1 /*****************************************************************************/
5 /* Local variable handling for the cc65 C compiler */
9 /* (C) 2000-2004 Ullrich von Bassewitz */
10 /* Römerstrasse 52 */
11 /* D-70794 Filderstadt */
12 /* EMail: uz@cc65.org */
15 /* This software is provided 'as-is', without any expressed or implied */
16 /* warranty. In no event will the authors be held liable for any damages */
17 /* arising from the use of this software. */
19 /* Permission is granted to anyone to use this software for any purpose, */
20 /* including commercial applications, and to alter it and redistribute it */
21 /* freely, subject to the following restrictions: */
23 /* 1. The origin of this software must not be misrepresented; you must not */
24 /* claim that you wrote the original software. If you use this software */
25 /* in a product, an acknowledgment in the product documentation would be */
26 /* appreciated but is not required. */
27 /* 2. Altered source versions must be plainly marked as such, and must not */
28 /* be misrepresented as being the original software. */
29 /* 3. This notice may not be removed or altered from any source */
32 /*****************************************************************************/
56 /*****************************************************************************/
58 /*****************************************************************************/
62 static unsigned ParseRegisterDecl (Declaration* Decl, unsigned* SC, int Reg)
63 /* Parse the declaration of a register variable. The function returns the
64 * symbol data, which is the offset of the variable in the register bank.
69 /* Determine if this is a compound variable */
70 int IsCompound = IsClassStruct (Decl->Type) || IsTypeArray (Decl->Type);
72 /* Get the size of the variable */
73 unsigned Size = SizeOf (Decl->Type);
75 /* Save the current contents of the register variable on stack */
76 F_AllocLocalSpace (CurrentFunc);
77 g_save_regvars (Reg, Size);
79 /* Check for an optional initialization */
80 if (CurTok.Tok == TOK_ASSIGN) {
87 /* Special handling for compound types */
90 /* Switch to read only data */
93 /* Define a label for the initialization data */
94 InitLabel = GetLocalLabel ();
95 g_defdatalabel (InitLabel);
97 /* Parse the initialization generating a memory image of the
98 * data in the RODATA segment. The function does return the size
99 * of the initialization data, which may be greater than the
100 * actual size of the type, if the type is a structure with a
101 * flexible array member that has been initialized. Since we must
102 * know the size of the data in advance for register variables,
103 * we cannot allow that here.
105 if (ParseInit (Decl->Type) != Size) {
106 Error ("Cannot initialize flexible array members of storage class `register'");
109 /* Generate code to copy this data into the variable space */
110 g_initregister (InitLabel, Reg, Size);
114 /* Parse the expression */
117 /* Convert it to the target type */
118 TypeConversion (&Expr, Decl->Type);
120 /* Load the value into the primary */
121 ExprLoad (CF_NONE, &Expr);
123 /* Store the value into the variable */
124 g_putstatic (CF_REGVAR | TypeOf (Decl->Type), Reg, 0);
128 /* Mark the variable as referenced */
132 /* Cannot allocate a variable of zero size */
134 Error ("Variable `%s' has unknown size", Decl->Ident);
137 /* Return the symbol data */
143 static unsigned ParseAutoDecl (Declaration* Decl, unsigned* SC)
144 /* Parse the declaration of an auto variable. The function returns the symbol
145 * data, which is the offset for variables on the stack, and the label for
153 /* Determine if this is a compound variable */
154 int IsCompound = IsClassStruct (Decl->Type) || IsTypeArray (Decl->Type);
156 /* Get the size of the variable */
157 unsigned Size = SizeOf (Decl->Type);
159 /* Check if this is a variable on the stack or in static memory */
160 if (IS_Get (&StaticLocals) == 0) {
162 /* Check for an optional initialization */
163 if (CurTok.Tok == TOK_ASSIGN) {
170 /* Special handling for compound types */
173 /* Switch to read only data */
176 /* Define a label for the initialization data */
177 InitLabel = GetLocalLabel ();
178 g_defdatalabel (InitLabel);
180 /* Parse the initialization generating a memory image of the
181 * data in the RODATA segment. The function will return the
182 * actual size of the initialization data, which may be
183 * greater than the size of the variable if it is a struct
184 * that contains a flexible array member and we're not in
187 Size = ParseInit (Decl->Type);
189 /* Now reserve space for the variable on the stack */
190 SymData = F_ReserveLocalSpace (CurrentFunc, Size);
192 /* Next, allocate the space on the stack. This means that the
193 * variable is now located at offset 0 from the current sp.
195 F_AllocLocalSpace (CurrentFunc);
197 /* Generate code to copy the initialization data into the
200 g_initauto (InitLabel, Size);
204 /* Allocate previously reserved local space */
205 F_AllocLocalSpace (CurrentFunc);
207 /* Setup the type flags for the assignment */
208 Flags = (Size == SIZEOF_CHAR)? CF_FORCECHAR : CF_NONE;
210 /* Parse the expression */
213 /* Convert it to the target type */
214 TypeConversion (&Expr, Decl->Type);
216 /* If the value is not const, load it into the primary.
217 * Otherwise pass the information to the code generator.
219 if (ED_IsConstAbsInt (&Expr)) {
222 ExprLoad (CF_NONE, &Expr);
227 g_push (Flags | TypeOf (Decl->Type), Expr.IVal);
231 /* Mark the variable as referenced */
234 /* Variable is located at the current SP */
238 /* Non-initialized local variable. Just keep track of
241 SymData = F_ReserveLocalSpace (CurrentFunc, Size);
246 /* Static local variables. */
247 *SC = (*SC & ~SC_AUTO) | SC_STATIC;
249 /* Put them into the BSS */
252 /* Define the variable label */
253 SymData = GetLocalLabel ();
254 g_defdatalabel (SymData);
256 /* Reserve space for the data */
259 /* Allow assignments */
260 if (CurTok.Tok == TOK_ASSIGN) {
269 /* Switch to read only data */
272 /* Define a label for the initialization data */
273 InitLabel = GetLocalLabel ();
274 g_defdatalabel (InitLabel);
276 /* Parse the initialization generating a memory image of the
277 * data in the RODATA segment.
279 ParseInit (Decl->Type);
281 /* Generate code to copy this data into the variable space */
282 g_initstatic (InitLabel, SymData, Size);
286 /* Parse the expression */
289 /* Convert it to the target type */
290 TypeConversion (&Expr, Decl->Type);
292 /* Load the value into the primary */
293 ExprLoad (CF_NONE, &Expr);
295 /* Store the value into the variable */
296 g_putstatic (TypeOf (Decl->Type), SymData, 0);
299 /* Mark the variable as referenced */
304 /* Cannot allocate a variable of zero size */
306 Error ("Variable `%s' has unknown size", Decl->Ident);
309 /* Return the symbol data */
315 static unsigned ParseStaticDecl (Declaration* Decl, unsigned* SC)
316 /* Parse the declaration of a static variable. The function returns the symbol
317 * data, which is the asm label of the variable.
322 /* Get the size of the variable */
323 unsigned Size = SizeOf (Decl->Type);
326 if (CurTok.Tok == TOK_ASSIGN) {
328 /* Initialization ahead, switch to data segment */
329 if (IsQualConst (Decl->Type)) {
335 /* Define the variable label */
336 SymData = GetLocalLabel ();
337 g_defdatalabel (SymData);
342 /* Allow initialization of static vars */
343 ParseInit (Decl->Type);
345 /* If the previous size has been unknown, it must be known now */
347 Size = SizeOf (Decl->Type);
350 /* Mark the variable as referenced */
355 /* Uninitialized data, use BSS segment */
358 /* Define the variable label */
359 SymData = GetLocalLabel ();
360 g_defdatalabel (SymData);
362 /* Reserve space for the data */
367 /* Cannot allocate a variable of zero size */
369 Error ("Variable `%s' has unknown size", Decl->Ident);
372 /* Return the symbol data */
378 static void ParseOneDecl (const DeclSpec* Spec)
379 /* Parse one variable declaration */
381 unsigned SC; /* Storage class for symbol */
382 unsigned SymData = 0; /* Symbol data (offset, label name, ...) */
383 Declaration Decl; /* Declaration data structure */
386 /* Remember the storage class for the new symbol */
387 SC = Spec->StorageClass;
389 /* Read the declaration */
390 ParseDecl (Spec, &Decl, DM_NEED_IDENT);
392 /* Set the correct storage class for functions */
393 if (IsTypeFunc (Decl.Type)) {
394 /* Function prototypes are always external */
395 if ((SC & SC_EXTERN) == 0) {
396 Warning ("Function must be extern");
398 SC |= SC_FUNC | SC_EXTERN;
402 /* If we don't have a name, this was flagged as an error earlier.
403 * To avoid problems later, use an anonymous name here.
405 if (Decl.Ident[0] == '\0') {
406 AnonName (Decl.Ident, "param");
409 /* Handle anything that needs storage (no functions, no typdefs) */
410 if ((SC & SC_FUNC) != SC_FUNC && (SC & SC_TYPEDEF) != SC_TYPEDEF) {
412 /* If we have a register variable, try to allocate a register and
413 * convert the declaration to "auto" if this is not possible.
415 int Reg = 0; /* Initialize to avoid gcc complains */
416 if ((SC & SC_REGISTER) != 0 && (Reg = F_AllocRegVar (CurrentFunc, Decl.Type)) < 0) {
417 /* No space for this register variable, convert to auto */
418 SC = (SC & ~SC_REGISTER) | SC_AUTO;
421 /* Check the variable type */
422 if ((SC & SC_REGISTER) == SC_REGISTER) {
423 /* Register variable */
424 SymData = ParseRegisterDecl (&Decl, &SC, Reg);
425 } else if ((SC & SC_AUTO) == SC_AUTO) {
427 SymData = ParseAutoDecl (&Decl, &SC);
428 } else if ((SC & SC_STATIC) == SC_STATIC) {
429 /* Static variable */
430 SymData = ParseStaticDecl (&Decl, &SC);
432 Internal ("Invalid storage class in ParseOneDecl: %04X", SC);
436 /* If the symbol is not marked as external, it will be defined now */
437 if ((SC & SC_EXTERN) == 0) {
441 /* Add the symbol to the symbol table */
442 AddLocalSym (Decl.Ident, Decl.Type, SC, SymData);
447 void DeclareLocals (void)
448 /* Declare local variables and types. */
450 /* Remember the current stack pointer */
451 int InitialStack = StackPtr;
453 /* Loop until we don't find any more variables */
456 /* Check variable declarations. We need to distinguish between a
457 * default int type and the end of variable declarations. So we
458 * will do the following: If there is no explicit storage class
459 * specifier *and* no explicit type given, *and* no type qualifiers
460 * have been read, it is assumed that we have reached the end of
464 ParseDeclSpec (&Spec, SC_AUTO, T_INT);
465 if ((Spec.Flags & DS_DEF_STORAGE) != 0 && /* No storage spec */
466 (Spec.Flags & DS_DEF_TYPE) != 0 && /* No type given */
467 GetQualifier (Spec.Type) == T_QUAL_NONE) { /* No type qualifier */
471 /* Accept type only declarations */
472 if (CurTok.Tok == TOK_SEMI) {
473 /* Type declaration only */
474 CheckEmptyDecl (&Spec);
479 /* Parse a comma separated variable list */
482 /* Parse one declaration */
483 ParseOneDecl (&Spec);
485 /* Check if there is more */
486 if (CurTok.Tok == TOK_COMMA) {
495 /* A semicolon must follow */
499 /* Be sure to allocate any reserved space for locals */
500 F_AllocLocalSpace (CurrentFunc);
502 /* In case we've allocated local variables in this block, emit a call to
503 * the stack checking routine if stack checks are enabled.
505 if (IS_Get (&CheckStack) && InitialStack != StackPtr) {