bintools/checklib/library/library.cpp
changeset 0 044383f39525
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bintools/checklib/library/library.cpp	Tue Oct 27 16:36:35 2009 +0000
@@ -0,0 +1,260 @@
+// Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+//
+// Initial Contributors:
+// Nokia Corporation - initial contribution.
+//
+// Contributors:
+//
+// Description:
+// Class for reading libraries in Unix "ar" format.
+// 
+//
+
+#include "library.h"
+
+#include "misc/endian.h" // For misc::reverse_bytes()
+
+#include <fstream>
+#include <stdexcept>
+#include <cassert>
+#include <iostream>
+#include <iomanip>
+#include <cstdlib>
+
+namespace
+{
+    // An ar library begins with this string.
+    const char MAGIC[] = "!<arch>\n";
+
+    // The size of an object header.
+    const int HEADER_LENGTH = 60;
+
+    // Each object *header* has this trailer.
+    const char TRAILER[] = "`\n";
+}
+
+
+Library::Library(const char a_file_name[])
+{
+    std::ifstream file(a_file_name, std::ios::in | std::ios::binary | std::ios::ate);
+
+    if ( ! file.is_open() )
+    {
+        throw std::runtime_error("couldn't open file");
+    }
+
+    unsigned size  = file.tellg();
+    m_mem_p = new char[size];
+
+    file.seekg(0, std::ios::beg);
+    file.read( const_cast<char*>(m_mem_p), size );
+
+    file.close();
+
+    const char* p1 = m_mem_p;
+    const char* p2 = p1 + size - 1;
+
+    // Eat all meta objects.
+
+    p1 = _eat_ar_header(p1, p2);
+    p1 = _eat_sym_table(p1, p2);
+    p1 = _eat_junk_objs(p1, p2);
+
+    m_first_p = p1; // Pointer to the start of the first "real" object.
+    m_last_p = p2;  // Pointer to end of the last real object.
+}
+
+Library::~Library()
+{
+    delete[] m_mem_p;
+}
+
+bool Library::contains_symbol(const char a_sym_name[]) const
+{
+    std::vector<const char*>::const_iterator p = m_symbols.begin();
+    std::vector<const char*>::const_iterator end_p = m_symbols.end();
+
+    for ( ; p != end_p; ++p)
+    {
+        if ( std::strcmp(a_sym_name, *p) == 0 ) return 1;
+    }
+
+    return 0;
+}
+
+const std::vector< std::pair<const char*, const char*> >* Library::get_objects() const
+{
+    if ( m_objects.empty() )
+    {
+        const char* p = m_first_p;
+
+        unsigned long size;
+
+        while (p < m_last_p)
+        {
+            p = _eat_obj_header(p, m_last_p, &size);
+
+            m_objects.push_back( std::pair<const char*, const char*>(p, p + size) );
+
+            p += size;
+        }
+    }
+
+    return &m_objects;
+}
+
+const char* Library::_eat_ar_header(const char* p1, const char* p2) const
+{
+    int magic_length = std::strlen(MAGIC);
+
+    if (p2 - p1 + 1 < magic_length)
+    {
+        throw std::runtime_error("library too small for magic word");
+    }
+
+    if ( std::strncmp(p1, MAGIC, magic_length) != 0 )
+    {
+        throw std::runtime_error("bad magic; this is not a valid library");
+    }
+
+    return (p1 + magic_length);
+}
+
+const char* Library::_eat_sym_table(const char* a_first_p, const char* a_last_p) const
+{
+    unsigned long obj_size;
+
+    const char* p = _eat_obj_header(a_first_p, a_last_p, &obj_size, "/               "); // Read the header of the symbol table.
+
+    if (p == a_first_p)
+    {
+        throw std::runtime_error("no library symbol table found");
+    }
+
+    const char* obj_end_p = p + obj_size;
+
+    // Check that we're 4-byte aligned.
+    assert( (reinterpret_cast<int>(p) & 0x3) == 0 );
+
+    uint32_t nr_of_syms = *reinterpret_cast<const int*>(p);
+    nr_of_syms = misc::reverse_bytes(nr_of_syms);
+
+    p += sizeof(nr_of_syms);            // Go past the integer we just read.
+    p += nr_of_syms * sizeof(uint32_t); // Go past all the offsets.
+
+    unsigned n = 0;
+
+    while (n < nr_of_syms && p < a_last_p)
+    {
+        m_symbols.push_back(p);
+
+        p += std::strlen(p) + 1; 
+
+        n++;
+    }
+
+    if (n != nr_of_syms)
+    {
+        throw std::runtime_error("inconsistent symbol table");
+    }
+
+    if (p > obj_end_p)
+    {
+        throw std::runtime_error("over-running symbol table");
+    }
+
+    return obj_end_p;
+}
+
+const char* Library::_eat_junk_objs(const char* p1, const char* p2) const
+{
+    unsigned long obj_size;
+    const char* p;
+
+    p = _eat_obj_header(p1, p2, &obj_size, "//              ");
+
+    if (p > p1)
+    {
+        p1 = p + obj_size;
+    }
+
+    p = _eat_obj_header(p1, p2, &obj_size, "/               ");
+
+    if (p > p1)
+    {
+        p1 = p + obj_size;
+    }
+
+    p = _eat_obj_header(p1, p2, &obj_size, "//              ");
+
+    if (p > p1)
+    {
+        p1 = p + obj_size;
+    }
+
+    return p1;
+}
+
+const char* Library::_eat_obj_header(const char* a_first_p, const char* a_last_p, unsigned long* a_size_p, const char* a_name) const
+{
+    const char* p = a_first_p;
+
+    // The header is 2-byte aligned, so ignore the previous object's trailing
+    // padding byte.
+    if ( reinterpret_cast<int>(p) & 1)
+    {
+        p++;
+    }
+
+    if (a_last_p - p + 1 < HEADER_LENGTH)
+    {
+        throw std::runtime_error("no space for library object header");
+    }
+
+    // At the moment We can only handle short names. This is enough for identifying
+    // the meta objects "/" (symbol table) and "//" (object table).
+
+    if ( a_name && std::strncmp(p, a_name, std::strlen(a_name)) != 0 )
+    {
+        return a_first_p;
+    }
+
+    p += 16; // Ignore the name field.
+    p += 12; // Ignore the modification time.
+    p +=  6; // Ignore the group ID.
+    p +=  6; // Ignore the user ID.
+    p +=  8; // Ignore the file mode.
+
+    // Read the object size.
+
+    if (a_size_p)
+    {
+        char* tail_p;
+        *a_size_p = std::strtoul(p, &tail_p, 0);
+
+        if (tail_p == p || tail_p > a_last_p + 1)
+        {
+            throw std::runtime_error("could not read library object size");
+        }
+    }
+
+    p += 10; // Jump over the object size field.
+
+    // Verify that the header trailer is correct.
+
+    int trailer_length = std::strlen(TRAILER);
+
+    if ( std::strncmp(p, TRAILER, trailer_length) != 0  )
+    {
+        throw std::runtime_error("incorrect library object header trailer");
+    }
+
+    return (p + trailer_length);
+}
+
+