relocatable wrapper.

ros · May 8, 2020 · a11153e · a11153e
1 parent 904f2a1
commit a11153e
Showing 1 changed file with 34 additions and 25 deletions.
diff --git a/cmake/templates/python_win32_wrapper.cpp.in b/cmake/templates/python_win32_wrapper.cpp.in
@@ -43,8 +43,13 @@
 #ifdef _WIN32
 
 #include <iostream>
+#include <fstream>
+#include <string>
+
 #include <windows.h>
 
+static const std::string SHEBANG = "#!";
+
 static std::string dirnameOf(const std::string& fname)
 {
     size_t pos = fname.find_last_of("\\/");
@@ -87,20 +92,42 @@ int main(int argc, char* argv[]) try
         fprintf(stderr, "[DEBUG] Python script name: %s\n", scriptName.c_str());
 #endif
 
-        // use quoted string to ensure the correct path is used
-        return "\"" + scriptName + "\"";
+        return scriptName;
     };
 
-    const auto GetPythonExecutable = []() -> std::string
+    const auto GetPythonExecutable = [](const std::string& exeFullPath) -> std::string
     {
-        std::string pythonExecutable = "@PYTHON_EXECUTABLE@";
+        std::string scriptName;
+        scriptName += dirnameOf(exeFullPath);
+        scriptName += "\\@ARG_SCRIPT_NAME@";
+
+        std::ifstream infile(scriptName);
+
+        std::string firstLine;
+        if (std::getline(infile, firstLine) && firstLine.find(SHEBANG) == 0)
+        {
+            firstLine.erase(0, SHEBANG.size());
+        }
+
+        // Default to Python executable registered in runtime environment
+        std::string pythonExecutable = "python.exe";
+        if (!firstLine.empty() && 
+            (INVALID_FILE_ATTRIBUTES != GetFileAttributes(firstLine.c_str()))) // check file existence
+        {
+            pythonExecutable = firstLine;
+        }
 
 #if defined(DEBUG)
         fprintf(stderr, "[DEBUG] Python executable: %s\n", pythonExecutable.c_str());
 #endif
 
+        return pythonExecutable;
+    };
+
+    const auto GetDoubleQuotedString = [](const std::string &input) -> std::string
+    {
         // use quoted string to ensure the correct path is used
-        return "\"" + pythonExecutable + "\"";
+        return "\"" + input + "\"";
     };
 
     const auto ExecuteCommand = [](std::string command, bool printError = false) -> unsigned long
@@ -169,27 +196,9 @@ int main(int argc, char* argv[]) try
     }
 #endif
 
-    auto pythonExecutable = GetPythonExecutable();
-    try
-    {
-        // check if the Python executable specified at configure time could be found
-        ExecuteCommand(pythonExecutable + " -c \"import sys; sys.exit(0)\"");
-    }
-    catch (...)
-    {
-        if (::GetLastError() == ERROR_FILE_NOT_FOUND)
-        {
-            // Python executable cannot be found, fall back to use Python executable registered in runtime environment
-            pythonExecutable = "python";
-        }
-        else
-        {
-            throw;
-        }
-    }
-
+    const auto pythonExecutable = GetPythonExecutable(GetCurrentModuleName());
     const auto pythonScript = FindPythonScript(GetCurrentModuleName());
-    std::string command = pythonExecutable + " " + pythonScript;
+    std::string command = GetDoubleQuotedString(pythonExecutable) + " " + GetDoubleQuotedString(pythonScript);
     for (auto i = 1; i < argc; ++i)
     {
         command += " ";