[yaml2obj] - Alow Size tag for describing SHT_HASH sections.

[grimar]

Summary

This is a follow-up for D68085 which allows using "Size"
tag together with "Content" tag or alone.

[jhenderson]

lib/ObjectYAML/ELFYAML.cpp

1215

clang-format?

1224

I might rephrase this and the below message as follows:

"Bucket" cannot be used with "Content" or "Size"

test/tools/yaml2obj/elf-hash-section.yaml

149

I'd say "SHT_HASH section" instead of "hash section" mostly to match the phrasing used elsewhere in this test.

173

Ditto

197–198

together then the -> together, the

Trailing full stop missing.

[grimar]

• Addressed review comments.

[jhenderson]

LGTM.

[MaskRay]

lib/ObjectYAML/ELFYAML.cpp

1220

You can delete a pair of ()

include/llvm/ObjectYAML/ELFYAML.h

struct NoBitsSection : Section {
 
   static bool classof(const Section *S) {
     return S->Kind == SectionKind::NoBits;
   }
 };
 
 struct HashSection : Section {
   Optional<yaml::BinaryRef> Content;
+  Optional<llvm::yaml::Hex64> Size;
   Optional<std::vector<uint32_t>> Bucket;
   Optional<std::vector<uint32_t>> Chain;
 
   HashSection() : Section(SectionKind::Hash) {}
 
   static bool classof(const Section *S) { return S->Kind == SectionKind::Hash; }
 };
 

lib/ObjectYAML/ELFEmitter.cpp

void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                          ContiguousBlobAccumulator &CBA) {
   raw_ostream &OS =
       CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
 
   unsigned Link = 0;
   if (SN2I.lookup(".dynsym", Link))
     SHeader.sh_link = Link;
 
-  if (Section.Content) {
-    SHeader.sh_size = writeContent(OS, Section.Content, None);
+  if (Section.Content || Section.Size) {
+    SHeader.sh_size = writeContent(OS, Section.Content, Section.Size);
     return;
   }
 
   support::endian::write<uint32_t>(OS, Section.Bucket->size(),
                                    ELFT::TargetEndianness);
   support::endian::write<uint32_t>(OS, Section.Chain->size(),
                                    ELFT::TargetEndianness);
   for (uint32_t Val : *Section.Bucket)

lib/ObjectYAML/ELFYAML.cpp

static void sectionMapping(IO &IO, ELFYAML::StackSizesSection &Section) {
   IO.mapOptional("Entries", Section.Entries);
 }
 
 static void sectionMapping(IO &IO, ELFYAML::HashSection &Section) {
   commonSectionMapping(IO, Section);
   IO.mapOptional("Content", Section.Content);
   IO.mapOptional("Bucket", Section.Bucket);
   IO.mapOptional("Chain", Section.Chain);
+  IO.mapOptional("Size", Section.Size);
 }
 
 static void sectionMapping(IO &IO, ELFYAML::NoBitsSection &Section) {
   commonSectionMapping(IO, Section);
   IO.mapOptional("Size", Section.Size, Hex64(0));
 }
 
 static void sectionMapping(IO &IO, ELFYAML::VerdefSection &Section) {
if (const auto *SS = dyn_cast<ELFYAML::StackSizesSection>(Section.get())) {
     if (SS->Size)
       return ".stack_sizes: Size and Entries cannot be used together";
     if (SS->Content)
       return ".stack_sizes: Content and Entries cannot be used together";
     return {};
   }
 
   if (const auto *HS = dyn_cast<ELFYAML::HashSection>(Section.get())) {
-    if (!HS->Content && !HS->Bucket && !HS->Chain)
-      return "one of \"Content\", \"Bucket\" and \"Chain\" must be specified";
+    if (!HS->Content && !HS->Bucket && !HS->Chain && !HS->Size)
+      return "one of \"Content\", \"Size\", \"Bucket\" and \"Chain\" must be specified";
+
+    if (HS->Content || HS->Size) {
+      if (HS->Size && HS->Content &&
+          (uint64_t)(*HS->Size) < HS->Content->binary_size())
+        return "\"Size\" must be greater than or equal to the content "
+               "size";
 
-    if (HS->Content) {
       if (HS->Bucket)
-        return "\"Content\" and \"Bucket\" cannot be used together";
+        return "\"Content\"/\"Size\" and \"Bucket\" cannot be used together";
       if (HS->Chain)
-        return "\"Content\" and \"Chain\" cannot be used together";
+        return "\"Content\"/\"Size\" and \"Chain\" cannot be used together";
       return {};
     }
 
     if ((HS->Bucket && !HS->Chain) || (!HS->Bucket && HS->Chain))
       return "\"Bucket\" and \"Chain\" must be used together";
     return {};
   }
 

test/tools/yaml2obj/elf-hash-section.yaml

- Name:   .hash
     Type:   SHT_HASH
     Bucket: [ 1, 2 ]
     Chain:  [ 3, 4, 5 ]
 
 ## Check we can't use "Content" and "Bucket" tags together.
 
 # RUN: not yaml2obj --docnum=3 %s 2>&1 | FileCheck %s --check-prefix=CONTENT-BUCKET
 
-# CONTENT-BUCKET: error: "Content" and "Bucket" cannot be used together
+# CONTENT-BUCKET: error: "Content"/"Size" and "Bucket" cannot be used together
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS32
   Data:    ELFDATA2LSB
   Type:    ET_DYN
   Machine: EM_386
 Sections:
   - Name:   .hash
     Type:   SHT_HASH
     Bucket: [ 1 ]
     Content: '00'
 
 ## Check we can't use "Content" and "Chain" tags together.
 
 # RUN: not yaml2obj --docnum=4 %s 2>&1 | FileCheck %s --check-prefix=CONTENT-CHAIN
 
-# CONTENT-CHAIN: error: "Content" and "Chain" cannot be used together
+# CONTENT-CHAIN: error: "Content"/"Size" and "Chain" cannot be used together
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS32
   Data:    ELFDATA2LSB
   Type:    ET_DYN
   Machine: EM_386
 Sections:
Sections:
   - Name:  .hash
     Type:  SHT_HASH
     Chain: [ 1 ]
 
 ## Check we report an error if neither "Bucket", "Chain" nor "Content" were set.
 
 # RUN: not yaml2obj --docnum=7 %s 2>&1 | FileCheck %s --check-prefix=NO-TAGS
 
-# NO-TAGS: error: one of "Content", "Bucket" and "Chain" must be specified
+# NO-TAGS: error: one of "Content", "Size", "Bucket" and "Chain" must be specified
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS32
   Data:    ELFDATA2LSB
   Type:    ET_DYN
   Machine: EM_386
 Sections:
   - Name:  .hash
     Type:  SHT_HASH
+
+## Check we can use only "Size" to create a hash section.
+
+# RUN: yaml2obj --docnum=8 %s -o %t8
+# RUN: llvm-readobj --sections --section-data %t8 | FileCheck %s --check-prefix=SIZE
+
+# SIZE:      Name: .hash
+# SIZE:      Size:
+# SIZE-SAME: 17
+# SIZE:      SectionData (
+# SIZE-NEXT:  0000: 00000000 00000000 00000000 00000000  |
+# SIZE-NEXT:  0010: 00                                   |
+# SIZE-NEXT: )
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name: .hash
+    Type: SHT_HASH
+    Size: 0x11
+
+## Check we can use "Size" and "Content" together to create a hash section.
+
+# RUN: yaml2obj --docnum=9 %s -o %t9
+# RUN: llvm-readobj --sections --section-data %t9 | FileCheck %s --check-prefix=SIZE-CONTENT
+
+# SIZE-CONTENT:      Name: .hash
+# SIZE-CONTENT:      Size:
+# SIZE-CONTENT-SAME: 5
+# SIZE-CONTENT:      SectionData (
+# SIZE-CONTENT-NEXT:  0000: 11223300 00 |
+# SIZE-CONTENT-NEXT: )
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name: .hash
+    Type: SHT_HASH
+    Size: 0x5
+    Content: "112233"
+
+## Check that when "Size" and "Content" are used together then the size
+## must be greater than or equal to the content size
+
+# RUN: not yaml2obj --docnum=10 %s 2>&1 | FileCheck %s --check-prefix=SIZE-CONTENT-ERR
+
+# SIZE-CONTENT-ERR: error: "Size" must be greater than or equal to the content size
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name: .hash
+    Type: SHT_HASH
+    Size: 0x1
+    Content: "1122"
+
+## Check we can't use "Size" and "Bucket" tags together.
+
+# RUN: not yaml2obj --docnum=11 %s 2>&1 | FileCheck %s --check-prefix=CONTENT-BUCKET
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name: .hash
+    Type: SHT_HASH
+    Size: 0x1
+    Bucket: [ 1 ]
+
+## Check we can't use "Size" and "Chain" tags together.
+
+# RUN: not yaml2obj --docnum=12 %s 2>&1 | FileCheck %s --check-prefix=CONTENT-CHAIN
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name: .hash
+    Type: SHT_HASH
+    Size: 0x1
+    Chain: [ 1 ]