[yaml2obj][obj2yaml][test] - Add base tests for relocation addends.

[grimar]

Summary

We had no test for Addend field of a relocation. Though the
current behavior is not ideal and might need to be fixed.

This patch adds 2 test cases to document the current
behavior and add a few FIXMEs. These FIXME are fixed in the
follow-up: https://reviews.llvm.org/D75527

[MaskRay]

llvm/test/tools/obj2yaml/relocation-addend.yaml

23

The stdint.h constant is named INT64_MIN

Testing the hexadecimal literal will be useful, too.

[grimar]

llvm/test/tools/obj2yaml/relocation-addend.yaml

23

It is a test for obj2yaml, it only can print decimals.

Hexadecimal values as inputs are tested in yaml2obj test suite.

The stdint.h constant is named INT64_MIN

I'll rename, thanks.

[jhenderson]

llvm/test/tools/obj2yaml/relocation-addend.yaml

2

Should we check 0 too? Not sure really, but I suppose it shows that the value 0 is printed, despite being entirely leading zeroes.

8

-1 -> 1

23

You don't need the '=' sign here. Just "with the value INT64_MIN" works.

55

-1 -> 1

llvm/test/tools/yaml2obj/ELF/relocation-addend.yaml

2

handles relocation addend descriptions

14

Single '#'.

17

in decimal form

Same elsewhere

28

'#'

[MaskRay]

I think a signed integer representation may look better in most situations. r_addend is usually additive, e.g. S + A, G + A. Due to PC-offset bias, an r_addend on x86-32/x86-64/ARM/MIPS is usually negative (well, x86-32/ARM/MIPS use REL instead of RELA), so we may see a lot of 0xFFFFFFFC. -4 is likely prettier.

[grimar]

• Addressed review comments.

llvm/test/tools/obj2yaml/relocation-addend.yaml

2

Reasonable. Done.

[jhenderson]

llvm/test/tools/obj2yaml/relocation-addend.yaml

84

I'm not sure we need a 32-bit case for this one, as the behaviour is independent of the bitness.

llvm/test/tools/yaml2obj/ELF/relocation-addend.yaml

2

Delete the second "handles"

[grimar]

• Addressed review comments.

llvm/test/tools/obj2yaml/relocation-addend.yaml

84

Yeah, that is why I have no 64-bit case at all. To improve,
I've changed this test to be "Case 3" and made it use the first YAML document.

[jhenderson]

LGTM. Might be worth waiting for @MaskRay too.

[MaskRay]

llvm/test/tools/obj2yaml/relocation-addend.yaml

73

Optional: yaml2obj --docnum=2 %s -D ADDEND=-1 | obj2yaml | FileCheck ... can omit intermediate object files.

llvm/test/tools/yaml2obj/ELF/relocation-addend.yaml

52

(You can omit Offset:)

61

Decimal commas are unneeded because 2147483647 below do not have them.

66

cmp %t4 %t5

cmp makes it clear that the object files are identical.

86

cmp %t7 %t8

[grimar]

llvm/test/tools/obj2yaml/relocation-addend.yaml

73

I prefer do not use "|" because I find such tests harder to work with when they fail.

llvm/test/tools/yaml2obj/ELF/relocation-addend.yaml

61

Because 2147483647 below are not a part of a comment :)
2,147,483,647 is easier to read.
(Imagine if I wanted to mention 2^63 in a comment, which is 9223372036854775807. It
would be better to write it as 9,223,372,036,854,775,807 instead I think).

66

Right. Done.

llvm/test/tools/obj2yaml/relocation-addend.yaml

+## Test how obj2yaml emits relocation addend descriptions.
+## We document that relocation addends are dumped as signed int64 decimal values.
+
+## Case 1: Check a 64-bit object.
+
+## Check how obj2yaml dumps an addend with an arbitrary positive value.
+## We use 1 as it is the first possible positive value.
+# RUN: yaml2obj --docnum=1 %s -o %t1 -D ADDEND=1
+# RUN: obj2yaml %t1 | FileCheck %s --check-prefix=ELF64 --match-full-lines -DADDEND=1
+
+# ELF64:      Relocations:
+# ELF64-NEXT:  - Symbol: foo
+# ELF64-NEXT:    Type:   R_X86_64_PC32
+# ELF64-NEXT:    Addend: [[ADDEND]]
+
+## Check how obj2yaml dumps an addend with an arbitrary negative value.
+## We use -1 as it is the first possible negative value.
+# RUN: yaml2obj --docnum=1 %s -o %t2 -D ADDEND=-1
+# RUN: obj2yaml %t2 | FileCheck %s --check-prefix=ELF64 --match-full-lines -DADDEND=-1
+
+## Check how obj2yaml dumps an addend with the value INT64_MAX.
+# RUN: yaml2obj --docnum=1 %s -o %t3 -D ADDEND=9223372036854775807
+# RUN: obj2yaml %t3 | FileCheck %s --check-prefix=ELF64 --match-full-lines -DADDEND=9223372036854775807
+
+## Check how obj2yaml dumps an addend with the value INT64_MIN.
+# RUN: yaml2obj --docnum=1 %s -o %t4 -D ADDEND=-9223372036854775808
+# RUN: obj2yaml %t4 | FileCheck %s --check-prefix=ELF64 --match-full-lines -DADDEND=-9223372036854775808
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_X86_64
+Sections:
+  - Name: .text
+    Type: SHT_PROGBITS
+  - Name: .rela.text
+    Type: SHT_RELA
+    Info: .text
+    Link: .symtab
+    Relocations:
+      - Type:   R_X86_64_PC32
+        Offset: 0x0
+        Symbol: foo
+        Addend: [[ADDEND]]
+Symbols:
+  - Name: foo
+
+## Check that obj2yaml omits zero addends.
+# RUN: yaml2obj --docnum=1 %s -o %t5 -D ADDEND=0
+# RUN: obj2yaml %t5 | FileCheck %s --implicit-check-not="Addend:"
+# RUN: yaml2obj --docnum=1 %s -o %t6 -D ADDEND=0x0
+# RUN: obj2yaml %t6 | FileCheck %s --implicit-check-not="Addend:"
+
+## Case 2: Check a 32-bit object.
+
+## Check how obj2yaml dumps an addend with an arbitrary positive value.
+## We use 1 as it is the first possible positive value.
+# RUN: yaml2obj --docnum=2 %s -o %t7 -D ADDEND=1
+# RUN: obj2yaml %t7 | FileCheck %s --check-prefix=ELF32 --match-full-lines -DADDEND=1
+
+# ELF32:      Relocations:
+# ELF32-NEXT:  - Symbol: foo
+# ELF32-NEXT:    Type:   R_386_PC32
+# ELF32-NEXT:    Addend: [[ADDEND]]
+
+## Check how obj2yaml dumps an addend with an arbitrary negative value.
+## We use -1 as it is the first possible negative value.
+# RUN: yaml2obj --docnum=2 %s -o %t8 -D ADDEND=-1
+# RUN: obj2yaml %t8 | FileCheck %s --check-prefix=ELF32 --match-full-lines -DADDEND=-1
+
+## Check how obj2yaml dumps an addend with the value INT32_MAX.
+# RUN: yaml2obj --docnum=2 %s -o %t9 -D ADDEND=2147483647
+# RUN: obj2yaml %t9 | FileCheck %s --check-prefix=ELF32 --match-full-lines -DADDEND=2147483647
+
+## Check how obj2yaml dumps an addend with the value INT32_MIN.
+# RUN: yaml2obj --docnum=2 %s -o %t10 -D ADDEND=-2147483648
+# RUN: obj2yaml %t10 | FileCheck %s --check-prefix=ELF32 --match-full-lines -DADDEND=-2147483648
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS32
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_386
+Sections:
+  - Name: .text
+    Type: SHT_PROGBITS
+  - Name: .rela.text
+    Type: SHT_RELA
+    Info: .text
+    Link: .symtab
+    Relocations:
+      - Type:   R_386_PC32
+        Offset: 0x0
+        Symbol: foo
+        Addend: [[ADDEND]]
+Symbols:
+  - Name: foo
+
+## Case 3: Check that obj2yaml omits zero addends.
+# RUN: yaml2obj --docnum=1 %s -o %t11 -D ADDEND=0
+# RUN: obj2yaml %t11 | FileCheck %s --implicit-check-not="Addend:"
+# RUN: yaml2obj --docnum=1 %s -o %t12 -D ADDEND=0x0
+# RUN: obj2yaml %t12 | FileCheck %s --implicit-check-not="Addend:"

llvm/test/tools/yaml2obj/ELF/relocation-addend.yaml

+## Here we document how yaml2obj handles relocation addend descriptions.
+
+## Case 1: Check a 64-bit object.
+
+## Case 1.1: Document we accept an addend with the
+## value INT64_MAX = 2^63-1 = 0x7FFFFFFFFFFFFFFF = 9223372036854775807.
+
+# RUN: yaml2obj %s -o %t1 -D ADDEND=9223372036854775807
+# RUN: llvm-readobj -r %t1 | FileCheck %s --check-prefix=MAX64
+# RUN: yaml2obj %s -o %t2 -D ADDEND=0x7FFFFFFFFFFFFFFF
+# RUN: llvm-readobj -r %t2 | FileCheck %s --check-prefix=MAX64
+
+# MAX64: 0x0 R_X86_64_PC32 foo 0x7FFFFFFFFFFFFFFF
+
+## Case 1.2: Check we report an error when an addend is greater than INT64_MAX and
+## it is in decimal form. We use (INT64_MAX + 1).
+# RUN: not yaml2obj %s -o %t3 -D ADDEND=9223372036854775808 2>&1 | FileCheck %s --check-prefix=OVERFLOW64
+
+# OVERFLOW64: error: invalid number
+
+## Case 1.3: Document we accept an addend with the
+## value INT64_MIN = -2^63 = 0x8000000000000000 = -9223372036854775808.
+
+# RUN: yaml2obj %s -o %t3 -D ADDEND=-9223372036854775808
+# RUN: llvm-readobj -r %t3 | FileCheck %s --check-prefix=MIN64
+
+# MIN64: 0x0 R_X86_64_PC32 foo 0x8000000000000000
+
+## FIXME: We should support the following case instead.
+# RUN: not yaml2obj %s -o /dev/null -D ADDEND=0x8000000000000000 2>&1 | FileCheck %s --check-prefix=OVERFLOW64
+
+## Case 1.4: Check we report an error when an addend is less than INT64_MIN and
+## it is in decimal form. We use (INT64_MIN - 1).
+# RUN: not yaml2obj %s -o /dev/null -D ADDEND=-9223372036854775809 2>&1 | FileCheck %s --check-prefix=OVERFLOW64
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_X86_64
+Sections:
+  - Name: .text
+    Type: SHT_PROGBITS
+  - Name: .rela.text
+    Type: SHT_RELA
+    Info: .text
+    Link: .symtab
+    Relocations:
+      - Type:   R_X86_64_PC32
+        Symbol: foo
+        Addend: [[ADDEND]]
+Symbols:
+  - Name: foo
+
+## Case 2: Check a 32-bit object.
+
+## Case 2.1: Document we accept an addend with the
+## value INT32_MAX = 2^31-1 = 0x7FFFFFFF = 2,147,483,647.
+
+# RUN: yaml2obj --docnum=2 %s -o %t4 -D ADDEND=2147483647
+# RUN: llvm-readobj -r %t4 | FileCheck %s --check-prefix=MAX32
+# RUN: yaml2obj --docnum=2 %s -o %t5 -D ADDEND=0x7FFFFFFF
+# RUN: cmp %t4 %t5
+
+# MAX32: 0x0 R_386_PC32 foo 0x7FFFFFFF{{$}}
+
+## Case 2.2: Check we report an error when an addend is greater than INT32_MAX and
+## it is specified in decimal form. We use (INT32_MAX + 1).
+
+## FIXME: The following case should fail, see OVERFLOW64.
+# RUN: yaml2obj --docnum=2 %s -o %t6 -D ADDEND=2147483648
+# RUN: llvm-readobj -r %t6 | FileCheck %s --check-prefix=OVERFLOW32-1
+
+# OVERFLOW32-1: 0x0 R_386_PC32 foo 0x80000000{{$}}
+
+## Case 2.3: Document we accept an addend with the
+## value INT32_MIN = -2^31 = 0x80000000 = -2,147,483,648.
+
+# RUN: yaml2obj --docnum=2 %s -o %t7 -D ADDEND=-2147483648
+# RUN: llvm-readobj -r %t7 | FileCheck %s --check-prefix=MIN32
+# RUN: yaml2obj --docnum=2 %s -o %t8 -D ADDEND=0x80000000
+# RUN: cmp %t7 %t8
+
+# MIN32: 0x0 R_386_PC32 foo 0x80000000{{$}}
+
+## Case 2.4: Check we report an error when an addend is less than INT32_MIN and
+## it is in decimal form. We use (INT32_MIN - 1).
+
+## FIXME: The following case should fail, see OVERFLOW64.
+# RUN: yaml2obj --docnum=2 %s -o %t9 -D ADDEND=-2147483649
+# RUN: llvm-readobj -r %t9 | FileCheck %s --check-prefix=OVERFLOW32-2
+
+# OVERFLOW32-2: 0x0 R_386_PC32 foo 0x7FFFFFFF{{$}}
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS32
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_386
+Sections:
+  - Name: .text
+    Type: SHT_PROGBITS
+  - Name: .rela.text
+    Type: SHT_RELA
+    Info: .text
+    Link: .symtab
+    Relocations:
+      - Type:   R_386_PC32
+        Symbol: foo
+        Addend: [[ADDEND]]
+Symbols:
+  - Name: foo