Commit | Line | Data |
1cfa4ec7 |
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 |
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 |
104 | } |
105 | |
106 | MODULE = DynaLoader PACKAGE = DynaLoader |
107 | |
108 | BOOT: |
cea2e8a9 |
109 | (void)dl_private_init(aTHX); |
1cfa4ec7 |
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); |
146174a9 |
119 | DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_load_file(%s,%x):\n", filename,flags)); |
1cfa4ec7 |
120 | RETVAL = dlopen(filename) ; |
146174a9 |
121 | DLDEBUG(2,PerlIO_printf(Perl_debug_log, " libref=%lx\n", (unsigned long) RETVAL)); |
1cfa4ec7 |
122 | ST(0) = sv_newmortal() ; |
123 | if (RETVAL == NULL) |
cea2e8a9 |
124 | SaveError(aTHX_ "%s",dlerror()) ; |
1cfa4ec7 |
125 | else |
c529f79d |
126 | sv_setiv( ST(0), PTR2IV(RETVAL) ); |
1cfa4ec7 |
127 | |
128 | |
129 | void * |
130 | dl_find_symbol(libhandle, symbolname) |
131 | void * libhandle |
132 | char * symbolname |
133 | CODE: |
146174a9 |
134 | DLDEBUG(2, PerlIO_printf(Perl_debug_log, |
1cfa4ec7 |
135 | "dl_find_symbol(handle=%lx, symbol=%s)\n", |
136 | (unsigned long) libhandle, symbolname)); |
137 | RETVAL = dlsym(libhandle, symbolname); |
146174a9 |
138 | DLDEBUG(2, PerlIO_printf(Perl_debug_log, |
1cfa4ec7 |
139 | " symbolref = %lx\n", (unsigned long) RETVAL)); |
140 | ST(0) = sv_newmortal() ; |
141 | if (RETVAL == NULL) |
cea2e8a9 |
142 | SaveError(aTHX_ "%s",dlerror()) ; |
1cfa4ec7 |
143 | else |
c529f79d |
144 | sv_setiv( ST(0), PTR2IV(RETVAL) ); |
1cfa4ec7 |
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: |
146174a9 |
161 | DLDEBUG(2,PerlIO_printf(Perl_debug_log, "dl_install_xsub(name=%s, symref=%lx)\n", |
1cfa4ec7 |
162 | perl_name, (unsigned long) symref)); |
cea2e8a9 |
163 | ST(0) = sv_2mortal(newRV((SV*)newXS(perl_name, |
164 | (void(*)(pTHX_ CV *))symref, |
165 | filename))); |
1cfa4ec7 |
166 | |
167 | |
168 | char * |
169 | dl_error() |
170 | CODE: |
171 | RETVAL = LastError ; |
172 | OUTPUT: |
173 | RETVAL |
174 | |
175 | # end. |