1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6 // Implement shared vtbl methods.
7
8 #include "xptcprivate.h"
9
10 // The Linux/PPC ABI (aka PPC/SYSV ABI) passes the first 8 integral
11 // parameters and the first 8 floating point parameters in registers
12 // (r3-r10 and f1-f8), no stack space is allocated for these by the
13 // caller. The rest of the parameters are passed in the callers stack
14 // area. The stack pointer has to retain 16-byte alignment, longlongs
15 // and doubles are aligned on 8-byte boundaries.
16
17 #define GPR_COUNT 8
18 #define FPR_COUNT 8
19
20 // PrepareAndDispatch() is called by SharedStub() and calls the actual method.
21 //
22 // - 'args[]' contains the arguments passed on stack
23 // - 'gprData[]' contains the arguments passed in integer registers
24 // - 'fprData[]' contains the arguments passed in floating point registers
25 //
26 // The parameters are mapped into an array of type 'nsXPTCMiniVariant'
27 // and then the method gets called.
28
29 extern "C" nsresult ATTRIBUTE_USED
PrepareAndDispatch(nsXPTCStubBase * self,uint32_t methodIndex,uint32_t * args,uint32_t * gprData,double * fprData)30 PrepareAndDispatch(nsXPTCStubBase* self,
31 uint32_t methodIndex,
32 uint32_t* args,
33 uint32_t *gprData,
34 double *fprData)
35 {
36 nsXPTCMiniVariant paramBuffer[PARAM_BUFFER_COUNT];
37 const nsXPTMethodInfo* info = nullptr;
38 uint32_t paramCount;
39 uint32_t i;
40
41 NS_ASSERTION(self,"no self");
42
43 self->mEntry->GetMethodInfo(uint16_t(methodIndex), &info);
44 NS_ASSERTION(info,"no method info");
45 if (! info)
46 return NS_ERROR_UNEXPECTED;
47
48 paramCount = info->GetParamCount();
49
50 const uint8_t indexOfJSContext = info->IndexOfJSContext();
51
52 uint32_t* ap = args;
53 uint32_t gpr = 1; // skip one GPR register
54 uint32_t fpr = 0;
55 uint32_t tempu32;
56 uint64_t tempu64;
57
58 for(i = 0; i < paramCount; i++) {
59 const nsXPTParamInfo& param = info->GetParam(i);
60 const nsXPTType& type = param.GetType();
61 nsXPTCMiniVariant* dp = ¶mBuffer[i];
62
63 if (i == indexOfJSContext) {
64 if (gpr < GPR_COUNT)
65 gpr++;
66 else
67 ap++;
68 }
69
70 if (!param.IsOut() && type == nsXPTType::T_DOUBLE) {
71 if (fpr < FPR_COUNT)
72 dp->val.d = fprData[fpr++];
73 else {
74 if ((uint32_t) ap & 4) ap++; // doubles are 8-byte aligned on stack
75 dp->val.d = *(double*) ap;
76 ap += 2;
77 }
78 continue;
79 }
80 else if (!param.IsOut() && type == nsXPTType::T_FLOAT) {
81 if (fpr < FPR_COUNT)
82 dp->val.f = (float) fprData[fpr++]; // in registers floats are passed as doubles
83 else
84 dp->val.f = *(float*) ap++;
85 continue;
86 }
87 else if (!param.IsOut() && (type == nsXPTType::T_I64
88 || type == nsXPTType::T_U64)) {
89 if (gpr & 1) gpr++; // longlongs are aligned in odd/even register pairs, eg. r5/r6
90 if ((gpr + 1) < GPR_COUNT) {
91 tempu64 = *(uint64_t*) &gprData[gpr];
92 gpr += 2;
93 }
94 else {
95 if ((uint32_t) ap & 4) ap++; // longlongs are 8-byte aligned on stack
96 tempu64 = *(uint64_t*) ap;
97 ap += 2;
98 }
99 }
100 else {
101 if (gpr < GPR_COUNT)
102 tempu32 = gprData[gpr++];
103 else
104 tempu32 = *ap++;
105 }
106
107 if(param.IsOut() || !type.IsArithmetic()) {
108 if (type == nsXPTType::T_JSVAL)
109 dp->val.p = *((void**) tempu32);
110 else
111 dp->val.p = (void*) tempu32;
112 continue;
113 }
114
115 switch(type) {
116 case nsXPTType::T_I8: dp->val.i8 = (int8_t) tempu32; break;
117 case nsXPTType::T_I16: dp->val.i16 = (int16_t) tempu32; break;
118 case nsXPTType::T_I32: dp->val.i32 = (int32_t) tempu32; break;
119 case nsXPTType::T_I64: dp->val.i64 = (int64_t) tempu64; break;
120 case nsXPTType::T_U8: dp->val.u8 = (uint8_t) tempu32; break;
121 case nsXPTType::T_U16: dp->val.u16 = (uint16_t) tempu32; break;
122 case nsXPTType::T_U32: dp->val.u32 = (uint32_t) tempu32; break;
123 case nsXPTType::T_U64: dp->val.u64 = (uint64_t) tempu64; break;
124 case nsXPTType::T_BOOL: dp->val.b = (bool) tempu32; break;
125 case nsXPTType::T_CHAR: dp->val.c = (char) tempu32; break;
126 case nsXPTType::T_WCHAR: dp->val.wc = (wchar_t) tempu32; break;
127
128 default:
129 NS_ERROR("bad type");
130 break;
131 }
132 }
133
134 nsresult result = self->mOuter->CallMethod((uint16_t)methodIndex,
135 info,
136 paramBuffer);
137
138 return result;
139 }
140
141 // Load r11 with the constant 'n' and branch to SharedStub().
142 //
143 // XXX Yes, it's ugly that we're relying on gcc's name-mangling here;
144 // however, it's quick, dirty, and'll break when the ABI changes on
145 // us, which is what we want ;-).
146
147
148 // gcc-3 version
149 //
150 // As G++3 ABI contains the length of the functionname in the mangled
151 // name, it is difficult to get a generic assembler mechanism like
152 // in the G++ 2.95 case.
153 // Create names would be like:
154 // _ZN14nsXPTCStubBase5Stub1Ev
155 // _ZN14nsXPTCStubBase6Stub12Ev
156 // _ZN14nsXPTCStubBase7Stub123Ev
157 // _ZN14nsXPTCStubBase8Stub1234Ev
158 // etc.
159 // Use assembler directives to get the names right...
160
161 # define STUB_ENTRY(n) \
162 __asm__ ( \
163 ".align 2 \n\t" \
164 ".if "#n" < 10 \n\t" \
165 ".globl _ZN14nsXPTCStubBase5Stub"#n"Ev \n\t" \
166 ".type _ZN14nsXPTCStubBase5Stub"#n"Ev,@function \n\n" \
167 "_ZN14nsXPTCStubBase5Stub"#n"Ev: \n\t" \
168 \
169 ".elseif "#n" < 100 \n\t" \
170 ".globl _ZN14nsXPTCStubBase6Stub"#n"Ev \n\t" \
171 ".type _ZN14nsXPTCStubBase6Stub"#n"Ev,@function \n\n" \
172 "_ZN14nsXPTCStubBase6Stub"#n"Ev: \n\t" \
173 \
174 ".elseif "#n" < 1000 \n\t" \
175 ".globl _ZN14nsXPTCStubBase7Stub"#n"Ev \n\t" \
176 ".type _ZN14nsXPTCStubBase7Stub"#n"Ev,@function \n\n" \
177 "_ZN14nsXPTCStubBase7Stub"#n"Ev: \n\t" \
178 \
179 ".else \n\t" \
180 ".err \"stub number "#n" >= 1000 not yet supported\"\n" \
181 ".endif \n\t" \
182 \
183 "li 11,"#n" \n\t" \
184 "b SharedStub@local \n" \
185 );
186
187 #define SENTINEL_ENTRY(n) \
188 nsresult nsXPTCStubBase::Sentinel##n() \
189 { \
190 NS_ERROR("nsXPTCStubBase::Sentinel called"); \
191 return NS_ERROR_NOT_IMPLEMENTED; \
192 }
193
194 #include "xptcstubsdef.inc"
195