[yaml2obj] - Allow setting custom section types for implicit sections.

[grimar]

Summary

We were hardcoding the final section type for sections that
are usually implicit. The patch fixes that.

This also fixes a few issues in existent test cases and removes
one precompiled object.

Depends on https://reviews.llvm.org/D63266

[jhenderson]

test/tools/llvm-readobj/elf-wrong-shstrtab-type.test

0–2

Change this comment to:
"Check we do not fail to dump the section headers when a .shstrtab section does not have a SHT_STRTAB type."

test/tools/yaml2obj/elf-symtab-shinfo.yaml

27–38

This change doesn't seem related?

test/tools/yaml2obj/explicit-dynsym-no-dynstr.yaml

22

Unrelated?

test/tools/yaml2obj/implicit-sections-types.test

5

flags -> types

5–6

restructure the second half of this sentence to:

"in case sections were implicitly added and not described in the YAML"

33

flags -> types

60

It might be nice if this picked a range of section types (e.g. SHT_RELA, SHT_DYNAMIC etc).

tools/yaml2obj/yaml2elf.cpp

471

Is the cast needed? It isn't above.

[grimar]

• Addressed review comments.

test/tools/yaml2obj/elf-symtab-shinfo.yaml

27–38

It is related. This test has a following check lines:

# CHECK:      Name: .dynsym
# CHECK-NEXT: Type: SHT_DYNSYM

We set SHT_DYNSYM by default before this patch.
But YAML seems contains SHT_SYMTAB by mistake.

This patch revealed this errors in this and other test cases, so I fixed them.

test/tools/yaml2obj/explicit-dynsym-no-dynstr.yaml

22

The same.

tools/yaml2obj/yaml2elf.cpp

471

Nope. Removed.

[jhenderson]

LGTM, with one nit.

test/tools/yaml2obj/implicit-sections-types.test

5

Missing trailing full stop.

test/tools/llvm-readobj/elf-wrong-shstrtab-type.test

-## wrong-shstrtab-type.elf-x86-64 contains .shstrtab section which has SHT_PROGBITS type.
-## Check we do not fail to dump the section headers in this case.
+## Check we do not fail to dump the section headers when
+## a .shstrtab section does not have a SHT_STRTAB type.
 
-# RUN: llvm-readobj -S %p/Inputs/wrong-shstrtab-type.elf-x86-64 | FileCheck %s --check-prefix LLVM
-# RUN: llvm-readelf -S %p/Inputs/wrong-shstrtab-type.elf-x86-64 | FileCheck %s --check-prefix GNU
+# RUN: yaml2obj %s -o %t1
+# RUN: llvm-readobj -S %t1 | FileCheck %s --check-prefix LLVM
+# RUN: llvm-readelf -S %t1 | FileCheck %s --check-prefix GNU
 
 # LLVM:      Name: .shstrtab
 # LLVM-NEXT: Type: SHT_PROGBITS
 
 # GNU: [Nr] Name      Type
-# GNU: [ 3] .shstrtab PROGBITS
+# GNU: [ 1] .shstrtab PROGBITS
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_DYN
+  Machine: EM_X86_64
+Sections:
+  - Name: .shstrtab
+    Type: SHT_PROGBITS

test/tools/yaml2obj/elf-symtab-shinfo.yaml

 # CHECK-NEXT: Address:
 # CHECK-NEXT: Offset:
 # CHECK-NEXT: Size:
 # CHECK-NEXT: Link:
 # CHECK-NEXT: Info: 26
  
 --- !ELF
 FileHeader:
-  Class:           ELFCLASS64
-  Data:            ELFDATA2LSB
-  Type:            ET_REL
-  Machine:         EM_X86_64
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_X86_64
 Sections:
-  - Name:          .symtab
-    Info:          42
-    Type:          SHT_SYMTAB
-  - Name:          .dynsym
-    Info:          26
-    Type:          SHT_SYMTAB
+  - Name: .symtab
+    Info: 42
+    Type: SHT_SYMTAB
+  - Name: .dynsym
+    Info: 26
+    Type: SHT_DYNSYM
 Symbols:
   - Name:    foo
     Binding: STB_GLOBAL
 DynamicSymbols:
   - Name:    bar
     Binding: STB_GLOBAL

test/tools/yaml2obj/elf-symtab-shtype.yaml

 ## Check we dont crash when .symtab has type different from SHT_SYMTAB.
 # RUN: yaml2obj %s -o %t
 # RUN: llvm-readobj --sections %t | FileCheck %s
 
-## TODO: the output is still SHT_SYMTAB because we do not yet
-## support changing it.
 # CHECK:      Name: .symtab
-# CHECK-NEXT: Type: SHT_SYMTAB
+# CHECK-NEXT: Type: SHT_DYNAMIC
 
 --- !ELF
-FileHeader:      
-  Class:           ELFCLASS64
-  Data:            ELFDATA2LSB
-  Type:            ET_REL
-  Machine:         EM_X86_64
-Sections:        
-  - Name:            .symtab
-    Type:            SHT_DYNAMIC
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_X86_64
+Sections:
+  - Name: .symtab
+    Type: SHT_DYNAMIC
 Symbols:
   - Name:    foo
     Binding: STB_GLOBAL

test/tools/yaml2obj/explicit-dynsym-no-dynstr.yaml

 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_DYN
   Machine: EM_X86_64
 Sections:
   - Name: .dynsym
-    Type: SHT_SYMTAB
+    Type: SHT_DYNSYM

test/tools/yaml2obj/implicit-sections-types.test

+## Here we check the types set for implicit sections
+## in different cases.
+
+## Check the types set by default in case sections were implicitly
+## added and not described in the YAML
+
+# RUN: yaml2obj --docnum=1 %s -o %t1
+# RUN: llvm-readobj -S %t1 | FileCheck %s --check-prefix=CASE1
+
+# CASE1:      Name: .symtab
+# CASE1-NEXT: Type: SHT_SYMTAB
+# CASE1:      Name: .strtab
+# CASE1-NEXT: Type: SHT_STRTAB
+# CASE1:      Name: .shstrtab
+# CASE1-NEXT: Type: SHT_STRTAB
+# CASE1:      Name: .dynsym
+# CASE1-NEXT: Type: SHT_DYNSYM
+# CASE1:      Name: .dynstr
+# CASE1-NEXT: Type: SHT_STRTAB
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_DYN
+  Machine: EM_X86_64
+## Needed to force the creation of the .dynsym and .dynstr.
+DynamicSymbols:
+  - Name:    foo
+  - Binding: STB_GLOBAL
+
+## Check we can set any arbitrary types when describing sections
+## that are usually implicit.
+
+# RUN: yaml2obj --docnum=2 %s -o %t2
+# RUN: llvm-readobj -S %t2 | FileCheck %s --check-prefix=CASE2
+
+# CASE2:      Name: .symtab
+# CASE2-NEXT: Type: SHT_DYNAMIC
+# CASE2:      Name: .strtab
+# CASE2-NEXT: Type: SHT_RELA
+# CASE2:      Name: .shstrtab
+# CASE2-NEXT: Type: SHT_PROGBITS
+# CASE2:      Name: .dynsym
+# CASE2-NEXT: Type: SHT_NOTE
+# CASE2:      Name: .dynstr
+# CASE2-NEXT: Type: SHT_NOBITS
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_DYN
+  Machine: EM_X86_64
+Sections:
+  - Name: .symtab
+    Type: SHT_DYNAMIC
+  - Name: .strtab
+    Type: SHT_RELA
+  - Name: .shstrtab
+    Type: SHT_PROGBITS
+  - Name: .dynsym
+    Type: SHT_NOTE
+  - Name: .dynstr
+    Type: SHT_NOBITS
+## Needed to set the proper content size for .symtab, so
+## that llvm-readobj can dump this section.
+Symbols:
+  - Name: foo

tools/yaml2obj/yaml2elf.cpp

if (RawSec->Size)
                                           : Twine("`DynamicSymbols`")) +
                                 " for symbol table section '"
                          << RawSec->Name << "'.\n";
     exit(1);
   }
 
   zero(SHeader);
   SHeader.sh_name = DotShStrtab.getOffset(IsStatic ? ".symtab" : ".dynsym");
+
+  if (YAMLSec)
+    SHeader.sh_type = YAMLSec->Type;
+  else
     SHeader.sh_type = IsStatic ? ELF::SHT_SYMTAB : ELF::SHT_DYNSYM;
 
   if (RawSec && !RawSec->Link.empty()) {
     // If the Link field is explicitly defined in the document,
     // we should use it.
     unsigned Index;
     if (!convertSectionIndex(SN2I, RawSec->Name, RawSec->Link, Index))
       return;
     SHeader.sh_link = Index;

 
 template <class ELFT>
 void ELFState<ELFT>::initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name,
                                              StringTableBuilder &STB,
                                              ContiguousBlobAccumulator &CBA,
                                              ELFYAML::Section *YAMLSec) {
   zero(SHeader);
   SHeader.sh_name = DotShStrtab.getOffset(Name);
-  SHeader.sh_type = ELF::SHT_STRTAB;
+  SHeader.sh_type = YAMLSec ? YAMLSec->Type : ELF::SHT_STRTAB;
   SHeader.sh_addralign = YAMLSec ? (uint64_t)YAMLSec->AddressAlign : 1;
 
   ELFYAML::RawContentSection *RawSec =
       dyn_cast_or_null<ELFYAML::RawContentSection>(YAMLSec);
 
   auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
   if (RawSec && (RawSec->Content || RawSec->Size)) {
     SHeader.sh_size = writeRawSectionData(OS, *RawSec);