RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-12-15 07:39:31 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

[yaml2obj][ELF] Don't monkeypatch the YAML sections.

Browse Source 
Previously, we would monkeypatch the vector of YAML::Section's in order
to ensure that the SHT_NULL entry is present. Now we just add it
unconditionally.

The proliferation of small numerical adjustments is beginning to
frighten me, but I can't think of a way having a single point of truth
for them without introducing a whole new layer  of data structures (i.e.
lots of code and complexity) between the YAML and binary ELF formats.

llvm-svn: 184260
This commit is contained in:
Sean Silva 2013-06-18 23:37:23 +00:00
parent 3fd655ca4d
commit af68c9e26b
1 changed files with 17 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
tools/yaml2obj/yaml2elf.cpp
View File

@ -209,27 +209,23 @@ static int writeELF(raw_ostream &OS, const ELFYAML::Object &Doc) {
Header.e_shentsize = sizeof(Elf_Shdr);
// Immediately following the ELF header.
Header.e_shoff = sizeof(Header);
std::vector<ELFYAML::Section> Sections = Doc.Sections;
if (Sections.empty() || Sections.front().Type != SHT_NULL) {
ELFYAML::Section S;
S.Type = SHT_NULL;
zero(S.Flags);
zero(S.Address);
zero(S.AddressAlign);
Sections.insert(Sections.begin(), S);
}
// "+ 2" for string table and section header string table.
Header.e_shnum = Sections.size() + 2;
const std::vector<ELFYAML::Section> &Sections = Doc.Sections;
// "+ 3" for
// - SHT_NULL entry (placed first, i.e. 0'th entry)
// - string table (.strtab) (placed second to last)
// - section header string table. (placed last)
Header.e_shnum = Sections.size() + 3;
// Place section header string table last.
Header.e_shstrndx = Sections.size() + 1;
const unsigned DotStrtabSecNo = Sections.size();
Header.e_shstrndx = Header.e_shnum - 1;
const unsigned DotStrtabSecNo = Header.e_shnum - 2;
SectionNameToIdxMap SN2I;
for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
StringRef Name = Sections[i].Name;
if (Name.empty())
continue;
if (SN2I.addName(Name, i)) {
// "+ 1" to take into account the SHT_NULL entry.
if (SN2I.addName(Name, i + 1)) {
errs() << "error: Repeated section name: '" << Name
<< "' at YAML section number " << i << ".\n";
return 1;
@ -244,6 +240,13 @@ static int writeELF(raw_ostream &OS, const ELFYAML::Object &Doc) {
Header.e_ehsize + Header.e_shentsize * Header.e_shnum;
ContiguousBlobAccumulator CBA(SectionContentBeginOffset, Buf);
std::vector<Elf_Shdr> SHeaders;
{
// Ensure SHN_UNDEF entry is present. An all-zero section header is a
// valid SHN_UNDEF entry since SHT_NULL == 0.
Elf_Shdr SHdr;
zero(SHdr);
SHeaders.push_back(SHdr);
}
StringTableBuilder DotStrTab;
for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
const ELFYAML::Section &Sec = Sections[i];