Commit | Line | Data |
---|---|---|
1cfa4ec7 GS |
1 | /* dl_vmesa.xs |
2 | * | |
3 | * Platform: VM/ESA, possibly others which use dllload etc. | |
4 | * Author: Neale Ferguson (neale@mailbox.tabnsw.com.au) | |
5 | * Created: 23rd Septemer, 1998 | |
6 | * | |
7 | * | |
8 | */ | |
9 | ||
10 | /* Porting notes: | |
11 | ||
12 | ||
13 | Definition of VM/ESA dynamic Linking functions | |
14 | ============================================== | |
15 | In order to make this implementation easier to understand here is a | |
16 | quick definition of the VM/ESA Dynamic Linking functions which are | |
17 | used here. | |
18 | ||
19 | dlopen | |
20 | ------ | |
21 | void * | |
22 | dlopen(const char *path) | |
23 | ||
24 | This function takes the name of a dynamic object file and returns | |
25 | a descriptor which can be used by dlsym later. It returns NULL on | |
26 | error. | |
27 | ||
28 | ||
29 | dllsym | |
30 | ------ | |
31 | void * | |
32 | dlsym(void *handle, char *symbol) | |
33 | ||
34 | Takes the handle returned from dlopen and the name of a symbol to | |
35 | get the address of. If the symbol was found a pointer is | |
36 | returned. It returns NULL on error. | |
37 | ||
38 | dlerror | |
39 | ------- | |
40 | char * dlerror() | |
41 | ||
42 | Returns a null-terminated string which describes the last error | |
43 | that occurred with the other dll functions. After each call to | |
44 | dlerror the error message will be reset to a null pointer. The | |
45 | SaveError function is used to save the error as soo as it happens. | |
46 | ||
47 | ||
48 | Return Types | |
49 | ============ | |
50 | In this implementation the two functions, dl_load_file & | |
51 | dl_find_symbol, return void *. This is because the underlying SunOS | |
52 | dynamic linker calls also return void *. This is not necessarily | |
53 | the case for all architectures. For example, some implementation | |
54 | will want to return a char * for dl_load_file. | |
55 | ||
56 | If void * is not appropriate for your architecture, you will have to | |
57 | change the void * to whatever you require. If you are not certain of | |
58 | how Perl handles C data types, I suggest you start by consulting | |
59 | Dean Roerich's Perl 5 API document. Also, have a look in the typemap | |
60 | file (in the ext directory) for a fairly comprehensive list of types | |
61 | that are already supported. If you are completely stuck, I suggest you | |
62 | post a message to perl5-porters, comp.lang.perl.misc or if you are really | |
63 | desperate to me. | |
64 | ||
65 | Remember when you are making any changes that the return value from | |
66 | dl_load_file is used as a parameter in the dl_find_symbol | |
67 | function. Also the return value from find_symbol is used as a parameter | |
68 | to install_xsub. | |
69 | ||
70 | ||
71 | Dealing with Error Messages | |
72 | ============================ | |
73 | In order to make the handling of dynamic linking errors as generic as | |
74 | possible you should store any error messages associated with your | |
75 | implementation with the StoreError function. | |
76 | ||
77 | In the case of VM/ESA the function dlerror returns the error message | |
78 | associated with the last dynamic link error. As the VM/ESA dynamic | |
79 | linker functions return NULL on error every call to a VM/ESA dynamic | |
80 | dynamic link routine is coded like this | |
81 | ||
82 | RETVAL = dlopen(filename) ; | |
83 | if (RETVAL == NULL) | |
cea2e8a9 | 84 | SaveError(aTHX_ "%s",dlerror()) ; |
1cfa4ec7 GS |
85 | |
86 | Note that SaveError() takes a printf format string. Use a "%s" as | |
87 | the first parameter if the error may contain and % characters. | |
88 | ||
89 | */ | |
90 | ||
91 | #include "EXTERN.h" | |
92 | #include "perl.h" | |
93 | #include "XSUB.h" | |
94 | #include <dll.h> | |
95 | ||
96 | ||
97 | #include "dlutils.c" /* SaveError() etc */ | |
98 | ||
99 | ||
100 | static void | |
cea2e8a9 | 101 | dl_private_init(pTHX) |
1cfa4ec7 | 102 | { |
cea2e8a9 | 103 | (void)dl_generic_private_init(aTHX); |
1cfa4ec7 GS |
104 | } |
105 | ||
106 | MODULE = DynaLoader PACKAGE = DynaLoader | |
107 | ||
108 | BOOT: | |
cea2e8a9 | 109 | (void)dl_private_init(aTHX); |
1cfa4ec7 GS |
110 | |
111 | ||
112 | void * | |
113 | dl_load_file(filename, flags=0) | |
114 | char * filename | |
115 | int flags | |
116 | CODE: | |
117 | if (flags & 0x01) | |
cea2e8a9 | 118 | Perl_warn(aTHX_ "Can't make loaded symbols global on this platform while loading %s",filename); |
1cfa4ec7 GS |
119 | DLDEBUG(1,PerlIO_printf(PerlIO_stderr(), "dl_load_file(%s,%x):\n", filename,flags)); |
120 | RETVAL = dlopen(filename) ; | |
121 | DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), " libref=%lx\n", (unsigned long) RETVAL)); | |
122 | ST(0) = sv_newmortal() ; | |
123 | if (RETVAL == NULL) | |
cea2e8a9 | 124 | SaveError(aTHX_ "%s",dlerror()) ; |
1cfa4ec7 GS |
125 | else |
126 | sv_setiv( ST(0), (IV)RETVAL); | |
127 | ||
128 | ||
129 | void * | |
130 | dl_find_symbol(libhandle, symbolname) | |
131 | void * libhandle | |
132 | char * symbolname | |
133 | CODE: | |
134 | DLDEBUG(2, PerlIO_printf(PerlIO_stderr(), | |
135 | "dl_find_symbol(handle=%lx, symbol=%s)\n", | |
136 | (unsigned long) libhandle, symbolname)); | |
137 | RETVAL = dlsym(libhandle, symbolname); | |
138 | DLDEBUG(2, PerlIO_printf(PerlIO_stderr(), | |
139 | " symbolref = %lx\n", (unsigned long) RETVAL)); | |
140 | ST(0) = sv_newmortal() ; | |
141 | if (RETVAL == NULL) | |
cea2e8a9 | 142 | SaveError(aTHX_ "%s",dlerror()) ; |
1cfa4ec7 GS |
143 | else |
144 | sv_setiv( ST(0), (IV)RETVAL); | |
145 | ||
146 | ||
147 | void | |
148 | dl_undef_symbols() | |
149 | PPCODE: | |
150 | ||
151 | ||
152 | ||
153 | # These functions should not need changing on any platform: | |
154 | ||
155 | void | |
156 | dl_install_xsub(perl_name, symref, filename="$Package") | |
157 | char * perl_name | |
158 | void * symref | |
159 | char * filename | |
160 | CODE: | |
161 | DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "dl_install_xsub(name=%s, symref=%lx)\n", | |
162 | perl_name, (unsigned long) symref)); | |
cea2e8a9 GS |
163 | ST(0) = sv_2mortal(newRV((SV*)newXS(perl_name, |
164 | (void(*)(pTHX_ CV *))symref, | |
165 | filename))); | |
1cfa4ec7 GS |
166 | |
167 | ||
168 | char * | |
169 | dl_error() | |
170 | CODE: | |
171 | RETVAL = LastError ; | |
172 | OUTPUT: | |
173 | RETVAL | |
174 | ||
175 | # end. |