1 files changed, 130 insertions, 0 deletions
diff --git a/.github/calcrom/ElfFile.cpp b/.github/calcrom/ElfFile.cpp
new file mode 100644
index 00000000..52ad2d06
--- /dev/null
+++ b/.github/calcrom/ElfFile.cpp
@@ -0,0 +1,130 @@
+#include <iostream>
+#include <cassert>
+#include <algorithm>
+#include <cstring>
+#include "ElfFile.h"
+
+void Elf32File::ReadElfHeaderAndVerify() {
+    handle.seekg(0);
+    handle.read((char *)ehdr.e_ident, EI_NIDENT);
+    assert(memcmp(ehdr.e_ident, ELFMAG, SELFMAG) == 0);
+    assert(ehdr.e_ident[EI_CLASS] == ELFCLASS32);
+    assert(ehdr.e_ident[EI_DATA] == ELFDATA2LSB);
+    assert(ehdr.e_ident[EI_VERSION] == EV_CURRENT);
+    handle.read((char*)&ehdr + EI_NIDENT, sizeof(ehdr) - EI_NIDENT);
+    assert(ehdr.e_shentsize == sizeof(Elf32_Shdr));
+}
+
+void Elf32File::ReadSectionHeaders() {
+    assert(shdr.empty());
+    shdr.resize(ehdr.e_shnum);
+    handle.seekg(ehdr.e_shoff);
+    handle.read((char*)shdr.data(), ehdr.e_shnum * ehdr.e_shentsize);
+}
+
+void Elf32File::ReadProgramHeaders() {
+    assert(phdr.empty());
+    phdr.resize(ehdr.e_phnum);
+    handle.seekg(ehdr.e_phoff);
+    handle.read((char*)phdr.data(), ehdr.e_phnum * ehdr.e_phentsize);
+}
+
+void Elf32File::ReadShstrtab() {
+    assert(shstrtab.empty());
+    shstrtab.resize(shdr[ehdr.e_shstrndx].sh_size);
+    handle.seekg(shdr[ehdr.e_shstrndx].sh_offset);
+    handle.read((char*)shstrtab.data(), shdr[ehdr.e_shstrndx].sh_size);
+}
+
+void Elf32File::ReadStrtab() {
+    assert(strtab.empty());
+    int i;
+    for (i = 1; i < ehdr.e_shnum; i++) {
+        if (i == ehdr.e_shstrndx) continue;
+        if (shdr[i].sh_type == SHT_STRTAB) break;
+    }
+    assert(i != ehdr.e_shnum);
+    strtab.resize(shdr[i].sh_size);
+    handle.seekg(shdr[i].sh_offset);
+    handle.read((char*)strtab.data(), shdr[i].sh_size);
+}
+
+void Elf32File::ReadSymtab() {
+    assert(symtab.empty());
+    auto sec = find_if(shdr.begin(), shdr.end(), [](Elf32_Shdr const& candidate) { return candidate.sh_type == SHT_SYMTAB; });
+    assert(sec != shdr.end());
+    symtab.resize(sec->sh_size);
+    handle.seekg(sec->sh_offset);
+    handle.read((char*)symtab.data(), sec->sh_size);
+}
+
+Elf32File::Elf32File(path const& filename, elfload load) {
+    open(filename, load);
+}
+
+void Elf32File::open(path const& filename, elfload load) {
+    assert(!is_open());
+    handle.open(filename, ios::binary);
+    assert(handle.good());
+    ReadElfHeaderAndVerify();
+    if (load & sections) {
+        ReadSectionHeaders();
+        ReadShstrtab();
+    }
+    if (load & programs) {
+        ReadProgramHeaders();
+    }
+    if (load & symbols) {
+        assert(load & sections);
+        ReadStrtab();
+        ReadSymtab();
+    }
+}
+
+void Elf32File::close() {
+    if (is_open()) {
+        handle.close();
+    }
+    memset(&ehdr, 0, sizeof(ehdr));
+    shdr.clear();
+    symtab.clear();
+    phdr.clear();
+    shstrtab.clear();
+    strtab.clear();
+}
+
+bool Elf32File::is_open() const {
+    return handle.is_open();
+}
+
+Elf32File::~Elf32File() {
+    close();
+}
+
+vector<Elf32_Shdr> &Elf32File::GetSectionHeaders() {
+    return shdr;
+}
+
+vector<Elf32_Phdr> &Elf32File::GetProgramHeaders() {
+    return phdr;
+}
+
+string Elf32File::GetSectionName(const Elf32_Shdr &section) const {
+    return string(shstrtab.data() + section.sh_name);
+}
+
+string Elf32File::GetSymbolName(const Elf32_Sym &symbol) const {
+    return string(strtab.data() + symbol.st_name);
+}
+
+Elf32_Sym &Elf32File::operator[](const string &name) {
+    return *find_if(symtab.begin(), symtab.end(), [&](Elf32_Sym const &sym) { return name == GetSymbolName(sym); });
+}
+
+Elf32_Sym &Elf32File::at(const string &name) {
+    auto ret = find_if(symtab.begin(), symtab.end(), [&](Elf32_Sym const &sym) { return name == GetSymbolName(sym); });
+    if (ret == symtab.end()) {
+        throw runtime_error("no symbol named " + name);
+    }
+    return *ret;
+}