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comparison: xpcom/reflect/xptcall/src/md/unix/xptcinvoke_arm_openbsd.cpp
xpcom/reflect/xptcall/src/md/unix/xptcinvoke_arm_openbsd.cpp
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
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| -1:000000000000 | 0:f88b34b903e6 |
|---|---|
| 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 /* Platform specific code to invoke XPCOM methods on native objects */ | |
| 7 | |
| 8 #include "xptcprivate.h" | |
| 9 | |
| 10 // Remember that these 'words' are 32bit DWORDS | |
| 11 | |
| 12 static uint32_t | |
| 13 invoke_count_words(uint32_t paramCount, nsXPTCVariant* s) | |
| 14 { | |
| 15 uint32_t result = 0; | |
| 16 for(uint32_t i = 0; i < paramCount; i++, s++) | |
| 17 { | |
| 18 if(s->IsPtrData()) | |
| 19 { | |
| 20 result++; | |
| 21 continue; | |
| 22 } | |
| 23 switch(s->type) | |
| 24 { | |
| 25 case nsXPTType::T_I8 : | |
| 26 case nsXPTType::T_I16 : | |
| 27 case nsXPTType::T_I32 : | |
| 28 result++; | |
| 29 break; | |
| 30 case nsXPTType::T_I64 : | |
| 31 result+=2; | |
| 32 break; | |
| 33 case nsXPTType::T_U8 : | |
| 34 case nsXPTType::T_U16 : | |
| 35 case nsXPTType::T_U32 : | |
| 36 result++; | |
| 37 break; | |
| 38 case nsXPTType::T_U64 : | |
| 39 result+=2; | |
| 40 break; | |
| 41 case nsXPTType::T_FLOAT : | |
| 42 result++; | |
| 43 break; | |
| 44 case nsXPTType::T_DOUBLE : | |
| 45 result+=2; | |
| 46 break; | |
| 47 case nsXPTType::T_BOOL : | |
| 48 case nsXPTType::T_CHAR : | |
| 49 case nsXPTType::T_WCHAR : | |
| 50 result++; | |
| 51 break; | |
| 52 default: | |
| 53 // all the others are plain pointer types | |
| 54 result++; | |
| 55 break; | |
| 56 } | |
| 57 } | |
| 58 return result; | |
| 59 } | |
| 60 | |
| 61 static void | |
| 62 invoke_copy_to_stack(uint32_t* d, uint32_t paramCount, nsXPTCVariant* s) | |
| 63 { | |
| 64 for(uint32_t i = 0; i < paramCount; i++, d++, s++) | |
| 65 { | |
| 66 if(s->IsPtrData()) | |
| 67 { | |
| 68 *((void**)d) = s->ptr; | |
| 69 continue; | |
| 70 } | |
| 71 switch(s->type) | |
| 72 { | |
| 73 case nsXPTType::T_I8 : *((int8_t*) d) = s->val.i8; break; | |
| 74 case nsXPTType::T_I16 : *((int16_t*) d) = s->val.i16; break; | |
| 75 case nsXPTType::T_I32 : *((int32_t*) d) = s->val.i32; break; | |
| 76 case nsXPTType::T_I64 : *((int64_t*) d) = s->val.i64; d++; break; | |
| 77 case nsXPTType::T_U8 : *((uint8_t*) d) = s->val.u8; break; | |
| 78 case nsXPTType::T_U16 : *((uint16_t*)d) = s->val.u16; break; | |
| 79 case nsXPTType::T_U32 : *((uint32_t*)d) = s->val.u32; break; | |
| 80 case nsXPTType::T_U64 : *((uint64_t*)d) = s->val.u64; d++; break; | |
| 81 case nsXPTType::T_FLOAT : *((float*) d) = s->val.f; break; | |
| 82 case nsXPTType::T_DOUBLE : *((double*) d) = s->val.d; d++; break; | |
| 83 case nsXPTType::T_BOOL : *((bool*) d) = s->val.b; break; | |
| 84 case nsXPTType::T_CHAR : *((char*) d) = s->val.c; break; | |
| 85 case nsXPTType::T_WCHAR : *((wchar_t*) d) = s->val.wc; break; | |
| 86 default: | |
| 87 // all the others are plain pointer types | |
| 88 *((void**)d) = s->val.p; | |
| 89 break; | |
| 90 } | |
| 91 } | |
| 92 } | |
| 93 | |
| 94 extern "C" { | |
| 95 struct my_params_struct { | |
| 96 nsISupports* that; | |
| 97 uint32_t Index; | |
| 98 uint32_t Count; | |
| 99 nsXPTCVariant* params; | |
| 100 uint32_t fn_count; | |
| 101 uint32_t fn_copy; | |
| 102 }; | |
| 103 } | |
| 104 | |
| 105 EXPORT_XPCOM_API(nsresult) | |
| 106 NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex, | |
| 107 uint32_t paramCount, nsXPTCVariant* params) | |
| 108 { | |
| 109 uint32_t result; | |
| 110 struct my_params_struct my_params; | |
| 111 my_params.that = that; | |
| 112 my_params.Index = methodIndex; | |
| 113 my_params.Count = paramCount; | |
| 114 my_params.params = params; | |
| 115 my_params.fn_copy = (uint32_t) &invoke_copy_to_stack; | |
| 116 my_params.fn_count = (uint32_t) &invoke_count_words; | |
| 117 | |
| 118 /* This is to call a given method of class that. | |
| 119 * The parameters are in params, the number is in paramCount. | |
| 120 * The routine will issue calls to count the number of words | |
| 121 * required for argument passing and to copy the arguments to | |
| 122 * the stack. | |
| 123 * Since APCS passes the first 3 params in r1-r3, we need to | |
| 124 * load the first three words from the stack and correct the stack | |
| 125 * pointer (sp) in the appropriate way. This means: | |
| 126 * | |
| 127 * 1.) more than 3 arguments: load r1-r3, correct sp and remember No. | |
| 128 * of bytes left on the stack in r4 | |
| 129 * | |
| 130 * 2.) <= 2 args: load r1-r3 (we won't be causing a stack overflow I hope), | |
| 131 * restore sp as if nothing had happened and set the marker r4 to zero. | |
| 132 * | |
| 133 * Afterwards sp will be restored using the value in r4 (which is not a temporary register | |
| 134 * and will be preserved by the function/method called according to APCS [ARM Procedure | |
| 135 * Calling Standard]). | |
| 136 * | |
| 137 * !!! IMPORTANT !!! | |
| 138 * This routine makes assumptions about the vtable layout of the c++ compiler. It's implemented | |
| 139 * for arm-linux GNU g++ >= 2.8.1 (including egcs and gcc-2.95.[1-3])! | |
| 140 * | |
| 141 */ | |
| 142 | |
| 143 #ifdef __GNUC__ | |
| 144 __asm__ __volatile__( | |
| 145 "ldr r1, [%1, #12] \n\t" /* prepare to call invoke_count_words */ | |
| 146 "ldr ip, [%1, #16] \n\t" /* r0=paramCount, r1=params */ | |
| 147 "ldr r0, [%1, #8] \n\t" | |
| 148 "mov lr, pc \n\t" /* call it... */ | |
| 149 "mov pc, ip \n\t" | |
| 150 "mov r4, r0, lsl #2 \n\t" /* This is the amount of bytes needed. */ | |
| 151 "sub sp, sp, r4 \n\t" /* use stack space for the args... */ | |
| 152 "mov r0, sp \n\t" /* prepare a pointer an the stack */ | |
| 153 "ldr r1, [%1, #8] \n\t" /* =paramCount */ | |
| 154 "ldr r2, [%1, #12] \n\t" /* =params */ | |
| 155 "ldr ip, [%1, #20] \n\t" /* =invoke_copy_to_stack */ | |
| 156 "mov lr, pc \n\t" /* copy args to the stack like the */ | |
| 157 "mov pc, ip \n\t" /* compiler would. */ | |
| 158 "ldr r0, [%1] \n\t" /* =that */ | |
| 159 "ldr r1, [r0, #0] \n\t" /* get that->vtable offset */ | |
| 160 "ldr r2, [%1, #4] \n\t" | |
| 161 "mov r2, r2, lsl #2 \n\t" /* a vtable_entry(x)=8 + (4 bytes * x) */ | |
| 162 "ldr ip, [r1, r2] \n\t" /* get method adress from vtable */ | |
| 163 "cmp r4, #12 \n\t" /* more than 3 arguments??? */ | |
| 164 "ldmgtia sp!, {r1, r2, r3}\n\t" /* yes: load arguments for r1-r3 */ | |
| 165 "subgt r4, r4, #12 \n\t" /* and correct the stack pointer */ | |
| 166 "ldmleia sp, {r1, r2, r3}\n\t" /* no: load r1-r3 from stack */ | |
| 167 "addle sp, sp, r4 \n\t" /* and restore stack pointer */ | |
| 168 "movle r4, #0 \n\t" /* a mark for restoring sp */ | |
| 169 "ldr r0, [%1, #0] \n\t" /* get (self) */ | |
| 170 "mov lr, pc \n\t" /* call mathod */ | |
| 171 "mov pc, ip \n\t" | |
| 172 "add sp, sp, r4 \n\t" /* restore stack pointer */ | |
| 173 "mov %0, r0 \n\t" /* the result... */ | |
| 174 : "=r" (result) | |
| 175 : "r" (&my_params), "m" (my_params) | |
| 176 : "r0", "r1", "r2", "r3", "r4", "ip", "lr", "sp" | |
| 177 ); | |
| 178 #else | |
| 179 #error "Unsupported compiler. Use g++ >= 2.8 for OpenBSD/arm." | |
| 180 #endif /* G++ >= 2.8 */ | |
| 181 | |
| 182 return result; | |
| 183 } |
