aslexternal.c revision 1.1.1.3 1 1.1 christos /******************************************************************************
2 1.1 christos *
3 1.1 christos * Module Name: aslexternal - ASL External opcode compiler support
4 1.1 christos *
5 1.1 christos *****************************************************************************/
6 1.1 christos
7 1.1 christos /*
8 1.1.1.2 christos * Copyright (C) 2000 - 2017, Intel Corp.
9 1.1 christos * All rights reserved.
10 1.1 christos *
11 1.1 christos * Redistribution and use in source and binary forms, with or without
12 1.1 christos * modification, are permitted provided that the following conditions
13 1.1 christos * are met:
14 1.1 christos * 1. Redistributions of source code must retain the above copyright
15 1.1 christos * notice, this list of conditions, and the following disclaimer,
16 1.1 christos * without modification.
17 1.1 christos * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 1.1 christos * substantially similar to the "NO WARRANTY" disclaimer below
19 1.1 christos * ("Disclaimer") and any redistribution must be conditioned upon
20 1.1 christos * including a substantially similar Disclaimer requirement for further
21 1.1 christos * binary redistribution.
22 1.1 christos * 3. Neither the names of the above-listed copyright holders nor the names
23 1.1 christos * of any contributors may be used to endorse or promote products derived
24 1.1 christos * from this software without specific prior written permission.
25 1.1 christos *
26 1.1 christos * Alternatively, this software may be distributed under the terms of the
27 1.1 christos * GNU General Public License ("GPL") version 2 as published by the Free
28 1.1 christos * Software Foundation.
29 1.1 christos *
30 1.1 christos * NO WARRANTY
31 1.1 christos * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 1.1 christos * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 1.1 christos * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 1.1 christos * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 1.1 christos * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 1.1 christos * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 1.1 christos * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 1.1 christos * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 1.1 christos * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 1.1 christos * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 1.1 christos * POSSIBILITY OF SUCH DAMAGES.
42 1.1 christos */
43 1.1 christos
44 1.1 christos #include "aslcompiler.h"
45 1.1 christos #include "aslcompiler.y.h"
46 1.1 christos #include "acparser.h"
47 1.1 christos #include "amlcode.h"
48 1.1 christos #include "acnamesp.h"
49 1.1 christos
50 1.1 christos
51 1.1 christos #define _COMPONENT ACPI_COMPILER
52 1.1 christos ACPI_MODULE_NAME ("aslexternal")
53 1.1 christos
54 1.1 christos
55 1.1 christos /* Local prototypes */
56 1.1 christos
57 1.1 christos static void
58 1.1 christos ExInsertArgCount (
59 1.1 christos ACPI_PARSE_OBJECT *Op);
60 1.1 christos
61 1.1 christos static void
62 1.1 christos ExMoveExternals (
63 1.1 christos ACPI_PARSE_OBJECT *DefinitionBlockOp);
64 1.1 christos
65 1.1 christos
66 1.1 christos /*******************************************************************************
67 1.1 christos *
68 1.1 christos * FUNCTION: ExDoExternal
69 1.1 christos *
70 1.1 christos * PARAMETERS: Op - Current Parse node
71 1.1 christos *
72 1.1 christos * RETURN: None
73 1.1 christos *
74 1.1 christos * DESCRIPTION: Add an External() definition to the global list. This list
75 1.1 christos * is used to generate External opcodes.
76 1.1 christos *
77 1.1 christos ******************************************************************************/
78 1.1 christos
79 1.1 christos void
80 1.1 christos ExDoExternal (
81 1.1 christos ACPI_PARSE_OBJECT *Op)
82 1.1 christos {
83 1.1 christos ACPI_PARSE_OBJECT *ListOp;
84 1.1 christos ACPI_PARSE_OBJECT *Prev;
85 1.1 christos ACPI_PARSE_OBJECT *Next;
86 1.1 christos ACPI_PARSE_OBJECT *ArgCountOp;
87 1.1 christos
88 1.1 christos
89 1.1 christos ArgCountOp = Op->Asl.Child->Asl.Next->Asl.Next;
90 1.1 christos ArgCountOp->Asl.AmlOpcode = AML_RAW_DATA_BYTE;
91 1.1 christos ArgCountOp->Asl.ParseOpcode = PARSEOP_BYTECONST;
92 1.1 christos ArgCountOp->Asl.Value.Integer = 0;
93 1.1 christos UtSetParseOpName (ArgCountOp);
94 1.1 christos
95 1.1 christos /* Create new list node of arbitrary type */
96 1.1 christos
97 1.1.1.3 christos ListOp = TrAllocateOp (PARSEOP_DEFAULT_ARG);
98 1.1 christos
99 1.1 christos /* Store External node as child */
100 1.1 christos
101 1.1 christos ListOp->Asl.Child = Op;
102 1.1 christos ListOp->Asl.Next = NULL;
103 1.1 christos
104 1.1 christos if (Gbl_ExternalsListHead)
105 1.1 christos {
106 1.1 christos /* Link new External to end of list */
107 1.1 christos
108 1.1 christos Prev = Gbl_ExternalsListHead;
109 1.1 christos Next = Prev;
110 1.1 christos while (Next)
111 1.1 christos {
112 1.1 christos Prev = Next;
113 1.1 christos Next = Next->Asl.Next;
114 1.1 christos }
115 1.1 christos
116 1.1 christos Prev->Asl.Next = ListOp;
117 1.1 christos }
118 1.1 christos else
119 1.1 christos {
120 1.1 christos Gbl_ExternalsListHead = ListOp;
121 1.1 christos }
122 1.1 christos }
123 1.1 christos
124 1.1 christos
125 1.1 christos /*******************************************************************************
126 1.1 christos *
127 1.1 christos * FUNCTION: ExInsertArgCount
128 1.1 christos *
129 1.1 christos * PARAMETERS: Op - Op for a method invocation
130 1.1 christos *
131 1.1 christos * RETURN: None
132 1.1 christos *
133 1.1 christos * DESCRIPTION: Obtain the number of arguments for a control method -- from
134 1.1 christos * the actual invocation.
135 1.1 christos *
136 1.1 christos ******************************************************************************/
137 1.1 christos
138 1.1 christos static void
139 1.1 christos ExInsertArgCount (
140 1.1 christos ACPI_PARSE_OBJECT *Op)
141 1.1 christos {
142 1.1 christos ACPI_PARSE_OBJECT *Next;
143 1.1 christos ACPI_PARSE_OBJECT *NameOp;
144 1.1 christos ACPI_PARSE_OBJECT *Child;
145 1.1 christos ACPI_PARSE_OBJECT *ArgCountOp;
146 1.1 christos char * ExternalName;
147 1.1 christos char * CallName;
148 1.1 christos UINT16 ArgCount = 0;
149 1.1 christos ACPI_STATUS Status;
150 1.1 christos
151 1.1 christos
152 1.1 christos CallName = AcpiNsGetNormalizedPathname (Op->Asl.Node, TRUE);
153 1.1 christos
154 1.1 christos Next = Gbl_ExternalsListHead;
155 1.1 christos while (Next)
156 1.1 christos {
157 1.1 christos ArgCount = 0;
158 1.1 christos
159 1.1 christos /* Skip if External node already handled */
160 1.1 christos
161 1.1.1.3 christos if (Next->Asl.Child->Asl.CompileFlags & OP_VISITED)
162 1.1 christos {
163 1.1 christos Next = Next->Asl.Next;
164 1.1 christos continue;
165 1.1 christos }
166 1.1 christos
167 1.1 christos NameOp = Next->Asl.Child->Asl.Child;
168 1.1 christos ExternalName = AcpiNsGetNormalizedPathname (NameOp->Asl.Node, TRUE);
169 1.1 christos
170 1.1 christos if (strcmp (CallName, ExternalName))
171 1.1 christos {
172 1.1 christos ACPI_FREE (ExternalName);
173 1.1 christos Next = Next->Asl.Next;
174 1.1 christos continue;
175 1.1 christos }
176 1.1 christos
177 1.1.1.3 christos Next->Asl.Child->Asl.CompileFlags |= OP_VISITED;
178 1.1 christos
179 1.1 christos /*
180 1.1 christos * Since we will reposition Externals to the Root, set Namepath
181 1.1 christos * to the fully qualified name and recalculate the aml length
182 1.1 christos */
183 1.1 christos Status = UtInternalizeName (ExternalName,
184 1.1 christos &NameOp->Asl.Value.String);
185 1.1 christos
186 1.1 christos ACPI_FREE (ExternalName);
187 1.1 christos if (ACPI_FAILURE (Status))
188 1.1 christos {
189 1.1 christos AslError (ASL_ERROR, ASL_MSG_COMPILER_INTERNAL,
190 1.1 christos NULL, "- Could not Internalize External");
191 1.1 christos break;
192 1.1 christos }
193 1.1 christos
194 1.1 christos NameOp->Asl.AmlLength = strlen (NameOp->Asl.Value.String);
195 1.1 christos
196 1.1 christos /* Get argument count */
197 1.1 christos
198 1.1 christos Child = Op->Asl.Child;
199 1.1 christos while (Child)
200 1.1 christos {
201 1.1 christos ArgCount++;
202 1.1 christos Child = Child->Asl.Next;
203 1.1 christos }
204 1.1 christos
205 1.1 christos /* Setup ArgCount operand */
206 1.1 christos
207 1.1 christos ArgCountOp = Next->Asl.Child->Asl.Child->Asl.Next->Asl.Next;
208 1.1 christos ArgCountOp->Asl.Value.Integer = ArgCount;
209 1.1 christos break;
210 1.1 christos }
211 1.1 christos
212 1.1 christos ACPI_FREE (CallName);
213 1.1 christos }
214 1.1 christos
215 1.1 christos
216 1.1 christos /*******************************************************************************
217 1.1 christos *
218 1.1 christos * FUNCTION: ExAmlExternalWalkBegin
219 1.1 christos *
220 1.1 christos * PARAMETERS: ASL_WALK_CALLBACK
221 1.1 christos *
222 1.1 christos * RETURN: None
223 1.1 christos *
224 1.1 christos * DESCRIPTION: Parse tree walk to create external opcode list for methods.
225 1.1 christos *
226 1.1 christos ******************************************************************************/
227 1.1 christos
228 1.1 christos ACPI_STATUS
229 1.1 christos ExAmlExternalWalkBegin (
230 1.1 christos ACPI_PARSE_OBJECT *Op,
231 1.1 christos UINT32 Level,
232 1.1 christos void *Context)
233 1.1 christos {
234 1.1 christos
235 1.1 christos /* External list head saved in the definition block op */
236 1.1 christos
237 1.1 christos if (Op->Asl.ParseOpcode == PARSEOP_DEFINITION_BLOCK)
238 1.1 christos {
239 1.1 christos Gbl_ExternalsListHead = Op->Asl.Value.Arg;
240 1.1 christos }
241 1.1 christos
242 1.1 christos if (!Gbl_ExternalsListHead)
243 1.1 christos {
244 1.1 christos return (AE_OK);
245 1.1 christos }
246 1.1 christos
247 1.1 christos if (Op->Asl.ParseOpcode != PARSEOP_METHODCALL)
248 1.1 christos {
249 1.1 christos return (AE_OK);
250 1.1 christos }
251 1.1 christos
252 1.1 christos /*
253 1.1 christos * The NameOp child under an ExternalOp gets turned into PARSE_METHODCALL
254 1.1 christos * by XfNamespaceLocateBegin(). Ignore these.
255 1.1 christos */
256 1.1 christos if (Op->Asl.Parent &&
257 1.1 christos Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_EXTERNAL)
258 1.1 christos {
259 1.1 christos return (AE_OK);
260 1.1 christos }
261 1.1 christos
262 1.1 christos ExInsertArgCount (Op);
263 1.1 christos return (AE_OK);
264 1.1 christos }
265 1.1 christos
266 1.1 christos
267 1.1 christos /*******************************************************************************
268 1.1 christos *
269 1.1 christos * FUNCTION: ExAmlExternalWalkEnd
270 1.1 christos *
271 1.1 christos * PARAMETERS: ASL_WALK_CALLBACK
272 1.1 christos *
273 1.1 christos * RETURN: None
274 1.1 christos *
275 1.1 christos * DESCRIPTION: Parse tree walk to create external opcode list for methods.
276 1.1 christos * Here, we just want to catch the case where a definition block
277 1.1 christos * has been completed. Then we move all of the externals into
278 1.1 christos * a single block in the parse tree and thus the AML code.
279 1.1 christos *
280 1.1 christos ******************************************************************************/
281 1.1 christos
282 1.1 christos ACPI_STATUS
283 1.1 christos ExAmlExternalWalkEnd (
284 1.1 christos ACPI_PARSE_OBJECT *Op,
285 1.1 christos UINT32 Level,
286 1.1 christos void *Context)
287 1.1 christos {
288 1.1 christos
289 1.1 christos if (Op->Asl.ParseOpcode == PARSEOP_DEFINITION_BLOCK)
290 1.1 christos {
291 1.1 christos /*
292 1.1 christos * Process any existing external list. (Support for
293 1.1 christos * multiple definition blocks in a single file/compile)
294 1.1 christos */
295 1.1 christos ExMoveExternals (Op);
296 1.1 christos Gbl_ExternalsListHead = NULL;
297 1.1 christos }
298 1.1 christos
299 1.1 christos return (AE_OK);
300 1.1 christos }
301 1.1 christos
302 1.1 christos
303 1.1 christos /*******************************************************************************
304 1.1 christos *
305 1.1 christos * FUNCTION: ExMoveExternals
306 1.1 christos *
307 1.1 christos * PARAMETERS: DefinitionBlockOp - Op for current definition block
308 1.1 christos *
309 1.1 christos * RETURN: None
310 1.1 christos *
311 1.1 christos * DESCRIPTION: Move all externals present in the source file into a single
312 1.1 christos * block of AML code, surrounded by an "If (0)" to prevent
313 1.1 christos * AML interpreters from attempting to execute the External
314 1.1 christos * opcodes.
315 1.1 christos *
316 1.1 christos ******************************************************************************/
317 1.1 christos
318 1.1 christos static void
319 1.1 christos ExMoveExternals (
320 1.1 christos ACPI_PARSE_OBJECT *DefinitionBlockOp)
321 1.1 christos {
322 1.1 christos ACPI_PARSE_OBJECT *ParentOp;
323 1.1 christos ACPI_PARSE_OBJECT *ExternalOp;
324 1.1 christos ACPI_PARSE_OBJECT *PredicateOp;
325 1.1 christos ACPI_PARSE_OBJECT *NextOp;
326 1.1 christos ACPI_PARSE_OBJECT *Prev;
327 1.1 christos ACPI_PARSE_OBJECT *Next;
328 1.1.1.2 christos char *ExternalName;
329 1.1 christos ACPI_OBJECT_TYPE ObjType;
330 1.1.1.3 christos ACPI_STATUS Status;
331 1.1 christos UINT32 i;
332 1.1 christos
333 1.1 christos
334 1.1 christos if (!Gbl_ExternalsListHead)
335 1.1 christos {
336 1.1 christos return;
337 1.1 christos }
338 1.1 christos
339 1.1 christos /* Remove the External nodes from the tree */
340 1.1 christos
341 1.1 christos NextOp = Gbl_ExternalsListHead;
342 1.1 christos while (NextOp)
343 1.1 christos {
344 1.1 christos /*
345 1.1 christos * The External is stored in child pointer of each node in the
346 1.1 christos * list
347 1.1 christos */
348 1.1 christos ExternalOp = NextOp->Asl.Child;
349 1.1 christos
350 1.1.1.2 christos /* Get/set the fully qualified name */
351 1.1.1.2 christos
352 1.1.1.2 christos ExternalName = AcpiNsGetNormalizedPathname (ExternalOp->Asl.Node, TRUE);
353 1.1.1.2 christos ExternalOp->Asl.ExternalName = ExternalName;
354 1.1.1.2 christos ExternalOp->Asl.Namepath = ExternalName;
355 1.1.1.2 christos
356 1.1 christos /* Set line numbers (for listings, etc.) */
357 1.1 christos
358 1.1 christos ExternalOp->Asl.LineNumber = 0;
359 1.1 christos ExternalOp->Asl.LogicalLineNumber = 0;
360 1.1 christos
361 1.1 christos Next = ExternalOp->Asl.Child;
362 1.1 christos Next->Asl.LineNumber = 0;
363 1.1 christos Next->Asl.LogicalLineNumber = 0;
364 1.1 christos
365 1.1.1.2 christos if (Next->Asl.ParseOpcode == PARSEOP_NAMESEG)
366 1.1.1.2 christos {
367 1.1.1.2 christos Next->Asl.ParseOpcode = PARSEOP_NAMESTRING;
368 1.1.1.2 christos }
369 1.1.1.3 christos
370 1.1.1.2 christos Next->Asl.ExternalName = ExternalName;
371 1.1.1.3 christos Status = UtInternalizeName (ExternalName, &Next->Asl.Value.String);
372 1.1.1.3 christos if (ACPI_FAILURE (Status))
373 1.1.1.3 christos {
374 1.1.1.3 christos AslError (ASL_ERROR, ASL_MSG_COMPILER_INTERNAL,
375 1.1.1.3 christos Next, "Could not internalize namestring");
376 1.1.1.3 christos return;
377 1.1.1.3 christos }
378 1.1.1.3 christos
379 1.1.1.2 christos Next->Asl.AmlLength = strlen (Next->Asl.Value.String);
380 1.1.1.2 christos
381 1.1 christos Next = Next->Asl.Next;
382 1.1 christos Next->Asl.LineNumber = 0;
383 1.1 christos Next->Asl.LogicalLineNumber = 0;
384 1.1 christos
385 1.1 christos Next = Next->Asl.Next;
386 1.1 christos Next->Asl.LineNumber = 0;
387 1.1 christos Next->Asl.LogicalLineNumber = 0;
388 1.1 christos
389 1.1 christos Next = Next->Asl.Next;
390 1.1 christos Next->Asl.LineNumber = 0;
391 1.1 christos Next->Asl.LogicalLineNumber = 0;
392 1.1 christos
393 1.1 christos ParentOp = ExternalOp->Asl.Parent;
394 1.1 christos Prev = Next = ParentOp->Asl.Child;
395 1.1 christos
396 1.1 christos /* Now find the External node's position in parse tree */
397 1.1 christos
398 1.1 christos while (Next != ExternalOp)
399 1.1 christos {
400 1.1 christos Prev = Next;
401 1.1 christos Next = Next->Asl.Next;
402 1.1 christos }
403 1.1 christos
404 1.1 christos /* Remove the External from the parse tree */
405 1.1 christos
406 1.1 christos if (Prev == ExternalOp)
407 1.1 christos {
408 1.1 christos /* External was the first child node */
409 1.1 christos
410 1.1 christos ParentOp->Asl.Child = ExternalOp->Asl.Next;
411 1.1 christos }
412 1.1 christos
413 1.1 christos Prev->Asl.Next = ExternalOp->Asl.Next;
414 1.1 christos ExternalOp->Asl.Next = NULL;
415 1.1 christos ExternalOp->Asl.Parent = Gbl_ExternalsListHead;
416 1.1 christos
417 1.1 christos /* Point the External to the next in the list */
418 1.1 christos
419 1.1 christos if (NextOp->Asl.Next)
420 1.1 christos {
421 1.1 christos ExternalOp->Asl.Next = NextOp->Asl.Next->Asl.Child;
422 1.1 christos }
423 1.1 christos
424 1.1 christos NextOp = NextOp->Asl.Next;
425 1.1 christos }
426 1.1 christos
427 1.1 christos /*
428 1.1 christos * Loop again to remove MethodObj Externals for which
429 1.1 christos * a MethodCall was not found (dead external reference)
430 1.1 christos */
431 1.1 christos Prev = Gbl_ExternalsListHead->Asl.Child;
432 1.1 christos Next = Prev;
433 1.1 christos while (Next)
434 1.1 christos {
435 1.1 christos ObjType = (ACPI_OBJECT_TYPE)
436 1.1 christos Next->Asl.Child->Asl.Next->Asl.Value.Integer;
437 1.1 christos
438 1.1 christos if (ObjType == ACPI_TYPE_METHOD &&
439 1.1.1.3 christos !(Next->Asl.CompileFlags & OP_VISITED))
440 1.1 christos {
441 1.1 christos if (Next == Prev)
442 1.1 christos {
443 1.1 christos Gbl_ExternalsListHead->Asl.Child = Next->Asl.Next;
444 1.1 christos Next->Asl.Next = NULL;
445 1.1 christos Prev = Gbl_ExternalsListHead->Asl.Child;
446 1.1 christos Next = Prev;
447 1.1 christos continue;
448 1.1 christos }
449 1.1 christos else
450 1.1 christos {
451 1.1 christos Prev->Asl.Next = Next->Asl.Next;
452 1.1 christos Next->Asl.Next = NULL;
453 1.1 christos Next = Prev->Asl.Next;
454 1.1 christos continue;
455 1.1 christos }
456 1.1 christos }
457 1.1 christos
458 1.1 christos Prev = Next;
459 1.1 christos Next = Next->Asl.Next;
460 1.1 christos }
461 1.1 christos
462 1.1 christos /* If list is now empty, don't bother to make If (0) block */
463 1.1 christos
464 1.1 christos if (!Gbl_ExternalsListHead->Asl.Child)
465 1.1 christos {
466 1.1 christos return;
467 1.1 christos }
468 1.1 christos
469 1.1 christos /* Convert Gbl_ExternalsListHead parent to If(). */
470 1.1 christos
471 1.1 christos Gbl_ExternalsListHead->Asl.ParseOpcode = PARSEOP_IF;
472 1.1 christos Gbl_ExternalsListHead->Asl.AmlOpcode = AML_IF_OP;
473 1.1.1.3 christos Gbl_ExternalsListHead->Asl.CompileFlags = OP_AML_PACKAGE;
474 1.1 christos UtSetParseOpName (Gbl_ExternalsListHead);
475 1.1 christos
476 1.1 christos /* Create a Zero op for the If predicate */
477 1.1 christos
478 1.1.1.3 christos PredicateOp = TrAllocateOp (PARSEOP_ZERO);
479 1.1 christos PredicateOp->Asl.AmlOpcode = AML_ZERO_OP;
480 1.1 christos
481 1.1 christos PredicateOp->Asl.Parent = Gbl_ExternalsListHead;
482 1.1 christos PredicateOp->Asl.Child = NULL;
483 1.1 christos PredicateOp->Asl.Next = Gbl_ExternalsListHead->Asl.Child;
484 1.1 christos Gbl_ExternalsListHead->Asl.Child = PredicateOp;
485 1.1 christos
486 1.1 christos /* Set line numbers (for listings, etc.) */
487 1.1 christos
488 1.1 christos Gbl_ExternalsListHead->Asl.LineNumber = 0;
489 1.1 christos Gbl_ExternalsListHead->Asl.LogicalLineNumber = 0;
490 1.1 christos
491 1.1 christos PredicateOp->Asl.LineNumber = 0;
492 1.1 christos PredicateOp->Asl.LogicalLineNumber = 0;
493 1.1 christos
494 1.1 christos /* Insert block back in the list */
495 1.1 christos
496 1.1 christos Prev = DefinitionBlockOp->Asl.Child;
497 1.1 christos Next = Prev;
498 1.1 christos
499 1.1 christos /* Find last default arg */
500 1.1 christos
501 1.1 christos for (i = 0; i < 6; i++)
502 1.1 christos {
503 1.1 christos Prev = Next;
504 1.1 christos Next = Prev->Asl.Next;
505 1.1 christos }
506 1.1 christos
507 1.1 christos if (Next)
508 1.1 christos {
509 1.1 christos /* Definition Block is not empty */
510 1.1 christos
511 1.1 christos Gbl_ExternalsListHead->Asl.Next = Next;
512 1.1 christos }
513 1.1 christos else
514 1.1 christos {
515 1.1 christos /* Definition Block is empty. */
516 1.1 christos
517 1.1 christos Gbl_ExternalsListHead->Asl.Next = NULL;
518 1.1 christos }
519 1.1 christos
520 1.1 christos Prev->Asl.Next = Gbl_ExternalsListHead;
521 1.1 christos Gbl_ExternalsListHead->Asl.Parent = Prev->Asl.Parent;
522 1.1 christos }
523