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[yaml2obj] - Allow setting cutom Flags for implicit sections. 

With this patch we get ability to set any flags we want
for implicit sections defined in YAML.

Differential revision: https://reviews.llvm.org/D63136

llvm-svn: 363367
This commit is contained in:
George Rimar 2019-06-14 11:01:14 +00:00
parent 822794ef85
commit cfa1a62a4c
6 changed files with 176 additions and 12 deletions
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2
llvm/include/llvm/ObjectYAML/ELFYAML.h
View File

@ -129,7 +129,7 @@ struct Section {
SectionKind Kind;
StringRef Name;
ELF_SHT Type;
ELF_SHF Flags;
Optional<ELF_SHF> Flags;
llvm::yaml::Hex64 Address;
StringRef Link;
llvm::yaml::Hex64 AddressAlign;

2
llvm/lib/ObjectYAML/ELFYAML.cpp
View File

@ -900,7 +900,7 @@ StringRef MappingTraits<ELFYAML::Symbol>::validate(IO &IO,
static void commonSectionMapping(IO &IO, ELFYAML::Section &Section) {
IO.mapOptional("Name", Section.Name, StringRef());
IO.mapRequired("Type", Section.Type);
IO.mapOptional("Flags", Section.Flags, ELFYAML::ELF_SHF(0));
IO.mapOptional("Flags", Section.Flags);
IO.mapOptional("Address", Section.Address, Hex64(0));
IO.mapOptional("Link", Section.Link, StringRef());
IO.mapOptional("AddressAlign", Section.AddressAlign, Hex64(0));

79
llvm/test/tools/yaml2obj/strtab-implicit-sections-flags.yaml Normal file
View File

@ -0,0 +1,79 @@
## For implicit string table sections, the `Flags` field can also
## be specified in YAML. Here we test the behavior in different cases.
## When flags are not explicitly specified, yaml2obj assigns no flags
## for .strtab and the SHF_ALLOC flag for .dynstr by default.
# RUN: yaml2obj --docnum=1 %s -o %t1
# RUN: llvm-readobj %t1 -S | FileCheck %s --check-prefix=CASE1
# CASE1: Name: .strtab
# CASE1-NEXT: Type: SHT_STRTAB
# CASE1-NEXT: Flags [
# CASE1-NEXT: ]
# CASE1: Name: .dynstr
# CASE1-NEXT: Type: SHT_STRTAB
# CASE1-NEXT: Flags [
# CASE1-NEXT: SHF_ALLOC
# CASE1-NEXT: ]
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_DYN
Machine: EM_X86_64
Sections:
- Name: .strtab
Type: SHT_STRTAB
- Name: .dynstr
Type: SHT_STRTAB
## Check we can set arbitrary flags for .strtab/.dynstr.
# RUN: yaml2obj --docnum=2 %s -o %t2
# RUN: llvm-readobj %t2 -S | FileCheck %s --check-prefix=CASE2
# CASE2: Name: .strtab
# CASE2-NEXT: Type: SHT_STRTAB
# CASE2-NEXT: Flags [
# CASE2-NEXT: SHF_ALLOC
# CASE2-NEXT: SHF_STRINGS
# CASE2-NEXT: ]
# CASE2: Name: .dynstr
# CASE2-NEXT: Type: SHT_STRTAB
# CASE2-NEXT: Flags [
# CASE2-NEXT: SHF_STRINGS
# CASE2-NEXT: ]
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_DYN
Machine: EM_X86_64
Sections:
- Name: .strtab
Type: SHT_STRTAB
Flags: [ SHF_ALLOC, SHF_STRINGS ]
- Name: .dynstr
Type: SHT_STRTAB
Flags: [ SHF_STRINGS ]
## Check no flags are set by default for .strtab when it is not
## described in the YAML.
# RUN: yaml2obj --docnum=3 %s -o %t3
# RUN: llvm-readobj %t3 -S | FileCheck %s --check-prefix=CASE3
# CASE3: Name: .strtab
# CASE3-NEXT: Type: SHT_STRTAB
# CASE3-NEXT: Flags [
# CASE3-NEXT: ]
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_DYN
Machine: EM_X86_64

79
llvm/test/tools/yaml2obj/symtab-implicit-sections-flags.yaml Normal file
View File

@ -0,0 +1,79 @@
## For implicit symbol table sections, the `Flags` field can also
## be specified in YAML. Here we test the behavior in different cases.
## When flags are not explicitly specified, yaml2obj assigns no flags
## for .symtab and the SHF_ALLOC flag for .dynsym by default.
# RUN: yaml2obj --docnum=1 %s -o %t1
# RUN: llvm-readobj %t1 -S | FileCheck %s --check-prefix=CASE1
# CASE1: Name: .symtab
# CASE1-NEXT: Type: SHT_SYMTAB
# CASE1-NEXT: Flags [
# CASE1-NEXT: ]
# CASE1: Name: .dynsym
# CASE1-NEXT: Type: SHT_DYNSYM
# CASE1-NEXT: Flags [
# CASE1-NEXT: SHF_ALLOC
# CASE1-NEXT: ]
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_DYN
Machine: EM_X86_64
Sections:
- Name: .symtab
Type: SHT_SYMTAB
- Name: .dynsym
Type: SHT_SYMTAB
## Check we can set arbitrary flags for .symtab/.dynsym.
# RUN: yaml2obj --docnum=2 %s -o %t2
# RUN: llvm-readobj %t2 -S | FileCheck %s --check-prefix=CASE2
# CASE2: Name: .symtab
# CASE2-NEXT: Type: SHT_SYMTAB
# CASE2-NEXT: Flags [
# CASE2-NEXT: SHF_ALLOC
# CASE2-NEXT: SHF_STRINGS
# CASE2-NEXT: ]
# CASE2: Name: .dynsym
# CASE2-NEXT: Type: SHT_DYNSYM
# CASE2-NEXT: Flags [
# CASE2-NEXT: SHF_STRINGS
# CASE2-NEXT: ]
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_DYN
Machine: EM_X86_64
Sections:
- Name: .symtab
Type: SHT_SYMTAB
Flags: [ SHF_ALLOC, SHF_STRINGS ]
- Name: .dynsym
Type: SHT_SYMTAB
Flags: [ SHF_STRINGS ]
## Check no flags are set by default for .symtab when it is not
## described in the YAML.
# RUN: yaml2obj --docnum=3 %s -o %t3
# RUN: llvm-readobj %t3 -S | FileCheck %s --check-prefix=CASE3
# CASE3: Name: .symtab
# CASE3-NEXT: Type: SHT_SYMTAB
# CASE3-NEXT: Flags [
# CASE3-NEXT: ]
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_DYN
Machine: EM_X86_64

3
llvm/tools/obj2yaml/elf2yaml.cpp
View File

@ -329,7 +329,8 @@ template <class ELFT>
std::error_code ELFDumper<ELFT>::dumpCommonSection(const Elf_Shdr *Shdr,
ELFYAML::Section &S) {
S.Type = Shdr->sh_type;
S.Flags = Shdr->sh_flags;
if (Shdr->sh_flags)
S.Flags = static_cast<ELFYAML::ELF_SHF>(Shdr->sh_flags);
S.Address = Shdr->sh_addr;
S.AddressAlign = Shdr->sh_addralign;
if (Shdr->sh_entsize)

23
llvm/tools/yaml2obj/yaml2elf.cpp
View File

@ -303,7 +303,8 @@ bool ELFState<ELFT>::initSectionHeaders(ELFState<ELFT> &State,
SHeader.sh_name = DotShStrtab.getOffset(SecName);
SHeader.sh_type = Sec->Type;
SHeader.sh_flags = Sec->Flags;
if (Sec->Flags)
SHeader.sh_flags = *Sec->Flags;
SHeader.sh_addr = Sec->Address;
SHeader.sh_addralign = Sec->AddressAlign;
@ -424,8 +425,10 @@ void ELFState<ELFT>::initSymtabSectionHeader(Elf_Shdr &SHeader,
SHeader.sh_link = Link;
}
if (!IsStatic)
SHeader.sh_flags |= ELF::SHF_ALLOC;
if (YAMLSec && YAMLSec->Flags)
SHeader.sh_flags = *YAMLSec->Flags;
else if (!IsStatic)
SHeader.sh_flags = ELF::SHF_ALLOC;
// If the symbol table section is explicitly described in the YAML
// then we should set the fields requested.
@ -481,14 +484,16 @@ void ELFState<ELFT>::initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name,
if (YAMLSec && YAMLSec->EntSize)
SHeader.sh_entsize = *YAMLSec->EntSize;
if (YAMLSec && YAMLSec->Flags)
SHeader.sh_flags = *YAMLSec->Flags;
else if (Name == ".dynstr")
SHeader.sh_flags = ELF::SHF_ALLOC;
// If .dynstr section is explicitly described in the YAML
// then we want to use its section address.
if (Name == ".dynstr") {
if (YAMLSec)
SHeader.sh_addr = YAMLSec->Address;
// We assume that .dynstr is always allocatable.
SHeader.sh_flags |= ELF::SHF_ALLOC;
}
// TODO: Allow this for any explicitly described section.
if (YAMLSec && Name == ".dynstr")
SHeader.sh_addr = YAMLSec->Address;
}
template <class ELFT>