ART: Allow method references across oat files for multi-image, 2nd attempt.
These were disabled because we didn't have sufficient
information about the multi-image layout when processing
link-time patches in OatWriter. This CL refactors the
ELF file creation so that the information is available.
Also clean up ImageWriter to use oat file indexes instead
of filenames and avoid reopening the oat file to retrieve
the checksum.
Change-Id: Icc7b528deca29da1e473c8f079521a36d6c4892f
diff --git a/compiler/elf_builder.h b/compiler/elf_builder.h
index b673eeb..f7da609 100644
--- a/compiler/elf_builder.h
+++ b/compiler/elf_builder.h
@@ -86,12 +86,24 @@
// Base class of all sections.
class Section : public OutputStream {
public:
- Section(ElfBuilder<ElfTypes>* owner, const std::string& name,
- Elf_Word type, Elf_Word flags, const Section* link,
- Elf_Word info, Elf_Word align, Elf_Word entsize)
- : OutputStream(name), owner_(owner), header_(),
- section_index_(0), name_(name), link_(link),
- started_(false), finished_(false), phdr_flags_(PF_R), phdr_type_(0) {
+ Section(ElfBuilder<ElfTypes>* owner,
+ const std::string& name,
+ Elf_Word type,
+ Elf_Word flags,
+ const Section* link,
+ Elf_Word info,
+ Elf_Word align,
+ Elf_Word entsize)
+ : OutputStream(name),
+ owner_(owner),
+ header_(),
+ section_index_(0),
+ name_(name),
+ link_(link),
+ started_(false),
+ finished_(false),
+ phdr_flags_(PF_R),
+ phdr_type_(0) {
DCHECK_GE(align, 1u);
header_.sh_type = type;
header_.sh_flags = flags;
@@ -228,12 +240,84 @@
DISALLOW_COPY_AND_ASSIGN(Section);
};
- // Writer of .dynstr .strtab and .shstrtab sections.
+ class CachedSection : public Section {
+ public:
+ CachedSection(ElfBuilder<ElfTypes>* owner,
+ const std::string& name,
+ Elf_Word type,
+ Elf_Word flags,
+ const Section* link,
+ Elf_Word info,
+ Elf_Word align,
+ Elf_Word entsize)
+ : Section(owner, name, type, flags, link, info, align, entsize), cache_() { }
+
+ Elf_Word Add(const void* data, size_t length) {
+ Elf_Word offset = cache_.size();
+ const uint8_t* d = reinterpret_cast<const uint8_t*>(data);
+ cache_.insert(cache_.end(), d, d + length);
+ return offset;
+ }
+
+ Elf_Word GetCacheSize() {
+ return cache_.size();
+ }
+
+ void Write() {
+ this->WriteFully(cache_.data(), cache_.size());
+ cache_.clear();
+ cache_.shrink_to_fit();
+ }
+
+ void WriteCachedSection() {
+ this->Start();
+ Write();
+ this->End();
+ }
+
+ private:
+ std::vector<uint8_t> cache_;
+ };
+
+ // Writer of .dynstr section.
+ class CachedStringSection FINAL : public CachedSection {
+ public:
+ CachedStringSection(ElfBuilder<ElfTypes>* owner,
+ const std::string& name,
+ Elf_Word flags,
+ Elf_Word align)
+ : CachedSection(owner,
+ name,
+ SHT_STRTAB,
+ flags,
+ /* link */ nullptr,
+ /* info */ 0,
+ align,
+ /* entsize */ 0) { }
+
+ Elf_Word Add(const std::string& name) {
+ if (CachedSection::GetCacheSize() == 0u) {
+ DCHECK(name.empty());
+ }
+ return CachedSection::Add(name.c_str(), name.length() + 1);
+ }
+ };
+
+ // Writer of .strtab and .shstrtab sections.
class StringSection FINAL : public Section {
public:
- StringSection(ElfBuilder<ElfTypes>* owner, const std::string& name,
- Elf_Word flags, Elf_Word align)
- : Section(owner, name, SHT_STRTAB, flags, nullptr, 0, align, 0),
+ StringSection(ElfBuilder<ElfTypes>* owner,
+ const std::string& name,
+ Elf_Word flags,
+ Elf_Word align)
+ : Section(owner,
+ name,
+ SHT_STRTAB,
+ flags,
+ /* link */ nullptr,
+ /* info */ 0,
+ align,
+ /* entsize */ 0),
current_offset_(0) {
}
@@ -252,42 +336,60 @@
};
// Writer of .dynsym and .symtab sections.
- class SymbolSection FINAL : public Section {
+ class SymbolSection FINAL : public CachedSection {
public:
- SymbolSection(ElfBuilder<ElfTypes>* owner, const std::string& name,
- Elf_Word type, Elf_Word flags, StringSection* strtab)
- : Section(owner, name, type, flags, strtab, 0,
- sizeof(Elf_Off), sizeof(Elf_Sym)) {
+ SymbolSection(ElfBuilder<ElfTypes>* owner,
+ const std::string& name,
+ Elf_Word type,
+ Elf_Word flags,
+ Section* strtab)
+ : CachedSection(owner,
+ name,
+ type,
+ flags,
+ strtab,
+ /* info */ 0,
+ sizeof(Elf_Off),
+ sizeof(Elf_Sym)) {
+ // The symbol table always has to start with NULL symbol.
+ Elf_Sym null_symbol = Elf_Sym();
+ CachedSection::Add(&null_symbol, sizeof(null_symbol));
}
// Buffer symbol for this section. It will be written later.
// If the symbol's section is null, it will be considered absolute (SHN_ABS).
// (we use this in JIT to reference code which is stored outside the debug ELF file)
- void Add(Elf_Word name, const Section* section,
- Elf_Addr addr, bool is_relative, Elf_Word size,
- uint8_t binding, uint8_t type, uint8_t other = 0) {
+ void Add(Elf_Word name,
+ const Section* section,
+ Elf_Addr addr,
+ bool is_relative,
+ Elf_Word size,
+ uint8_t binding,
+ uint8_t type,
+ uint8_t other = 0) {
+ DCHECK(section != nullptr || !is_relative);
+ Elf_Addr abs_addr = addr + (is_relative ? section->GetAddress() : 0);
+ Elf_Word section_index =
+ (section != nullptr) ? section->GetSectionIndex() : static_cast<Elf_Word>(SHN_ABS);
+ Add(name, section_index, abs_addr, size, binding, type, other);
+ }
+
+ void Add(Elf_Word name,
+ Elf_Word section_index,
+ Elf_Addr addr,
+ Elf_Word size,
+ uint8_t binding,
+ uint8_t type,
+ uint8_t other = 0) {
Elf_Sym sym = Elf_Sym();
sym.st_name = name;
- sym.st_value = addr + (is_relative ? section->GetAddress() : 0);
+ sym.st_value = addr;
sym.st_size = size;
sym.st_other = other;
- sym.st_shndx = (section != nullptr ? section->GetSectionIndex()
- : static_cast<Elf_Word>(SHN_ABS));
+ sym.st_shndx = section_index;
sym.st_info = (binding << 4) + (type & 0xf);
- symbols_.push_back(sym);
+ CachedSection::Add(&sym, sizeof(sym));
}
-
- void Write() {
- // The symbol table always has to start with NULL symbol.
- Elf_Sym null_symbol = Elf_Sym();
- this->WriteFully(&null_symbol, sizeof(null_symbol));
- this->WriteFully(symbols_.data(), symbols_.size() * sizeof(symbols_[0]));
- symbols_.clear();
- symbols_.shrink_to_fit();
- }
-
- private:
- std::vector<Elf_Sym> symbols_;
};
ElfBuilder(InstructionSet isa, OutputStream* output)
@@ -309,6 +411,8 @@
debug_line_(this, ".debug_line", SHT_PROGBITS, 0, nullptr, 0, 1, 0),
shstrtab_(this, ".shstrtab", 0, 1),
started_(false),
+ write_program_headers_(false),
+ loaded_size_(0u),
virtual_address_(0) {
text_.phdr_flags_ = PF_R | PF_X;
bss_.phdr_flags_ = PF_R | PF_W;
@@ -380,6 +484,14 @@
void End() {
DCHECK(started_);
+ // Note: loaded_size_ == 0 for tests that don't write .rodata, .text, .bss,
+ // .dynstr, dynsym, .hash and .dynamic. These tests should not read loaded_size_.
+ // TODO: Either refactor the .eh_frame creation so that it counts towards loaded_size_,
+ // or remove all support for .eh_frame. (The currently unused .eh_frame counts towards
+ // the virtual_address_ but we don't consider it for loaded_size_.)
+ CHECK(loaded_size_ == 0 || loaded_size_ == RoundUp(virtual_address_, kPageSize))
+ << loaded_size_ << " " << virtual_address_;
+
// Write section names and finish the section headers.
shstrtab_.Start();
shstrtab_.Write("");
@@ -434,45 +546,58 @@
// information like the address and size of .rodata and .text.
// It also contains other metadata like the SONAME.
// The .dynamic section is found using the PT_DYNAMIC program header.
- void WriteDynamicSection(const std::string& elf_file_path) {
+ void PrepareDynamicSection(const std::string& elf_file_path,
+ Elf_Word rodata_size,
+ Elf_Word text_size,
+ Elf_Word bss_size) {
std::string soname(elf_file_path);
size_t directory_separator_pos = soname.rfind('/');
if (directory_separator_pos != std::string::npos) {
soname = soname.substr(directory_separator_pos + 1);
}
- dynstr_.Start();
- dynstr_.Write(""); // dynstr should start with empty string.
- dynsym_.Add(dynstr_.Write("oatdata"), &rodata_, 0, true,
- rodata_.GetSize(), STB_GLOBAL, STT_OBJECT);
- if (text_.GetSize() != 0u) {
- dynsym_.Add(dynstr_.Write("oatexec"), &text_, 0, true,
- text_.GetSize(), STB_GLOBAL, STT_OBJECT);
- dynsym_.Add(dynstr_.Write("oatlastword"), &text_, text_.GetSize() - 4,
- true, 4, STB_GLOBAL, STT_OBJECT);
- } else if (rodata_.GetSize() != 0) {
- // rodata_ can be size 0 for dwarf_test.
- dynsym_.Add(dynstr_.Write("oatlastword"), &rodata_, rodata_.GetSize() - 4,
- true, 4, STB_GLOBAL, STT_OBJECT);
- }
- if (bss_.finished_) {
- dynsym_.Add(dynstr_.Write("oatbss"), &bss_,
- 0, true, bss_.GetSize(), STB_GLOBAL, STT_OBJECT);
- dynsym_.Add(dynstr_.Write("oatbsslastword"), &bss_,
- bss_.GetSize() - 4, true, 4, STB_GLOBAL, STT_OBJECT);
- }
- Elf_Word soname_offset = dynstr_.Write(soname);
- dynstr_.End();
+ // Calculate addresses of .text, .bss and .dynstr.
+ DCHECK_EQ(rodata_.header_.sh_addralign, static_cast<Elf_Word>(kPageSize));
+ DCHECK_EQ(text_.header_.sh_addralign, static_cast<Elf_Word>(kPageSize));
+ DCHECK_EQ(bss_.header_.sh_addralign, static_cast<Elf_Word>(kPageSize));
+ DCHECK_EQ(dynstr_.header_.sh_addralign, static_cast<Elf_Word>(kPageSize));
+ Elf_Word rodata_address = rodata_.GetAddress();
+ Elf_Word text_address = RoundUp(rodata_address + rodata_size, kPageSize);
+ Elf_Word bss_address = RoundUp(text_address + text_size, kPageSize);
+ Elf_Word dynstr_address = RoundUp(bss_address + bss_size, kPageSize);
- dynsym_.Start();
- dynsym_.Write();
- dynsym_.End();
+ // Cache .dynstr, .dynsym and .hash data.
+ dynstr_.Add(""); // dynstr should start with empty string.
+ Elf_Word rodata_index = rodata_.GetSectionIndex();
+ Elf_Word oatdata = dynstr_.Add("oatdata");
+ dynsym_.Add(oatdata, rodata_index, rodata_address, rodata_size, STB_GLOBAL, STT_OBJECT);
+ if (text_size != 0u) {
+ Elf_Word text_index = rodata_index + 1u;
+ Elf_Word oatexec = dynstr_.Add("oatexec");
+ dynsym_.Add(oatexec, text_index, text_address, text_size, STB_GLOBAL, STT_OBJECT);
+ Elf_Word oatlastword = dynstr_.Add("oatlastword");
+ Elf_Word oatlastword_address = text_address + text_size - 4;
+ dynsym_.Add(oatlastword, text_index, oatlastword_address, 4, STB_GLOBAL, STT_OBJECT);
+ } else if (rodata_size != 0) {
+ // rodata_ can be size 0 for dwarf_test.
+ Elf_Word oatlastword = dynstr_.Add("oatlastword");
+ Elf_Word oatlastword_address = rodata_address + rodata_size - 4;
+ dynsym_.Add(oatlastword, rodata_index, oatlastword_address, 4, STB_GLOBAL, STT_OBJECT);
+ }
+ if (bss_size != 0u) {
+ Elf_Word bss_index = rodata_index + 1u + (text_size != 0 ? 1u : 0u);
+ Elf_Word oatbss = dynstr_.Add("oatbss");
+ dynsym_.Add(oatbss, bss_index, bss_address, bss_size, STB_GLOBAL, STT_OBJECT);
+ Elf_Word oatbsslastword = dynstr_.Add("oatbsslastword");
+ Elf_Word bsslastword_address = bss_address + bss_size - 4;
+ dynsym_.Add(oatbsslastword, bss_index, bsslastword_address, 4, STB_GLOBAL, STT_OBJECT);
+ }
+ Elf_Word soname_offset = dynstr_.Add(soname);
// We do not really need a hash-table since there is so few entries.
// However, the hash-table is the only way the linker can actually
// determine the number of symbols in .dynsym so it is required.
- hash_.Start();
- int count = dynsym_.GetSize() / sizeof(Elf_Sym); // Includes NULL.
+ int count = dynsym_.GetCacheSize() / sizeof(Elf_Sym); // Includes NULL.
std::vector<Elf_Word> hash;
hash.push_back(1); // Number of buckets.
hash.push_back(count); // Number of chains.
@@ -484,21 +609,44 @@
hash.push_back(i + 1); // Each symbol points to the next one.
}
hash.push_back(0); // Last symbol terminates the chain.
- hash_.WriteFully(hash.data(), hash.size() * sizeof(hash[0]));
- hash_.End();
+ hash_.Add(hash.data(), hash.size() * sizeof(hash[0]));
- dynamic_.Start();
+ // Calculate addresses of .dynsym, .hash and .dynamic.
+ DCHECK_EQ(dynstr_.header_.sh_flags, dynsym_.header_.sh_flags);
+ DCHECK_EQ(dynsym_.header_.sh_flags, hash_.header_.sh_flags);
+ Elf_Word dynsym_address =
+ RoundUp(dynstr_address + dynstr_.GetCacheSize(), dynsym_.header_.sh_addralign);
+ Elf_Word hash_address =
+ RoundUp(dynsym_address + dynsym_.GetCacheSize(), hash_.header_.sh_addralign);
+ DCHECK_EQ(dynamic_.header_.sh_addralign, static_cast<Elf_Word>(kPageSize));
+ Elf_Word dynamic_address = RoundUp(hash_address + dynsym_.GetCacheSize(), kPageSize);
+
Elf_Dyn dyns[] = {
- { DT_HASH, { hash_.GetAddress() } },
- { DT_STRTAB, { dynstr_.GetAddress() } },
- { DT_SYMTAB, { dynsym_.GetAddress() } },
+ { DT_HASH, { hash_address } },
+ { DT_STRTAB, { dynstr_address } },
+ { DT_SYMTAB, { dynsym_address } },
{ DT_SYMENT, { sizeof(Elf_Sym) } },
- { DT_STRSZ, { dynstr_.GetSize() } },
+ { DT_STRSZ, { dynstr_.GetCacheSize() } },
{ DT_SONAME, { soname_offset } },
{ DT_NULL, { 0 } },
};
- dynamic_.WriteFully(&dyns, sizeof(dyns));
- dynamic_.End();
+ dynamic_.Add(&dyns, sizeof(dyns));
+
+ loaded_size_ = RoundUp(dynamic_address + dynamic_.GetCacheSize(), kPageSize);
+ }
+
+ void WriteDynamicSection() {
+ dynstr_.WriteCachedSection();
+ dynsym_.WriteCachedSection();
+ hash_.WriteCachedSection();
+ dynamic_.WriteCachedSection();
+
+ CHECK_EQ(loaded_size_, RoundUp(dynamic_.GetAddress() + dynamic_.GetSize(), kPageSize));
+ }
+
+ Elf_Word GetLoadedSize() {
+ CHECK_NE(loaded_size_, 0u);
+ return loaded_size_;
}
// Returns true if all writes and seeks on the output stream succeeded.
@@ -676,10 +824,10 @@
Section rodata_;
Section text_;
Section bss_;
- StringSection dynstr_;
+ CachedStringSection dynstr_;
SymbolSection dynsym_;
- Section hash_;
- Section dynamic_;
+ CachedSection hash_;
+ CachedSection dynamic_;
Section eh_frame_;
Section eh_frame_hdr_;
StringSection strtab_;
@@ -694,12 +842,14 @@
std::vector<Section*> sections_;
bool started_;
+ bool write_program_headers_;
+
+ // The size of the memory taken by the ELF file when loaded.
+ size_t loaded_size_;
// Used for allocation of virtual address space.
Elf_Addr virtual_address_;
- size_t write_program_headers_;
-
DISALLOW_COPY_AND_ASSIGN(ElfBuilder);
};