1 #include "PythonReadline.h"
2
3 #ifdef LLDB_USE_LIBEDIT_READLINE_COMPAT_MODULE
4
5 #include <cstdio>
6
7 #include <editline/readline.h>
8
9 // Simple implementation of the Python readline module using libedit.
10 // In the event that libedit is excluded from the build, this turns
11 // back into a null implementation that blocks the module from pulling
12 // in the GNU readline shared lib, which causes linkage confusion when
13 // both readline and libedit's readline compatibility symbols collide.
14 //
15 // Currently it only installs a PyOS_ReadlineFunctionPointer, without
16 // implementing any of the readline module methods. This is meant to
17 // work around LLVM pr18841 to avoid seg faults in the stock Python
18 // readline.so linked against GNU readline.
19 //
20 // Bug on the cpython side: https://bugs.python.org/issue38634
21
22 PyDoc_STRVAR(moduleDocumentation,
23 "Simple readline module implementation based on libedit.");
24
25 static struct PyModuleDef readline_module = {
26 PyModuleDef_HEAD_INIT, // m_base
27 "lldb_editline", // m_name
28 moduleDocumentation, // m_doc
29 -1, // m_size
30 nullptr, // m_methods
31 nullptr, // m_reload
32 nullptr, // m_traverse
33 nullptr, // m_clear
34 nullptr, // m_free
35 };
36
simple_readline(FILE * stdin,FILE * stdout,const char * prompt)37 static char *simple_readline(FILE *stdin, FILE *stdout, const char *prompt) {
38 rl_instream = stdin;
39 rl_outstream = stdout;
40 char *line = readline(prompt);
41 if (!line) {
42 char *ret = (char *)PyMem_RawMalloc(1);
43 if (ret != nullptr)
44 *ret = '\0';
45 return ret;
46 }
47 if (*line)
48 add_history(line);
49 int n = strlen(line);
50 char *ret = (char *)PyMem_RawMalloc(n + 2);
51 if (ret) {
52 memcpy(ret, line, n);
53 free(line);
54 ret[n] = '\n';
55 ret[n + 1] = '\0';
56 }
57 return ret;
58 }
59
initlldb_readline(void)60 PyMODINIT_FUNC initlldb_readline(void) {
61 PyOS_ReadlineFunctionPointer = simple_readline;
62
63 return PyModule_Create(&readline_module);
64 }
65 #endif
66