | FileCheck %s
 ;
 ; Tests for a merge error where attributes are inserted twice into the same DIE.
 ;
 ; $ cat ab.h
 ; typedef int foo_t;
 ; class A {

llvm/test/Linker/type-unique-simple2.ll

-; REQUIRES: default_triple
+; REQUIRES: default_triple, object-emission
 
 ; RUN: llvm-link %S/Inputs/type-unique-simple2-a.ll %S/Inputs/type-unique-simple2-b.ll -S -o %t
 ; RUN: cat %t | FileCheck %S/Inputs/type-unique-simple2-a.ll -check-prefix=LINK
 ; RUN: %llc_dwarf -filetype=obj -O0 < %t > %t2
 ; RUN: llvm-dwarfdump -v -debug-info %t2 | FileCheck %S/Inputs/type-unique-simple2-a.ll

llvm/test/Linker/type-unique-type-array-a.ll

-; REQUIRES: default_triple
+; REQUIRES: default_triple, object-emission
 ;
 ; RUN: llvm-link %s %p/type-unique-type-array-b.ll -S -o - | %llc_dwarf -filetype=obj -O0 | llvm-dwarfdump -v -debug-info - | FileCheck %s
 ;
 ; rdar://problem/17628609
 ;
 ; cat -n a.cpp
 ;     1 struct SA {
 ;     2   int a;

llvm/test/lit.cfg.py

def have_cxx_shared_library():
     return False
 
 if have_cxx_shared_library():
     config.available_features.add('cxx-shared-library')
 
 if config.libcxx_used:
     config.available_features.add('libcxx-used')
 
+# Direct object generation
+if not 'xcore' in config.target_triple:
+    config.available_features.add('object-emission')
+
 # LLVM can be configured with an empty default triple
 # Some tests are "generic" and require a valid default triple
 if config.target_triple:
     config.available_features.add('default_triple')
 
 import subprocess