header.cpp revision 1663a6c12fdf4732d7ea0a0406af6085b3c408e4 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17/* common includes */
18#include "Dalvik.h"
19#include "interp/InterpDefs.h"
20#include "mterp/Mterp.h"
21#include <math.h>                   // needed for fmod, fmodf
22#include "mterp/common/FindInterface.h"
23
24/*
25 * Configuration defines.  These affect the C implementations, i.e. the
26 * portable interpreter(s) and C stubs.
27 *
28 * Some defines are controlled by the Makefile, e.g.:
29 *   WITH_INSTR_CHECKS
30 *   WITH_TRACKREF_CHECKS
31 *   EASY_GDB
32 *   NDEBUG
33 */
34
35#ifdef WITH_INSTR_CHECKS            /* instruction-level paranoia (slow!) */
36# define CHECK_BRANCH_OFFSETS
37# define CHECK_REGISTER_INDICES
38#endif
39
40/*
41 * Some architectures require 64-bit alignment for access to 64-bit data
42 * types.  We can't just use pointers to copy 64-bit values out of our
43 * interpreted register set, because gcc may assume the pointer target is
44 * aligned and generate invalid code.
45 *
46 * There are two common approaches:
47 *  (1) Use a union that defines a 32-bit pair and a 64-bit value.
48 *  (2) Call memcpy().
49 *
50 * Depending upon what compiler you're using and what options are specified,
51 * one may be faster than the other.  For example, the compiler might
52 * convert a memcpy() of 8 bytes into a series of instructions and omit
53 * the call.  The union version could cause some strange side-effects,
54 * e.g. for a while ARM gcc thought it needed separate storage for each
55 * inlined instance, and generated instructions to zero out ~700 bytes of
56 * stack space at the top of the interpreter.
57 *
58 * The default is to use memcpy().  The current gcc for ARM seems to do
59 * better with the union.
60 */
61#if defined(__ARM_EABI__)
62# define NO_UNALIGN_64__UNION
63#endif
64
65
66//#define LOG_INSTR                   /* verbose debugging */
67/* set and adjust ANDROID_LOG_TAGS='*:i jdwp:i dalvikvm:i dalvikvmi:i' */
68
69/*
70 * Export another copy of the PC on every instruction; this is largely
71 * redundant with EXPORT_PC and the debugger code.  This value can be
72 * compared against what we have stored on the stack with EXPORT_PC to
73 * help ensure that we aren't missing any export calls.
74 */
75#if WITH_EXTRA_GC_CHECKS > 1
76# define EXPORT_EXTRA_PC() (self->currentPc2 = pc)
77#else
78# define EXPORT_EXTRA_PC()
79#endif
80
81/*
82 * Adjust the program counter.  "_offset" is a signed int, in 16-bit units.
83 *
84 * Assumes the existence of "const u2* pc" and "const u2* curMethod->insns".
85 *
86 * We don't advance the program counter until we finish an instruction or
87 * branch, because we do want to have to unroll the PC if there's an
88 * exception.
89 */
90#ifdef CHECK_BRANCH_OFFSETS
91# define ADJUST_PC(_offset) do {                                            \
92        int myoff = _offset;        /* deref only once */                   \
93        if (pc + myoff < curMethod->insns ||                                \
94            pc + myoff >= curMethod->insns + dvmGetMethodInsnsSize(curMethod)) \
95        {                                                                   \
96            char* desc;                                                     \
97            desc = dexProtoCopyMethodDescriptor(&curMethod->prototype);     \
98            LOGE("Invalid branch %d at 0x%04x in %s.%s %s",                 \
99                myoff, (int) (pc - curMethod->insns),                       \
100                curMethod->clazz->descriptor, curMethod->name, desc);       \
101            free(desc);                                                     \
102            dvmAbort();                                                     \
103        }                                                                   \
104        pc += myoff;                                                        \
105        EXPORT_EXTRA_PC();                                                  \
106    } while (false)
107#else
108# define ADJUST_PC(_offset) do {                                            \
109        pc += _offset;                                                      \
110        EXPORT_EXTRA_PC();                                                  \
111    } while (false)
112#endif
113
114/*
115 * If enabled, log instructions as we execute them.
116 */
117#ifdef LOG_INSTR
118# define ILOGD(...) ILOG(LOG_DEBUG, __VA_ARGS__)
119# define ILOGV(...) ILOG(LOG_VERBOSE, __VA_ARGS__)
120# define ILOG(_level, ...) do {                                             \
121        char debugStrBuf[128];                                              \
122        snprintf(debugStrBuf, sizeof(debugStrBuf), __VA_ARGS__);            \
123        if (curMethod != NULL)                                              \
124            ALOG(_level, LOG_TAG"i", "%-2d|%04x%s",                          \
125                self->threadId, (int)(pc - curMethod->insns), debugStrBuf); \
126        else                                                                \
127            ALOG(_level, LOG_TAG"i", "%-2d|####%s",                          \
128                self->threadId, debugStrBuf);                               \
129    } while(false)
130void dvmDumpRegs(const Method* method, const u4* framePtr, bool inOnly);
131# define DUMP_REGS(_meth, _frame, _inOnly) dvmDumpRegs(_meth, _frame, _inOnly)
132static const char kSpacing[] = "            ";
133#else
134# define ILOGD(...) ((void)0)
135# define ILOGV(...) ((void)0)
136# define DUMP_REGS(_meth, _frame, _inOnly) ((void)0)
137#endif
138
139/* get a long from an array of u4 */
140static inline s8 getLongFromArray(const u4* ptr, int idx)
141{
142#if defined(NO_UNALIGN_64__UNION)
143    union { s8 ll; u4 parts[2]; } conv;
144
145    ptr += idx;
146    conv.parts[0] = ptr[0];
147    conv.parts[1] = ptr[1];
148    return conv.ll;
149#else
150    s8 val;
151    memcpy(&val, &ptr[idx], 8);
152    return val;
153#endif
154}
155
156/* store a long into an array of u4 */
157static inline void putLongToArray(u4* ptr, int idx, s8 val)
158{
159#if defined(NO_UNALIGN_64__UNION)
160    union { s8 ll; u4 parts[2]; } conv;
161
162    ptr += idx;
163    conv.ll = val;
164    ptr[0] = conv.parts[0];
165    ptr[1] = conv.parts[1];
166#else
167    memcpy(&ptr[idx], &val, 8);
168#endif
169}
170
171/* get a double from an array of u4 */
172static inline double getDoubleFromArray(const u4* ptr, int idx)
173{
174#if defined(NO_UNALIGN_64__UNION)
175    union { double d; u4 parts[2]; } conv;
176
177    ptr += idx;
178    conv.parts[0] = ptr[0];
179    conv.parts[1] = ptr[1];
180    return conv.d;
181#else
182    double dval;
183    memcpy(&dval, &ptr[idx], 8);
184    return dval;
185#endif
186}
187
188/* store a double into an array of u4 */
189static inline void putDoubleToArray(u4* ptr, int idx, double dval)
190{
191#if defined(NO_UNALIGN_64__UNION)
192    union { double d; u4 parts[2]; } conv;
193
194    ptr += idx;
195    conv.d = dval;
196    ptr[0] = conv.parts[0];
197    ptr[1] = conv.parts[1];
198#else
199    memcpy(&ptr[idx], &dval, 8);
200#endif
201}
202
203/*
204 * If enabled, validate the register number on every access.  Otherwise,
205 * just do an array access.
206 *
207 * Assumes the existence of "u4* fp".
208 *
209 * "_idx" may be referenced more than once.
210 */
211#ifdef CHECK_REGISTER_INDICES
212# define GET_REGISTER(_idx) \
213    ( (_idx) < curMethod->registersSize ? \
214        (fp[(_idx)]) : (assert(!"bad reg"),1969) )
215# define SET_REGISTER(_idx, _val) \
216    ( (_idx) < curMethod->registersSize ? \
217        (fp[(_idx)] = (u4)(_val)) : (assert(!"bad reg"),1969) )
218# define GET_REGISTER_AS_OBJECT(_idx)       ((Object *)GET_REGISTER(_idx))
219# define SET_REGISTER_AS_OBJECT(_idx, _val) SET_REGISTER(_idx, (s4)_val)
220# define GET_REGISTER_INT(_idx) ((s4) GET_REGISTER(_idx))
221# define SET_REGISTER_INT(_idx, _val) SET_REGISTER(_idx, (s4)_val)
222# define GET_REGISTER_WIDE(_idx) \
223    ( (_idx) < curMethod->registersSize-1 ? \
224        getLongFromArray(fp, (_idx)) : (assert(!"bad reg"),1969) )
225# define SET_REGISTER_WIDE(_idx, _val) \
226    ( (_idx) < curMethod->registersSize-1 ? \
227        (void)putLongToArray(fp, (_idx), (_val)) : assert(!"bad reg") )
228# define GET_REGISTER_FLOAT(_idx) \
229    ( (_idx) < curMethod->registersSize ? \
230        (*((float*) &fp[(_idx)])) : (assert(!"bad reg"),1969.0f) )
231# define SET_REGISTER_FLOAT(_idx, _val) \
232    ( (_idx) < curMethod->registersSize ? \
233        (*((float*) &fp[(_idx)]) = (_val)) : (assert(!"bad reg"),1969.0f) )
234# define GET_REGISTER_DOUBLE(_idx) \
235    ( (_idx) < curMethod->registersSize-1 ? \
236        getDoubleFromArray(fp, (_idx)) : (assert(!"bad reg"),1969.0) )
237# define SET_REGISTER_DOUBLE(_idx, _val) \
238    ( (_idx) < curMethod->registersSize-1 ? \
239        (void)putDoubleToArray(fp, (_idx), (_val)) : assert(!"bad reg") )
240#else
241# define GET_REGISTER(_idx)                 (fp[(_idx)])
242# define SET_REGISTER(_idx, _val)           (fp[(_idx)] = (_val))
243# define GET_REGISTER_AS_OBJECT(_idx)       ((Object*) fp[(_idx)])
244# define SET_REGISTER_AS_OBJECT(_idx, _val) (fp[(_idx)] = (u4)(_val))
245# define GET_REGISTER_INT(_idx)             ((s4)GET_REGISTER(_idx))
246# define SET_REGISTER_INT(_idx, _val)       SET_REGISTER(_idx, (s4)_val)
247# define GET_REGISTER_WIDE(_idx)            getLongFromArray(fp, (_idx))
248# define SET_REGISTER_WIDE(_idx, _val)      putLongToArray(fp, (_idx), (_val))
249# define GET_REGISTER_FLOAT(_idx)           (*((float*) &fp[(_idx)]))
250# define SET_REGISTER_FLOAT(_idx, _val)     (*((float*) &fp[(_idx)]) = (_val))
251# define GET_REGISTER_DOUBLE(_idx)          getDoubleFromArray(fp, (_idx))
252# define SET_REGISTER_DOUBLE(_idx, _val)    putDoubleToArray(fp, (_idx), (_val))
253#endif
254
255/*
256 * Get 16 bits from the specified offset of the program counter.  We always
257 * want to load 16 bits at a time from the instruction stream -- it's more
258 * efficient than 8 and won't have the alignment problems that 32 might.
259 *
260 * Assumes existence of "const u2* pc".
261 */
262#define FETCH(_offset)     (pc[(_offset)])
263
264/*
265 * Extract instruction byte from 16-bit fetch (_inst is a u2).
266 */
267#define INST_INST(_inst)    ((_inst) & 0xff)
268
269/*
270 * Replace the opcode (used when handling breakpoints).  _opcode is a u1.
271 */
272#define INST_REPLACE_OP(_inst, _opcode) (((_inst) & 0xff00) | _opcode)
273
274/*
275 * Extract the "vA, vB" 4-bit registers from the instruction word (_inst is u2).
276 */
277#define INST_A(_inst)       (((_inst) >> 8) & 0x0f)
278#define INST_B(_inst)       ((_inst) >> 12)
279
280/*
281 * Get the 8-bit "vAA" 8-bit register index from the instruction word.
282 * (_inst is u2)
283 */
284#define INST_AA(_inst)      ((_inst) >> 8)
285
286/*
287 * The current PC must be available to Throwable constructors, e.g.
288 * those created by the various exception throw routines, so that the
289 * exception stack trace can be generated correctly.  If we don't do this,
290 * the offset within the current method won't be shown correctly.  See the
291 * notes in Exception.c.
292 *
293 * This is also used to determine the address for precise GC.
294 *
295 * Assumes existence of "u4* fp" and "const u2* pc".
296 */
297#define EXPORT_PC()         (SAVEAREA_FROM_FP(fp)->xtra.currentPc = pc)
298
299/*
300 * Check to see if "obj" is NULL.  If so, throw an exception.  Assumes the
301 * pc has already been exported to the stack.
302 *
303 * Perform additional checks on debug builds.
304 *
305 * Use this to check for NULL when the instruction handler calls into
306 * something that could throw an exception (so we have already called
307 * EXPORT_PC at the top).
308 */
309static inline bool checkForNull(Object* obj)
310{
311    if (obj == NULL) {
312        dvmThrowNullPointerException(NULL);
313        return false;
314    }
315#ifdef WITH_EXTRA_OBJECT_VALIDATION
316    if (!dvmIsHeapAddressObject(obj)) {
317        LOGE("Invalid object %p", obj);
318        dvmAbort();
319    }
320#endif
321#ifndef NDEBUG
322    if (obj->clazz == NULL || ((u4) obj->clazz) <= 65536) {
323        /* probable heap corruption */
324        LOGE("Invalid object class %p (in %p)", obj->clazz, obj);
325        dvmAbort();
326    }
327#endif
328    return true;
329}
330
331/*
332 * Check to see if "obj" is NULL.  If so, export the PC into the stack
333 * frame and throw an exception.
334 *
335 * Perform additional checks on debug builds.
336 *
337 * Use this to check for NULL when the instruction handler doesn't do
338 * anything else that can throw an exception.
339 */
340static inline bool checkForNullExportPC(Object* obj, u4* fp, const u2* pc)
341{
342    if (obj == NULL) {
343        EXPORT_PC();
344        dvmThrowNullPointerException(NULL);
345        return false;
346    }
347#ifdef WITH_EXTRA_OBJECT_VALIDATION
348    if (!dvmIsHeapAddress(obj)) {
349        LOGE("Invalid object %p", obj);
350        dvmAbort();
351    }
352#endif
353#ifndef NDEBUG
354    if (obj->clazz == NULL || ((u4) obj->clazz) <= 65536) {
355        /* probable heap corruption */
356        LOGE("Invalid object class %p (in %p)", obj->clazz, obj);
357        dvmAbort();
358    }
359#endif
360    return true;
361}
362