cc65/src/ca65/symtab.c

/*****************************************************************************/
/*                                                                           */
/*                                 symtab.c                                  */
/*                                                                           */
/*                 Symbol table for the ca65 macroassembler                  */
/*                                                                           */
/*                                                                           */
/*                                                                           */
/* (C) 1998-2014, 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 <string.h>

/* common */
#include "addrsize.h"
#include "check.h"
#include "hashfunc.h"
#include "mmodel.h"
#include "scopedefs.h"
#include "symdefs.h"
#include "xmalloc.h"

/* ca65 */
#include "dbginfo.h"
#include "error.h"
#include "expr.h"
#include "global.h"
#include "objfile.h"
#include "scanner.h"
#include "segment.h"
#include "sizeof.h"
#include "span.h"
#include "spool.h"
#include "studyexpr.h"
#include "symtab.h"



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



/* Combined symbol entry flags used within this module */
#define SF_UNDEFMASK    (SF_REFERENCED | SF_DEFINED | SF_IMPORT)
#define SF_UNDEFVAL     (SF_REFERENCED)

/* Symbol tables */
SymTable*           CurrentScope = 0;   /* Pointer to current symbol table */
SymTable*           RootScope    = 0;   /* Root symbol table */
static SymTable*    LastScope    = 0;   /* Pointer to last scope in list */
static unsigned     ScopeCount   = 0;   /* Number of scopes */

/* Symbol table variables */
static unsigned     ImportCount = 0;    /* Counter for import symbols */
static unsigned     ExportCount = 0;    /* Counter for export symbols */



/*****************************************************************************/
/*                         Internally used functions                         */
/*****************************************************************************/



static int IsDbgSym (const SymEntry* S)
/* Return true if this is a debug symbol */
{
    if ((S->Flags & (SF_DEFINED | SF_UNUSED)) == SF_DEFINED) {
        /* Defined symbols are debug symbols if they aren't sizes */
        return !IsSizeOfSymbol (S);
    } else {
        /* Others are debug symbols if they're referenced imports */
        return ((S->Flags & SF_REFIMP) == SF_REFIMP);
    }
}



static unsigned ScopeTableSize (unsigned Level)
/* Get the size of a table for the given lexical level */
{
    switch (Level) {
        case 0:         return 213;
        case 1:         return  53;
        default:        return  29;
    }
}



static SymTable* NewSymTable (SymTable* Parent, const StrBuf* Name)
/* Allocate a symbol table on the heap and return it */
{
    /* Determine the lexical level and the number of table slots */
    unsigned Level = Parent? Parent->Level + 1 : 0;
    unsigned Slots = ScopeTableSize (Level);

    /* Allocate memory */
    SymTable* S = xmalloc (sizeof (SymTable) + (Slots-1) * sizeof (SymEntry*));

    /* Set variables and clear hash table entries */
    S->Next         = 0;
    S->Left         = 0;
    S->Right        = 0;
    S->Childs       = 0;
    S->Label        = 0;
    S->Spans        = AUTO_COLLECTION_INITIALIZER;
    S->Id           = ScopeCount++;
    S->Flags        = ST_NONE;
    S->AddrSize     = ADDR_SIZE_DEFAULT;
    S->Type         = SCOPE_UNDEF;
    S->Level        = Level;
    S->TableSlots   = Slots;
    S->TableEntries = 0;
    S->Parent       = Parent;
    S->Name         = GetStrBufId (Name);
    while (Slots--) {
        S->Table[Slots] = 0;
    }

    /* Insert the symbol table into the list of all symbol tables */
    if (RootScope == 0) {
        RootScope = S;
    } else {
        LastScope->Next = S;
    }
    LastScope = S;

    /* Insert the symbol table into the child tree of the parent */
    if (Parent) {
        SymTable* T = Parent->Childs;
        if (T == 0) {
            /* First entry */
            Parent->Childs = S;
        } else {
            while (1) {
                /* Choose next entry */
                int Cmp = SB_Compare (Name, GetStrBuf (T->Name));
                if (Cmp < 0) {
                    if (T->Left) {
                        T = T->Left;
                    } else {
                        T->Left = S;
                        break;
                    }
                } else if (Cmp > 0) {
                    if (T->Right) {
                        T = T->Right;
                    } else {
                        T->Right = S;
                        break;
                    }
                } else {
                    /* Duplicate scope name */
                    Internal ("Duplicate scope name: `%m%p'", Name);
                }
            }
        }
    }

    /* Return the prepared struct */
    return S;
}



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



void SymEnterLevel (const StrBuf* ScopeName, unsigned char Type,
                    unsigned char AddrSize, SymEntry* ScopeLabel)
/* Enter a new lexical level */
{
    /* Map a default address size to something real */
    if (AddrSize == ADDR_SIZE_DEFAULT) {
        /* Use the segment address size */
        AddrSize = GetCurrentSegAddrSize ();
    }

    /* If we have a current scope, search for the given name and create a
    ** new one if it doesn't exist. If this is the root scope, just create it.
    */
    if (CurrentScope) {

        /* Search for the scope, create a new one */
        CurrentScope = SymFindScope (CurrentScope, ScopeName, SYM_ALLOC_NEW);

        /* Check if the scope has been defined before */
        if (CurrentScope->Flags & ST_DEFINED) {
            Error ("Duplicate scope `%m%p'", ScopeName);
        }

    } else {
        CurrentScope = RootScope = NewSymTable (0, ScopeName);
    }

    /* Mark the scope as defined and set type, address size and owner symbol */
    CurrentScope->Flags    |= ST_DEFINED;
    CurrentScope->AddrSize = AddrSize;
    CurrentScope->Type     = Type;
    CurrentScope->Label    = ScopeLabel;

    /* If this is a scope that allows to emit data into segments, add spans
    ** for all currently existing segments. Doing this for just a few scope
    ** types is not really necessary but an optimization, because it does not
    ** allocate memory for useless data (unhandled types here don't occupy
    ** space in any segment).
    */
    if (CurrentScope->Type <= SCOPE_HAS_DATA) {
        OpenSpanList (&CurrentScope->Spans);
    }
}



void SymLeaveLevel (void)
/* Leave the current lexical level */
{
    /* If this is a scope that allows to emit data into segments, close the
    ** open the spans.
    */
    if (CurrentScope->Type <= SCOPE_HAS_DATA) {
        CloseSpanList (&CurrentScope->Spans);
    }

    /* If we have spans, the first one is the segment that was active, when the
    ** scope was opened. Set the size of the scope to the number of data bytes
    ** emitted into this segment. If we have an owner symbol set the size of
    ** this symbol, too.
    */
    if (CollCount (&CurrentScope->Spans) > 0) {
        const Span* S = CollAtUnchecked (&CurrentScope->Spans, 0);
        unsigned long Size = GetSpanSize (S);
        DefSizeOfScope (CurrentScope, Size);
        if (CurrentScope->Label) {
            DefSizeOfSymbol (CurrentScope->Label, Size);
        }
    }

    /* Mark the scope as closed */
    CurrentScope->Flags |= ST_CLOSED;

    /* Leave the scope */
    CurrentScope = CurrentScope->Parent;
}



SymTable* SymFindScope (SymTable* Parent, const StrBuf* Name, SymFindAction Action)
/* Find a scope in the given enclosing scope */
{
    SymTable** T = &Parent->Childs;
    while (*T) {
        int Cmp = SB_Compare (Name, GetStrBuf ((*T)->Name));
        if (Cmp < 0) {
            T = &(*T)->Left;
        } else if (Cmp > 0) {
            T = &(*T)->Right;
        } else {
            /* Found the scope */
            return *T;
        }
    }

    /* Create a new scope if requested and we didn't find one */
    if (*T == 0 && (Action & SYM_ALLOC_NEW) != 0) {
        *T = NewSymTable (Parent, Name);
    }

    /* Return the scope */
    return *T;
}



SymTable* SymFindAnyScope (SymTable* Parent, const StrBuf* Name)
/* Find a scope in the given or any of its parent scopes. The function will
** never create a new symbol, since this can only be done in one specific
** scope.
*/
{
    SymTable* Scope;
    do {
        /* Search in the current table */
        Scope = SymFindScope (Parent, Name, SYM_FIND_EXISTING);
        if (Scope == 0) {
            /* Not found, search in the parent scope, if we have one */
            Parent = Parent->Parent;
        }
    } while (Scope == 0 && Parent != 0);

    return Scope;
}



SymEntry* SymFindLocal (SymEntry* Parent, const StrBuf* Name, SymFindAction Action)
/* Find a cheap local symbol. If Action contains SYM_ALLOC_NEW and the entry is
** not found, create a new one. Return the entry found, or the new entry
** created, or - in case Action is SYM_FIND_EXISTING - return 0.
*/

{
    SymEntry* S;
    int Cmp;

    /* Local symbol, get the table */
    if (!Parent) {
        /* No last global, so there's no local table */
        Error ("No preceeding global symbol");
        if (Action & SYM_ALLOC_NEW) {
            return NewSymEntry (Name, SF_LOCAL);
        } else {
            return 0;
        }
    }

    /* Search for the symbol if we have a table */
    Cmp = SymSearchTree (Parent->Locals, Name, &S);

    /* If we found an entry, return it */
    if (Cmp == 0) {
        return S;
    }

    if (Action & SYM_ALLOC_NEW) {

        /* Otherwise create a new entry, insert and return it */
        SymEntry* N = NewSymEntry (Name, SF_LOCAL);
        N->Sym.Entry = Parent;
        if (S == 0) {
            Parent->Locals = N;
        } else if (Cmp < 0) {
            S->Left = N;
        } else {
            S->Right = N;
        }
        return N;
    }

    /* We did not find the entry and AllocNew is false. */
    return 0;
}



SymEntry* SymFind (SymTable* Scope, const StrBuf* Name, SymFindAction Action)
/* Find a new symbol table entry in the given table. If Action contains
** SYM_ALLOC_NEW and the entry is not found, create a new one. Return the
** entry found, or the new entry created, or - in case Action is
** SYM_FIND_EXISTING - return 0.
*/
{
    SymEntry* S;

    /* Global symbol: Get the hash value for the name */
    unsigned Hash = HashBuf (Name) % Scope->TableSlots;

    /* Search for the entry */
    int Cmp = SymSearchTree (Scope->Table[Hash], Name, &S);

    /* If we found an entry, return it */
    if (Cmp == 0) {
        if ((Action & SYM_CHECK_ONLY) == 0 && SymTabIsClosed (Scope)) {
            S->Flags |= SF_FIXED;
        }
        return S;
    }

    if (Action & SYM_ALLOC_NEW) {

        /* Otherwise create a new entry, insert and return it. If the scope is
        ** already closed, mark the symbol as fixed so it won't be resolved
        ** by a symbol in the enclosing scopes later.
        */
        SymEntry* N = NewSymEntry (Name, SF_NONE);
        if (SymTabIsClosed (Scope)) {
            N->Flags |= SF_FIXED;
        }
        N->Sym.Tab = Scope;
        if (S == 0) {
            Scope->Table[Hash] = N;
        } else if (Cmp < 0) {
            S->Left = N;
        } else {
            S->Right = N;
        }
        ++Scope->TableEntries;
        return N;

    }

    /* We did not find the entry and AllocNew is false. */
    return 0;
}



SymEntry* SymFindAny (SymTable* Scope, const StrBuf* Name)
/* Find a symbol in the given or any of its parent scopes. The function will
** never create a new symbol, since this can only be done in one specific
** scope.
*/
{
    /* Generate the name hash */
    unsigned Hash = HashBuf (Name);

    /* Search for the symbol */
    SymEntry* Sym;
    do {
        /* Search in the current table. Ignore entries flagged with SF_UNUSED,
        ** because for such symbols there is a real entry in one of the parent
        ** scopes.
        */
        if (SymSearchTree (Scope->Table[Hash % Scope->TableSlots], Name, &Sym) == 0) {
            if (Sym->Flags & SF_UNUSED) {
                Sym = 0;
            } else {
                /* Found, return it */
                break;
            }
        } else {
            Sym = 0;
        }

        /* Not found, search in the parent scope, if we have one */
        Scope = Scope->Parent;

    } while (Sym == 0 && Scope != 0);

    /* Return the result */
    return Sym;
}



static void SymCheckUndefined (SymEntry* S)
/* Handle an undefined symbol */
{
    /* Undefined symbol. It may be...
    **
    **   - An undefined symbol in a nested lexical level. If the symbol is not
    **     fixed to this level, search for the symbol in the higher levels and
    **     make the entry a trampoline entry if we find one.
    **
    **   - If the symbol is not found, it is a real undefined symbol. If the
    **     AutoImport flag is set, make it an import. If the AutoImport flag is
    **     not set, it's an error.
    */
    SymEntry* Sym = 0;
    if ((S->Flags & SF_FIXED) == 0) {
        SymTable* Tab = GetSymParentScope (S);
        while (Tab) {
            Sym = SymFind (Tab, GetStrBuf (S->Name), SYM_FIND_EXISTING | SYM_CHECK_ONLY);
            if (Sym && (Sym->Flags & (SF_DEFINED | SF_IMPORT)) != 0) {
                /* We've found a symbol in a higher level that is
                ** either defined in the source, or an import.
                */
                 break;
            }
            /* No matching symbol found in this level. Look further */
            Tab = Tab->Parent;
        }
    }

    if (Sym) {

        /* We found the symbol in a higher level. Transfer the flags and
        ** address size from the local symbol to that in the higher level
        ** and check for problems.
        */
        if (S->Flags & SF_EXPORT) {
            if (Sym->Flags & SF_IMPORT) {
                /* The symbol is already marked as import */
                LIError (&S->RefLines,
                         "Symbol `%s' is already an import",
                         GetString (Sym->Name));
            }
            if ((Sym->Flags & SF_EXPORT) == 0) {
                /* Mark the symbol as an export */
                Sym->Flags |= SF_EXPORT;
                Sym->ExportSize = S->ExportSize;
                if (Sym->ExportSize == ADDR_SIZE_DEFAULT) {
                    /* Use the actual size of the symbol */
                    Sym->ExportSize = Sym->AddrSize;
                }
                if (Sym->AddrSize > Sym->ExportSize) {
                    /* We're exporting a symbol smaller than it actually is */
                    LIWarning (&Sym->DefLines, 1,
                               "Symbol `%m%p' is %s but exported %s",
                               GetSymName (Sym),
                               AddrSizeToStr (Sym->AddrSize),
                               AddrSizeToStr (Sym->ExportSize));
                }
            }
        }
        if (S->Flags & SF_REFERENCED) {
            /* Mark as referenced and move the line info */
            Sym->Flags |= SF_REFERENCED;
            CollTransfer (&Sym->RefLines, &S->RefLines);
            CollDeleteAll (&S->RefLines);
        }

        /* Transfer all expression references */
        SymTransferExprRefs (S, Sym);

        /* Mark the symbol as unused removing all other flags */
        S->Flags = SF_UNUSED;

    } else {
        /* The symbol is definitely undefined */
        if (S->Flags & SF_EXPORT) {
            /* We will not auto-import an export */
            LIError (&S->RefLines,
                     "Exported symbol `%m%p' was never defined",
                     GetSymName (S));
        } else {
            if (AutoImport) {
                /* Mark as import, will be indexed later */
                S->Flags |= SF_IMPORT;
                /* Use the address size for code */
                S->AddrSize = CodeAddrSize;
                /* Mark point of import */
                GetFullLineInfo (&S->DefLines);
            } else {
                /* Error */
                LIError (&S->RefLines,
                         "Symbol `%m%p' is undefined",
                         GetSymName (S));
            }
        }
    }
}



void SymCheck (void)
/* Run through all symbols and check for anomalies and errors */
{
    SymEntry* S;

    /* Check for open scopes */
    if (CurrentScope->Parent != 0) {
        Error ("Local scope was not closed");
    }

    /* First pass: Walk through all symbols, checking for undefined's and
    ** changing them to trampoline symbols or make them imports.
    */
    S = SymList;
    while (S) {
        /* If the symbol is marked as global, mark it as export, if it is
        ** already defined, otherwise mark it as import.
        */
        if (S->Flags & SF_GLOBAL) {
            if (S->Flags & SF_DEFINED) {
                SymExportFromGlobal (S);
            } else {
                SymImportFromGlobal (S);
            }
        }

        /* Handle undefined symbols */
        if ((S->Flags & SF_UNDEFMASK) == SF_UNDEFVAL) {
            /* This is an undefined symbol. Handle it. */
            SymCheckUndefined (S);
        }

        /* Next symbol */
        S = S->List;
    }

    /* Second pass: Walk again through the symbols. Count exports and imports
    ** and set address sizes where this has not happened before. Ignore
    ** undefined's, since we handled them in the last pass, and ignore unused
    ** symbols, since we handled them in the last pass, too.
    */
    S = SymList;
    while (S) {
        if ((S->Flags & SF_UNUSED) == 0 &&
            (S->Flags & SF_UNDEFMASK) != SF_UNDEFVAL) {

            /* Check for defined symbols that were never referenced */
            if (IsSizeOfSymbol (S)) {
                /* Remove line infos, we don't need them any longer */
                ReleaseFullLineInfo (&S->DefLines);
                ReleaseFullLineInfo (&S->RefLines);
            } else if ((S->Flags & SF_DEFINED) != 0 && (S->Flags & SF_REFERENCED) == 0) {
                LIWarning (&S->DefLines, 2,
                           "Symbol `%m%p' is defined but never used",
                           GetSymName (S));
            }

            /* Assign an index to all imports */
            if (S->Flags & SF_IMPORT) {
                if ((S->Flags & (SF_REFERENCED | SF_FORCED)) == SF_NONE) {
                    /* Imported symbol is not referenced */
                    LIWarning (&S->DefLines, 2,
                               "Symbol `%m%p' is imported but never used",
                               GetSymName (S));
                } else {
                    /* Give the import an id, count imports */
                    S->ImportId = ImportCount++;
                }
            }

            /* Count exports, assign the export ID */
            if (S->Flags & SF_EXPORT) {
                S->ExportId = ExportCount++;
            }

            /* If the symbol is defined but has an unknown address size,
            ** recalculate it.
            */
            if (SymHasExpr (S) && S->AddrSize == ADDR_SIZE_DEFAULT) {
                ExprDesc ED;
                ED_Init (&ED);
                StudyExpr (S->Expr, &ED);
                S->AddrSize = ED.AddrSize;
                if (SymIsExport (S)) {
                    if (S->ExportSize == ADDR_SIZE_DEFAULT) {
                        /* Use the real export size */
                        S->ExportSize = S->AddrSize;
                    } else if (S->AddrSize > S->ExportSize) {
                        /* We're exporting a symbol smaller than it actually is */
                        LIWarning (&S->DefLines, 1,
                                   "Symbol `%m%p' is %s but exported %s",
                                   GetSymName (S),
                                   AddrSizeToStr (S->AddrSize),
                                   AddrSizeToStr (S->ExportSize));
                    }
                }
                ED_Done (&ED);
            }

            /* If the address size of the symbol was guessed, check the guess
            ** against the actual address size and print a warning if the two
            ** differ.
            */
            if (S->AddrSize != ADDR_SIZE_DEFAULT) {
                /* Do we have data for this address size? */
                if (S->AddrSize <= sizeof (S->GuessedUse) / sizeof (S->GuessedUse[0])) {
                    /* Get the file position where the symbol was used */
                    const FilePos* P = S->GuessedUse[S->AddrSize - 1];
                    if (P) {
                        PWarning (P, 0,
                                  "Didn't use %s addressing for `%m%p'",
                                  AddrSizeToStr (S->AddrSize),
                                  GetSymName (S));
                    }
                }
            }

        }

        /* Next symbol */
        S = S->List;
    }
}



void SymDump (FILE* F)
/* Dump the symbol table */
{
    SymEntry* S = SymList;

    while (S) {
        /* Ignore unused symbols */
        if ((S->Flags & SF_UNUSED) == 0) {
            fprintf (F,
                     "%-24s %s %s %s %s %s\n",
                     SB_GetConstBuf (GetSymName (S)),
                     (S->Flags & SF_DEFINED)? "DEF" : "---",
                     (S->Flags & SF_REFERENCED)? "REF" : "---",
                     (S->Flags & SF_IMPORT)? "IMP" : "---",
                     (S->Flags & SF_EXPORT)? "EXP" : "---",
                     AddrSizeToStr (S->AddrSize));
        }
        /* Next symbol */
        S = S->List;
    }
}



void WriteImports (void)
/* Write the imports list to the object file */
{
    SymEntry* S;

    /* Tell the object file module that we're about to start the imports */
    ObjStartImports ();

    /* Write the import count to the list */
    ObjWriteVar (ImportCount);

    /* Walk throught list and write all valid imports to the file. An import
    ** is considered valid, if it is either referenced, or the forced bit is
    ** set. Otherwise, the import is ignored (no need to link in something
    ** that isn't used).
    */
    S = SymList;
    while (S) {
        if ((S->Flags & (SF_UNUSED | SF_IMPORT)) == SF_IMPORT &&
            (S->Flags & (SF_REFERENCED | SF_FORCED)) != 0) {

            ObjWrite8 (S->AddrSize);
            ObjWriteVar (S->Name);
            WriteLineInfo (&S->DefLines);
            WriteLineInfo (&S->RefLines);
        }
        S = S->List;
    }

    /* Done writing imports */
    ObjEndImports ();
}



void WriteExports (void)
/* Write the exports list to the object file */
{
    SymEntry* S;
    unsigned Type;

    /* Tell the object file module that we're about to start the exports */
    ObjStartExports ();

    /* Write the export count to the list */
    ObjWriteVar (ExportCount);

    /* Walk throught list and write all exports to the file */
    S = SymList;
    while (S) {
        if ((S->Flags & (SF_UNUSED | SF_EXPORT)) == SF_EXPORT) {

            /* Get the expression bits and the value */
            long ConstVal;
            unsigned SymFlags = GetSymInfoFlags (S, &ConstVal);

            /* Check if this symbol has a size. If so, remember it in the
            ** flags.
            */
            long Size;
            SymEntry* SizeSym = FindSizeOfSymbol (S);
            if (SizeSym != 0 && SymIsConst (SizeSym, &Size)) {
                SymFlags |= SYM_SIZE;
            }

            /* Count the number of ConDes types */
            for (Type = 0; Type < CD_TYPE_COUNT; ++Type) {
                if (S->ConDesPrio[Type] != CD_PRIO_NONE) {
                    SYM_INC_CONDES_COUNT (SymFlags);
                }
            }

            /* Write the type and the export size */
            ObjWriteVar (SymFlags);
            ObjWrite8 (S->ExportSize);

            /* Write any ConDes declarations */
            if (SYM_GET_CONDES_COUNT (SymFlags) > 0) {
                for (Type = 0; Type < CD_TYPE_COUNT; ++Type) {
                    unsigned char Prio = S->ConDesPrio[Type];
                    if (Prio != CD_PRIO_NONE) {
                        ObjWrite8 (CD_BUILD (Type, Prio));
                    }
                }
            }

            /* Write the name */
            ObjWriteVar (S->Name);

            /* Write the value */
            if (SYM_IS_CONST (SymFlags)) {
                /* Constant value */
                ObjWrite32 (ConstVal);
            } else {
                /* Expression involved */
                WriteExpr (S->Expr);
            }

            /* If the symbol has a size, write it to the file */
            if (SYM_HAS_SIZE (SymFlags)) {
                ObjWriteVar (Size);
            }

            /* Write the line infos */
            WriteLineInfo (&S->DefLines);
            WriteLineInfo (&S->RefLines);
        }
        S = S->List;
    }

    /* Done writing exports */
    ObjEndExports ();
}



void WriteDbgSyms (void)
/* Write a list of all symbols to the object file */
{
    unsigned Count;
    SymEntry* S;

    /* Tell the object file module that we're about to start the debug info */
    ObjStartDbgSyms ();

    /* Check if debug info is requested */
    if (DbgSyms) {

        /* Walk through the list, give each symbol an id and count them */
        Count = 0;
        S = SymList;
        while (S) {
            if (IsDbgSym (S)) {
                S->DebugSymId = Count++;
            }
            S = S->List;
        }

        /* Write the symbol count to the list */
        ObjWriteVar (Count);

        /* Walk through list and write all symbols to the file. Ignore size
        ** symbols.
        */
        S = SymList;
        while (S) {
            if (IsDbgSym (S)) {

                /* Get the expression bits and the value */
                long ConstVal;
                unsigned SymFlags = GetSymInfoFlags (S, &ConstVal);

                /* Check if this symbol has a size. If so, remember it in the
                ** flags.
                */
                long Size;
                SymEntry* SizeSym = FindSizeOfSymbol (S);
                if (SizeSym != 0 && SymIsConst (SizeSym, &Size)) {
                    SymFlags |= SYM_SIZE;
                }

                /* Write the type */
                ObjWriteVar (SymFlags);

                /* Write the address size */
                ObjWrite8 (S->AddrSize);

                /* Write the id of the parent. For normal symbols, this is a
                ** scope (symbol table), for cheap locals, it's a symbol.
                */
                if (SYM_IS_STD (SymFlags)) {
                    ObjWriteVar (S->Sym.Tab->Id);
                } else {
                    ObjWriteVar (S->Sym.Entry->DebugSymId);
                }

                /* Write the name */
                ObjWriteVar (S->Name);

                /* Write the value */
                if (SYM_IS_CONST (SymFlags)) {
                    /* Constant value */
                    ObjWrite32 (ConstVal);
                } else {
                    /* Expression involved */
                    WriteExpr (S->Expr);
                }

                /* If the symbol has a size, write it to the file */
                if (SYM_HAS_SIZE (SymFlags)) {
                    ObjWriteVar (Size);
                }

                /* If the symbol is an im- or export, write out the ids */
                if (SYM_IS_IMPORT (SymFlags)) {
                    ObjWriteVar (GetSymImportId (S));
                }
                if (SYM_IS_EXPORT (SymFlags)) {
                    ObjWriteVar (GetSymExportId (S));
                }

                /* Write the line infos */
                WriteLineInfo (&S->DefLines);
                WriteLineInfo (&S->RefLines);
            }
            S = S->List;
        }

    } else {

        /* No debug symbols */
        ObjWriteVar (0);

    }

    /* Write the high level symbols */
    WriteHLLDbgSyms ();

    /* Done writing debug symbols */
    ObjEndDbgSyms ();
}



void WriteScopes (void)
/* Write the scope table to the object file */
{
    /* Tell the object file module that we're about to start the scopes */
    ObjStartScopes ();

    /* We will write scopes only if debug symbols are requested */
    if (DbgSyms) {

        /* Get head of list */
        SymTable* S = RootScope;

        /* Write the scope count to the file */
        ObjWriteVar (ScopeCount);

        /* Walk through all scopes and write them to the file */
        while (S) {

            /* Flags for this scope */
            unsigned Flags = 0;

            /* Check if this scope has a size. If so, remember it in the
            ** flags.
            */
            long Size;
            SymEntry* SizeSym = FindSizeOfScope (S);
            if (SizeSym != 0 && SymIsConst (SizeSym, &Size)) {
                Flags |= SCOPE_SIZE;
            }

            /* Check if the scope has a label */
            if (S->Label) {
                Flags |= SCOPE_LABELED;
            }

            /* Scope must be defined */
            CHECK (S->Type != SCOPE_UNDEF);

            /* Id of parent scope */
            if (S->Parent) {
                ObjWriteVar (S->Parent->Id);
            } else {
                ObjWriteVar (0);
            }

            /* Lexical level */
            ObjWriteVar (S->Level);

            /* Scope flags */
            ObjWriteVar (Flags);

            /* Type of scope */
            ObjWriteVar (S->Type);

            /* Name of the scope */
            ObjWriteVar (S->Name);

            /* If the scope has a size, write it to the file */
            if (SCOPE_HAS_SIZE (Flags)) {
                ObjWriteVar (Size);
            }

            /* If the scope has a label, write its id to the file */
            if (SCOPE_HAS_LABEL (Flags)) {
                ObjWriteVar (S->Label->DebugSymId);
            }

            /* Spans for this scope */
            WriteSpanList (&S->Spans);

            /* Next scope */
            S = S->Next;
        }

    } else {

        /* No debug info requested */
        ObjWriteVar (0);

    }

    /* Done writing the scopes */
    ObjEndScopes ();
}