Vendor import of lldb trunk r256945:

https://llvm.org/svn/llvm-project/lldb/trunk@256945

1 files changed, 76 insertions, 0 deletions

diff --git a/scripts/Python/modules/readline/readline.cpp b/scripts/Python/modules/readline/readline.cpp
new file mode 100644
index 0000000..d66ccf4
--- /dev/null
+++ b/scripts/Python/modules/readline/readline.cpp
@@ -0,0 +1,76 @@
+// NOTE: Since Python may define some pre-processor definitions which affect the
+// standard headers on some systems, you must include Python.h before any
+// standard headers are included.
+#include "Python.h"
+
+#include <stdio.h>
+
+#ifndef LLDB_DISABLE_LIBEDIT
+#include <editline/readline.h>
+#endif
+
+// Simple implementation of the Python readline module using libedit.
+// In the event that libedit is excluded from the build, this turns
+// back into a null implementation that blocks the module from pulling
+// in the GNU readline shared lib, which causes linkage confusion when
+// both readline and libedit's readline compatibility symbols collide.
+//
+// Currently it only installs a PyOS_ReadlineFunctionPointer, without
+// implementing any of the readline module methods. This is meant to
+// work around LLVM pr18841 to avoid seg faults in the stock Python
+// readline.so linked against GNU readline.
+
+static struct PyMethodDef moduleMethods[] =
+{
+    {nullptr, nullptr, 0, nullptr}
+};
+
+#ifndef LLDB_DISABLE_LIBEDIT
+PyDoc_STRVAR(
+    moduleDocumentation,
+    "Simple readline module implementation based on libedit.");
+#else
+PyDoc_STRVAR(
+    moduleDocumentation,
+    "Stub module meant to avoid linking GNU readline.");
+#endif
+
+#ifndef LLDB_DISABLE_LIBEDIT
+static char*
+simple_readline(FILE *stdin, FILE *stdout, char *prompt)
+{
+    rl_instream = stdin;
+    rl_outstream = stdout;
+    char* line = readline(prompt);
+    if (!line)
+    {
+        char* ret = (char*)PyMem_Malloc(1);
+        if (ret != NULL)
+            *ret = '\0';
+        return ret;
+    }
+    if (*line)
+        add_history(line);
+    int n = strlen(line);
+    char* ret = (char*)PyMem_Malloc(n + 2);
+    strncpy(ret, line, n);
+    free(line);
+    ret[n] = '\n';
+    ret[n+1] = '\0';
+    return ret;
+}
+#endif
+
+PyMODINIT_FUNC
+initreadline(void)
+{
+#ifndef LLDB_DISABLE_LIBEDIT
+    PyOS_ReadlineFunctionPointer = simple_readline;
+#endif
+    Py_InitModule4(
+        "readline",
+        moduleMethods,
+        moduleDocumentation,
+        static_cast<PyObject *>(NULL),
+        PYTHON_API_VERSION);
+}