/**
 * Configure the back end (optimizer and code generator)
 *
 * Compiler implementation of the
 * $(LINK2 https://www.dlang.org, D programming language).
 *
 * Copyright:   Copyright (C) 2000-2025 by The D Language Foundation, All Rights Reserved
 * Authors:     $(LINK2 https://www.digitalmars.com, Walter Bright)
 * License:     $(LINK2 https://www.boost.org/LICENSE_1_0.txt, Boost License 1.0)
 * Source:      $(LINK2 https://github.com/dlang/dmd/blob/master/compiler/src/dmd/backend/backconfig.d, backend/backconfig.d)
 */

module dmd.backend.backconfig;

import core.stdc.stdio;

import dmd.backend.cdef;
import dmd.backend.cc;
import dmd.backend.code;
import dmd.backend.global;
import dmd.backend.goh : GlobalOptimizer;
import dmd.backend.ty;
import dmd.backend.type;

import dmd.backend.dwarfdbginf;

nothrow:
@safe:

/**************************************
 * Initialize configuration for backend.
 * Params:
    arm           = true for generating AArch64 code
    model         = 32 for 32 bit code,
                    64 for 64 bit code,
    exe           = true for exe file,
                    false for dll or shared library (generate PIC code)
    trace         =  add profiling code
    nofloat       = do not pull in floating point code
    vasm          = print generated assembler for each function
    verbose       = verbose compile
    optimize      = optimize code
    symdebug      = add symbolic debug information,
                    1 for D,
                    2 for fake it with C symbolic debug info
    alwaysframe   = always create standard function frame
    stackstomp    = add stack stomping code
    ibt           = generate Indirect Branch Tracking code
    avx           = use AVX instruction set (0, 1, 2)
    pic           = position independence level (0, 1, 2)
    useModuleInfo = implement ModuleInfo
    useTypeInfo   = implement TypeInfo
    useExceptions = implement exception handling
    dwarf         = DWARF version used
    _version      = Compiler version
    exefmt        = Executable file format
    generatedMain = a main entrypoint is generated
    dataimports   = do not place data symbols into read-only segment,
                    it might be necessary to resolve relocations at runtime
 */
public
@trusted
void out_config_init(
        bool arm,       // true for generating AArch64 code
        int model,
        bool exe,
        bool trace,
        bool nofloat,
        bool vasm,      // print generated assembler for each function
        bool verbose,
        bool optimize,
        int symdebug,
        bool alwaysframe,
        bool stackstomp,
        bool ibt,
        ubyte avx,
        ubyte pic,
        bool useModuleInfo,
        bool useTypeInfo,
        bool useExceptions,
        ubyte dwarf,
        string _version,
        exefmt_t exefmt,
        bool generatedMain,     // a main entrypoint is generated
        bool dataimports,
        ref GlobalOptimizer go,
        ErrorCallbackBackend errorCallback)
{
    //printf("out_config_init()\n");

    errorCallbackBackend = errorCallback;
    auto cfg = &config;

    cfg._version = _version;
    if (arm)
        cfg.target_cpu = TARGET_AArch64;
    if (!cfg.target_cpu)
    {   cfg.target_cpu = TARGET_PentiumPro;
        cfg.target_scheduler = cfg.target_cpu;
    }
    cfg.fulltypes = CVNONE;
    cfg.fpxmmregs = false;
    if (!arm)
        cfg.inline8087 = 1;
    cfg.memmodel = 0;
    cfg.flags |= CFGuchar;   // make sure TYchar is unsigned
    cfg.exe = exefmt;
    tytab[TYchar] |= TYFLuns;
    if (generatedMain)
        cfg.flags2 |= CFG2genmain;
    if (ibt)
        cfg.flags3 |= CFG3ibt;

    if (dwarf < 3 || dwarf > 5)
    {
        if (dwarf)
        {
            error(Srcpos.init, "DWARF version %u is not supported", dwarf);
        }

        // Default DWARF version
        cfg.dwarf = 3;
    }
    else
    {
        cfg.dwarf = dwarf;
    }

    if (cfg.exe & EX_windos)
    {
        if (model == 64)
        {
            cfg.fpxmmregs = true;
            cfg.avx = avx;
            cfg.ehmethod = useExceptions ? EHmethod.EH_DM : EHmethod.EH_NONE;

            cfg.flags |= CFGnoebp;       // test suite fails without this
            //cfg.flags |= CFGalwaysframe;
            cfg.flags |= CFGromable; // put switch tables in code segment
            cfg.objfmt = OBJ_MSCOFF;
        }
        else
        {
            cfg.ehmethod = useExceptions ? EHmethod.EH_WIN32 : EHmethod.EH_NONE;
            cfg.flags |= CFGnoebp;       // test suite fails without this
            cfg.objfmt = OBJ_MSCOFF;
            cfg.flags |= CFGnoebp;    // test suite fails without this
        }

        if (dataimports)
            cfg.flags2 |= CFG2noreadonly;
        if (exe)
            cfg.wflags |= WFexe;         // EXE file only optimizations
        cfg.flags4 |= CFG4underscore;
    }
    if (cfg.exe & (EX_LINUX | EX_LINUX64))
    {
        cfg.fpxmmregs = true;
        cfg.avx = avx;
        if (model == 64)
        {
            cfg.ehmethod = useExceptions ? EHmethod.EH_DWARF : EHmethod.EH_NONE;
        }
        else
        {
            cfg.ehmethod = useExceptions ? EHmethod.EH_DWARF : EHmethod.EH_NONE;
            if (!exe)
                cfg.flags |= CFGromable; // put switch tables in code segment
        }
        cfg.flags |= CFGnoebp;
        switch (pic)
        {
            case 0:         // PIC.fixed
                break;

            case 1:         // PIC.pic
                cfg.flags3 |= CFG3pic;
                break;

            case 2:         // PIC.pie
                cfg.flags3 |= CFG3pic | CFG3pie;
                break;

            default:
                assert(0);
        }
        if (symdebug)
            cfg.flags |= CFGalwaysframe;

        cfg.objfmt = OBJ_ELF;
    }
    if (cfg.exe & (EX_OSX | EX_OSX64))
    {
        cfg.fpxmmregs = true;
        cfg.avx = avx;
        cfg.ehmethod = useExceptions ? EHmethod.EH_DWARF : EHmethod.EH_NONE;
        cfg.flags |= CFGnoebp;
        if (!exe)
        {
            cfg.flags3 |= CFG3pic;
            if (model == 64)
                cfg.flags |= CFGalwaysframe; // autotester fails without this
                                                // https://issues.dlang.org/show_bug.cgi?id=21042
        }
        if (symdebug)
            cfg.flags |= CFGalwaysframe;
        cfg.flags |= CFGromable; // put switch tables in code segment
        cfg.objfmt = OBJ_MACH;
    }
    if (cfg.exe & (EX_FREEBSD | EX_FREEBSD64))
    {
        if (model == 64)
        {
            cfg.ehmethod = useExceptions ? EHmethod.EH_DWARF : EHmethod.EH_NONE;
            cfg.fpxmmregs = true;
            cfg.avx = avx;
        }
        else
        {
            cfg.ehmethod = useExceptions ? EHmethod.EH_DWARF : EHmethod.EH_NONE;
            if (!exe)
                cfg.flags |= CFGromable; // put switch tables in code segment
        }
        cfg.flags |= CFGnoebp;
        if (!exe)
        {
            cfg.flags3 |= CFG3pic;
        }
        if (symdebug)
            cfg.flags |= CFGalwaysframe;
        cfg.objfmt = OBJ_ELF;
    }
    if (cfg.exe & (EX_OPENBSD | EX_OPENBSD64))
    {
        if (model == 64)
        {
            cfg.fpxmmregs = true;
            cfg.avx = avx;
        }
        else
        {
            if (!exe)
                cfg.flags |= CFGromable; // put switch tables in code segment
        }
        cfg.flags |= CFGnoebp;
        cfg.flags |= CFGalwaysframe;
        if (!exe)
            cfg.flags3 |= CFG3pic;
        cfg.objfmt = OBJ_ELF;
        cfg.ehmethod = useExceptions ? EHmethod.EH_DWARF : EHmethod.EH_NONE;
    }
    if (cfg.exe == EX_DRAGONFLYBSD64)
    {
        if (model == 64)
        {
            cfg.ehmethod = useExceptions ? EHmethod.EH_DWARF : EHmethod.EH_NONE;
            cfg.fpxmmregs = true;
            cfg.avx = avx;
        }
        else
        {
            assert(0);                      // Only 64-bit supported on DragonFlyBSD
        }
        cfg.flags |= CFGnoebp;
        if (!exe)
        {
            cfg.flags3 |= CFG3pic;
            cfg.flags |= CFGalwaysframe; // PIC needs a frame for TLS fixups
        }
        cfg.objfmt = OBJ_ELF;
    }
    if (cfg.exe & (EX_SOLARIS | EX_SOLARIS64))
    {
        if (model == 64)
        {
            cfg.fpxmmregs = true;
            cfg.avx = avx;
        }
        else
        {
            if (!exe)
                cfg.flags |= CFGromable; // put switch tables in code segment
        }
        cfg.flags |= CFGnoebp;
        cfg.flags |= CFGalwaysframe;
        if (!exe)
            cfg.flags3 |= CFG3pic;
        cfg.objfmt = OBJ_ELF;
        cfg.ehmethod = useExceptions ? EHmethod.EH_DWARF : EHmethod.EH_NONE;
    }

    cfg.flags2 |= CFG2nodeflib;      // no default library
    cfg.flags3 |= CFG3eseqds;
static if (0)
{
    if (env.getEEcontext().EEcompile != 2)
        cfg.flags4 |= CFG4allcomdat;
    if (env.nochecks())
        cfg.flags4 |= CFG4nochecks;  // no runtime checking
}
    if (cfg.exe & (EX_OSX | EX_OSX64))
    {
    }
    else
    {
        cfg.flags4 |= CFG4allcomdat;
    }
    if (trace)
        cfg.flags |= CFGtrace;       // turn on profiler
    if (nofloat)
        cfg.flags3 |= CFG3wkfloat;

    configv.vasm = vasm;
    configv.verbose = verbose;

    if (optimize)
        go_flag(go, cast(char*)"-o".ptr);

    if (symdebug)
    {
        if (cfg.exe & (EX_LINUX | EX_LINUX64 | EX_OPENBSD | EX_OPENBSD64 | EX_FREEBSD | EX_FREEBSD64 | EX_DRAGONFLYBSD64 |
                          EX_SOLARIS | EX_SOLARIS64 | EX_OSX | EX_OSX64))
        {
            configv.addlinenumbers = 1;
            cfg.fulltypes = (symdebug == 1) ? CVDWARF_D : CVDWARF_C;
        }
        if (cfg.exe & (EX_windos))
        {
            if (cfg.objfmt == OBJ_MSCOFF)
            {
                configv.addlinenumbers = 1;
                cfg.fulltypes = CV8;
                if(symdebug > 1)
                    cfg.flags2 |= CFG2gms;
            }
            else
            {
                configv.addlinenumbers = 1;
                cfg.fulltypes = CV4;
            }
        }
        if (!optimize)
            cfg.flags |= CFGalwaysframe;
    }
    else
    {
        configv.addlinenumbers = 0;
        cfg.fulltypes = CVNONE;
        //cfg.flags &= ~CFGalwaysframe;
    }

    if (alwaysframe)
        cfg.flags |= CFGalwaysframe;
    if (stackstomp)
        cfg.flags2 |= CFG2stomp;

    cfg.useModuleInfo = useModuleInfo;
    cfg.useTypeInfo = useTypeInfo;
    cfg.useExceptions = useExceptions;

    cod3_setdefault();
    if (arm)
    {
        cfg.fpxmmregs = false; // add SIMD support later
        util_set64(cfg.exe);
        type_init();
        cod3_setAArch64();
    }
    else if (model == 64)
    {
        util_set64(cfg.exe);
        type_init();
        cod3_set64();
    }
    else
    {
        util_set32(cfg.exe);
        type_init();
        cod3_set32();
    }

    if (cfg.objfmt == OBJ_MACH)
        machDebugSectionsInit();
    else if (cfg.objfmt == OBJ_ELF)
        elfDebugSectionsInit();
    rtlsym_init(); // uses fregsaved, so must be after it's set inside cod3_set*
}

/****************************
 * Transmit internal compiler debugging flags.
 */
@trusted
void out_config_debug(
        bool b,
        bool c,
        bool f,
        bool r,
        bool w,
        bool x,
        bool y
    )
{
    debugb = b;
    debugc = c;
    debugf = f;
    debugr = r;
    debugw = w;
    debugx = x;
    debugy = y;
}

/*************************************
 */

@trusted
void util_set16()
{
    // The default is 16 bits
    _tysize[TYldouble] = 10;
    _tysize[TYildouble] = 10;
    _tysize[TYcldouble] = 20;

    _tyalignsize[TYldouble] = 2;
    _tyalignsize[TYildouble] = 2;
    _tyalignsize[TYcldouble] = 2;
}

/*******************************
 * Redo tables from 8086/286 to 386/486.
 */

@trusted
void util_set32(exefmt_t exe)
{
    _tyrelax[TYenum] = TYlong;
    _tyrelax[TYint]  = TYlong;
    _tyrelax[TYuint] = TYlong;

    tyequiv[TYint] = TYlong;
    tyequiv[TYuint] = TYulong;

    _tysize[TYenum] = LONGSIZE;
    _tysize[TYint ] = LONGSIZE;
    _tysize[TYuint] = LONGSIZE;
    _tysize[TYnullptr] = LONGSIZE;
    _tysize[TYnptr] = LONGSIZE;
    _tysize[TYnref] = LONGSIZE;
if (exe & (EX_LINUX | EX_LINUX64 | EX_FREEBSD | EX_FREEBSD64 | EX_OPENBSD | EX_OPENBSD64 | EX_DRAGONFLYBSD64 | EX_SOLARIS | EX_SOLARIS64))
{
    _tysize[TYldouble] = 12;
    _tysize[TYildouble] = 12;
    _tysize[TYcldouble] = 24;
}
if (exe & (EX_OSX | EX_OSX64))
{
    _tysize[TYldouble] = 16;
    _tysize[TYildouble] = 16;
    _tysize[TYcldouble] = 32;
}
if (exe & EX_windos)
{
    _tysize[TYldouble] = 10;
    _tysize[TYildouble] = 10;
    _tysize[TYcldouble] = 20;
}

    _tysize[TYsptr] = LONGSIZE;
    _tysize[TYcptr] = LONGSIZE;
    _tysize[TYfptr] = 6;     // NOTE: There are codgen test that check
    _tysize[TYvptr] = 6;     // _tysize[x] == _tysize[TYfptr] so don't set
    _tysize[TYfref] = 6;     // _tysize[TYfptr] to _tysize[TYnptr]

    _tyalignsize[TYenum] = LONGSIZE;
    _tyalignsize[TYint ] = LONGSIZE;
    _tyalignsize[TYuint] = LONGSIZE;
    _tyalignsize[TYnullptr] = LONGSIZE;
    _tyalignsize[TYnref] = LONGSIZE;
    _tyalignsize[TYnptr] = LONGSIZE;
if (exe & (EX_LINUX | EX_LINUX64 | EX_FREEBSD | EX_FREEBSD64 | EX_OPENBSD | EX_OPENBSD64 | EX_DRAGONFLYBSD64 | EX_SOLARIS | EX_SOLARIS64))
{
    _tyalignsize[TYldouble] = 4;
    _tyalignsize[TYildouble] = 4;
    _tyalignsize[TYcldouble] = 4;
}
else if (exe & (EX_OSX | EX_OSX64))
{
    _tyalignsize[TYldouble] = 16;
    _tyalignsize[TYildouble] = 16;
    _tyalignsize[TYcldouble] = 16;
}
if (exe & EX_windos)
{
    _tyalignsize[TYldouble] = 2;
    _tyalignsize[TYildouble] = 2;
    _tyalignsize[TYcldouble] = 2;
}

    _tyalignsize[TYsptr] = LONGSIZE;
    _tyalignsize[TYcptr] = LONGSIZE;
    _tyalignsize[TYfptr] = LONGSIZE;     // NOTE: There are codgen test that check
    _tyalignsize[TYvptr] = LONGSIZE;     // _tysize[x] == _tysize[TYfptr] so don't set
    _tyalignsize[TYfref] = LONGSIZE;     // _tysize[TYfptr] to _tysize[TYnptr]

    _tysize[TYimmutPtr] = _tysize[TYnptr];
    _tysize[TYsharePtr] = _tysize[TYnptr];
    _tysize[TYrestrictPtr] = _tysize[TYnptr];
    _tysize[TYfgPtr] = _tysize[TYnptr];
    _tyalignsize[TYimmutPtr] = _tyalignsize[TYnptr];
    _tyalignsize[TYsharePtr] = _tyalignsize[TYnptr];
    _tyalignsize[TYrestrictPtr] = _tyalignsize[TYnptr];
    _tyalignsize[TYfgPtr] = _tyalignsize[TYnptr];
}

/*******************************
 * Redo tables from 8086/286 to I64.
 */

@trusted
void util_set64(exefmt_t exe)
{
    _tyrelax[TYenum] = TYlong;
    _tyrelax[TYint]  = TYlong;
    _tyrelax[TYuint] = TYlong;

    tyequiv[TYint] = TYlong;
    tyequiv[TYuint] = TYulong;

    _tysize[TYenum] = LONGSIZE;
    _tysize[TYint ] = LONGSIZE;
    _tysize[TYuint] = LONGSIZE;
    _tysize[TYnullptr] = 8;
    _tysize[TYnptr] = 8;
    _tysize[TYnref] = 8;
    if (exe & (EX_LINUX | EX_LINUX64 | EX_FREEBSD | EX_FREEBSD64 | EX_OPENBSD |
                      EX_OPENBSD64 | EX_DRAGONFLYBSD64 | EX_SOLARIS | EX_SOLARIS64 | EX_OSX | EX_OSX64))
    {
        _tysize[TYldouble] = 16;
        _tysize[TYildouble] = 16;
        _tysize[TYcldouble] = 32;
    }
    if (exe & EX_windos)
    {
        _tysize[TYldouble] = 10;
        _tysize[TYildouble] = 10;
        _tysize[TYcldouble] = 20;
    }
    _tysize[TYsptr] = 8;
    _tysize[TYcptr] = 8;
    _tysize[TYfptr] = 10;    // NOTE: There are codgen test that check
    _tysize[TYvptr] = 10;    // _tysize[x] == _tysize[TYfptr] so don't set
    _tysize[TYfref] = 10;    // _tysize[TYfptr] to _tysize[TYnptr]

    _tyalignsize[TYenum] = LONGSIZE;
    _tyalignsize[TYint ] = LONGSIZE;
    _tyalignsize[TYuint] = LONGSIZE;
    _tyalignsize[TYnullptr] = 8;
    _tyalignsize[TYnptr] = 8;
    _tyalignsize[TYnref] = 8;
    if (exe & (EX_LINUX | EX_LINUX64 | EX_FREEBSD | EX_FREEBSD64 | EX_OPENBSD | EX_OPENBSD64 | EX_DRAGONFLYBSD64 | EX_SOLARIS | EX_SOLARIS64))
    {
        _tyalignsize[TYldouble] = 16;
        _tyalignsize[TYildouble] = 16;
        _tyalignsize[TYcldouble] = 16;
    }
    if (exe & (EX_OSX | EX_OSX64))
    {
        _tyalignsize[TYldouble] = 16;
        _tyalignsize[TYildouble] = 16;
        _tyalignsize[TYcldouble] = 16;
    }
    if (exe & EX_windos)
    {
        _tyalignsize[TYldouble] = 2;
        _tyalignsize[TYildouble] = 2;
        _tyalignsize[TYcldouble] = 2;
    }
    _tyalignsize[TYsptr] = 8;
    _tyalignsize[TYcptr] = 8;
    _tyalignsize[TYfptr] = 8;
    _tyalignsize[TYvptr] = 8;
    _tyalignsize[TYfref] = 8;
    tytab[TYjfunc] &= ~TYFLpascal;  // set so caller cleans the stack (as in C)

    TYptrdiff = TYllong;
    TYsize = TYullong;
    TYsize_t = TYullong;
    TYdelegate = TYcent;
    TYdarray = TYucent;

    _tysize[TYimmutPtr] = _tysize[TYnptr];
    _tysize[TYsharePtr] = _tysize[TYnptr];
    _tysize[TYrestrictPtr] = _tysize[TYnptr];
    _tysize[TYfgPtr] = _tysize[TYnptr];
    _tyalignsize[TYimmutPtr] = _tyalignsize[TYnptr];
    _tyalignsize[TYsharePtr] = _tyalignsize[TYnptr];
    _tyalignsize[TYrestrictPtr] = _tyalignsize[TYnptr];
    _tyalignsize[TYfgPtr] = _tyalignsize[TYnptr];
}
