fxos/lib/passes/print.cpp

//---------------------------------------------------------------------------//
//  1100101 |_ mov #0, r4         __                                         //
//     11   |_ <0xb380 %5c4>     / _|_ _____ ___                             //
//     0110 |_ 3.50 -> 3.60     |  _\ \ / _ (_-<                             //
//          |_ base# + offset   |_| /_\_\___/__/                             //
//---------------------------------------------------------------------------//

#include <fxos/passes/print.h>
#include <fxos/vspace.h>
#include <fxos/util/format.h>

#include <cstdarg>
#include <cstring>

namespace FxOS {

PrintPass::PrintPass(Disassembly &disasm):
    InstructionPass(disasm), m_symtables {}, m_last_address {0xffffffff}
{
    /* Default parameters: all 0 */

    /* Use an OS observer to describe syscalls in header lines */
    m_os = disasm.vspace.os_analysis();

    /* Use the symbol tables from the virtual space */
    m_symtables.push_back(disasm.vspace.symbols);
}

bool PrintPass::analyzeInstruction(uint32_t pc, Instruction &i)
{
    /* Ellipsis if there is a gap since last instruction */

    if(m_last_address + 1 != 0 && pc != m_last_address + 2)
        printf(" ...\n");

    /* Preliminary syscall number */

    int syscall_id;
    if(m_os && (syscall_id = m_os->find_syscall(pc)) >= 0) {
        printf("\n<%%%03x", syscall_id);
        auto maybe_str = symquery(Symbol::Syscall, syscall_id);
        if(maybe_str)
            printf(" %s", (*maybe_str).c_str());
        printf(">\n");
    }

    /* Raw data if instruction cannot be decoded */

    printf(" %08x:  %04x", pc, (i.inst ? i.inst->opcode : i.opcode));
    if(!i.inst) {
        printf("\n");
        m_last_address = pc;
        return true;
    }

    /* Mnemonic */

    static char const *suffixes[5] = {"", ".b", ".w", "", ".l"};
    char const *suffix = suffixes[(i.inst->opsize <= 4) ? i.inst->opsize : 0];

    int spacing
        = i.inst->arg_count ? 8 - strlen(i.inst->mnemonic) - strlen(suffix) : 0;
    printf("   %s%s%*s", i.inst->mnemonic, suffix, spacing, "");

    /* Arguments */

    for(size_t n = 0; n < i.inst->arg_count; n++) {
        AsmArgument const &arg = i.inst->args[n];
        Argument const &a = i.args[n];

        if(n)
            printf(", ");

        queue(arg.str());
        if(arg.kind == AsmArgument::PcJump)
            pcjumploc(a);
        else if(arg.kind == AsmArgument::PcRel)
            pcrelloc(a);
        else if(arg.kind == AsmArgument::PcAddr)
            pcaddrloc(a);
        queue_flush();
    }

    printf("\n");
    m_last_address = pc;
    return true;
}

std::optional<std::string> PrintPass::symquery(
    Symbol::Type type, uint32_t value)
{
    for(int i = m_symtables.size() - 1; i >= 0; i--) {
        SymbolTable const &st = m_symtables[i];

        auto maybe_str = st.query(type, value);
        if(maybe_str)
            return maybe_str;
    }

    return std::nullopt;
}

void PrintPass::queue(std::string str, bool override)
{
    if(override && m_messages.size())
        m_messages.pop_back();

    m_messages.push_back(str);
}

void PrintPass::queue_flush()
{
    for(size_t i = 0; i < m_messages.size(); i++) {
        if(i != 0)
            printf(" ");
        printf("%s", m_messages[i].c_str());
    }

    m_messages.clear();
}

void PrintPass::pcjumploc(Argument const &a)
{
    if(!RelConstDomain().is_constant(a.location))
        return;
    if(promote_pcjump_loc == Never)
        return;

    queue(format("<%s>", a.location.str()), promote_pcjump_loc == Promote);
    syscall(a);
}

void PrintPass::pcrelloc(Argument const &a)
{
    if(!RelConstDomain().is_constant(a.location))
        return;
    if(promote_pcrel_loc == Never)
        return;

    queue(format("<%s>", a.location.str()), promote_pcrel_loc == Promote);
    pcrelval(a);
}

void PrintPass::pcrelval(Argument const &a)
{
    if(!a.value)
        return;
    if(promote_pcrel_value == Never)
        return;

    queue(a.value.str(), promote_pcrel_value == Promote);
    syscall(a);
}

void PrintPass::syscall(Argument const &a)
{
    if(!a.value)
        return;

    /* If this is not a syscall, try to display as a symbol instead */
    if(promote_syscall == Never || a.syscall_id < 0) {
        symbol(a);
        return;
    }

    queue(format("%%%03x", a.syscall_id), promote_syscall == Promote);
    syscallname(a);
}

void PrintPass::syscallname(Argument const &a)
{
    if(a.syscall_id < 0)
        return;

    auto maybe_name = symquery(Symbol::Syscall, a.syscall_id);
    if(!maybe_name)
        return;

    queue(*maybe_name, promote_syscallname == Promote);
}

void PrintPass::symbol(Argument const &a)
{
    if(!a.value)
        return;

    auto maybe_name
        = symquery(Symbol::Address, RelConstDomain().constant_value(a.value));
    if(!maybe_name)
        return;

    queue(*maybe_name, promote_symbol == Promote);
}

void PrintPass::pcaddrloc(Argument const &a)
{
    if(!RelConstDomain().is_constant(a.location))
        return;
    if(promote_pcaddr_loc == Never)
        return;

    queue(format("<%s>", a.location.str()), promote_pcaddr_loc == Promote);
}

} /* namespace FxOS */