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774b4bb424
cc65/src/cc65/symtab.c
cuz 774b4bb424 Some work on function stuff. 
Use xsprintf from the common directory.
Use hashstr from the common directory.


git-svn-id: svn://svn.cc65.org/cc65/trunk@36 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-06-08 20:27:05 +00:00

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/*****************************************************************************/
/* */
/* symtab.c */
/* */
/* Symbol table management for the cc65 C compiler */
/* */
/* */
/* */
/* (C) 2000 Ullrich von Bassewitz */
/* Wacholderweg 14 */
/* D-70597 Stuttgart */
/* EMail: uz@musoftware.de */
/* */
/* */
/* 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 <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include "../common/hashstr.h"
#include "asmcode.h"
#include "asmlabel.h"
#include "check.h"
#include "codegen.h"
#include "datatype.h"
#include "declare.h"
#include "error.h"
#include "funcdesc.h"
#include "global.h"
#include "io.h"
#include "mem.h"
#include "symentry.h"
#include "symtab.h"
/*****************************************************************************/
/* Data */
/*****************************************************************************/
/* An empty symbol table */
SymTable EmptySymTab = {
0, /* PrevTab */
0, /* SymHead */
0, /* SymTail */
0, /* SymCount */
1, /* Size */
{ 0 } /* Tab[1] */
};
/* Symbol table sizes */
#define SYMTAB_SIZE_GLOBAL 211U
#define SYMTAB_SIZE_FUNCTION 29U
#define SYMTAB_SIZE_BLOCK 13U
#define SYMTAB_SIZE_STRUCT 19U
#define SYMTAB_SIZE_LABEL 7U
/* Predefined lexical levels */
#define LEX_LEVEL_GLOBAL 1U
/* The current and root symbol tables */
static unsigned LexicalLevel = 0; /* For safety checks */
static SymTable* SymTab0 = 0;
static SymTable* SymTab = 0;
static SymTable* StructTab0 = 0;
static SymTable* StructTab = 0;
static SymTable* EnumTab0 = 0;
static SymTable* EnumTab = 0;
static SymTable* LabelTab = 0;
/*****************************************************************************/
/* struct SymTable */
/*****************************************************************************/
static SymTable* NewSymTable (unsigned Size)
/* Create and return a symbol table for the given lexical level */
{
unsigned I;
/* Allocate memory for the table */
SymTable* S = xmalloc (sizeof (SymTable) + (Size-1) * sizeof (SymEntry*));
/* Initialize the symbol table structure */
S->PrevTab = 0;
S->SymHead = 0;
S->SymTail = 0;
S->SymCount = 0;
S->Size = Size;
for (I = 0; I < Size; ++I) {
S->Tab[I] = 0;
}
/* Return the symbol table */
return S;
}
static void FreeSymTable (SymTable* S)
/* Free the given symbo table including all symbols */
{
/* Free all symbols */
SymEntry* Sym = S->SymHead;
while (Sym) {
SymEntry* NextSym = Sym->NextSym;
FreeSymEntry (Sym);
Sym = NextSym;
}
/* Free the table itself */
xfree (S);
}
/*****************************************************************************/
/* Check symbols in a table */
/*****************************************************************************/
static void CheckSymTable (SymTable* Tab)
/* Check a symbol table for open references, unused symbols ... */
{
SymEntry* Entry = Tab->SymHead;
while (Entry) {
/* Get the storage flags for tne entry */
unsigned Flags = Entry->Flags;
/* Ignore typedef entries */
if ((Flags & SC_TYPEDEF) != SC_TYPEDEF) {
/* Check if the symbol is one with storage, and it if it was
* defined but not used.
*/
if (((Flags & SC_AUTO) || (Flags & SC_STATIC)) && (Flags & SC_EXTERN) == 0) {
if ((Flags & SC_DEF) && !(Flags & SC_REF)) {
if (Flags & SC_PARAM) {
Warning (WARN_UNUSED_PARM, Entry->Name);
} else {
Warning (WARN_UNUSED_ITEM, Entry->Name);
}
}
}
/* If the entry is a label, check if it was defined in the function */
if (Flags & SC_LABEL) {
if ((Flags & SC_DEF) == 0) {
/* Undefined label */
Error (ERR_UNDEFINED_LABEL, Entry->Name);
} else if ((Flags & SC_REF) == 0) {
/* Defined but not used */
Warning (WARN_UNUSED_ITEM, Entry->Name);
}
}
}
/* Next entry */
Entry = Entry->NextSym;
}
}
/*****************************************************************************/
/* Handling of lexical levels */
/*****************************************************************************/
void EnterGlobalLevel (void)
/* Enter the program global lexical level */
{
/* Safety */
PRECONDITION (++LexicalLevel == LEX_LEVEL_GLOBAL);
/* Create and assign the symbol table */
SymTab0 = SymTab = NewSymTable (SYMTAB_SIZE_GLOBAL);
/* Create and assign the struct table */
StructTab0 = StructTab = NewSymTable (SYMTAB_SIZE_GLOBAL);
/* Create and assign the enum table */
EnumTab0 = EnumTab = NewSymTable (SYMTAB_SIZE_GLOBAL);
}
void LeaveGlobalLevel (void)
/* Leave the program global lexical level */
{
/* Safety */
PRECONDITION (LexicalLevel-- == LEX_LEVEL_GLOBAL);
/* Check the tables */
CheckSymTable (SymTab0);
/* Dump the tables if requested */
if (Debug) {
PrintSymTable (SymTab0, stdout, "Global symbol table");
PrintSymTable (StructTab0, stdout, "Global struct table");
PrintSymTable (EnumTab0, stdout, "Global enum table");
}
/* Don't delete the symbol and struct tables! */
SymTab0 = SymTab = 0;
StructTab0 = StructTab = 0;
EnumTab0 = EnumTab = 0;
}
void EnterFunctionLevel (void)
/* Enter function lexical level */
{
SymTable* S;
/* New lexical level */
++LexicalLevel;
/* Get a new symbol table and make it current */
S = NewSymTable (SYMTAB_SIZE_FUNCTION);
S->PrevTab = SymTab;
SymTab = S;
/* Get a new struct table and make it current */
S = NewSymTable (SYMTAB_SIZE_FUNCTION);
S->PrevTab = StructTab;
StructTab = S;
/* Get a new enum table and make it current */
S = NewSymTable (SYMTAB_SIZE_FUNCTION);
S->PrevTab = EnumTab;
EnumTab = S;
/* Create and assign a new label table */
LabelTab = NewSymTable (SYMTAB_SIZE_LABEL);
}
void RememberFunctionLevel (struct FuncDesc* F)
/* Remember the symbol tables for the level and leave the level without checks */
{
/* Leave the lexical level */
--LexicalLevel;
/* Remember the tables */
F->SymTab = SymTab;
F->StructTab = StructTab;
F->EnumTab = EnumTab;
/* Don't delete the tables */
SymTab = SymTab->PrevTab;
StructTab = StructTab->PrevTab;
EnumTab = EnumTab->PrevTab;
}
void ReenterFunctionLevel (struct FuncDesc* F)
/* Reenter the function lexical level using the existing tables from F */
{
/* New lexical level */
++LexicalLevel;
/* Make the tables current again */
F->SymTab->PrevTab = SymTab;
SymTab = F->SymTab;
F->StructTab->PrevTab = StructTab;
StructTab = F->StructTab;
F->EnumTab->PrevTab = EnumTab;
EnumTab = F->EnumTab;
/* Create and assign a new label table */
LabelTab = NewSymTable (SYMTAB_SIZE_LABEL);
}
void LeaveFunctionLevel (void)
/* Leave function lexical level */
{
/* Leave the lexical level */
--LexicalLevel;
/* Check the tables */
CheckSymTable (SymTab);
CheckSymTable (LabelTab);
/* Drop the label table if it is empty */
if (LabelTab->SymCount == 0) {
FreeSymTable (LabelTab);
}
/* Don't delete the tables */
SymTab = SymTab->PrevTab;
StructTab = StructTab->PrevTab;
EnumTab = EnumTab->PrevTab;
LabelTab = 0;
}
void EnterBlockLevel (void)
/* Enter a nested block in a function */
{
SymTable* S;
/* New lexical level */
++LexicalLevel;
/* Get a new symbol table and make it current */
S = NewSymTable (SYMTAB_SIZE_BLOCK);
S->PrevTab = SymTab;
SymTab = S;
/* Get a new struct table and make it current */
S = NewSymTable (SYMTAB_SIZE_BLOCK);
S->PrevTab = StructTab;
StructTab = S;
/* Get a new enum table and make it current */
S = NewSymTable (SYMTAB_SIZE_BLOCK);
S->PrevTab = EnumTab;
EnumTab = S;
}
void LeaveBlockLevel (void)
/* Leave a nested block in a function */
{
/* Leave the lexical level */
--LexicalLevel;
/* Check the tables */
CheckSymTable (SymTab);
/* Don't delete the tables */
SymTab = SymTab->PrevTab;
StructTab = StructTab->PrevTab;
EnumTab = EnumTab->PrevTab;
}
void EnterStructLevel (void)
/* Enter a nested block for a struct definition */
{
SymTable* S;
/* Get a new symbol table and make it current. Note: Structs and enums
* nested in struct scope are NOT local to the struct but visible in the
* outside scope. So we will NOT create a new struct or enum table.
*/
S = NewSymTable (SYMTAB_SIZE_BLOCK);
S->PrevTab = SymTab;
SymTab = S;
}
void LeaveStructLevel (void)
/* Leave a nested block for a struct definition */
{
/* Don't delete the table */
SymTab = SymTab->PrevTab;
}
/*****************************************************************************/
/* Find functions */
/*****************************************************************************/
static SymEntry* FindSymInTable (const SymTable* T, const char* Name, unsigned Hash)
/* Search for an entry in one table */
{
/* Get the start of the hash chain */
SymEntry* E = T->Tab [Hash % T->Size];
while (E) {
/* Compare the name */
if (strcmp (E->Name, Name) == 0) {
/* Found */
return E;
}
/* Not found, next entry in hash chain */
E = E->NextHash;
}
/* Not found */
return 0;
}
static SymEntry* FindSymInTree (const SymTable* Tab, const char* Name)
/* Find the symbol with the given name in the table tree that starts with T */
{
/* Get the hash over the name */
unsigned Hash = HashStr (Name);
/* Check all symbol tables for the symbol */
while (Tab) {
/* Try to find the symbol in this table */
SymEntry* E = FindSymInTable (Tab, Name, Hash);
/* Bail out if we found it */
if (E != 0) {
return E;
}
/* Repeat the search in the next higher lexical level */
Tab = Tab->PrevTab;
}
/* Not found */
return 0;
}
SymEntry* FindSym (const char* Name)
/* Find the symbol with the given name */
{
return FindSymInTree (SymTab, Name);
}
SymEntry* FindStructSym (const char* Name)
/* Find the symbol with the given name in the struct table */
{
return FindSymInTree (StructTab, Name);
}
SymEntry* FindEnumSym (const char* Name)
/* Find the symbol with the given name in the enum table */
{
return FindSymInTree (EnumTab, Name);
}
SymEntry* FindStructField (const type* Type, const char* Name)
/* Find a struct field in the fields list */
{
SymEntry* Field = 0;
/* The given type may actually be a pointer to struct */
if (Type[0] == T_PTR) {
++Type;
}
/* Non-structs do not have any struct fields... */
if (IsStruct (Type)) {
const SymTable* Tab;
/* Get a pointer to the struct/union type */
const SymEntry* Struct = (const SymEntry*) Decode (Type+1);
CHECK (Struct != 0);
/* Get the field symbol table from the struct entry.
* Beware: The table may not exist.
*/
Tab = Struct->V.S.SymTab;
/* Now search in the struct symbol table */
if (Tab) {
Field = FindSymInTable (Struct->V.S.SymTab, Name, HashStr (Name));
}
}
return Field;
}
/*****************************************************************************/
/* Add stuff to the symbol table */
/*****************************************************************************/
static void AddSymEntry (SymTable* T, SymEntry* S)
/* Add a symbol to a symbol table */
{
/* Get the hash value for the name */
unsigned Hash = HashStr (S->Name) % T->Size;
/* Insert the symbol into the list of all symbols in this level */
if (T->SymTail) {
T->SymTail->NextSym = S;
}
S->PrevSym = T->SymTail;
T->SymTail = S;
if (T->SymHead == 0) {
/* First symbol */
T->SymHead = S;
}
T->SymCount++;
/* Insert the symbol into the hash chain */
S->NextHash = T->Tab[Hash];
T->Tab[Hash] = S;
/* Tell the symbol in which table it is */
S->Owner = T;
}
SymEntry* AddStructSym (const char* Name, unsigned Size, SymTable* Tab)
/* Add a struct/union entry and return it */
{
/* Do we have an entry with this name already? */
SymEntry* Entry = FindSymInTable (StructTab, Name, HashStr (Name));
if (Entry) {
/* We do have an entry. This may be a forward, so check it. */
if (Entry->Flags != SC_STRUCT) {
/* Existing symbol is not a struct */
Error (ERR_SYMBOL_KIND);
} else if (Size > 0 && Entry->V.S.Size > 0) {
/* Both structs are definitions. */
Error (ERR_MULTIPLE_DEFINITION, Name);
} else {
/* Define the struct size if it is given */
if (Size > 0) {
Entry->V.S.SymTab = Tab;
Entry->V.S.Size = Size;
}
}
} else {
/* Create a new entry */
Entry = NewSymEntry (Name, SC_STRUCT);
/* Set the struct data */
Entry->V.S.SymTab = Tab;
Entry->V.S.Size = Size;
/* Add it to the current table */
AddSymEntry (StructTab, Entry);
}
/* Return the entry */
return Entry;
}
SymEntry* AddEnumSym (const char* Name, int Val)
/* Add an enum symbol to the symbol table and return it */
{
/* Do we have an entry with this name already? */
SymEntry* Entry = FindSymInTable (SymTab, Name, HashStr (Name));
if (Entry) {
if (Entry->Flags != SC_ENUM) {
Error (ERR_SYMBOL_KIND);
} else {
Error (ERR_MULTIPLE_DEFINITION, Name);
}
return Entry;
}
/* Create a new entry */
Entry = NewSymEntry (Name, SC_ENUM);
/* Enum values are ints */
Entry->Type = TypeDup (type_int);
/* Set the enum data */
Entry->V.EnumVal = Val;
/* Add the entry to the symbol table */
AddSymEntry (SymTab, Entry);
/* Return the entry */
return Entry;
}
SymEntry* AddLabelSym (const char* Name, unsigned Flags)
/* Add a goto label to the label table */
{
/* Do we have an entry with this name already? */
SymEntry* Entry = FindSymInTable (LabelTab, Name, HashStr (Name));
if (Entry) {
if ((Entry->Flags & SC_DEF) != 0 && (Flags & SC_DEF) != 0) {
/* Trying to define the label more than once */
Error (ERR_MULTIPLE_DEFINITION, Name);
}
Entry->Flags |= Flags;
} else {
/* Create a new entry */
Entry = NewSymEntry (Name, SC_LABEL | Flags);
/* Set a new label number */
Entry->V.Label = GetLabel ();
/* Add the entry to the label table */
AddSymEntry (LabelTab, Entry);
}
/* Return the entry */
return Entry;
}
SymEntry* AddLocalSym (const char* Name, type* Type, unsigned Flags, int Offs)
/* Add a local symbol and return the symbol entry */
{
SymEntry* Entry;
/* Functions declared inside of functions do always have external linkage */
if (Type != 0 && IsFunc (Type)) {
if ((Flags & (SC_DEFAULT | SC_EXTERN)) == 0) {
Warning (WARN_FUNC_MUST_BE_EXTERN);
}
Flags = SC_EXTERN;
}
/* Do we have an entry with this name already? */
Entry = FindSymInTable (SymTab, Name, HashStr (Name));
if (Entry) {
/* We have a symbol with this name already */
Error (ERR_MULTIPLE_DEFINITION, Name);
} else {
/* Create a new entry */
Entry = NewSymEntry (Name, Flags);
/* Set the symbol attributes */
Entry->Type = TypeDup (Type);
Entry->V.Offs = Offs;
/* Add the entry to the symbol table */
AddSymEntry (SymTab, Entry);
}
/* Return the entry */
return Entry;
}
SymEntry* AddGlobalSym (const char* Name, type* Type, unsigned Flags)
/* Add an external or global symbol to the symbol table and return the entry */
{
/* Functions must be inserted in the global symbol table */
SymTable* Tab = IsFunc (Type)? SymTab0 : SymTab;
/* Do we have an entry with this name already? */
SymEntry* Entry = FindSymInTable (Tab, Name, HashStr (Name));
if (Entry) {
type* EType;
/* We have a symbol with this name already */
if (Entry->Flags & SC_TYPE) {
Error (ERR_MULTIPLE_DEFINITION, Name);
return Entry;
}
/* Get the type string of the existing symbol */
EType = Entry->Type;
/* If we are handling arrays, the old entry or the new entry may be an
* incomplete declaration. Accept this, and if the exsting entry is
* incomplete, complete it.
*/
if (IsArray (Type) && IsArray (EType)) {
/* Get the array sizes */
unsigned Size = Decode (Type + 1);
unsigned ESize = Decode (EType + 1);
if ((Size != 0 && ESize != 0) ||
TypeCmp (Type+DECODE_SIZE+1, EType+DECODE_SIZE+1) != 0) {
/* Types not identical: Duplicate definition */
Error (ERR_MULTIPLE_DEFINITION, Name);
} else {
/* Check if we have a size in the existing definition */
if (ESize == 0) {
/* Existing, size not given, use size from new def */
Encode (EType + 1, Size);
}
}
} else {
/* New type must be identical */
if (!EqualTypes (EType, Type) != 0) {
Error (ERR_MULTIPLE_DEFINITION, Name);
}
/* In case of a function, use the new type descriptor, since it
* contains pointers to the new symbol tables that are needed if
* an actual function definition follows.
*/
if (IsFunc (Type)) {
CopyEncode (Type+1, EType+1);
}
}
/* Add the new flags */
Entry->Flags |= Flags;
} else {
/* Create a new entry */
Entry = NewSymEntry (Name, Flags);
/* Set the symbol attributes */
Entry->Type = TypeDup (Type);
/* Add the entry to the symbol table */
AddSymEntry (Tab, Entry);
}
/* Return the entry */
return Entry;
}
/*****************************************************************************/
/* Code */
/*****************************************************************************/
SymTable* GetSymTab (void)
/* Return the current symbol table */
{
return SymTab;
}
static int EqualSymTables (SymTable* Tab1, SymTable* Tab2)
/* Compare two symbol tables. Return 1 if they are equal and 0 otherwise */
{
/* Compare the parameter lists */
SymEntry* Sym1 = Tab1->SymHead;
SymEntry* Sym2 = Tab2->SymHead;
/* Compare the fields */
while (Sym1 && Sym2) {
/* Compare this field */
if (!EqualTypes (Sym1->Type, Sym2->Type)) {
/* Field types not equal */
return 0;
}
/* Get the pointers to the next fields */
Sym1 = Sym1->NextSym;
Sym2 = Sym2->NextSym;
}
/* Check both pointers against NULL to compare the field count */
return (Sym1 == 0 && Sym2 == 0);
}
int EqualTypes (const type* Type1, const type* Type2)
/* Recursively compare two types. Return 1 if the types match, return 0
* otherwise.
*/
{
int v1, v2;
SymEntry* Sym1;
SymEntry* Sym2;
SymTable* Tab1;
SymTable* Tab2;
FuncDesc* F1;
FuncDesc* F2;
/* Shortcut here: If the pointers are identical, the types are identical */
if (Type1 == Type2) {
return 1;
}
/* Compare two types. Determine, where they differ */
while (*Type1 == *Type2 && *Type1 != T_END) {
switch (*Type1) {
case T_FUNC:
/* Compare the function descriptors */
F1 = DecodePtr (Type1+1);
F2 = DecodePtr (Type2+1);
if ((F1->Flags & ~FD_IMPLICIT) != (F2->Flags & ~FD_IMPLICIT)) {
/* Flags differ */
return 0;
}
/* Compare the parameter lists */
if (EqualSymTables (F1->SymTab, F2->SymTab) == 0 ||
EqualSymTables (F1->StructTab, F2->StructTab) == 0 ||
EqualSymTables (F1->EnumTab, F2->EnumTab) == 0) {
/* One of the tables is not identical */
return 0;
}
/* Skip the FuncDesc pointers to compare the return type */
Type1 += DECODE_SIZE;
Type2 += DECODE_SIZE;
break;
case T_ARRAY:
/* Check member count */
v1 = Decode (Type1+1);
v2 = Decode (Type2+1);
if (v1 != 0 && v2 != 0 && v1 != v2) {
/* Member count given but different */
return 0;
}
Type1 += DECODE_SIZE;
Type2 += DECODE_SIZE;
break;
case T_STRUCT:
case T_UNION:
/* Compare the fields recursively. To do that, we fetch the
* pointer to the struct definition from the type, and compare
* the fields.
*/
Sym1 = DecodePtr (Type1+1);
Sym2 = DecodePtr (Type2+1);
/* Get the field tables from the struct entry */
Tab1 = Sym1->V.S.SymTab;
Tab2 = Sym2->V.S.SymTab;
/* One or both structs may be forward definitions. In this case,
* the symbol tables are both non existant. Assume that the
* structs are equal in this case.
*/
if (Tab1 != 0 && Tab2 != 0) {
if (EqualSymTables (Tab1, Tab2) == 0) {
/* Field lists are not equal */
return 0;
}
}
/* Structs are equal */
Type1 += DECODE_SIZE;
Type2 += DECODE_SIZE;
break;
}
++Type1;
++Type2;
}
/* Done, types are equal */
return 1;
}
void MakeZPSym (const char* Name)
/* Mark the given symbol as zero page symbol */
{
/* Get the symbol table entry */
SymEntry* Entry = FindSymInTable (SymTab, Name, HashStr (Name));
/* Mark the symbol as zeropage */
if (Entry) {
Entry->Flags |= SC_ZEROPAGE;
} else {
Error (ERR_UNDEFINED_SYMBOL, Name);
}
}
void PrintSymTable (const SymTable* Tab, FILE* F, const char* Header, ...)
/* Write the symbol table to the given file */
{
unsigned Len;
const SymEntry* Entry;
/* Print the header */
va_list ap;
va_start (ap, Header);
fputc ('\n', F);
Len = vfprintf (F, Header, ap);
va_end (ap);
fputc ('\n', F);
/* Underline the header */
while (Len--) {
fputc ('=', F);
}
fputc ('\n', F);
/* Dump the table */
Entry = Tab->SymHead;
if (Entry == 0) {
fprintf (F, "(empty)\n");
} else {
while (Entry) {
DumpSymEntry (F, Entry);
Entry = Entry->NextSym;
}
}
fprintf (F, "\n\n\n");
}
void EmitExternals (void)
/* Write import/export statements for external symbols */
{
SymEntry* Entry;
AddEmptyLine ();
Entry = SymTab->SymHead;
while (Entry) {
unsigned Flags = Entry->Flags;
if (Flags & SC_EXTERN) {
/* Only defined or referenced externs */
if ((Flags & SC_REF) != 0 && (Flags & SC_DEF) == 0) {
/* An import */
g_defimport (Entry->Name, Flags & SC_ZEROPAGE);
} else if (Flags & SC_DEF) {
/* An export */
g_defexport (Entry->Name, Flags & SC_ZEROPAGE);
}
}
Entry = Entry->NextSym;
}
}
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