1 /*****************************************************************************/
5 /* Goto and label handling for the cc65 C compiler */
9 /* (C) 2000 Ullrich von Bassewitz */
11 /* D-70597 Stuttgart */
12 /* EMail: uz@musoftware.de */
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 /*****************************************************************************/
52 /*****************************************************************************/
54 /*****************************************************************************/
58 void GotoStatement (void)
59 /* Process a goto statement. */
64 /* Label name must follow */
65 if (CurTok.Tok == TOK_IDENT) {
67 /* Add a new label symbol if we don't have one until now */
68 SymEntry* Entry = AddLabelSym (CurTok.Ident, SC_REF | SC_GOTO);
70 /* Jump to the label */
71 g_jump (Entry->V.L.Label);
73 /* Eat the label name */
76 } else if (CurTok.Tok == TOK_STAR && IS_Get (&Standard) >= STD_CC65) {
77 SymEntry *arr, *idx, *cur;
86 /* arr[foo], we only support simple foo for now */
87 if (CurTok.Tok == TOK_IDENT &&
88 (arr = FindSym (CurTok.Ident))) {
93 if (!IsTypeArray(arr->Type) || SizeOf(arr->Type) == 0 ||
94 SizeOf(GetElementType(arr->Type)) != 2)
95 Error ("Expected array");
96 if (GetElementCount(arr->Type) > 127)
97 Error ("Only arrays with <= 127 labels are supported, got %lu",
98 GetElementCount(arr->Type));
100 if (CurTok.Tok == TOK_ICONST) {
104 if (CPUIsets[CPU] & CPU_ISET_65SC02) {
105 AddCodeLine ("ldx #$%02X", val * 2);
106 AddCodeLine ("jmp (.loword(%s),x)", arr->AsmName);
108 AddCodeLine ("ldy #$%02X", val * 2);
109 AddCodeLine ("lda %s,y", arr->AsmName);
110 AddCodeLine ("ldx %s+1,y", arr->AsmName);
111 AddCodeLine ("jmp callax");
113 } else if (CurTok.Tok == TOK_IDENT &&
114 (idx = FindSym (CurTok.Ident))) {
116 LoadExpr (CF_NONE, &desc);
117 AddCodeLine ("asl a");
119 if (CPUIsets[CPU] & CPU_ISET_65SC02) {
121 AddCodeLine ("jmp (.loword(%s),x)", arr->AsmName);
124 AddCodeLine ("lda %s,y", arr->AsmName);
125 AddCodeLine ("ldx %s+1,y", arr->AsmName);
126 AddCodeLine ("jmp callax");
129 Error ("Only simple expressions are supported for computed goto");
134 /* Loop over all target labels, specifying this as a jump point.
135 ** It's not exact - if there's multiple gotos, the last will be used,
136 ** but it's only needed so the optimizer does not remove the labels.
138 I = CS_GetEntryCount (CS->Code) - 1;
139 E = CS_GetEntry (CS->Code, I);
141 tab = GetLabelSymTab ();
145 if ((cur->Flags & (SC_LABEL|SC_GOTO_IND)) == (SC_LABEL|SC_GOTO_IND)) {
146 cur->V.L.IndJumpFrom = E;
154 Error ("Label name expected");
161 /* Define a label. */
163 /* Add a label symbol */
164 SymEntry* Entry = AddLabelSym (CurTok.Ident, SC_DEF);
166 /* Emit the jump label */
167 CodeLabel* L = CS_AddLabel (CS->Code, LocalLabelName (Entry->V.L.Label));
168 if (Entry->V.L.IndJumpFrom) {
169 CollAppend (&L->JumpFrom, Entry->V.L.IndJumpFrom);
172 /* Eat the ident and colon */