Impl ELF symbols extraction

1 files changed, 33 insertions, 1 deletions

diff --git a/src/elf_image.h b/src/elf_image.h
index b7c7123..b753008 100644
--- a/src/elf_image.h
+++ b/src/elf_image.h
@@ -13,7 +13,7 @@ namespace ELF {
 struct ProgramHeader32Table {
     const ProgramHeader32 *headers{};
     size_t size{};
-    static ProgramHeader32Table FromBytes(const DataView &, DataEncoding);
+    static ProgramHeader32Table FromView(const DataView &, DataEncoding);
 };
 
 struct Segment {
@@ -26,6 +26,7 @@ class Image {
     char *const _error;
     const Header32 _h;
     const ProgramHeader32Table _pht;
+    const SectionHeader32 _shstrtab, _symtab, _strtab;
 public:
     explicit Image(DataBuffer&&);
     ~Image();
@@ -50,6 +51,37 @@ public:
         return DataView{};
     };
     constexpr const char *Error() const { return _error; }
+    ELF::SectionHeader32 GetSectionHeaderByName(const char *name) const;
+    constexpr const ELF::SectionHeader32 GetSectionHeader(uint32_t index) const
+    {
+        if (index > _h.shnum) {
+            return SectionHeader32{};
+        }
+        const size_t offset = _h.shoff + kSectionHeaderSize * index;
+        if (offset + kSectionHeaderSize > _data.buffer_size) {
+            return SectionHeader32{};
+        }
+        return SectionHeader32::FromBytes(
+                _data.buffer + offset, _h.ident.data_encoding);
+    }
+    uint32_t GetSectionHeaderIndexByName(const char *name) const;
+    constexpr ELF::Symbol32 GetSymbolByIndex(uint32_t index) const
+    {
+        if (!IsValid()) {
+            return Symbol32{};
+        }
+        if (_symtab.entsize == 0 || index >= _symtab.size / _symtab.entsize) {
+            return Symbol32{};
+        }
+        auto symbol = Symbol32::FromBytes(
+                _data.buffer + _symtab.offset + _symtab.entsize * index,
+                _h.ident.data_encoding);
+        if (symbol.namendx < _strtab.size && _data.buffer[_strtab.offset + _strtab.size] == '\0') {
+            symbol.name = reinterpret_cast<const char *>(
+                    _data.buffer + _strtab.offset + symbol.namendx);
+        }
+        return symbol;
+    }
 };
 
 }