1 /*****************************************************************************/
5 /* Expression evaluation for the ld65 linker */
9 /* (C) 1998-2011, 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 /*****************************************************************************/
51 /*****************************************************************************/
53 /*****************************************************************************/
57 /* Structure for parsing segment based expression trees */
58 typedef struct SegExprDesc SegExprDesc;
60 long Val; /* The offset value */
61 int TooComplex; /* Expression too complex */
62 Segment* Seg; /* Segment reference if any */
67 /*****************************************************************************/
69 /*****************************************************************************/
73 ExprNode* NewExprNode (ObjData* O, unsigned char Op);
74 /* Create a new expression node */
76 void FreeExpr (ExprNode* Root);
77 /* Free the expression tree, Root is pointing to. */
79 int IsConstExpr (ExprNode* Root);
80 /* Return true if the given expression is a constant expression, that is, one
81 ** with no references to external symbols.
84 Import* GetExprImport (ExprNode* Expr);
85 /* Get the import data structure for a symbol expression node */
87 Export* GetExprExport (ExprNode* Expr);
88 /* Get the exported symbol for a symbol expression node */
90 Section* GetExprSection (ExprNode* Expr);
91 /* Get the segment for a section expression node */
93 long GetExprVal (ExprNode* Expr);
94 /* Get the value of a constant expression */
96 void GetSegExprVal (ExprNode* Expr, SegExprDesc* D);
97 /* Check if the given expression consists of a segment reference and only
98 ** constant values, additions and subtractions. If anything else is found,
99 ** set D->TooComplex to true. The function will initialize D.
102 ExprNode* LiteralExpr (long Val, ObjData* O);
103 /* Return an expression tree that encodes the given literal value */
105 ExprNode* MemoryExpr (MemoryArea* Mem, long Offs, ObjData* O);
106 /* Return an expression tree that encodes an offset into the memory area */
108 ExprNode* SegmentExpr (Segment* Seg, long Offs, ObjData* O);
109 /* Return an expression tree that encodes an offset into a segment */
111 ExprNode* SectionExpr (Section* Sec, long Offs, ObjData* O);
112 /* Return an expression tree that encodes an offset into a section */
114 ExprNode* ReadExpr (FILE* F, ObjData* O);
115 /* Read an expression from the given file */
117 int EqualExpr (ExprNode* E1, ExprNode* E2);
118 /* Check if two expressions are identical. */