op_header.cpp

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#include <cstring>
#include <iostream>
#include <cstdlib>
#include <iomanip>
#include <set>
#include <sstream>
#include <cstring>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include "op_config.h"
#include "op_exception.h"
#include "odb.h"
#include "op_cpu_type.h"
#include "op_file.h"
#include "op_header.h"
#include "op_events.h"
#include "string_manip.h"
#include "format_output.h"
#include "xml_utils.h"
#include "cverb.h"

using namespace std;

extern verbose vbfd;

void op_check_header(opd_header const & h1, opd_header const & h2,
             string const & filename)
{
    if (h1.mtime != h2.mtime) {
        ostringstream os;
        os << "header timestamps are different ("
           << h1.mtime << ", " << h2.mtime << ") for "
           << filename << "\n";
        throw op_fatal_error(os.str());
    }

    if (h1.is_kernel != h2.is_kernel) {
        ostringstream os;
        os << "header is_kernel flags are different for "
           << filename << "\n";
        throw op_fatal_error(os.str());
    }
    
    // Note that in the generated ELF file for anonymous code the vma
    // of the symbol is exaclty the same vma as the code had during sampling.
    
    // Note that we don't check CPU speed since that can vary
    // freely on the same machine
}


namespace {

set<string> warned_files;

}

bool is_jit_sample(string const & filename)
{
    // suffix for JIT sample files (see FIXME in check_mtime() below)
    string suf = ".jo";
    
    string::size_type pos;
    pos = filename.rfind(suf);
    // for JIT sample files do not output the warning to stderr.
    if (pos != string::npos && pos == filename.size() - suf.size())
        return true;
    else
        return false;
}

void check_mtime(string const & file, opd_header const & header)
{
    u64 newmtime = op_get_mtime(file.c_str());

    if (newmtime == header.mtime)
        return;

    if (warned_files.find(file) != warned_files.end())
        return;

    warned_files.insert(file);

    // Files we couldn't get mtime of have zero mtime
    if (!header.mtime) {
        // FIXME: header.mtime for JIT sample files is 0. The problem could be that
        //        in opd_mangling.c:opd_open_sample_file() the call of fill_header()
        //        think that the JIT sample file is not a binary file.
        if (is_jit_sample(file)) {
            cverb << vbfd << "warning: could not check that the binary file "
                  << file << " has not been modified since "
                  "the profile was taken. Results may be inaccurate.\n";
        } else {
            cerr << "warning: could not check that the binary file "
                 << file << " has not been modified since "
                 "the profile was taken. Results may be inaccurate.\n";
        }
    } else {
        static bool warned_already = false;

        cerr << "warning: the last modified time of the binary file "
             "does not match that of the sample file for " << file
             << "\n";

        if (!warned_already) {
            cerr << "Either this is the wrong binary or the binary "
            "has been modified since the sample file was created.\n";
            warned_already = true;
        }
    }
}


opd_header const read_header(string const & sample_filename)
{
    int fd = open(sample_filename.c_str(), O_RDONLY);
    if (fd < 0)
        throw op_fatal_error("Can't open sample file:" +
                     sample_filename);

    opd_header header;
    if (read(fd, &header, sizeof(header)) != sizeof(header)) {
        close(fd);
        throw op_fatal_error("Can't read sample file header:" +
                     sample_filename);
    }

    if (memcmp(header.magic, OPD_MAGIC, sizeof(header.magic))) {
        close(fd);
        throw op_fatal_error("Invalid sample file, "
                     "bad magic number: " +
                     sample_filename);
    }

    close(fd);

    return header;
}


namespace {

string const op_print_event(op_cpu cpu_type, u32 type, u32 um, u32 count)
{
    string str;

    if (cpu_type == CPU_TIMER_INT) {
        str += "Profiling through timer interrupt";
        return str;
    }

    struct op_event * event = op_find_event(cpu_type, type, um);

    if (!event) {
        event = op_find_event_any(cpu_type, type);
        if (!event) { 
            cerr << "Could not locate event " << int(type) << endl;
            str = "Unknown event";
            return str;
        }
    }

    char const * um_desc = 0;

    for (size_t i = 0; i < event->unit->num; ++i) {
        if (event->unit->um[i].value == um)
            um_desc = event->unit->um[i].desc;
    }

    str += string("Counted ") + event->name;
    str += string(" events (") + event->desc + ")";

    if (cpu_type != CPU_RTC) {
        str += " with a unit mask of 0x";

        ostringstream ss;
        ss << hex << setw(2) << setfill('0') << unsigned(um);
        str += ss.str();

        str += " (";
        str += um_desc ? um_desc : "multiple flags";
        str += ")";
    }

    str += " count " + op_lexical_cast<string>(count);
    return str;
}

string const op_xml_print_event(op_cpu cpu_type, u32 type, u32 um, u32 count)
{
    string unit_mask;

    if (cpu_type == CPU_TIMER_INT || cpu_type == CPU_RTC)
        return xml_utils::get_timer_setup((size_t)count);

    struct op_event * event = op_find_event(cpu_type, type, um);
    if (!event) {
        event = op_find_event_any(cpu_type, type);
        if (!event) { 
            cerr << "Could not locate event " << int(type) << endl;
            return "";
        }
    }

    if (cpu_type != CPU_RTC) {
        ostringstream str_out;
        str_out << um;
        unit_mask = str_out.str();
    }

    return xml_utils::get_event_setup(string(event->name),
        (size_t)count, unit_mask);
}

}

string const describe_header(opd_header const & header)
{
    op_cpu cpu = static_cast<op_cpu>(header.cpu_type);

    if (want_xml)
        return op_xml_print_event(cpu, header.ctr_event,
                          header.ctr_um, header.ctr_count);
    else
        return op_print_event(cpu, header.ctr_event,
                          header.ctr_um, header.ctr_count);
}


string const describe_cpu(opd_header const & header)
{
    op_cpu cpu = static_cast<op_cpu>(header.cpu_type);

    string str;
    if (want_xml) {
        string cpu_name = op_get_cpu_name(cpu);

        str = xml_utils::get_profile_header(cpu_name, header.cpu_speed);
    } else {
        str += string("CPU: ") + op_get_cpu_type_str(cpu);
        if (header.cpu_speed > 0) {
            ostringstream ss;

            str += ", speed ";
            ss << header.cpu_speed;
            str += ss.str() + " MHz (estimated)";
        }
    }
    return str;
}