Add coff_file_reader to extract info/from dll/lib files without dumpbin

Calling dumpbin was very slow in some cases (e.g. boost).
With coff_file_reader we directly examine the binary for the few bits we need.

1 files changed, 263 insertions, 0 deletions

diff --git a/toolsrc/src/coff_file_reader.cpp b/toolsrc/src/coff_file_reader.cpp
new file mode 100644
index 000000000..593bb18d1
--- /dev/null
+++ b/toolsrc/src/coff_file_reader.cpp
@@ -0,0 +1,263 @@
+#include "coff_file_reader.h"
+#include <iostream>
+#include <cstdint>
+#include <algorithm>
+#include "vcpkg_Checks.h"
+#include <set>
+#include <fstream>
+
+using namespace std;
+
+namespace vcpkg {namespace COFFFileReader
+{
+    template <class T>
+    static T reinterpret_bytes(const char* data)
+    {
+        return (*reinterpret_cast<const T *>(&data[0]));
+    }
+
+    template <class T>
+    static T read_value_from_stream(fstream& fs)
+    {
+        T data;
+        fs.read(reinterpret_cast<char*>(&data), sizeof data);
+        return data;
+    }
+
+    template <class T>
+    static T peek_value_from_stream(fstream& fs)
+    {
+        fpos_t original_pos = fs.tellg().seekpos();
+        T data;
+        fs.read(reinterpret_cast<char*>(&data), sizeof data);
+        fs.seekg(original_pos);
+        return data;
+    }
+
+    static void verify_equal_strings(const char* expected, const char* actual, int size)
+    {
+        Checks::check_exit(memcmp(expected, actual, size) == 0, "Incorrect string found. Expected: %s but found %s", expected, actual);
+    }
+
+    static void read_and_verify_PE_signature(fstream& fs)
+    {
+        static const size_t OFFSET_TO_PE_SIGNATURE_OFFSET = 0x3c;
+
+        static const char* PE_SIGNATURE = "PE\0\0";
+        static const size_t PE_SIGNATURE_SIZE = 4;
+
+        fs.seekg(OFFSET_TO_PE_SIGNATURE_OFFSET, ios_base::beg);
+        const int32_t offset_to_PE_signature = read_value_from_stream<int32_t>(fs);
+
+        fs.seekg(offset_to_PE_signature);
+        char signature[PE_SIGNATURE_SIZE];
+        fs.read(signature, PE_SIGNATURE_SIZE);
+        verify_equal_strings(PE_SIGNATURE, signature, PE_SIGNATURE_SIZE);
+        fs.seekg(offset_to_PE_signature + PE_SIGNATURE_SIZE, ios_base::beg);
+    }
+
+    static fpos_t align_to(const fpos_t unaligned_offset, const int alignment_size)
+    {
+        fpos_t aligned_offset = unaligned_offset - 1;
+        aligned_offset /= alignment_size;
+        aligned_offset += 1;
+        aligned_offset *= alignment_size;
+        return aligned_offset;
+    }
+
+    struct coff_file_header
+    {
+        static const size_t HEADER_SIZE = 20;
+
+        static coff_file_header read(fstream& fs)
+        {
+            coff_file_header ret;
+            ret.data.resize(HEADER_SIZE);
+            fs.read(&ret.data[0], HEADER_SIZE);
+            return ret;
+        }
+
+        static coff_file_header peek(fstream& fs)
+        {
+            auto original_pos = fs.tellg().seekpos();
+            coff_file_header ret = read(fs);
+            fs.seekg(original_pos);
+            return ret;
+        }
+
+        MachineType machineType() const
+        {
+            static const size_t MACHINE_TYPE_OFFSET = 0;
+            static const size_t MACHINE_TYPE_SIZE = 2;
+
+            std::string machine_field_as_string = data.substr(MACHINE_TYPE_OFFSET, MACHINE_TYPE_SIZE);
+            const uint16_t machine = reinterpret_bytes<uint16_t>(machine_field_as_string.c_str());
+            return getMachineType(machine);
+        }
+
+    private:
+        std::string data;
+    };
+
+    struct archive_member_header
+    {
+        static const size_t HEADER_SIZE = 60;
+
+        static archive_member_header read(fstream& fs)
+        {
+            static const size_t HEADER_END_OFFSET = 58;
+            static const char* HEADER_END = "`\n";
+            static const size_t HEADER_END_SIZE = 2;
+
+            archive_member_header ret;
+            ret.data.resize(HEADER_SIZE);
+            fs.read(&ret.data[0], HEADER_SIZE);
+
+            const std::string header_end = ret.data.substr(HEADER_END_OFFSET, HEADER_END_SIZE);
+            verify_equal_strings(HEADER_END, header_end.c_str(), HEADER_END_SIZE);
+
+            return ret;
+        }
+
+        std::string name() const
+        {
+            static const size_t HEADER_NAME_OFFSET = 0;
+            static const size_t HEADER_NAME_SIZE = 16;
+            return data.substr(HEADER_NAME_OFFSET, HEADER_NAME_SIZE);
+        }
+
+        uint64_t member_size() const
+        {
+            static const size_t HEADER_SIZE_OFFSET = 48;
+            static const size_t HEADER_SIZE_FIELD_SIZE = 10;
+            const std::string as_string = data.substr(HEADER_SIZE_OFFSET, HEADER_SIZE_FIELD_SIZE);
+            // This is in ASCII decimal representation
+            const uint64_t value = std::strtoull(as_string.c_str(), nullptr, 10);
+            return value;
+        }
+
+        std::string data;
+    };
+
+    struct import_header
+    {
+        static const size_t HEADER_SIZE = 20;
+
+        static import_header read(fstream& fs)
+        {
+            static const size_t SIG1_OFFSET = 0;
+            static const uint16_t SIG1 = static_cast<uint16_t>(MachineType::UNKNOWN);
+            static const size_t SIG1_SIZE = 2;
+
+            static const size_t SIG2_OFFSET = 2;
+            static const uint16_t SIG2 = 0xFFFF;
+            static const size_t SIG2_SIZE = 2;
+
+            import_header ret;
+            ret.data.resize(HEADER_SIZE);
+            fs.read(&ret.data[0], HEADER_SIZE);
+
+            const std::string sig1_as_string = ret.data.substr(SIG1_OFFSET, SIG1_SIZE);
+            const uint16_t sig1 = reinterpret_bytes<uint16_t>(sig1_as_string.c_str());
+            Checks::check_exit(sig1 == SIG1, "Sig1 was incorrect. Expected %s but got %s", SIG1, sig1);
+
+            const std::string sig2_as_string = ret.data.substr(SIG2_OFFSET, SIG2_SIZE);
+            const uint16_t sig2 = reinterpret_bytes<uint16_t>(sig2_as_string.c_str());
+            Checks::check_exit(sig2 == SIG2, "Sig2 was incorrect. Expected %s but got %s", SIG2, sig2);
+
+            return ret;
+        }
+
+        static import_header peek(fstream& fs)
+        {
+            auto original_pos = fs.tellg().seekpos();
+            import_header ret = read(fs);
+            fs.seekg(original_pos);
+            return ret;
+        }
+
+        MachineType machineType() const
+        {
+            static const size_t MACHINE_TYPE_OFFSET = 6;
+            static const size_t MACHINE_TYPE_SIZE = 2;
+
+            std::string machine_field_as_string = data.substr(MACHINE_TYPE_OFFSET, MACHINE_TYPE_SIZE);
+            const uint16_t machine = reinterpret_bytes<uint16_t>(machine_field_as_string.c_str());
+            return getMachineType(machine);
+        }
+
+    private:
+        std::string data;
+    };
+
+    static void skip_archive_member(fstream& fs, uint64_t member_size)
+    {
+        static const size_t ALIGNMENT_SIZE = 2;
+
+        const fpos_t new_offset = align_to(member_size, ALIGNMENT_SIZE);
+        fs.seekg(new_offset, ios_base::cur);
+    }
+
+    static void read_and_verify_archive_file_signature(fstream& fs)
+    {
+        static const char* FILE_START = "!<arch>\n";
+        static const size_t FILE_START_SIZE = 8;
+
+        fs.seekg(fs.beg);
+
+        char file_start[FILE_START_SIZE];
+        fs.read(file_start, FILE_START_SIZE);
+        verify_equal_strings(FILE_START, file_start, FILE_START_SIZE);
+    }
+
+    dll_info read_dll(const fs::path path)
+    {
+        std::fstream fs(path, std::ios::in | std::ios::binary | std::ios::ate);
+        Checks::check_exit(fs.is_open(), "Could not open file %s for reading", path.generic_string());
+
+        read_and_verify_PE_signature(fs);
+        coff_file_header header = coff_file_header::read(fs);
+        MachineType machine = header.machineType();
+        return {machine};
+    }
+
+    lib_info read_lib(const fs::path path)
+    {
+        std::fstream fs(path, std::ios::in | std::ios::binary | std::ios::ate);
+        Checks::check_exit(fs.is_open(), "Could not open file %s for reading", path.generic_string());
+
+        read_and_verify_archive_file_signature(fs);
+
+        // First Linker Member
+        const archive_member_header first_linker_member_header = archive_member_header::read(fs);
+        Checks::check_exit(first_linker_member_header.name().substr(0, 2) == "/ ", "Could not find proper first linker member");
+        skip_archive_member(fs, first_linker_member_header.member_size());
+
+        const archive_member_header second_linker_member_header = archive_member_header::read(fs);
+        Checks::check_exit(second_linker_member_header.name().substr(0, 2) == "/ ", "Could not find proper second linker member");
+        // The first 4 bytes contains the number of archive members
+        const uint32_t archive_member_count = peek_value_from_stream<uint32_t>(fs);
+        skip_archive_member(fs, second_linker_member_header.member_size());
+
+        bool hasLongnameMemberHeader = peek_value_from_stream<uint16_t>(fs) == 0x2F2F;
+        if (hasLongnameMemberHeader)
+        {
+            const archive_member_header longnames_member_header = archive_member_header::read(fs);
+            skip_archive_member(fs, longnames_member_header.member_size());
+        }
+
+        std::set<MachineType> machine_types;
+        // Next we have the obj and pseudo-object files
+        for (uint32_t i = 0; i < archive_member_count; i++)
+        {
+            const archive_member_header header = archive_member_header::read(fs);
+            const uint16_t first_two_bytes = peek_value_from_stream<uint16_t>(fs);
+            const bool isImportHeader = getMachineType(first_two_bytes) == MachineType::UNKNOWN;
+            const MachineType machine = isImportHeader ? import_header::peek(fs).machineType() : coff_file_header::peek(fs).machineType();
+            machine_types.insert(machine);
+            skip_archive_member(fs, header.member_size());
+        }
+
+        return {std::vector<MachineType>(machine_types.cbegin(), machine_types.cend())};
+    }
+}}