source/Host/macosx/Symbols.cpp

//===-- Symbols.cpp ---------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "lldb/Host/Symbols.h"

// C Includes
#include <dirent.h>
#include <mach-o/loader.h>
#include <mach-o/fat.h>

// C++ Includes
// Other libraries and framework includes
#include <CoreFoundation/CoreFoundation.h>

// Project includes
#include "CFCReleaser.h"
#include "lldb/Core/ArchSpec.h"
#include "lldb/Core/DataBuffer.h"
#include "lldb/Core/DataExtractor.h"
#include "lldb/Core/Timer.h"
#include "lldb/Core/UUID.h"

using namespace lldb;
using namespace lldb_private;

extern "C" {
CFURLRef DBGCopyFullDSYMURLForUUID (CFUUIDRef uuid, CFURLRef exec_url);
CFDictionaryRef DBGCopyDSYMPropertyLists (CFURLRef dsym_url);
};

static bool
SkinnyMachOFileContainsArchAndUUID
(
    const FileSpec &file_spec,
    const ArchSpec *arch,
    const UUID *uuid,   // the UUID we are looking for
    off_t file_offset,
    DataExtractor& data,
    uint32_t data_offset,
    const uint32_t magic
)
{
    assert(magic == MH_CIGAM || magic == MH_MAGIC || magic == MH_CIGAM_64 || magic == MH_MAGIC_64);
    if (magic == MH_MAGIC || magic == MH_MAGIC_64)
        data.SetByteOrder (eByteOrderHost);
    else if (eByteOrderHost == eByteOrderBig)
        data.SetByteOrder (eByteOrderLittle);
    else
        data.SetByteOrder (eByteOrderBig);

    uint32_t i;
    const uint32_t cputype      = data.GetU32(&data_offset);    // cpu specifier
    const uint32_t cpusubtype   = data.GetU32(&data_offset);    // machine specifier
    data_offset+=4; // Skip mach file type
    const uint32_t ncmds        = data.GetU32(&data_offset);    // number of load commands
    const uint32_t sizeofcmds   = data.GetU32(&data_offset);    // the size of all the load commands
    data_offset+=4; // Skip flags

    // Check the architecture if we have a valid arch pointer
    if (arch)
    {
        ArchSpec file_arch(cputype, cpusubtype);

        if (file_arch != *arch)
            return false;
    }

    // The file exists, and if a valid arch pointer was passed in we know
    // if already matches, so we can return if we aren't looking for a specific
    // UUID
    if (uuid == NULL)
        return true;

    if (magic == MH_CIGAM_64 || magic == MH_MAGIC_64)
        data_offset += 4;   // Skip reserved field for in mach_header_64

    // Make sure we have enough data for all the load commands
    if (magic == MH_CIGAM_64 || magic == MH_MAGIC_64)
    {
        if (data.GetByteSize() < sizeof(struct mach_header_64) + sizeofcmds)
        {
            DataBufferSP data_buffer_sp (file_spec.ReadFileContents (file_offset, sizeof(struct mach_header_64) + sizeofcmds));
            data.SetData (data_buffer_sp);
        }
    }
    else
    {
        if (data.GetByteSize() < sizeof(struct mach_header) + sizeofcmds)
        {
            DataBufferSP data_buffer_sp (file_spec.ReadFileContents (file_offset, sizeof(struct mach_header) + sizeofcmds));
            data.SetData (data_buffer_sp);
        }
    }

    for (i=0; i<ncmds; i++)
    {
        const uint32_t cmd_offset = data_offset;    // Save this data_offset in case parsing of the segment goes awry!
        uint32_t cmd        = data.GetU32(&data_offset);
        uint32_t cmd_size   = data.GetU32(&data_offset);
        if (cmd == LC_UUID)
        {
            UUID file_uuid (data.GetData(&data_offset, 16), 16);
            return file_uuid == *uuid;
        }
        data_offset = cmd_offset + cmd_size;
    }
    return false;
}

bool
UniversalMachOFileContainsArchAndUUID
(
    const FileSpec &file_spec,
    const ArchSpec *arch,
    const UUID *uuid,
    off_t file_offset,
    DataExtractor& data,
    uint32_t data_offset,
    const uint32_t magic
)
{
    assert(magic == FAT_CIGAM || magic == FAT_MAGIC);

    // Universal mach-o files always have their headers encoded as BIG endian
    data.SetByteOrder(eByteOrderBig);

    uint32_t i;
    const uint32_t nfat_arch = data.GetU32(&data_offset);   // number of structs that follow
    const uint32_t fat_header_and_arch_size = sizeof(struct fat_header) + nfat_arch * sizeof(struct fat_arch);
    if (data.GetByteSize() < fat_header_and_arch_size)
    {
        DataBufferSP data_buffer_sp (file_spec.ReadFileContents (file_offset, fat_header_and_arch_size));
        data.SetData (data_buffer_sp);
    }

    for (i=0; i<nfat_arch; i++)
    {
        cpu_type_t      arch_cputype        = data.GetU32(&data_offset);    // cpu specifier (int)
        cpu_subtype_t   arch_cpusubtype     = data.GetU32(&data_offset);    // machine specifier (int)
        uint32_t        arch_offset         = data.GetU32(&data_offset);    // file offset to this object file
    //  uint32_t        arch_size           = data.GetU32(&data_offset);    // size of this object file
    //  uint32_t        arch_align          = data.GetU32(&data_offset);    // alignment as a power of 2
        data_offset += 8;   // Skip size and align as we don't need those
        // Only process this slice if the cpu type/subtype matches
        if (arch)
        {
            ArchSpec fat_arch(arch_cputype, arch_cpusubtype);
            if (fat_arch != *arch)
                continue;
        }

        // Create a buffer with only the arch slice date in it
        DataExtractor arch_data;
        DataBufferSP data_buffer_sp (file_spec.ReadFileContents (file_offset + arch_offset, 0x1000));
        arch_data.SetData(data_buffer_sp);
        uint32_t arch_data_offset = 0;
        uint32_t arch_magic = arch_data.GetU32(&arch_data_offset);

        switch (arch_magic)
        {
        case MH_CIGAM:          // 32 bit mach-o file
        case MH_MAGIC:          // 32 bit mach-o file
        case MH_CIGAM_64:       // 64 bit mach-o file
        case MH_MAGIC_64:       // 64 bit mach-o file
            if (SkinnyMachOFileContainsArchAndUUID (file_spec, arch, uuid, file_offset + arch_offset, arch_data, arch_data_offset, arch_magic))
                return true;
            break;
        }
    }
    return false;
}

static bool
FileAtPathContainsArchAndUUID
(
    const FileSpec &file_spec,
    const ArchSpec *arch,
    const UUID *uuid
)
{
    DataExtractor data;
    off_t file_offset = 0;
    DataBufferSP data_buffer_sp (file_spec.ReadFileContents (file_offset, 0x1000));

    if (data_buffer_sp && data_buffer_sp->GetByteSize() > 0)
    {
        data.SetData(data_buffer_sp);

        uint32_t data_offset = 0;
        uint32_t magic = data.GetU32(&data_offset);

        switch (magic)
        {
        // 32 bit mach-o file
        case MH_CIGAM:
        case MH_MAGIC:
        case MH_CIGAM_64:
        case MH_MAGIC_64:
            return SkinnyMachOFileContainsArchAndUUID (file_spec, arch, uuid, file_offset, data, data_offset, magic);

        // fat mach-o file
        case FAT_CIGAM:
        case FAT_MAGIC:
            return UniversalMachOFileContainsArchAndUUID (file_spec, arch, uuid, file_offset, data, data_offset, magic);

        default:
            break;
        }
    }
    return false;
}

static FileSpec
LocateDSYMMachFileInDSYMBundle
(
    const FileSpec& dsym_bundle_fspec,
    const UUID *uuid,
    const ArchSpec *arch)
{
    char path[PATH_MAX];

    FileSpec dsym_fspec;

    if (dsym_bundle_fspec.GetPath(path, sizeof(path)))
    {
        ::strncat (path, "/Contents/Resources/DWARF", sizeof(path) - strlen(path) - 1);

        DIR* dirp = ::opendir(path);
        if (dirp != NULL)
        {
            const size_t path_len = strlen(path);
            const int bytes_left = sizeof(path) - path_len - 1;
            struct dirent* dp;
            while ((dp = readdir(dirp)) != NULL)
            {
                // Only search directories
                if (dp->d_type == DT_DIR || dp->d_type == DT_UNKNOWN)
                {
                    if (dp->d_namlen == 1 && dp->d_name[0] == '.')
                        continue;

                    if (dp->d_namlen == 2 && dp->d_name[0] == '.' && dp->d_name[1] == '.')
                        continue;
                }

                if (dp->d_type == DT_REG || dp->d_type == DT_UNKNOWN)
                {
                    ::strncpy (&path[path_len], dp->d_name, bytes_left);

                    dsym_fspec.SetFile(path);
                    if (FileAtPathContainsArchAndUUID (dsym_fspec, arch, uuid))
                        return dsym_fspec;
                }
            }
        }
    }
    dsym_fspec.Clear();
    return dsym_fspec;
}

static int
LocateMacOSXFilesUsingDebugSymbols
(
    const FileSpec *exec_fspec, // An executable path that may or may not be correct if UUID is specified
    const ArchSpec* arch,       // Limit the search to files with this architecture if non-NULL
    const UUID *uuid,           // Match the UUID value if non-NULL,
    FileSpec *out_exec_fspec,   // If non-NULL, try and find the executable
    FileSpec *out_dsym_fspec    // If non-NULL try and find the debug symbol file
)
{
    int items_found = 0;

    if (out_exec_fspec)
        out_exec_fspec->Clear();

    if (out_dsym_fspec)
        out_dsym_fspec->Clear();

    if (uuid && uuid->IsValid())
    {
        // Try and locate the dSYM file using DebugSymbols first
        const UInt8 *module_uuid = (const UInt8 *)uuid->GetBytes();
        if (module_uuid != NULL)
        {
            CFCReleaser<CFUUIDRef> module_uuid_ref(::CFUUIDCreateWithBytes ( NULL,
                                                                            module_uuid[0],
                                                                            module_uuid[1],
                                                                            module_uuid[2],
                                                                            module_uuid[3],
                                                                            module_uuid[4],
                                                                            module_uuid[5],
                                                                            module_uuid[6],
                                                                            module_uuid[7],
                                                                            module_uuid[8],
                                                                            module_uuid[9],
                                                                            module_uuid[10],
                                                                            module_uuid[11],
                                                                            module_uuid[12],
                                                                            module_uuid[13],
                                                                            module_uuid[14],
                                                                            module_uuid[15]));

            if (module_uuid_ref.get())
            {
                CFCReleaser<CFURLRef> exec_url;

                if (exec_fspec)
                {
                    char exec_cf_path[PATH_MAX];
                    if (exec_fspec->GetPath(exec_cf_path, sizeof(exec_cf_path)))
                        exec_url.reset(::CFURLCreateFromFileSystemRepresentation (NULL,
                                                                                  (const UInt8 *)exec_cf_path,
                                                                                  strlen(exec_cf_path),
                                                                                  FALSE));
                }

                CFCReleaser<CFURLRef> dsym_url (::DBGCopyFullDSYMURLForUUID(module_uuid_ref.get(), exec_url.get()));
                char path[PATH_MAX];

                if (dsym_url.get())
                {
                    if (out_dsym_fspec)
                    {
                        if (::CFURLGetFileSystemRepresentation (dsym_url.get(), true, (UInt8*)path, sizeof(path)-1))
                        {
                            out_dsym_fspec->SetFile(path);

                            if (out_dsym_fspec->GetFileType () == FileSpec::eFileTypeDirectory)
                            {
                                *out_dsym_fspec = LocateDSYMMachFileInDSYMBundle (*out_dsym_fspec, uuid, arch);
                                if (*out_dsym_fspec)
                                    ++items_found;
                            }
                            else
                            {
                                ++items_found;
                            }
                        }
                    }

                    if (out_exec_fspec)
                    {
                        CFCReleaser<CFDictionaryRef> dict(::DBGCopyDSYMPropertyLists (dsym_url.get()));;
                        if (dict.get())
                        {
                            CFStringRef exec_cf_path = static_cast<CFStringRef>(::CFDictionaryGetValue (dict.get(), CFSTR("DBGSymbolRichExecutable")));
                            if (exec_cf_path && ::CFStringGetFileSystemRepresentation (exec_cf_path, path, sizeof(path)))
                            {
                                ++items_found;
                                out_dsym_fspec->SetFile(path);
                            }
                        }
                    }
                }
            }
        }
    }
    return items_found;
}

static bool
LocateDSYMInVincinityOfExecutable (const FileSpec *exec_fspec, const ArchSpec* arch, const UUID *uuid, FileSpec &dsym_fspec)
{
    if (exec_fspec)
    {
        char path[PATH_MAX];
        if (exec_fspec->GetPath(path, sizeof(path)))
        {
            // Make sure the module isn't already just a dSYM file...
            if (strcasestr(path, ".dSYM/Contents/Resources/DWARF") == NULL)
            {
                size_t obj_file_path_length = strlen(path);
                strncat(path, ".dSYM/Contents/Resources/DWARF/", sizeof(path));
                strncat(path, exec_fspec->GetFilename().AsCString(), sizeof(path));

                dsym_fspec.SetFile(path);

                if (FileAtPathContainsArchAndUUID (dsym_fspec, arch, uuid))
                {
                    return true;
                }
                else
                {
                    path[obj_file_path_length] = '\0';

                    char *last_dot = strrchr(path, '.');
                    while (last_dot != NULL && last_dot[0])
                    {
                        char *next_slash = strchr(last_dot, '/');
                        if (next_slash != NULL)
                        {
                            *next_slash = '\0';
                            strncat(path, ".dSYM/Contents/Resources/DWARF/", sizeof(path));
                            strncat(path, exec_fspec->GetFilename().AsCString(), sizeof(path));
                            dsym_fspec.SetFile(path);
                            if (dsym_fspec.Exists())
                                return true;
                            else
                            {
                                *last_dot = '\0';
                                char *prev_slash = strrchr(path, '/');
                                if (prev_slash != NULL)
                                    *prev_slash = '\0';
                                else
                                    break;
                            }
                        }
                        else
                        {
                            break;
                        }
                    }
                }
            }
        }
    }
    dsym_fspec.Clear();
    return false;
}

FileSpec
Symbols::LocateExecutableObjectFile (const FileSpec *exec_fspec, const ArchSpec* arch, const UUID *uuid)
{
    Timer scoped_timer (__PRETTY_FUNCTION__,
                        "LocateExecutableObjectFile (file = %s, arch = %s, uuid = %p)",
                        exec_fspec ? exec_fspec->GetFilename().AsCString ("<NULL>") : "<NULL>",
                        arch ? arch->AsCString() : "<NULL>",
                        uuid);

    FileSpec objfile_fspec;
    if (exec_fspec && FileAtPathContainsArchAndUUID (*exec_fspec, arch, uuid))
        objfile_fspec = *exec_fspec;
    else
        LocateMacOSXFilesUsingDebugSymbols (exec_fspec, arch, uuid, &objfile_fspec, NULL);
    return objfile_fspec;
}

FileSpec
Symbols::LocateExecutableSymbolFile (const FileSpec *exec_fspec, const ArchSpec* arch, const UUID *uuid)
{
    Timer scoped_timer (__PRETTY_FUNCTION__,
                        "LocateExecutableSymbolFile (file = %s, arch = %s, uuid = %p)",
                        exec_fspec ? exec_fspec->GetFilename().AsCString ("<NULL>") : "<NULL>",
                        arch ? arch->AsCString() : "<NULL>",
                        uuid);

    FileSpec symbol_fspec;
    // First try and find the dSYM in the same directory as the executable or in
    // an appropriate parent directory
    if (LocateDSYMInVincinityOfExecutable (exec_fspec, arch, uuid, symbol_fspec) == false)
    {
        // We failed to easily find the dSYM above, so use DebugSymbols
        LocateMacOSXFilesUsingDebugSymbols (exec_fspec, arch, uuid, NULL, &symbol_fspec);
    }
    return symbol_fspec;
}