Create libelffile library for ELF file manipulation.

Move some of our tooling to library to make it reusable.

Remove MIPS support from the ELF builder.  This is slightly
easier than making it independent of the runtime.

Bug: 110133331
Test: test.py -b --host
Change-Id: I93343808d0e27ee8e1117e713a2503e8179fc245

1 files changed, 0 insertions, 173 deletions

diff --git a/compiler/debug/elf_debug_reader.h b/compiler/debug/elf_debug_reader.h
deleted file mode 100644
index 1820e7cdc7..0000000000
--- a/compiler/debug/elf_debug_reader.h
+++ /dev/null
@@ -1,173 +0,0 @@
-/*
- * Copyright (C) 2018 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ART_COMPILER_DEBUG_ELF_DEBUG_READER_H_
-#define ART_COMPILER_DEBUG_ELF_DEBUG_READER_H_
-
-#include "base/array_ref.h"
-#include "debug/dwarf/headers.h"
-#include "elf.h"
-#include "xz_utils.h"
-
-#include <map>
-#include <string_view>
-
-namespace art {
-namespace debug {
-
-// Trivial ELF file reader.
-//
-// It is the bare minimum needed to read mini-debug-info symbols for unwinding.
-// We use it to merge JIT mini-debug-infos together or to prune them after GC.
-template <typename ElfTypes>
-class ElfDebugReader {
- public:
-  // Note that the input buffer might be misaligned.
-  typedef typename ElfTypes::Ehdr ALIGNED(1) Elf_Ehdr;
-  typedef typename ElfTypes::Shdr ALIGNED(1) Elf_Shdr;
-  typedef typename ElfTypes::Sym ALIGNED(1) Elf_Sym;
-  typedef typename ElfTypes::Addr ALIGNED(1) Elf_Addr;
-
-  // Call Frame Information.
-  struct CFI {
-    uint32_t length;  // Length excluding the size of this field.
-    int32_t cie_pointer;  // Offset in the section or -1 for CIE.
-
-    const uint8_t* data() const { return reinterpret_cast<const uint8_t*>(this); }
-    size_t size() const { return sizeof(uint32_t) + length; }
-  } PACKED(1);
-
-  // Common Information Entry.
-  struct CIE : public CFI {
-  } PACKED(1);
-
-  // Frame Description Entry.
-  struct FDE : public CFI {
-    Elf_Addr sym_addr;
-    Elf_Addr sym_size;
-  } PACKED(1);
-
-  explicit ElfDebugReader(ArrayRef<const uint8_t> file) : file_(file) {
-    header_ = Read<Elf_Ehdr>(/*offset=*/ 0);
-    CHECK(header_->checkMagic());
-    CHECK_EQ(header_->e_ehsize, sizeof(Elf_Ehdr));
-    CHECK_EQ(header_->e_shentsize, sizeof(Elf_Shdr));
-
-    // Find all ELF sections.
-    sections_ = Read<Elf_Shdr>(header_->e_shoff, header_->e_shnum);
-    for (const Elf_Shdr& section : sections_) {
-      const char* name = Read<char>(sections_[header_->e_shstrndx].sh_offset + section.sh_name);
-      section_map_[std::string_view(name)] = &section;
-    }
-
-    // Decompressed embedded debug symbols, if any.
-    const Elf_Shdr* gnu_debugdata = section_map_[".gnu_debugdata"];
-    if (gnu_debugdata != nullptr) {
-      auto compressed = Read<uint8_t>(gnu_debugdata->sh_offset, gnu_debugdata->sh_size);
-      XzDecompress(compressed, &decompressed_gnu_debugdata_);
-      gnu_debugdata_reader_.reset(new ElfDebugReader(decompressed_gnu_debugdata_));
-    }
-  }
-
-  explicit ElfDebugReader(std::vector<uint8_t>& file)
-      : ElfDebugReader(ArrayRef<const uint8_t>(file)) {
-  }
-
-  const Elf_Ehdr* GetHeader() { return header_; }
-
-  ArrayRef<Elf_Shdr> GetSections() { return sections_; }
-
-  const Elf_Shdr* GetSection(const char* name) { return section_map_[name]; }
-
-  template <typename VisitSym>
-  void VisitFunctionSymbols(VisitSym visit_sym) {
-    const Elf_Shdr* symtab = GetSection(".symtab");
-    const Elf_Shdr* strtab = GetSection(".strtab");
-    const Elf_Shdr* text = GetSection(".text");
-    if (symtab != nullptr && strtab != nullptr) {
-      CHECK_EQ(symtab->sh_entsize, sizeof(Elf_Sym));
-      size_t count = symtab->sh_size / sizeof(Elf_Sym);
-      for (const Elf_Sym& symbol : Read<Elf_Sym>(symtab->sh_offset, count)) {
-        if (symbol.getType() == STT_FUNC && &sections_[symbol.st_shndx] == text) {
-          visit_sym(symbol, Read<char>(strtab->sh_offset + symbol.st_name));
-        }
-      }
-    }
-    if (gnu_debugdata_reader_ != nullptr) {
-      gnu_debugdata_reader_->VisitFunctionSymbols(visit_sym);
-    }
-  }
-
-  template <typename VisitSym>
-  void VisitDynamicSymbols(VisitSym visit_sym) {
-    const Elf_Shdr* dynsym = GetSection(".dynsym");
-    const Elf_Shdr* dynstr = GetSection(".dynstr");
-    if (dynsym != nullptr && dynstr != nullptr) {
-      CHECK_EQ(dynsym->sh_entsize, sizeof(Elf_Sym));
-      size_t count = dynsym->sh_size / sizeof(Elf_Sym);
-      for (const Elf_Sym& symbol : Read<Elf_Sym>(dynsym->sh_offset, count)) {
-        visit_sym(symbol, Read<char>(dynstr->sh_offset + symbol.st_name));
-      }
-    }
-  }
-
-  template <typename VisitCIE, typename VisitFDE>
-  void VisitDebugFrame(VisitCIE visit_cie, VisitFDE visit_fde) {
-    const Elf_Shdr* debug_frame = GetSection(".debug_frame");
-    if (debug_frame != nullptr) {
-      for (size_t offset = 0; offset < debug_frame->sh_size;) {
-        const CFI* entry = Read<CFI>(debug_frame->sh_offset + offset);
-        DCHECK_LE(entry->size(), debug_frame->sh_size - offset);
-        if (entry->cie_pointer == -1) {
-          visit_cie(Read<CIE>(debug_frame->sh_offset + offset));
-        } else {
-          const FDE* fde = Read<FDE>(debug_frame->sh_offset + offset);
-          visit_fde(fde, Read<CIE>(debug_frame->sh_offset + fde->cie_pointer));
-        }
-        offset += entry->size();
-      }
-    }
-    if (gnu_debugdata_reader_ != nullptr) {
-      gnu_debugdata_reader_->VisitDebugFrame(visit_cie, visit_fde);
-    }
-  }
-
- private:
-  template<typename T>
-  const T* Read(size_t offset) {
-    DCHECK_LE(offset + sizeof(T), file_.size());
-    return reinterpret_cast<const T*>(file_.data() + offset);
-  }
-
-  template<typename T>
-  ArrayRef<const T> Read(size_t offset, size_t count) {
-    DCHECK_LE(offset + count * sizeof(T), file_.size());
-    return ArrayRef<const T>(Read<T>(offset), count);
-  }
-
-  ArrayRef<const uint8_t> const file_;
-  const Elf_Ehdr* header_;
-  ArrayRef<const Elf_Shdr> sections_;
-  std::unordered_map<std::string_view, const Elf_Shdr*> section_map_;
-  std::vector<uint8_t> decompressed_gnu_debugdata_;
-  std::unique_ptr<ElfDebugReader> gnu_debugdata_reader_;
-
-  DISALLOW_COPY_AND_ASSIGN(ElfDebugReader);
-};
-
-}  // namespace debug
-}  // namespace art
-#endif  // ART_COMPILER_DEBUG_ELF_DEBUG_READER_H_