cpython/PC/getpathp.c at 930badd414dd2376b1875e1775cb40855a87e180 · python/cpython · GitHub

Repository navigation

History

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

635

636

637

638

639

640

641

642

643

644

645

646

647

648

649

650

651

652

653

654

655

656

657

658

659

660

661

662

663

664

665

666

667

668

669

670

671

672

673

674

675

676

677

678

679

680

681

682

683

684

685

686

687

688

689

690

691

692

693

694

695

696

697

698

699

700

701

702

703

704

705

706

707

708

709

710

711

712

713

714

715

716

717

718

719

720

721

722

723

724

725

726

727

728

729

730

731

732

733

734

735

736

737

738

739

740

741

742

743

744

745

746

747

748

749

750

751

752

753

754

755

756

757

758

759

760

761

762

763

764

765

766

767

768

769

770

771

772

773

774

775

776

777

778

779

780

781

782

783

784

785

786

787

788

789

790

791

792

793

794

795

796

797

798

799

800

801

802

803

804

805

806

807

808

809

810

811

812

813

814

815

816

817

818

819

820

821

822

823

824

825

826

827

828

829

830

831

832

833

834

835

836

837

838

839

840

841

842

843

844

845

846

847

848

849

850

851

852

853

854

855

856

857

858

859

860

861

862

863

864

865

866

867

868

869

870

871

872

873

874

875

876

877

878

879

880

881

882

883

884

885

886

887

888

889

890

891

892

893

894

895

896

897

898

899

900

901

902

903

904

905

906

907

908

909

910

911

912

913

914

915

916

917

918

919

920

921

922

923

924

925

926

927

928

929

930

931

932

933

934

935

936

937

938

939

940

941

942

943

944

945

946

947

948

949

950

951

952

953

954

955

956

957

958

959

960

961

962

963

964

965

966

967

968

969

970

971

972

973

974

975

976

977

978

979

980

981

982

983

984

985

986

987

988

989

990

991

992

993

994

995

996

997

998

999

1000

/* Return the initial module search path. */

/* Used by DOS, Windows 3.1, Windows 95/98, Windows NT. */

/* ----------------------------------------------------------------

PATH RULES FOR WINDOWS:

This describes how sys.path is formed on Windows. It describes the

functionality, not the implementation (ie, the order in which these

are actually fetched is different). The presence of a python._pth or

pythonXY._pth file alongside the program overrides these rules - see

below.

* Python always adds an empty entry at the start, which corresponds

to the current directory.

* If the PYTHONPATH env. var. exists, its entries are added next.

* We look in the registry for "application paths" - that is, sub-keys

under the main PythonPath registry key. These are added next (the

order of sub-key processing is undefined).

HKEY_CURRENT_USER is searched and added first.

HKEY_LOCAL_MACHINE is searched and added next.

(Note that all known installers only use HKLM, so HKCU is typically

empty)

* We attempt to locate the "Python Home" - if the PYTHONHOME env var

is set, we believe it. Otherwise, we use the path of our host .EXE's

to try and locate one of our "landmarks" and deduce our home.

- If we DO have a Python Home: The relevant sub-directories (Lib,

DLLs, etc) are based on the Python Home

- If we DO NOT have a Python Home, the core Python Path is

loaded from the registry. This is the main PythonPath key,

and both HKLM and HKCU are combined to form the path)

* Iff - we can not locate the Python Home, have not had a PYTHONPATH

specified, and can't locate any Registry entries (ie, we have _nothing_

we can assume is a good path), a default path with relative entries is

used (eg. .\Lib;.\DLLs, etc)

If a '._pth' file exists adjacent to the executable with the same base name

(e.g. python._pth adjacent to python.exe) or adjacent to the shared library

(e.g. python36._pth adjacent to python36.dll), it is used in preference to

the above process. The shared library file takes precedence over the

executable. The path file must contain a list of paths to add to sys.path,

one per line. Each path is relative to the directory containing the file.

Blank lines and comments beginning with '#' are permitted.

In the presence of this ._pth file, no other paths are added to the search

path, the registry finder is not enabled, site.py is not imported and

isolated mode is enabled. The site package can be enabled by including a

line reading "import site"; no other imports are recognized. Any invalid

entry (other than directories that do not exist) will result in immediate

termination of the program.

The end result of all this is:

* When running python.exe, or any other .exe in the main Python directory

(either an installed version, or directly from the PCbuild directory),

the core path is deduced, and the core paths in the registry are

ignored. Other "application paths" in the registry are always read.

* When Python is hosted in another exe (different directory, embedded via

COM, etc), the Python Home will not be deduced, so the core path from

the registry is used. Other "application paths" in the registry are

always read.

* If Python can't find its home and there is no registry (eg, frozen

exe, some very strange installation setup) you get a path with

some default, but relative, paths.

* An embedding application can use Py_SetPath() to override all of

these automatic path computations.

* An install of Python can fully specify the contents of sys.path using

either a 'EXENAME._pth' or 'DLLNAME._pth' file, optionally including

"import site" to enable the site module.

---------------------------------------------------------------- */

#include "Python.h"

#include "internal/pystate.h"

#include "osdefs.h"

#include <wchar.h>

#ifndef MS_WINDOWS

#error getpathp.c should only be built on Windows

#endif

#include <windows.h>

#include <shlwapi.h>

#ifdef HAVE_SYS_TYPES_H

#include <sys/types.h>

#endif /* HAVE_SYS_TYPES_H */

#ifdef HAVE_SYS_STAT_H

#include <sys/stat.h>

#endif /* HAVE_SYS_STAT_H */

#include <string.h>

/* Search in some common locations for the associated Python libraries.

* Py_GetPath() tries to return a sensible Python module search path.

* The approach is an adaptation for Windows of the strategy used in

* ../Modules/getpath.c; it uses the Windows Registry as one of its

* information sources.

* Py_SetPath() can be used to override this mechanism. Call Py_SetPath

* with a semicolon separated path prior to calling Py_Initialize.

#ifndef LANDMARK

#define LANDMARK L"lib\\os.py"

#endif

typedef struct {

const wchar_t *path_env; /* PATH environment variable */

const wchar_t *home; /* PYTHONHOME environment variable */

/* Registry key "Software\Python\PythonCore\PythonPath" */

wchar_t *machine_path; /* from HKEY_LOCAL_MACHINE */

wchar_t *user_path; /* from HKEY_CURRENT_USER */

wchar_t argv0_path[MAXPATHLEN+1];

wchar_t zip_path[MAXPATHLEN+1];

} PyCalculatePath;

/* determine if "ch" is a separator character */

static int

is_sep(wchar_t ch)

{

#ifdef ALTSEP

return ch == SEP || ch == ALTSEP;

#else

return ch == SEP;

#endif

}

/* assumes 'dir' null terminated in bounds. Never writes

beyond existing terminator. */

static void

reduce(wchar_t *dir)

{

size_t i = wcsnlen_s(dir, MAXPATHLEN+1);

if (i >= MAXPATHLEN+1) {

Py_FatalError("buffer overflow in getpathp.c's reduce()");

}

while (i > 0 && !is_sep(dir[i]))

--i;

dir[i] = '\0';

}

static int

change_ext(wchar_t *dest, const wchar_t *src, const wchar_t *ext)

{

size_t src_len = wcsnlen_s(src, MAXPATHLEN+1);

size_t i = src_len;

if (i >= MAXPATHLEN+1) {

Py_FatalError("buffer overflow in getpathp.c's reduce()");

}

while (i > 0 && src[i] != '.' && !is_sep(src[i]))

--i;

if (i == 0) {

dest[0] = '\0';

return -1;

}

if (is_sep(src[i])) {

i = src_len;

}

if (wcsncpy_s(dest, MAXPATHLEN+1, src, i) ||

wcscat_s(dest, MAXPATHLEN+1, ext))

{

dest[0] = '\0';

return -1;

}

return 0;

}

static int

exists(const wchar_t *filename)

{

return GetFileAttributesW(filename) != 0xFFFFFFFF;

}

/* Is module -- check for .pyc too.

Assumes 'filename' MAXPATHLEN+1 bytes long -

may extend 'filename' by one character. */

static int

ismodule(wchar_t *filename, int update_filename)

{

size_t n;

if (exists(filename)) {

return 1;

}

/* Check for the compiled version of prefix. */

n = wcsnlen_s(filename, MAXPATHLEN+1);

if (n < MAXPATHLEN) {

int exist = 0;

filename[n] = L'c';

filename[n + 1] = L'\0';

exist = exists(filename);

if (!update_filename) {

filename[n] = L'\0';

}

return exist;

}

return 0;

}

/* Add a path component, by appending stuff to buffer.

buffer must have at least MAXPATHLEN + 1 bytes allocated, and contain a

NUL-terminated string with no more than MAXPATHLEN characters (not counting

the trailing NUL). It's a fatal error if it contains a string longer than

that (callers must be careful!). If these requirements are met, it's

guaranteed that buffer will still be a NUL-terminated string with no more

than MAXPATHLEN characters at exit. If stuff is too long, only as much of

stuff as fits will be appended.

static int _PathCchCombineEx_Initialized = 0;

typedef HRESULT(__stdcall *PPathCchCombineEx) (PWSTR pszPathOut, size_t cchPathOut,

PCWSTR pszPathIn, PCWSTR pszMore,

unsigned long dwFlags);

static PPathCchCombineEx _PathCchCombineEx;

static void

join(wchar_t *buffer, const wchar_t *stuff)

{

if (_PathCchCombineEx_Initialized == 0) {

HMODULE pathapi = LoadLibraryExW(L"api-ms-win-core-path-l1-1-0.dll", NULL,

LOAD_LIBRARY_SEARCH_SYSTEM32);

if (pathapi) {

_PathCchCombineEx = (PPathCchCombineEx)GetProcAddress(pathapi, "PathCchCombineEx");

}

else {

_PathCchCombineEx = NULL;

}

_PathCchCombineEx_Initialized = 1;

}

if (_PathCchCombineEx) {

if (FAILED(_PathCchCombineEx(buffer, MAXPATHLEN+1, buffer, stuff, 0))) {

Py_FatalError("buffer overflow in getpathp.c's join()");

}

} else {

if (!PathCombineW(buffer, buffer, stuff)) {

Py_FatalError("buffer overflow in getpathp.c's join()");

}

static int _PathCchCanonicalizeEx_Initialized = 0;

typedef HRESULT(__stdcall *PPathCchCanonicalizeEx) (PWSTR pszPathOut, size_t cchPathOut,

PCWSTR pszPathIn, unsigned long dwFlags);

static PPathCchCanonicalizeEx _PathCchCanonicalizeEx;

static _PyInitError canonicalize(wchar_t *buffer, const wchar_t *path)

{

if (buffer == NULL) {

return _Py_INIT_NO_MEMORY();

}

if (_PathCchCanonicalizeEx_Initialized == 0) {

HMODULE pathapi = LoadLibraryExW(L"api-ms-win-core-path-l1-1-0.dll", NULL,

LOAD_LIBRARY_SEARCH_SYSTEM32);

if (pathapi) {

_PathCchCanonicalizeEx = (PPathCchCanonicalizeEx)GetProcAddress(pathapi, "PathCchCanonicalizeEx");

}

else {

_PathCchCanonicalizeEx = NULL;

}

_PathCchCanonicalizeEx_Initialized = 1;

}

if (_PathCchCanonicalizeEx) {

if (FAILED(_PathCchCanonicalizeEx(buffer, MAXPATHLEN + 1, path, 0))) {

return _Py_INIT_ERR("buffer overflow in getpathp.c's canonicalize()");

}

else {

if (!PathCanonicalizeW(buffer, path)) {

return _Py_INIT_ERR("buffer overflow in getpathp.c's canonicalize()");

}

return _Py_INIT_OK();

}

/* gotlandmark only called by search_for_prefix, which ensures

'prefix' is null terminated in bounds. join() ensures

'landmark' can not overflow prefix if too long. */

static int

gotlandmark(wchar_t *prefix, const wchar_t *landmark)

{

int ok;

Py_ssize_t n = wcsnlen_s(prefix, MAXPATHLEN);

join(prefix, landmark);

ok = ismodule(prefix, FALSE);

prefix[n] = '\0';

return ok;

}

/* assumes argv0_path is MAXPATHLEN+1 bytes long, already \0 term'd.

assumption provided by only caller, calculate_path_impl() */

static int

search_for_prefix(wchar_t *prefix, const wchar_t *argv0_path, const wchar_t *landmark)

{

/* Search from argv0_path, until landmark is found */

wcscpy_s(prefix, MAXPATHLEN + 1, argv0_path);

do {

if (gotlandmark(prefix, landmark)) {

return 1;

}

reduce(prefix);

} while (prefix[0]);

return 0;

}

#ifdef Py_ENABLE_SHARED

/* a string loaded from the DLL at startup.*/

extern const char *PyWin_DLLVersionString;

/* Load a PYTHONPATH value from the registry.

Load from either HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER.

Works in both Unicode and 8bit environments. Only uses the

Ex family of functions so it also works with Windows CE.

Returns NULL, or a pointer that should be freed.

XXX - this code is pretty strange, as it used to also

work on Win16, where the buffer sizes werent available

in advance. It could be simplied now Win16/Win32s is dead!

static wchar_t *

getpythonregpath(HKEY keyBase, int skipcore)

{

HKEY newKey = 0;

DWORD dataSize = 0;

DWORD numKeys = 0;

LONG rc;

wchar_t *retval = NULL;

WCHAR *dataBuf = NULL;

static const WCHAR keyPrefix[] = L"Software\\Python\\PythonCore\\";

static const WCHAR keySuffix[] = L"\\PythonPath";

size_t versionLen, keyBufLen;

DWORD index;

WCHAR *keyBuf = NULL;

WCHAR *keyBufPtr;

WCHAR **ppPaths = NULL;

/* Tried to use sysget("winver") but here is too early :-( */

versionLen = strlen(PyWin_DLLVersionString);

/* Space for all the chars, plus one \0 */

keyBufLen = sizeof(keyPrefix) +

sizeof(WCHAR)*(versionLen-1) +

sizeof(keySuffix);

keyBuf = keyBufPtr = PyMem_RawMalloc(keyBufLen);

if (keyBuf==NULL) {

goto done;

}

memcpy_s(keyBufPtr, keyBufLen, keyPrefix, sizeof(keyPrefix)-sizeof(WCHAR));

keyBufPtr += Py_ARRAY_LENGTH(keyPrefix) - 1;

mbstowcs(keyBufPtr, PyWin_DLLVersionString, versionLen);

keyBufPtr += versionLen;

/* NULL comes with this one! */

memcpy(keyBufPtr, keySuffix, sizeof(keySuffix));

/* Open the root Python key */

rc=RegOpenKeyExW(keyBase,

keyBuf, /* subkey */

0, /* reserved */

KEY_READ,

&newKey);

if (rc!=ERROR_SUCCESS) {

goto done;

}

/* Find out how big our core buffer is, and how many subkeys we have */

rc = RegQueryInfoKeyW(newKey, NULL, NULL, NULL, &numKeys, NULL, NULL,

NULL, NULL, &dataSize, NULL, NULL);

if (rc!=ERROR_SUCCESS) {

goto done;

}

if (skipcore) {

dataSize = 0; /* Only count core ones if we want them! */

}

/* Allocate a temp array of char buffers, so we only need to loop

reading the registry once

ppPaths = PyMem_RawMalloc( sizeof(WCHAR *) * numKeys );

if (ppPaths==NULL) {

goto done;

}

memset(ppPaths, 0, sizeof(WCHAR *) * numKeys);

/* Loop over all subkeys, allocating a temp sub-buffer. */

for(index=0;index<numKeys;index++) {

WCHAR keyBuf[MAX_PATH+1];

HKEY subKey = 0;

DWORD reqdSize = MAX_PATH+1;

/* Get the sub-key name */

DWORD rc = RegEnumKeyExW(newKey, index, keyBuf, &reqdSize,

NULL, NULL, NULL, NULL );

if (rc!=ERROR_SUCCESS) {

goto done;

}

/* Open the sub-key */

rc=RegOpenKeyExW(newKey,

keyBuf, /* subkey */

0, /* reserved */

KEY_READ,

&subKey);

if (rc!=ERROR_SUCCESS) {

goto done;

}

/* Find the value of the buffer size, malloc, then read it */

RegQueryValueExW(subKey, NULL, 0, NULL, NULL, &reqdSize);

if (reqdSize) {

ppPaths[index] = PyMem_RawMalloc(reqdSize);

if (ppPaths[index]) {

RegQueryValueExW(subKey, NULL, 0, NULL,

(LPBYTE)ppPaths[index],

&reqdSize);

dataSize += reqdSize + 1; /* 1 for the ";" */

}

RegCloseKey(subKey);

}

/* return null if no path to return */

if (dataSize == 0) {

goto done;

}

/* original datasize from RegQueryInfo doesn't include the \0 */

dataBuf = PyMem_RawMalloc((dataSize+1) * sizeof(WCHAR));

if (dataBuf) {

WCHAR *szCur = dataBuf;

/* Copy our collected strings */

for (index=0;index<numKeys;index++) {

if (index > 0) {

*(szCur++) = L';';

dataSize--;

}

if (ppPaths[index]) {

Py_ssize_t len = wcslen(ppPaths[index]);

wcsncpy(szCur, ppPaths[index], len);

szCur += len;

assert(dataSize > (DWORD)len);

dataSize -= (DWORD)len;

}

if (skipcore) {

*szCur = '\0';

}

else {

/* If we have no values, we don't need a ';' */

if (numKeys) {

*(szCur++) = L';';

dataSize--;

}

/* Now append the core path entries -

this will include the NULL

rc = RegQueryValueExW(newKey, NULL, 0, NULL,

(LPBYTE)szCur, &dataSize);

if (rc != ERROR_SUCCESS) {

PyMem_RawFree(dataBuf);

goto done;

}

/* And set the result - caller must free */

retval = dataBuf;

}

done:

/* Loop freeing my temp buffers */

if (ppPaths) {

for(index=0; index<numKeys; index++)

PyMem_RawFree(ppPaths[index]);

PyMem_RawFree(ppPaths);

}

if (newKey) {

RegCloseKey(newKey);

}

PyMem_RawFree(keyBuf);

return retval;

}

#endif /* Py_ENABLE_SHARED */

static _PyInitError

get_dll_path(PyCalculatePath *calculate, _PyPathConfig *config)

{

wchar_t dll_path[MAXPATHLEN+1];

memset(dll_path, 0, sizeof(dll_path));

#ifdef Py_ENABLE_SHARED

extern HANDLE PyWin_DLLhModule;

if (PyWin_DLLhModule) {

if (!GetModuleFileNameW(PyWin_DLLhModule, dll_path, MAXPATHLEN)) {

dll_path[0] = 0;

}

#else

dll_path[0] = 0;

#endif

config->dll_path = _PyMem_RawWcsdup(dll_path);

if (config->dll_path == NULL) {

return _Py_INIT_NO_MEMORY();

}

return _Py_INIT_OK();

}

static _PyInitError

get_program_full_path(const _PyCoreConfig *core_config,

PyCalculatePath *calculate, _PyPathConfig *config)

{

const wchar_t *pyvenv_launcher;

wchar_t program_full_path[MAXPATHLEN+1];

memset(program_full_path, 0, sizeof(program_full_path));

if (!GetModuleFileNameW(NULL, program_full_path, MAXPATHLEN)) {

/* GetModuleFileName should never fail when passed NULL */

return _Py_INIT_ERR("Cannot determine program path");

}

/* The launcher may need to force the executable path to a

* different environment, so override it here. */

pyvenv_launcher = _wgetenv(L"__PYVENV_LAUNCHER__");

if (pyvenv_launcher && pyvenv_launcher[0]) {

_wputenv_s(L"__PYVENV_BASE_EXECUTABLE__", program_full_path);

wcscpy_s(program_full_path, MAXPATHLEN+1, pyvenv_launcher);

/* bpo-35873: Clear the environment variable to avoid it being

* inherited by child processes. */

_wputenv_s(L"__PYVENV_LAUNCHER__", L"");

}

config->program_full_path = PyMem_RawMalloc(

sizeof(wchar_t) * (MAXPATHLEN + 1));

return canonicalize(config->program_full_path,

program_full_path);

}

static int

read_pth_file(_PyPathConfig *config, wchar_t *prefix, const wchar_t *path,

int *isolated, int *nosite)

{

FILE *sp_file = _Py_wfopen(path, L"r");

if (sp_file == NULL) {

return 0;

}

wcscpy_s(prefix, MAXPATHLEN+1, path);

reduce(prefix);

*isolated = 1;

*nosite = 1;

size_t bufsiz = MAXPATHLEN;

size_t prefixlen = wcslen(prefix);

wchar_t *buf = (wchar_t*)PyMem_RawMalloc(bufsiz * sizeof(wchar_t));

if (buf == NULL) {

goto error;

}

buf[0] = '\0';

while (!feof(sp_file)) {

char line[MAXPATHLEN + 1];

char *p = fgets(line, MAXPATHLEN + 1, sp_file);

if (!p) {

break;

}

if (*p == '\0' || *p == '\r' || *p == '\n' || *p == '#') {

continue;

}

while (*++p) {

if (*p == '\r' || *p == '\n') {

*p = '\0';

break;

}

if (strcmp(line, "import site") == 0) {

*nosite = 0;

continue;

} else if (strncmp(line, "import ", 7) == 0) {

Py_FatalError("only 'import site' is supported in ._pth file");

}

DWORD wn = MultiByteToWideChar(CP_UTF8, 0, line, -1, NULL, 0);

wchar_t *wline = (wchar_t*)PyMem_RawMalloc((wn + 1) * sizeof(wchar_t));

if (wline == NULL) {

goto error;

}

wn = MultiByteToWideChar(CP_UTF8, 0, line, -1, wline, wn + 1);

wline[wn] = '\0';

size_t usedsiz = wcslen(buf);

while (usedsiz + wn + prefixlen + 4 > bufsiz) {

bufsiz += MAXPATHLEN;

wchar_t *tmp = (wchar_t*)PyMem_RawRealloc(buf, (bufsiz + 1) *

sizeof(wchar_t));

if (tmp == NULL) {

PyMem_RawFree(wline);

goto error;

}

buf = tmp;

}

if (usedsiz) {

wcscat_s(buf, bufsiz, L";");

usedsiz += 1;

}

errno_t result;

_Py_BEGIN_SUPPRESS_IPH

result = wcscat_s(buf, bufsiz, prefix);

_Py_END_SUPPRESS_IPH

if (result == EINVAL) {

Py_FatalError("invalid argument during ._pth processing");

} else if (result == ERANGE) {

Py_FatalError("buffer overflow during ._pth processing");

}

wchar_t *b = &buf[usedsiz];

join(b, wline);

PyMem_RawFree(wline);

}

fclose(sp_file);

config->module_search_path = buf;

return 1;

error:

PyMem_RawFree(buf);

fclose(sp_file);

return 0;

}

static void

calculate_init(PyCalculatePath *calculate,

const _PyCoreConfig *core_config)

{

calculate->home = core_config->home;

calculate->path_env = _wgetenv(L"PATH");

}

static int

get_pth_filename(wchar_t *spbuffer, _PyPathConfig *config)

{

if (config->dll_path[0]) {

if (!change_ext(spbuffer, config->dll_path, L"._pth") &&

exists(spbuffer))

{

return 1;

}

if (config->program_full_path[0]) {

if (!change_ext(spbuffer, config->program_full_path, L"._pth") &&

exists(spbuffer))

{

return 1;

}

return 0;

}

static int

calculate_pth_file(_PyPathConfig *config, wchar_t *prefix)

{

wchar_t spbuffer[MAXPATHLEN+1];

if (!get_pth_filename(spbuffer, config)) {

return 0;

}

/* FIXME, bpo-32030: Global configuration variables should not be modified

here, _PyPathConfig_Init() is called early in Python initialization:

see pymain_cmdline(). */

return read_pth_file(config, prefix, spbuffer,

&Py_IsolatedFlag, &Py_NoSiteFlag);

}

/* Search for an environment configuration file, first in the

executable's directory and then in the parent directory.

If found, open it for use when searching for prefixes.

static void

calculate_pyvenv_file(PyCalculatePath *calculate)

{

wchar_t envbuffer[MAXPATHLEN+1];

const wchar_t *env_cfg = L"pyvenv.cfg";

wcscpy_s(envbuffer, MAXPATHLEN+1, calculate->argv0_path);

join(envbuffer, env_cfg);

FILE *env_file = _Py_wfopen(envbuffer, L"r");

if (env_file == NULL) {

errno = 0;

reduce(envbuffer);

join(envbuffer, env_cfg);

env_file = _Py_wfopen(envbuffer, L"r");

if (env_file == NULL) {

errno = 0;

}

if (env_file == NULL) {

return;

}

/* Look for a 'home' variable and set argv0_path to it, if found */

wchar_t tmpbuffer[MAXPATHLEN+1];

if (_Py_FindEnvConfigValue(env_file, L"home", tmpbuffer, MAXPATHLEN)) {

wcscpy_s(calculate->argv0_path, MAXPATHLEN+1, tmpbuffer);

}

fclose(env_file);

}

#define INIT_ERR_BUFFER_OVERFLOW() _Py_INIT_ERR("buffer overflow")

static void

calculate_home_prefix(PyCalculatePath *calculate, wchar_t *prefix)

{

if (calculate->home == NULL || *calculate->home == '\0') {

if (calculate->zip_path[0] && exists(calculate->zip_path)) {

wcscpy_s(prefix, MAXPATHLEN+1, calculate->zip_path);

reduce(prefix);

calculate->home = prefix;

}

else if (search_for_prefix(prefix, calculate->argv0_path, LANDMARK)) {

calculate->home = prefix;

}

else {

calculate->home = NULL;

}

else {

wcscpy_s(prefix, MAXPATHLEN+1, calculate->home);

}

static _PyInitError

calculate_module_search_path(const _PyCoreConfig *core_config,

PyCalculatePath *calculate, _PyPathConfig *config,

wchar_t *prefix)

{

int skiphome = calculate->home==NULL ? 0 : 1;

#ifdef Py_ENABLE_SHARED

calculate->machine_path = getpythonregpath(HKEY_LOCAL_MACHINE, skiphome);

calculate->user_path = getpythonregpath(HKEY_CURRENT_USER, skiphome);

#endif

/* We only use the default relative PYTHONPATH if we haven't

anything better to use! */

int skipdefault = (core_config->module_search_path_env != NULL ||

calculate->home != NULL ||

calculate->machine_path != NULL ||

calculate->user_path != NULL);

/* We need to construct a path from the following parts.

(1) the PYTHONPATH environment variable, if set;

(2) for Win32, the zip archive file path;

(3) for Win32, the machine_path and user_path, if set;

(4) the PYTHONPATH config macro, with the leading "."

of each component replaced with home, if set;

(5) the directory containing the executable (argv0_path).

The length calculation calculates #4 first.

Extra rules:

- If PYTHONHOME is set (in any way) item (3) is ignored.

- If registry values are used, (4) and (5) are ignored.

/* Calculate size of return buffer */

size_t bufsz = 0;

if (calculate->home != NULL) {

const wchar_t *p;

bufsz = 1;

for (p = PYTHONPATH; *p; p++) {

if (*p == DELIM) {

bufsz++; /* number of DELIM plus one */

}

bufsz *= wcslen(calculate->home);

}

bufsz += wcslen(PYTHONPATH) + 1;

bufsz += wcslen(calculate->argv0_path) + 1;

if (calculate->user_path) {

bufsz += wcslen(calculate->user_path) + 1;

}

if (calculate->machine_path) {

bufsz += wcslen(calculate->machine_path) + 1;

}

bufsz += wcslen(calculate->zip_path) + 1;

if (core_config->module_search_path_env != NULL) {

bufsz += wcslen(core_config->module_search_path_env) + 1;

}

wchar_t *buf, *start_buf;

buf = PyMem_RawMalloc(bufsz * sizeof(wchar_t));

if (buf == NULL) {

/* We can't exit, so print a warning and limp along */

fprintf(stderr, "Can't malloc dynamic PYTHONPATH.\n");

if (core_config->module_search_path_env) {

fprintf(stderr, "Using environment $PYTHONPATH.\n");

config->module_search_path = core_config->module_search_path_env;

}

else {

fprintf(stderr, "Using default static path.\n");

config->module_search_path = PYTHONPATH;

}

return _Py_INIT_OK();

}

start_buf = buf;

if (core_config->module_search_path_env) {

if (wcscpy_s(buf, bufsz - (buf - start_buf),

core_config->module_search_path_env)) {

return INIT_ERR_BUFFER_OVERFLOW();

}

buf = wcschr(buf, L'\0');

*buf++ = DELIM;

}

if (calculate->zip_path[0]) {

if (wcscpy_s(buf, bufsz - (buf - start_buf), calculate->zip_path)) {

return INIT_ERR_BUFFER_OVERFLOW();

}

buf = wcschr(buf, L'\0');

*buf++ = DELIM;

}

if (calculate->user_path) {

if (wcscpy_s(buf, bufsz - (buf - start_buf), calculate->user_path)) {

return INIT_ERR_BUFFER_OVERFLOW();

}

buf = wcschr(buf, L'\0');

*buf++ = DELIM;

}

if (calculate->machine_path) {

if (wcscpy_s(buf, bufsz - (buf - start_buf), calculate->machine_path)) {

return INIT_ERR_BUFFER_OVERFLOW();

}

buf = wcschr(buf, L'\0');

*buf++ = DELIM;

}

if (calculate->home == NULL) {

if (!skipdefault) {

if (wcscpy_s(buf, bufsz - (buf - start_buf), PYTHONPATH)) {

return INIT_ERR_BUFFER_OVERFLOW();

}

buf = wcschr(buf, L'\0');

*buf++ = DELIM;

}

} else {

const wchar_t *p = PYTHONPATH;

const wchar_t *q;

size_t n;

for (;;) {

q = wcschr(p, DELIM);

if (q == NULL) {

n = wcslen(p);

}

else {

n = q-p;

}

if (p[0] == '.' && is_sep(p[1])) {

if (wcscpy_s(buf, bufsz - (buf - start_buf), calculate->home)) {

return INIT_ERR_BUFFER_OVERFLOW();

}

buf = wcschr(buf, L'\0');

p++;

n--;

}

wcsncpy(buf, p, n);

buf += n;

*buf++ = DELIM;

if (q == NULL) {

break;

}

p = q+1;

}

if (calculate->argv0_path) {

wcscpy(buf, calculate->argv0_path);

buf = wcschr(buf, L'\0');

*buf++ = DELIM;

}

*(buf - 1) = L'\0';

/* Now to pull one last hack/trick. If sys.prefix is

empty, then try and find it somewhere on the paths

we calculated. We scan backwards, as our general policy

is that Python core directories are at the *end* of

sys.path. We assume that our "lib" directory is

on the path, and that our 'prefix' directory is

the parent of that.

if (prefix[0] == L'\0') {

wchar_t lookBuf[MAXPATHLEN+1];

const wchar_t *look = buf - 1; /* 'buf' is at the end of the buffer */

while (1) {

Py_ssize_t nchars;

const wchar_t *lookEnd = look;

/* 'look' will end up one character before the

start of the path in question - even if this

is one character before the start of the buffer

while (look >= start_buf && *look != DELIM)

look--;

nchars = lookEnd-look;

wcsncpy(lookBuf, look+1, nchars);

lookBuf[nchars] = L'\0';

/* Up one level to the parent */

reduce(lookBuf);

if (search_for_prefix(prefix, lookBuf, LANDMARK)) {

break;

}

/* If we are out of paths to search - give up */

if (look < start_buf) {

break;

}

look--;

}

config->module_search_path = start_buf;

return _Py_INIT_OK();

}

static _PyInitError

calculate_path_impl(const _PyCoreConfig *core_config,

PyCalculatePath *calculate, _PyPathConfig *config)

{

_PyInitError err;

err = get_dll_path(calculate, config);

if (_Py_INIT_FAILED(err)) {

return err;

}

err = get_program_full_path(core_config, calculate, config);

if (_Py_INIT_FAILED(err)) {

return err;

}

/* program_full_path guaranteed \0 terminated in MAXPATH+1 bytes. */

wcscpy_s(calculate->argv0_path, MAXPATHLEN+1, config->program_full_path);

reduce(calculate->argv0_path);

wchar_t prefix[MAXPATHLEN+1];

memset(prefix, 0, sizeof(prefix));

/* Search for a sys.path file */

if (calculate_pth_file(config, prefix)) {

goto done;

}

calculate_pyvenv_file(calculate);

/* Calculate zip archive path from DLL or exe path */

change_ext(calculate->zip_path,

config->dll_path[0] ? config->dll_path : config->program_full_path,

L".zip");

calculate_home_prefix(calculate, prefix);

View remainder of file in raw view

cpython/PC/getpathp.c at 930badd414dd2376b1875e1775cb40855a87e180 · python/cpython · GitHub

Repository navigation

Expand file tree

Breadcrumbs

getpathp.c

Latest commit

History

Breadcrumbs

getpathp.c

File metadata and controls