/*****************************************************************************/
/*                                                                           */
/*                                segments.c                                 */
/*                                                                           */
/*                   Segment handling for the ld65 linker                    */
/*                                                                           */
/*                                                                           */
/*                                                                           */
/* (C) 1998-2012, Ullrich von Bassewitz                                      */
/*                Roemerstrasse 52                                           */
/*                D-70794 Filderstadt                                        */
/* EMail:         uz@cc65.org                                                */
/*                                                                           */
/*                                                                           */
/* This software is provided 'as-is', without any expressed or implied       */
/* warranty.  In no event will the authors be held liable for any damages    */
/* arising from the use of this software.                                    */
/*                                                                           */
/* Permission is granted to anyone to use this software for any purpose,     */
/* including commercial applications, and to alter it and redistribute it    */
/* freely, subject to the following restrictions:                            */
/*                                                                           */
/* 1. The origin of this software must not be misrepresented; you must not   */
/*    claim that you wrote the original software. If you use this software   */
/*    in a product, an acknowledgment in the product documentation would be  */
/*    appreciated but is not required.                                       */
/* 2. Altered source versions must be plainly marked as such, and must not   */
/*    be misrepresented as being the original software.                      */
/* 3. This notice may not be removed or altered from any source              */
/*    distribution.                                                          */
/*                                                                           */
/*****************************************************************************/



#include <stdlib.h>
#include <string.h>

/* common */
#include "addrsize.h"
#include "alignment.h"
#include "check.h"
#include "coll.h"
#include "exprdefs.h"
#include "fragdefs.h"
#include "hashfunc.h"
#include "print.h"
#include "segdefs.h"
#include "symdefs.h"
#include "xmalloc.h"

/* ld65 */
#include "error.h"
#include "expr.h"
#include "fileio.h"
#include "fragment.h"
#include "global.h"
#include "lineinfo.h"
#include "segments.h"
#include "spool.h"



/*****************************************************************************/
/*                                   Data                                    */
/*****************************************************************************/



/* Hash table */
#define HASHTAB_MASK    0x3FU
#define HASHTAB_SIZE    (HASHTAB_MASK + 1)
static Segment*         HashTab[HASHTAB_SIZE];

/* List of all segments */
static Collection       SegmentList = STATIC_COLLECTION_INITIALIZER;



/*****************************************************************************/
/*                                   Code                                    */
/*****************************************************************************/



static Segment* NewSegment (unsigned Name, unsigned char AddrSize)
/* Create a new segment and initialize it */
{
    unsigned Hash;

    /* Allocate memory */
    Segment* S = xmalloc (sizeof (Segment));

    /* Initialize the fields */
    S->Name        = Name;
    S->Next        = 0;
    S->Flags       = SEG_FLAG_NONE;
    S->Sections    = EmptyCollection;
    S->MemArea     = 0;
    S->PC          = 0;
    S->Size        = 0;
    S->OutputName  = 0;
    S->OutputOffs  = 0;
    S->Alignment   = 1;
    S->FillVal     = 0;
    S->AddrSize    = AddrSize;
    S->ReadOnly    = 0;
    S->Dumped      = 0;

    /* Insert the segment into the segment list and assign the segment id */
    S->Id = CollCount (&SegmentList);
    CollAppend (&SegmentList, S);

    /* Insert the segment into the segment hash list */
    Hash = (S->Name & HASHTAB_MASK);
    S->Next = HashTab[Hash];
    HashTab[Hash] = S;

    /* Return the new entry */
    return S;
}



Segment* GetSegment (unsigned Name, unsigned char AddrSize, const char* ObjName)
/* Search for a segment and return an existing one. If the segment does not
** exist, create a new one and return that. ObjName is only used for the error
** message and may be NULL if the segment is linker generated.
*/
{
    /* Try to locate the segment in the table */
    Segment* S = SegFind (Name);

    /* If we don't have that segment already, allocate it using the type of
    ** the first section.
    */
    if (S == 0) {
        /* Create a new segment */
        S = NewSegment (Name, AddrSize);
    } else {
        /* Check if the existing segment has the requested address size */
        if (S->AddrSize != AddrSize) {
            /* Allow an empty object name */
            if (ObjName == 0) {
                ObjName = "[linker generated]";
            }
            Error ("Module '%s': Type mismatch for segment '%s'", ObjName,
                   GetString (Name));
        }
    }

    /* Return the segment */
    return S;
}



Section* NewSection (Segment* Seg, unsigned long Alignment, unsigned char AddrSize)
/* Create a new section for the given segment */
{
    /* Allocate memory */
    Section* S = xmalloc (sizeof (Section));

    /* Initialize the data */
    S->Next     = 0;
    S->Seg      = Seg;
    S->Obj      = 0;
    S->FragRoot = 0;
    S->FragLast = 0;
    S->Size     = 0;
    S->Alignment= Alignment;
    S->AddrSize = AddrSize;

    /* Calculate the alignment bytes needed for the section */
    S->Fill = AlignCount (Seg->Size, S->Alignment);

    /* Adjust the segment size and set the section offset */
    Seg->Size  += S->Fill;
    S->Offs     = Seg->Size;    /* Current size is offset */

    /* Insert the section into the segment */
    CollAppend (&Seg->Sections, S);

    /* Return the struct */
    return S;
}



Section* ReadSection (FILE* F, ObjData* O)
/* Read a section from a file */
{
    unsigned      Name;
    unsigned      Size;
    unsigned long Alignment;
    unsigned char Type;
    unsigned      FragCount;
    Segment*      S;
    Section*      Sec;

    /* Read the segment data */
    (void) Read32 (F);          /* File size of data */
    Name      = MakeGlobalStringId (O, ReadVar (F));    /* Segment name */
                ReadVar (F);    /* Segment flags (currently unused) */
    Size      = ReadVar (F);    /* Size of data */
    Alignment = ReadVar (F);    /* Alignment */
    Type      = Read8 (F);      /* Segment type */
    FragCount = ReadVar (F);    /* Number of fragments */


    /* Print some data */
    Print (stdout, 2,
           "Module '%s': Found segment '%s', size = %u, alignment = %lu, type = %u\n",
           GetObjFileName (O), GetString (Name), Size, Alignment, Type);

    /* Get the segment for this section */
    S = GetSegment (Name, Type, GetObjFileName (O));

    /* Allocate the section we will return later */
    Sec = NewSection (S, Alignment, Type);

    /* Remember the object file this section was from */
    Sec->Obj = O;

    /* Set up the combined segment alignment */
    if (Sec->Alignment > 1) {
        Alignment = LeastCommonMultiple (S->Alignment, Sec->Alignment);
        if (Alignment > MAX_ALIGNMENT) {
            Error ("Combined alignment for segment '%s' is %lu which exceeds "
                   "%lu. Last module requiring alignment was '%s'.",
                   GetString (Name), Alignment, MAX_ALIGNMENT,
                   GetObjFileName (O));
        } else if (Alignment >= LARGE_ALIGNMENT && Alignment > S->Alignment && Alignment > Sec->Alignment && !LargeAlignment) {
            Warning ("Combined alignment for segment '%s' is suspiciously "
                     "large (%lu). Last module requiring alignment was '%s'.",
                     GetString (Name), Alignment, GetObjFileName (O));
        }
        S->Alignment = Alignment;
    }

    /* Start reading fragments from the file and insert them into the section . */
    while (FragCount--) {

        Fragment* Frag;

        /* Read the fragment type */
        unsigned char Type = Read8 (F);

        /* Extract the check mask from the type */
        unsigned char Bytes = Type & FRAG_BYTEMASK;
        Type &= FRAG_TYPEMASK;

        /* Handle the different fragment types */
        switch (Type) {

            case FRAG_LITERAL:
                Frag = NewFragment (Type, ReadVar (F), Sec);
                ReadData (F, Frag->LitBuf, Frag->Size);
                break;

            case FRAG_EXPR:
            case FRAG_SEXPR:
                Frag = NewFragment (Type, Bytes, Sec);
                Frag->Expr = ReadExpr (F, O);
                break;

            case FRAG_FILL:
                /* Will allocate memory, but we don't care... */
                Frag = NewFragment (Type, ReadVar (F), Sec);
                break;

            default:
                Error ("Unknown fragment type in module '%s', segment '%s': %02X",
                       GetObjFileName (O), GetString (S->Name), Type);
                /* NOTREACHED */
                return 0;
        }

        /* Read the line infos into the list of the fragment */
        ReadLineInfoList (F, O, &Frag->LineInfos);

        /* Remember the module we had this fragment from */
        Frag->Obj = O;
    }

    /* Return the section */
    return Sec;
}



Segment* SegFind (unsigned Name)
/* Return the given segment or NULL if not found. */
{
    Segment* S = HashTab[Name & HASHTAB_MASK];
    while (S) {
        if (Name == S->Name) {
            /* Found */
            break;
        }
        S = S->Next;
    }
    /* Not found */
    return S;
}



int IsBSSType (Segment* S)
/* Check if the given segment is a BSS style segment, that is, it does not
** contain non-zero data.
*/
{
    /* Loop over all sections */
    unsigned I;
    for (I = 0; I < CollCount (&S->Sections); ++I) {

        /* Get the next section */
        Section* Sec = CollAtUnchecked (&S->Sections, I);

        /* Loop over all fragments */
        Fragment* F = Sec->FragRoot;
        while (F) {
            if (F->Type == FRAG_LITERAL) {
                unsigned char* Data = F->LitBuf;
                unsigned long Count = F->Size;
                while (Count--) {
                    if (*Data++ != 0) {
                        return 0;
                    }
                }
            } else if (F->Type == FRAG_EXPR || F->Type == FRAG_SEXPR) {
                if (GetExprVal (F->Expr) != 0) {
                    return 0;
                }
            }
            F = F->Next;
        }
    }
    return 1;
}



void SegDump (void)
/* Dump the segments and it's contents */
{
    unsigned I, J;
    unsigned long Count;
    unsigned char* Data;

    for (I = 0; I < CollCount (&SegmentList); ++I) {
        Segment* Seg = CollAtUnchecked (&SegmentList, I);
        printf ("Segment: %s (%lu)\n", GetString (Seg->Name), Seg->Size);
        for (J = 0; J < CollCount (&Seg->Sections); ++J) {
            Section* S = CollAtUnchecked (&Seg->Sections, J);
            unsigned J;
            Fragment* F = S->FragRoot;
            printf ("  Section:\n");
            while (F) {
                switch (F->Type) {

                    case FRAG_LITERAL:
                        printf ("    Literal (%u bytes):", F->Size);
                        Count = F->Size;
                        Data  = F->LitBuf;
                        J = 100;
                        while (Count--) {
                            if (J > 75) {
                                printf ("\n   ");
                                J = 3;
                            }
                            printf (" %02X", *Data++);
                            J += 3;
                        }
                        printf ("\n");
                        break;

                    case FRAG_EXPR:
                        printf ("    Expression (%u bytes):\n", F->Size);
                        printf ("    ");
                        DumpExpr (F->Expr, 0);
                        break;

                    case FRAG_SEXPR:
                        printf ("    Signed expression (%u bytes):\n", F->Size);
                        printf ("      ");
                        DumpExpr (F->Expr, 0);
                        break;

                    case FRAG_FILL:
                        printf ("    Empty space (%u bytes)\n", F->Size);
                        break;

                    default:
                        Internal ("Invalid fragment type: %02X", F->Type);
                }
                F = F->Next;
            }
        }
    }
}



unsigned SegWriteConstExpr (FILE* F, ExprNode* E, int Signed, unsigned Size)
/* Write a supposedly constant expression to the target file. Do a range
** check and return one of the SEG_EXPR_xxx codes.
*/
{
    static const unsigned long U_Hi[4] = {
        0x000000FFUL, 0x0000FFFFUL, 0x00FFFFFFUL, 0xFFFFFFFFUL
    };
    static const long S_Hi[4] = {
        0x0000007FL, 0x00007FFFL, 0x007FFFFFL, 0x7FFFFFFFL
    };
    static const long S_Lo[4] = {
        ~0x0000007FL, ~0x00007FFFL, ~0x007FFFFFL, ~0x7FFFFFFFL
    };


    /* Get the expression value */
    long Val = GetExprVal (E);

    /* Check the size */
    CHECK (Size >= 1 && Size <= 4);

    /* Check for a range error */
    if (Signed) {
        if (Val > S_Hi[Size-1] || Val < S_Lo[Size-1]) {
            /* Range error */
            return SEG_EXPR_RANGE_ERROR;
        }
    } else {
        if (((unsigned long)Val) > U_Hi[Size-1]) {
            /* Range error */
            return SEG_EXPR_RANGE_ERROR;
        }
    }

    /* Write the value to the file */
    WriteVal (F, Val, Size);

    /* Success */
    return SEG_EXPR_OK;
}



void SegWrite (const char* TgtName, FILE* Tgt, Segment* S, SegWriteFunc F, void* Data)
/* Write the data from the given segment to a file. For expressions, F is
** called (see description of SegWriteFunc above).
*/
{
    unsigned      I;
    int           Sign;
    unsigned long Offs = 0;


    /* Remember the output file and offset for the segment */
    S->OutputName = TgtName;
    S->OutputOffs = (unsigned long) ftell (Tgt);

    /* Loop over all sections in this segment */
    for (I = 0; I < CollCount (&S->Sections); ++I) {

        Section*        Sec = CollAtUnchecked (&S->Sections, I);
        Fragment*       Frag;
        unsigned char   FillVal;

        /* Output were this section is from */
        Print (stdout, 2, "      Section from \"%s\"\n", GetObjFileName (Sec->Obj));

        /* If we have fill bytes, write them now. Beware: If this is the
        ** first section, the fill value is not considered part of the segment
        ** and therefore taken from the memory area.
        */
        FillVal = (I == 0)? S->MemArea->FillVal : S->FillVal;
        Print (stdout, 2, "        Filling 0x%lx bytes with 0x%02x\n",
               Sec->Fill, FillVal);
        WriteMult (Tgt, FillVal, Sec->Fill);
        Offs += Sec->Fill;

        /* Loop over all fragments in this section */
        Frag = Sec->FragRoot;
        while (Frag) {

            /* Output fragment data */
            switch (Frag->Type) {

                case FRAG_LITERAL:
                    WriteData (Tgt, Frag->LitBuf, Frag->Size);
                    break;

                case FRAG_EXPR:
                case FRAG_SEXPR:
                    Sign = (Frag->Type == FRAG_SEXPR);
                    /* Call the users function and evaluate the result */
                    switch (F (Frag->Expr, Sign, Frag->Size, Offs, Data)) {

                        case SEG_EXPR_OK:
                            break;

                        case SEG_EXPR_RANGE_ERROR:
                            Error ("Range error in module '%s', line %u",
                                   GetFragmentSourceName (Frag),
                                   GetFragmentSourceLine (Frag));
                            break;

                        case SEG_EXPR_TOO_COMPLEX:
                            Error ("Expression too complex in module '%s', line %u",
                                   GetFragmentSourceName (Frag),
                                   GetFragmentSourceLine (Frag));
                            break;

                        case SEG_EXPR_INVALID:
                            Error ("Invalid expression in module '%s', line %u",
                                   GetFragmentSourceName (Frag),
                                   GetFragmentSourceLine (Frag));
                            break;

                        default:
                            Internal ("Invalid return code from SegWriteFunc");
                    }
                    break;

                case FRAG_FILL:
                    WriteMult (Tgt, S->FillVal, Frag->Size);
                    break;

                default:
                    Internal ("Invalid fragment type: %02X", Frag->Type);
            }

            /* Update the offset */
            Print (stdout, 2, "        Fragment with 0x%x bytes\n",
                   Frag->Size);
            Offs += Frag->Size;

            /* Next fragment */
            Frag = Frag->Next;
        }
    }
}



unsigned SegmentCount (void)
/* Return the total number of segments */
{
    return CollCount (&SegmentList);
}



static int CmpSegStart (const void* K1, const void* K2)
/* Compare function for qsort */
{
    /* Get the real segment pointers */
    const Segment* S1 = *(const Segment**)K1;
    const Segment* S2 = *(const Segment**)K2;

    /* Compare the start addresses */
    if (S1->PC > S2->PC) {
        return 1;
    } else if (S1->PC < S2->PC) {
        return -1;
    } else {
        /* Sort segments with equal starts by name */
        return strcmp (GetString (S1->Name), GetString (S2->Name));
    }
}



void PrintSegmentMap (FILE* F)
/* Print a segment map to the given file */
{

    /* Allocate memory for the segment pool */
    Segment** SegPool = xmalloc (CollCount (&SegmentList) * sizeof (Segment*));

    /* Copy the segment pointers */
    unsigned I;
    for (I = 0; I < CollCount (&SegmentList); ++I) {
        SegPool[I] = CollAtUnchecked (&SegmentList, I);
    }

    /* Sort the array by increasing start addresses */
    qsort (SegPool, CollCount (&SegmentList), sizeof (Segment*), CmpSegStart);

    /* Print a header */
    fprintf (F, "Name                   Start     End    Size  Align\n"
                "----------------------------------------------------\n");

    /* Print the segments */
    for (I = 0; I < CollCount (&SegmentList); ++I) {

        /* Get a pointer to the segment */
        Segment* S = SegPool[I];

        /* Print empty segments only if explicitly requested */
        if (VerboseMap || S->Size > 0) {
            /* Print the segment data */
            long End = S->PC + S->Size;
            if (S->Size > 0) {
                /* Point to last element addressed */
                --End;
            }
            fprintf (F, "%-20s  %06lX  %06lX  %06lX  %05lX\n",
                     GetString (S->Name), S->PC, End, S->Size, S->Alignment);
        }
    }

    /* Free the segment pool */
    xfree (SegPool);
}



void PrintDbgSegments (FILE* F)
/* Output the segments to the debug file */
{
    /* Walk over all segments */
    unsigned I;
    for (I = 0; I < CollCount (&SegmentList); ++I) {

        /* Get the next segment */
        const Segment* S = CollAtUnchecked (&SegmentList, I);

        /* Print the segment data */
        fprintf (F,
                 "seg\tid=%u,name=\"%s\",start=0x%06lX,size=0x%04lX,addrsize=%s,type=%s",
                 S->Id, GetString (S->Name), S->PC, S->Size,
                 AddrSizeToStr (S->AddrSize),
                 S->ReadOnly? "ro" : "rw");
        if (S->OutputName) {
            fprintf (F, ",oname=\"%s\",ooffs=%lu",
                     S->OutputName, S->OutputOffs);
        }
        fputc ('\n', F);
    }
}



void CheckSegments (void)
/* Walk through the segment list and check if there are segments that were
** not written to the output file. Output an error if this is the case.
*/
{
    unsigned I;
    for (I = 0; I < CollCount (&SegmentList); ++I) {

        /* Get the next segment */
        const Segment* S = CollAtUnchecked (&SegmentList, I);

        /* Check it */
        if (S->Size > 0 && S->Dumped == 0) {
            Error ("Missing memory area assignment for segment '%s'",
                   GetString (S->Name));
        }
    }
}