mercurial/exewrapper.c
author Gregory Szorc <gregory.szorc@gmail.com>
Mon, 11 Nov 2019 18:55:42 -0800
changeset 43667 94eac340d212
parent 40989 ef7119cd4965
child 47326 825d5a5907b4
permissions -rw-r--r--
packaging: stage files and dynamically generate WiX installer Like we did for Inno, we want to make the WiX installer "dumb" and simply consume source files from a directory tree rather than have to define every single file in installer files. This will greatly decrease the amount of effort required to maintain the WiX installer since we don't have to think that much about keeping files in sync. This commit changes the WiX packager to populate a staging directory as part of packaging. After it does so, it scans that directory and dynamically generates WiX XML defining the content within. The IDs and GUIDs being generated are deterministic. So, upgrades should work as expected in Windows Installer land. (WiX has a "heat" tool that can generate XML by walking the filesystem but it doesn't have this deterministic property, sadly.) As part of this change, GUIDs are now effectively reset. So the next upgrade should be a complete wipe and replace. This could potentially cause issues. But in my local testing, I was able to upgrade an existing 5.1.2 install without issue. Compared to the previous commit, the installed files differ in the following: * A ReleaseNotes.txt file is now included * A hgrc.d/editor.rc file is now generated (mercurial.rc has been updated to reflect this logical change to the content source) * All files are marked as read-only. Previously, only a subset of files were. This should help prevent unwanted tampering. Although we may want to consider use cases like modifying template files... This change also means that Inno and WiX are now using very similar code for managing the install layout. This means that on disk both packages are nearly identical. The differences in install layout are as follows: * Inno has a Copying.txt vs a COPYING.rtf for WiX. (The WiX installer wants to use RTF.) * Inno has a Mercurial.url file that is an internet shortcut to www.mercurial-scm.org. (This could potentially be removed.) * Inno includes msvc[mpr]90.dll files and WiX does not. (WiX installs the MSVC runtime via merge modules.) * Inno includes unins000.{dat,exe} files. (WiX's state is managed by Windows Installer, which places things elsewhere.) Because file lists are dynamically generated now, the test ensuring things remain in sync has been deleted. Good riddance. While this is a huge step towards unifying the Windows installers, there's still some improvements that can be made. But I think it is worth celebrating the milestone of getting both Inno and WiX to essentially share core packaging code and workflows. That should make it much easier to change the installers going forward. This will aid support of Python 3. Differential Revision: https://phab.mercurial-scm.org/D7173

/*
 exewrapper.c - wrapper for calling a python script on Windows

 Copyright 2012 Adrian Buehlmann <adrian@cadifra.com> and others

 This software may be used and distributed according to the terms of the
 GNU General Public License version 2 or any later version.
*/

#include <Python.h>
#include <stdio.h>
#include <tchar.h>
#include <windows.h>

#include "hgpythonlib.h"

#ifdef __GNUC__
int strcat_s(char *d, size_t n, const char *s)
{
	return !strncat(d, s, n);
}
int strcpy_s(char *d, size_t n, const char *s)
{
	return !strncpy(d, s, n);
}

#define _tcscpy_s strcpy_s
#define _tcscat_s strcat_s
#define _countof(array) (sizeof(array) / sizeof(array[0]))
#endif

static TCHAR pyscript[MAX_PATH + 10];
static TCHAR pyhome[MAX_PATH + 10];
static TCHAR pydllfile[MAX_PATH + 10];

int _tmain(int argc, TCHAR *argv[])
{
	TCHAR *p;
	int ret;
	int i;
	int n;
	TCHAR **pyargv;
	WIN32_FIND_DATA fdata;
	HANDLE hfind;
	const char *err;
	HMODULE pydll;
	void(__cdecl * Py_SetPythonHome)(TCHAR * home);
	int(__cdecl * Py_Main)(int argc, TCHAR *argv[]);

#if PY_MAJOR_VERSION >= 3
	Py_LegacyWindowsStdioFlag = 1;
#endif

	if (GetModuleFileName(NULL, pyscript, _countof(pyscript)) == 0) {
		err = "GetModuleFileName failed";
		goto bail;
	}

	p = _tcsrchr(pyscript, '.');
	if (p == NULL) {
		err = "malformed module filename";
		goto bail;
	}
	*p = 0; /* cut trailing ".exe" */
	_tcscpy_s(pyhome, _countof(pyhome), pyscript);

	hfind = FindFirstFile(pyscript, &fdata);
	if (hfind != INVALID_HANDLE_VALUE) {
		/* pyscript exists, close handle */
		FindClose(hfind);
	} else {
		/* file pyscript isn't there, take <pyscript>exe.py */
		_tcscat_s(pyscript, _countof(pyscript), _T("exe.py"));
	}

	pydll = NULL;

	p = _tcsrchr(pyhome, _T('\\'));
	if (p == NULL) {
		err = "can't find backslash in module filename";
		goto bail;
	}
	*p = 0; /* cut at directory */

	/* check for private Python of HackableMercurial */
	_tcscat_s(pyhome, _countof(pyhome), _T("\\hg-python"));

	hfind = FindFirstFile(pyhome, &fdata);
	if (hfind != INVALID_HANDLE_VALUE) {
		/* Path .\hg-python exists. We are probably in HackableMercurial
		scenario, so let's load python dll from this dir. */
		FindClose(hfind);
		_tcscpy_s(pydllfile, _countof(pydllfile), pyhome);
		_tcscat_s(pydllfile, _countof(pydllfile),
		          _T("\\") _T(HGPYTHONLIB) _T(".dll"));
		pydll = LoadLibrary(pydllfile);
		if (pydll == NULL) {
			err = "failed to load private Python DLL " HGPYTHONLIB
			      ".dll";
			goto bail;
		}
		Py_SetPythonHome =
		    (void *)GetProcAddress(pydll, "Py_SetPythonHome");
		if (Py_SetPythonHome == NULL) {
			err = "failed to get Py_SetPythonHome";
			goto bail;
		}
		Py_SetPythonHome(pyhome);
	}

	if (pydll == NULL) {
		pydll = LoadLibrary(_T(HGPYTHONLIB) _T(".dll"));
		if (pydll == NULL) {
			err = "failed to load Python DLL " HGPYTHONLIB ".dll";
			goto bail;
		}
	}

	Py_Main = (void *)GetProcAddress(pydll, "Py_Main");
	if (Py_Main == NULL) {
		err = "failed to get Py_Main";
		goto bail;
	}

	/*
	Only add the pyscript to the args, if it's not already there. It may
	already be there, if the script spawned a child process of itself, in
	the same way as it got called, that is, with the pyscript already in
	place. So we optionally accept the pyscript as the first argument
	(argv[1]), letting our exe taking the role of the python interpreter.
	*/
	if (argc >= 2 && _tcscmp(argv[1], pyscript) == 0) {
		/*
		pyscript is already in the args, so there is no need to copy
		the args and we can directly call the python interpreter with
		the original args.
		*/
		return Py_Main(argc, argv);
	}

	/*
	Start assembling the args for the Python interpreter call. We put the
	name of our exe (argv[0]) in the position where the python.exe
	canonically is, and insert the pyscript next.
	*/
	pyargv = malloc((argc + 5) * sizeof(TCHAR *));
	if (pyargv == NULL) {
		err = "not enough memory";
		goto bail;
	}
	n = 0;
	pyargv[n++] = argv[0];
	pyargv[n++] = pyscript;

	/* copy remaining args from the command line */
	for (i = 1; i < argc; i++)
		pyargv[n++] = argv[i];
	/* argv[argc] is guaranteed to be NULL, so we forward that guarantee */
	pyargv[n] = NULL;

	ret = Py_Main(n, pyargv); /* The Python interpreter call */

	free(pyargv);
	return ret;

bail:
	fprintf(stderr, "abort: %s\n", err);
	return 255;
}