summaryrefslogtreecommitdiffstats
path: root/win/tkWin32Dll.c
blob: 9ff374e4dffe076b40081cee574ca4611f987247 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
/*
 * tkWin32Dll.c --
 *
 *	This file contains a stub dll entry point.
 *
 * Copyright (c) 1995 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tkWinInt.h"
#ifndef STATIC_BUILD

#ifdef HAVE_NO_SEH

/*
 * Unlike Borland and Microsoft, we don't register exception handlers by
 * pushing registration records onto the runtime stack. Instead, we register
 * them by creating an TCLEXCEPTION_REGISTRATION within the activation record.
 */

typedef struct TCLEXCEPTION_REGISTRATION {
    struct TCLEXCEPTION_REGISTRATION *link;
    EXCEPTION_DISPOSITION (*handler)(
	    struct _EXCEPTION_RECORD*, void*, struct _CONTEXT*, void*);
    void *ebp;
    void *esp;
    int status;
} TCLEXCEPTION_REGISTRATION;

/*
 * Need to add noinline flag to DllMain declaration so that gcc -O3 does not
 * inline asm code into DllEntryPoint and cause a compile time error because
 * of redefined local labels.
 */

BOOL APIENTRY		DllMain(HINSTANCE hInst, DWORD reason,
			    LPVOID reserved) __attribute__ ((noinline));

#else /* !HAVE_NO_SEH */

/*
 * The following declaration is for the VC++ DLL entry point.
 */

BOOL APIENTRY		DllMain(HINSTANCE hInst, DWORD reason,
			    LPVOID reserved);
#endif /* HAVE_NO_SEH */

/*
 *----------------------------------------------------------------------
 *
 * DllEntryPoint --
 *
 *	This wrapper function is used by Borland to invoke the initialization
 *	code for Tk. It simply calls the DllMain routine.
 *
 * Results:
 *	See DllMain.
 *
 * Side effects:
 *	See DllMain.
 *
 *----------------------------------------------------------------------
 */

BOOL APIENTRY
DllEntryPoint(
    HINSTANCE hInst,		/* Library instance handle. */
    DWORD reason,		/* Reason this function is being called. */
    LPVOID reserved)		/* Not used. */
{
    return DllMain(hInst, reason, reserved);
}

/*
 *----------------------------------------------------------------------
 *
 * DllMain --
 *
 *	DLL entry point. It is only necessary to specify our dll here so that
 *	resources are found correctly. Otherwise Tk will initialize and clean
 *	up after itself through other methods, in order to be consistent
 *	whether the build is static or dynamic.
 *
 * Results:
 *	Always TRUE.
 *
 * Side effects:
 *	This might call some synchronization functions, but MSDN documentation
 *	states: "Waiting on synchronization objects in DllMain can cause a
 *	deadlock."
 *
 *----------------------------------------------------------------------
 */

BOOL APIENTRY
DllMain(
    HINSTANCE hInstance,
    DWORD reason,
    LPVOID reserved)
{
#ifdef HAVE_NO_SEH
    TCLEXCEPTION_REGISTRATION registration;
#endif
    (void)reserved;

    /*
     * If we are attaching to the DLL from a new process, tell Tk about the
     * hInstance to use.
     */

    switch (reason) {
    case DLL_PROCESS_ATTACH:
	DisableThreadLibraryCalls(hInstance);
	TkWinSetHINSTANCE(hInstance);
	break;

    case DLL_PROCESS_DETACH:
	/*
	 * Protect the call to TkFinalize in an SEH block. We can't be
	 * guarenteed Tk is always being unloaded from a stable condition.
	 */

#ifdef HAVE_NO_SEH
#   ifdef __WIN64
	__asm__ __volatile__ (

	    /*
	     * Construct an TCLEXCEPTION_REGISTRATION to protect the call to
	     * TkFinalize
	     */

	    "leaq	%[registration], %%rdx"		"\n\t"
	    "movq	%%gs:0,		%%rax"		"\n\t"
	    "movq	%%rax,		0x0(%%rdx)"	"\n\t" /* link */
	    "leaq	1f(%%rip),	%%rax"		"\n\t"
	    "movq	%%rax,		0x8(%%rdx)"	"\n\t" /* handler */
	    "movq	%%rbp,		0x10(%%rdx)"	"\n\t" /* rbp */
	    "movq	%%rsp,		0x18(%%rdx)"	"\n\t" /* rsp */
	    "movl	%[error],	0x20(%%rdx)"	"\n\t" /* status */

	    /*
	     * Link the TCLEXCEPTION_REGISTRATION on the chain
	     */

	    "movq	%%rdx,		%%gs:0"		"\n\t"

	    /*
	     * Call TkFinalize
	     */

	    "movq	$0x0,		0x0(%%rsp)"		"\n\t"
	    "call	TkFinalize"			"\n\t"

	    /*
	     * Come here on a normal exit. Recover the TCLEXCEPTION_REGISTRATION
	     * and store a TCL_OK status
	     */

	    "movq	%%gs:0,		%%rdx"		"\n\t"
	    "movl	%[ok],		%%eax"		"\n\t"
	    "movl	%%eax,		0x20(%%rdx)"	"\n\t"
	    "jmp	2f"				"\n"

	    /*
	     * Come here on an exception. Get the TCLEXCEPTION_REGISTRATION that
	     * we previously put on the chain.
	     */

	    "1:"					"\t"
	    "movq	%%gs:0,		%%rdx"		"\n\t"
	    "movq	0x10(%%rdx),	%%rdx"		"\n\t"

	    /*
	     * Come here however we exited. Restore context from the
	     * TCLEXCEPTION_REGISTRATION in case the stack is unbalanced.
	     */

	    "2:"					"\t"
	    "movq	0x18(%%rdx),	%%rsp"		"\n\t"
	    "movq	0x10(%%rdx),	%%rbp"		"\n\t"
	    "movq	0x0(%%rdx),	%%rax"		"\n\t"
	    "movq	%%rax,		%%gs:0"		"\n\t"

	    :
	    /* No outputs */
	    :
	    [registration]	"m"	(registration),
	    [ok]		"i"	(TCL_OK),
	    [error]		"i"	(TCL_ERROR)
	    :
	    "%rax", "%rbx", "%rcx", "%rdx", "%rsi", "%rdi", "memory"
	);

#   else
	__asm__ __volatile__ (

	    /*
	     * Construct an TCLEXCEPTION_REGISTRATION to protect the call to
	     * TkFinalize
	     */

	    "leal	%[registration], %%edx"		"\n\t"
	    "movl	%%fs:0,		%%eax"		"\n\t"
	    "movl	%%eax,		0x0(%%edx)"	"\n\t" /* link */
	    "leal	1f,		%%eax"		"\n\t"
	    "movl	%%eax,		0x4(%%edx)"	"\n\t" /* handler */
	    "movl	%%ebp,		0x8(%%edx)"	"\n\t" /* ebp */
	    "movl	%%esp,		0xc(%%edx)"	"\n\t" /* esp */
	    "movl	%[error],	0x10(%%edx)"	"\n\t" /* status */

	    /*
	     * Link the TCLEXCEPTION_REGISTRATION on the chain
	     */

	    "movl	%%edx,		%%fs:0"		"\n\t"

	    /*
	     * Call TkFinalize
	     */

	    "movl	$0x0,		0x0(%%esp)"		"\n\t"
	    "call	_TkFinalize"			"\n\t"

	    /*
	     * Come here on a normal exit. Recover the TCLEXCEPTION_REGISTRATION
	     * and store a TCL_OK status
	     */

	    "movl	%%fs:0,		%%edx"		"\n\t"
	    "movl	%[ok],		%%eax"		"\n\t"
	    "movl	%%eax,		0x10(%%edx)"	"\n\t"
	    "jmp	2f"				"\n"

	    /*
	     * Come here on an exception. Get the TCLEXCEPTION_REGISTRATION that
	     * we previously put on the chain.
	     */

	    "1:"					"\t"
	    "movl	%%fs:0,		%%edx"		"\n\t"
	    "movl	0x8(%%edx),	%%edx"		"\n"


	    /*
	     * Come here however we exited. Restore context from the
	     * TCLEXCEPTION_REGISTRATION in case the stack is unbalanced.
	     */

	    "2:"					"\t"
	    "movl	0xc(%%edx),	%%esp"		"\n\t"
	    "movl	0x8(%%edx),	%%ebp"		"\n\t"
	    "movl	0x0(%%edx),	%%eax"		"\n\t"
	    "movl	%%eax,		%%fs:0"		"\n\t"

	    :
	    /* No outputs */
	    :
	    [registration]	"m"	(registration),
	    [ok]		"i"	(TCL_OK),
	    [error]		"i"	(TCL_ERROR)
	    :
	    "%eax", "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory"
	);

#   endif
#else /* HAVE_NO_SEH */
	__try {
	    /*
	     * Run and remove our exit handlers, if they haven't already been
	     * run. Just in case we are being unloaded prior to Tcl (it can
	     * happen), we won't leave any dangling pointers hanging around
	     * for when Tcl gets unloaded later.
	     */

	    TkFinalize(NULL);
	} __except (EXCEPTION_EXECUTE_HANDLER) {
	    /* empty handler body. */
	}
#endif

	break;
    }
    return TRUE;
}

#endif /* !STATIC_BUILD */

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */