getpath.py: add support for mingw

- always normalize the PREFIX to an absolute path
- use `/` when MSYSTEM is defined

Include/pylifecycle.h

@@ -21,6 +21,7 @@ PyAPI_FUNC(int) Py_IsInitialized(void);
 PyAPI_FUNC(PyThreadState *) Py_NewInterpreter(void);
 PyAPI_FUNC(void) Py_EndInterpreter(PyThreadState *);
 
+PyAPI_FUNC(wchar_t) Py_GetAltSepW(const wchar_t *);
 PyAPI_FUNC(wchar_t) Py_GetSepW(const wchar_t *);
 PyAPI_FUNC(char) Py_GetSepA(const char *);
 

Modules/getpath.c

@@ -68,6 +68,7 @@ getpath_abspath(PyObject *Py_UNUSED(self), PyObject *args)
     if (path) {
         wchar_t *abs;
         if (_Py_abspath((const wchar_t *)_Py_normpath(path, -1), &abs) == 0 && abs) {
+            abs = _Py_normpath(abs, -1);
             r = PyUnicode_FromWideChar(abs, -1);
             PyMem_RawFree((void *)abs);
         } else {
@@ -884,6 +885,11 @@ _PyConfig_InitPathConfig(PyConfig *config, int compute_path_config)
 #else
         !decode_to_dict(dict, "os_name", "posix") ||
 #endif
+#ifdef __MINGW32__
+        !int_to_dict(dict, "is_mingw", 1) ||
+#else
+        !int_to_dict(dict, "is_mingw", 0) ||
+#endif
 #ifdef WITH_NEXT_FRAMEWORK
         !int_to_dict(dict, "WITH_NEXT_FRAMEWORK", 1) ||
 #else
@@ -910,6 +916,9 @@ _PyConfig_InitPathConfig(PyConfig *config, int compute_path_config)
         !funcs_to_dict(dict, config->pathconfig_warnings) ||
 #ifndef MS_WINDOWS
         PyDict_SetItemString(dict, "winreg", Py_None) < 0 ||
+#endif
+#ifdef __MINGW32__
+        !env_to_dict(dict, "ENV_MSYSTEM", 0) ||
 #endif
         PyDict_SetItemString(dict, "__builtins__", PyEval_GetBuiltins()) < 0
     ) {

Modules/getpath.py

@@ -30,6 +30,7 @@
 
 # ** Values known at compile time **
 # os_name           -- [in] one of 'nt', 'posix', 'darwin'
+# is_mingw          -- [in] True if targeting MinGW
 # PREFIX            -- [in] sysconfig.get_config_var(...)
 # EXEC_PREFIX       -- [in] sysconfig.get_config_var(...)
 # PYTHONPATH        -- [in] sysconfig.get_config_var(...)
@@ -51,6 +52,7 @@
 # ENV_PYTHONHOME          -- [in] getenv(...)
 # ENV_PYTHONEXECUTABLE    -- [in] getenv(...)
 # ENV___PYVENV_LAUNCHER__ -- [in] getenv(...)
+# ENV_MSYSTEM             -- [in] getenv(...)
 
 # ** Values calculated at runtime **
 # config            -- [in/out] dict of the PyConfig structure
@@ -185,8 +187,27 @@
     ZIP_LANDMARK = f'{platlibdir}/python{VERSION_MAJOR}{VERSION_MINOR}.zip'
     DELIM = ':'
     SEP = '/'
+    ALTSEP = None
 
-elif os_name == 'nt':
+elif os_name == 'nt' and is_mingw:
+    BUILDDIR_TXT = 'pybuilddir.txt'
+    BUILD_LANDMARK = 'Modules/Setup.local'
+    DEFAULT_PROGRAM_NAME = f'python{VERSION_MAJOR}'
+    STDLIB_SUBDIR = f'{platlibdir}/python{VERSION_MAJOR}.{VERSION_MINOR}'
+    STDLIB_LANDMARKS = [f'{STDLIB_SUBDIR}/os.py', f'{STDLIB_SUBDIR}/os.pyc']
+    PLATSTDLIB_LANDMARK = f'{platlibdir}/python{VERSION_MAJOR}.{VERSION_MINOR}/lib-dynload'
+    BUILDSTDLIB_LANDMARKS = ['Lib/os.py']
+    VENV_LANDMARK = 'pyvenv.cfg'
+    ZIP_LANDMARK = f'{platlibdir}/python{VERSION_MAJOR}{VERSION_MINOR}.zip'
+    DELIM = ';'
+    if ENV_MSYSTEM:
+        SEP = '/'
+        ALTSEP = '\\'
+    else:
+        SEP = '\\'
+        ALTSEP = '/'
+
+elif os_name == 'nt': # MSVC
     BUILDDIR_TXT = 'pybuilddir.txt'
     BUILD_LANDMARK = f'{VPATH}\\Modules\\Setup.local'
     DEFAULT_PROGRAM_NAME = f'python'
@@ -199,6 +220,7 @@
     WINREG_KEY = f'SOFTWARE\\Python\\PythonCore\\{PYWINVER}\\PythonPath'
     DELIM = ';'
     SEP = '\\'
+    ALTSEP = '/'
 
 
 # ******************************************************************************
@@ -263,10 +285,10 @@ def search_up(prefix, *landmarks, test=isfile):
     if not executable:
         executable = real_executable
 
-if not executable and SEP in program_name:
+if not executable and (SEP in program_name or 
+                       (ALTSEP and ALTSEP in program_name)):
     # Resolve partial path program_name against current directory
     executable = abspath(program_name)
-
 if not executable:
     # All platforms default to real_executable if known at this
     # stage. POSIX does not set this value.
@@ -497,15 +519,15 @@ def search_up(prefix, *landmarks, test=isfile):
     except (FileNotFoundError, PermissionError):
         if isfile(joinpath(real_executable_dir, BUILD_LANDMARK)):
             build_prefix = joinpath(real_executable_dir, VPATH)
-            if os_name == 'nt':
+            if os_name == 'nt' and not is_mingw:
                 # QUIRK: Windows builds need platstdlib_dir to be the executable
                 # dir. Normally the builddir marker handles this, but in this
                 # case we need to correct manually.
                 platstdlib_dir = real_executable_dir
 
     if build_prefix:
-        if os_name == 'nt':
-            # QUIRK: No searching for more landmarks on Windows
+        if os_name == 'nt' and not is_mingw:
+            # QUIRK: No searching for more landmarks on MSVC
             build_stdlib_prefix = build_prefix
         else:
             build_stdlib_prefix = search_up(build_prefix, *BUILDSTDLIB_LANDMARKS)
@@ -597,7 +619,7 @@ def search_up(prefix, *landmarks, test=isfile):
 
     # Detect exec_prefix by searching from executable for the platstdlib_dir
     if PLATSTDLIB_LANDMARK and not exec_prefix:
-        if os_name == 'nt':
+        if os_name == 'nt' and (not is_mingw):
             # QUIRK: Windows always assumed these were the same
             # gh-100320: Our PYDs are assumed to be relative to the Lib directory
             # (that is, prefix) rather than the executable (that is, executable_dir)
@@ -607,7 +629,7 @@ def search_up(prefix, *landmarks, test=isfile):
         if not exec_prefix and EXEC_PREFIX:
             exec_prefix = EXEC_PREFIX
         if not exec_prefix or not isdir(joinpath(exec_prefix, PLATSTDLIB_LANDMARK)):
-            if os_name == 'nt':
+            if os_name == 'nt' and (not is_mingw):
                 # QUIRK: If DLLs is missing on Windows, don't warn, just assume
                 # that they're in exec_prefix
                 if not platstdlib_dir:
@@ -660,7 +682,7 @@ def search_up(prefix, *landmarks, test=isfile):
             pythonpath.append(abspath(p))
 
     # Then add the default zip file
-    if os_name == 'nt':
+    if os_name == 'nt' and (not is_mingw):
         # QUIRK: Windows uses the library directory rather than the prefix
         if library:
             library_dir = dirname(library)
@@ -673,7 +695,7 @@ def search_up(prefix, *landmarks, test=isfile):
     else:
         pythonpath.append(joinpath(prefix, ZIP_LANDMARK))
 
-    if os_name == 'nt' and use_environment and winreg:
+    if (not is_mingw) and os_name == 'nt' and use_environment and winreg:
         # QUIRK: Windows also lists paths in the registry. Paths are stored
         # as the default value of each subkey of
         # {HKCU,HKLM}\Software\Python\PythonCore\{winver}\PythonPath
@@ -714,7 +736,7 @@ def search_up(prefix, *landmarks, test=isfile):
     if not platstdlib_dir and exec_prefix:
         platstdlib_dir = joinpath(exec_prefix, PLATSTDLIB_LANDMARK)
 
-    if os_name == 'nt':
+    if os_name == 'nt' and (not is_mingw):
         # QUIRK: Windows generates paths differently
         if platstdlib_dir:
             pythonpath.append(platstdlib_dir)
@@ -742,8 +764,8 @@ def search_up(prefix, *landmarks, test=isfile):
 
 # QUIRK: Non-Windows replaces prefix/exec_prefix with defaults when running
 # in build directory. This happens after pythonpath calculation.
-if os_name != 'nt' and build_prefix:
-    prefix = config.get('prefix') or PREFIX
+if (os_name != 'nt' or is_mingw) and build_prefix:
+    prefix = config.get('prefix') or abspath(PREFIX)
     exec_prefix = config.get('exec_prefix') or EXEC_PREFIX or prefix
 
 

Python/fileutils.c

@@ -2050,7 +2050,11 @@ _Py_abspath(const wchar_t *path, wchar_t **abspath_p)
     }
 
 #ifdef MS_WINDOWS
-    return _PyOS_getfullpathname(path, abspath_p);
+    if (_PyOS_getfullpathname(path, abspath_p) < 0){
+        return -1;
+    }
+    *abspath_p = _Py_normpath(*abspath_p, -1);
+    return 0;
 #else
     wchar_t cwd[MAXPATHLEN + 1];
     cwd[Py_ARRAY_LENGTH(cwd) - 1] = 0;
@@ -2194,11 +2198,16 @@ _Py_normpath(wchar_t *path, Py_ssize_t size)
     wchar_t *minP2 = path;  // the beginning of the destination range
     wchar_t lastC = L'\0';  // the last ljusted character, p2[-1] in most cases
 
+    const wchar_t sep = Py_GetSepW(NULL);
+#ifdef ALTSEP
+    const wchar_t altsep = Py_GetAltSepW(NULL);
+#endif
+
 #define IS_END(x) (pEnd ? (x) == pEnd : !*(x))
 #ifdef ALTSEP
-#define IS_SEP(x) (*(x) == SEP || *(x) == ALTSEP)
+#define IS_SEP(x) (*(x) == sep || *(x) == altsep)
 #else
-#define IS_SEP(x) (*(x) == SEP)
+#define IS_SEP(x) (*(x) == sep)
 #endif
 #define SEP_OR_END(x) (IS_SEP(x) || IS_END(x))
 
@@ -2209,7 +2218,7 @@ _Py_normpath(wchar_t *path, Py_ssize_t size)
             path++;
         }
         p1 = p2 = minP2 = path;
-        lastC = SEP;
+        lastC = sep;
     }
 #ifdef MS_WINDOWS
     // Skip past drive segment and update minP2
@@ -2223,13 +2232,13 @@ _Py_normpath(wchar_t *path, Py_ssize_t size)
     // and network paths, including the first segment.
     else if (IS_SEP(&p1[0]) && IS_SEP(&p1[1])) {
         int sepCount = 2;
-        *p2++ = SEP;
-        *p2++ = SEP;
+        *p2++ = sep;
+        *p2++ = sep;
         p1 += 2;
         for (; !IS_END(p1) && sepCount; ++p1) {
             if (IS_SEP(p1)) {
                 --sepCount;
-                *p2++ = lastC = SEP;
+                *p2++ = lastC = sep;
             } else {
                 *p2++ = lastC = *p1;
             }
@@ -2246,26 +2255,26 @@ _Py_normpath(wchar_t *path, Py_ssize_t size)
         *p2++ = *p1++;
         *p2++ = *p1++;
         minP2 = p2 - 1;  // Absolute path has SEP at minP2
-        lastC = SEP;
+        lastC = sep;
     }
 #endif /* MS_WINDOWS */
 
     /* if pEnd is specified, check that. Else, check for null terminator */
     for (; !IS_END(p1); ++p1) {
         wchar_t c = *p1;
 #ifdef ALTSEP
-        if (c == ALTSEP) {
-            c = SEP;
+        if (c == altsep) {
+            c = sep;
         }
 #endif
-        if (lastC == SEP) {
+        if (lastC == sep) {
             if (c == L'.') {
                 int sep_at_1 = SEP_OR_END(&p1[1]);
                 int sep_at_2 = !sep_at_1 && SEP_OR_END(&p1[2]);
                 if (sep_at_2 && p1[1] == L'.') {
                     wchar_t *p3 = p2;
-                    while (p3 != minP2 && *--p3 == SEP) { }
-                    while (p3 != minP2 && *(p3 - 1) != SEP) { --p3; }
+                    while (p3 != minP2 && *--p3 == sep) { }
+                    while (p3 != minP2 && *(p3 - 1) != sep) { --p3; }
                     if (p2 == minP2
                         || (p3[0] == L'.' && p3[1] == L'.' && IS_SEP(&p3[2])))
                     {
@@ -2274,7 +2283,7 @@ _Py_normpath(wchar_t *path, Py_ssize_t size)
                         *p2++ = L'.';
                         *p2++ = L'.';
                         lastC = L'.';
-                    } else if (p3[0] == SEP) {
+                    } else if (p3[0] == sep) {
                         // Absolute path, so absorb segment
                         p2 = p3 + 1;
                     } else {
@@ -2285,7 +2294,7 @@ _Py_normpath(wchar_t *path, Py_ssize_t size)
                 } else {
                     *p2++ = lastC = c;
                 }
-            } else if (c == SEP) {
+            } else if (c == sep) {
             } else {
                 *p2++ = lastC = c;
             }
@@ -2295,7 +2304,7 @@ _Py_normpath(wchar_t *path, Py_ssize_t size)
     }
     *p2 = L'\0';
     if (p2 != minP2) {
-        while (--p2 != minP2 && *p2 == SEP) {
+        while (--p2 != minP2 && *p2 == sep) {
             *p2 = L'\0';
         }
     }

Python/pathconfig.c

@@ -129,7 +129,7 @@ Py_GetSepW(const wchar_t *name)
     return sep;
 }
 
-static wchar_t
+wchar_t
 Py_GetAltSepW(const wchar_t *name)
 {
     char sep = Py_GetSepW(name);