1 /*****************************************************************************/
5 /* Conditional assembly support for ca65 */
9 /* (C) 2000-2011, Ullrich von Bassewitz */
10 /* Roemerstrasse 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 /*****************************************************************************/
48 /*****************************************************************************/
50 /*****************************************************************************/
54 /* Maximum count of nested .ifs */
57 /* Set of bitmapped flags for the if descriptor */
59 ifNone = 0x0000, /* No flag */
60 ifCond = 0x0001, /* IF condition was true */
61 ifParentCond= 0x0002, /* IF condition of parent */
62 ifElse = 0x0004, /* We had a .ELSE branch */
63 ifNeedTerm = 0x0008, /* Need .ENDIF termination */
66 /* The overall .IF condition */
71 /*****************************************************************************/
73 /*****************************************************************************/
77 /* One .IF descriptor */
78 typedef struct IfDesc IfDesc;
80 unsigned Flags; /* Bitmapped flags, see above */
81 Collection LineInfos; /* File position of the .IF */
82 const char* Name; /* Name of the directive */
86 static IfDesc IfStack [MAX_IFS];
87 static unsigned IfCount = 0;
91 static IfDesc* GetCurrentIf (void)
92 /* Return the current .IF descriptor */
97 return &IfStack[IfCount-1];
103 static int GetOverallIfCond (void)
104 /* Get the overall condition based on all conditions on the stack. */
106 /* Since the last entry contains the overall condition of the parent, we
107 * must check it in combination of the current condition. If there is no
108 * last entry, the overall condition is true.
110 return (IfCount == 0) ||
111 ((IfStack[IfCount-1].Flags & (ifCond | ifParentCond)) == (ifCond | ifParentCond));
116 static void CalcOverallIfCond (void)
117 /* Caclulate the overall condition based on all conditions on the stack. */
119 IfCond = GetOverallIfCond ();
124 static void SetIfCond (IfDesc* ID, int C)
125 /* Set the .IF condition */
130 ID->Flags &= ~ifCond;
136 static void ElseClause (IfDesc* ID, const char* Directive)
137 /* Enter an .ELSE clause */
139 /* Check if we have an open .IF - otherwise .ELSE is not allowed */
141 Error ("Unexpected %s", Directive);
145 /* Check for a duplicate else, then remember that we had one */
146 if (ID->Flags & ifElse) {
147 /* We already had a .ELSE ! */
148 Error ("Duplicate .ELSE");
152 /* Condition is inverted now */
158 static IfDesc* AllocIf (const char* Directive, int NeedTerm)
159 /* Alloc a new element from the .IF stack */
163 /* Check for stack overflow */
164 if (IfCount >= MAX_IFS) {
165 Fatal ("Too many nested .IFs");
168 /* Get the next element */
169 ID = &IfStack[IfCount];
171 /* Initialize elements */
172 ID->Flags = NeedTerm? ifNeedTerm : ifNone;
173 if (GetOverallIfCond ()) {
174 /* The parents .IF condition is true */
175 ID->Flags |= ifParentCond;
177 ID->LineInfos = EmptyCollection;
178 GetFullLineInfo (&ID->LineInfos, 0);
179 ID->Name = Directive;
181 /* One more slot allocated */
184 /* Return the result */
190 static void FreeIf (void)
191 /* Free all .IF descriptors until we reach one with the NeedTerm bit set */
195 IfDesc* ID = GetCurrentIf();
197 Error (" Unexpected .ENDIF");
200 Done = (ID->Flags & ifNeedTerm) != 0;
208 /*****************************************************************************/
210 /*****************************************************************************/
214 void DoConditionals (void)
215 /* Catch all for conditional directives */
221 switch (CurTok.Tok) {
227 ElseClause (D, ".ELSE");
229 /* Remember the data for the .ELSE */
230 GetFullLineInfo (&D->LineInfos, 0);
233 /* Calculate the new overall condition */
234 CalcOverallIfCond ();
243 /* Handle as if there was an .ELSE first */
244 ElseClause (D, ".ELSEIF");
246 /* Calculate the new overall if condition */
247 CalcOverallIfCond ();
249 /* Allocate and prepare a new descriptor */
250 D = AllocIf (".ELSEIF", 0);
253 /* Ignore the new condition if we are inside a false .ELSE
254 * branch. This way we won't get any errors about undefined
255 * symbols or similar...
258 SetIfCond (D, ConstExpression ());
262 /* Get the new overall condition */
263 CalcOverallIfCond ();
267 /* We're done with this .IF.. - remove the descriptor(s) */
270 /* Be sure not to read the next token until the .IF stack
271 * has been cleanup up, since we may be at end of file.
276 /* Get the new overall condition */
277 CalcOverallIfCond ();
281 D = AllocIf (".IF", 1);
284 SetIfCond (D, ConstExpression ());
287 CalcOverallIfCond ();
291 D = AllocIf (".IFBLANK", 1);
294 if (TokIsSep (CurTok.Tok)) {
301 CalcOverallIfCond ();
305 D = AllocIf (".IFCONST", 1);
308 ExprNode* Expr = Expression();
309 SetIfCond (D, IsConstExpr (Expr, 0));
313 CalcOverallIfCond ();
317 D = AllocIf (".IFDEF", 1);
320 SymEntry* Sym = ParseAnySymName (SYM_FIND_EXISTING);
321 SetIfCond (D, Sym != 0 && SymIsDef (Sym));
323 CalcOverallIfCond ();
327 D = AllocIf (".IFNBLANK", 1);
330 if (TokIsSep (CurTok.Tok)) {
337 CalcOverallIfCond ();
341 D = AllocIf (".IFNCONST", 1);
344 ExprNode* Expr = Expression();
345 SetIfCond (D, !IsConstExpr (Expr, 0));
349 CalcOverallIfCond ();
353 D = AllocIf (".IFNDEF", 1);
356 SymEntry* Sym = ParseAnySymName (SYM_FIND_EXISTING);
357 SetIfCond (D, Sym == 0 || !SymIsDef (Sym));
360 CalcOverallIfCond ();
364 D = AllocIf (".IFNREF", 1);
367 SymEntry* Sym = ParseAnySymName (SYM_FIND_EXISTING);
368 SetIfCond (D, Sym == 0 || !SymIsRef (Sym));
371 CalcOverallIfCond ();
375 D = AllocIf (".IFP02", 1);
378 SetIfCond (D, GetCPU() == CPU_6502);
381 CalcOverallIfCond ();
385 D = AllocIf (".IFP816", 1);
388 SetIfCond (D, GetCPU() == CPU_65816);
391 CalcOverallIfCond ();
395 D = AllocIf (".IFPC02", 1);
398 SetIfCond (D, GetCPU() == CPU_65C02);
401 CalcOverallIfCond ();
405 D = AllocIf (".IFPSC02", 1);
408 SetIfCond (D, GetCPU() == CPU_65SC02);
411 CalcOverallIfCond ();
415 D = AllocIf (".IFREF", 1);
418 SymEntry* Sym = ParseAnySymName (SYM_FIND_EXISTING);
419 SetIfCond (D, Sym != 0 && SymIsRef (Sym));
422 CalcOverallIfCond ();
431 } while (IfCond == 0 && CurTok.Tok != TOK_EOF);
436 int CheckConditionals (void)
437 /* Check if the current token is one that starts a conditional directive, and
438 * call DoConditionals if so. Return true if a conditional directive was found,
439 * return false otherwise.
442 switch (CurTok.Tok) {
469 void CheckOpenIfs (void)
470 /* Called from the scanner before closing an input file. Will check for any
471 * open .ifs in this file.
477 /* Get the current file number and check if the topmost entry on the
478 * .IF stack was inserted with this file number
480 IfDesc* D = GetCurrentIf ();
482 /* There are no open .IFs */
486 LI = CollConstAt (&D->LineInfos, 0);
487 if (LI->Pos.Name != CurTok.Pos.Name) {
488 /* The .if is from another file, bail out */
492 /* Start of .if is in the file we're about to leave */
493 LIError (&D->LineInfos, "Conditional assembly branch was never closed");
497 /* Calculate the new overall .IF condition */
498 CalcOverallIfCond ();
503 unsigned GetIfStack (void)
504 /* Get the current .IF stack pointer */
511 void CleanupIfStack (unsigned SP)
512 /* Cleanup the .IF stack, remove anything above the given stack pointer */
514 while (IfCount > SP) {
518 /* Calculate the new overall .IF condition */
519 CalcOverallIfCond ();