packaging: process Inno Setup files with Jinja2

I want to make the Inno Setup files dynamically generated.
This will enable us to do things like automatically derive the
set of files to be packaged instead of having to manually
keep lists of files in sync across installers.

As the first step towards this, we process the Inno Setup
files with Jinja2.

As part of this conversion, we had to escape syntax in
mercurial.iss that conflicts with Jinja2. I also took the
opportunity to include modpath.iss via Jinja2 instead of
using Inno's preprocessor. This keeps the Python code a
bit simpler.

Differential Revision: https://phab.mercurial-scm.org/D7158

contrib/packaging/hgpackaging/inno.py

@@ -1,93 +1,112 b''
 # inno.py - Inno Setup functionality.
 #
 # Copyright 2019 Gregory Szorc <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 # no-check-code because Python 3 native.
 
 import os
 import pathlib
 import shutil
 import subprocess
 
+import jinja2
+
 from .py2exe import build_py2exe
 from .util import find_vc_runtime_files
 
 EXTRA_PACKAGES = {
     'dulwich',
     'keyring',
     'pygments',
     'win32ctypes',
 }
 
 
 def build(
     source_dir: pathlib.Path,
     build_dir: pathlib.Path,
     python_exe: pathlib.Path,
     iscc_exe: pathlib.Path,
     version=None,
 ):
     """Build the Inno installer.
 
     Build files will be placed in ``build_dir``.
 
     py2exe's setup.py doesn't use setuptools. It doesn't have modern logic
     for finding the Python 2.7 toolchain. So, we require the environment
     to already be configured with an active toolchain.
     """
     if not iscc_exe.exists():
         raise Exception('%s does not exist' % iscc_exe)
 
     vc_x64 = r'\x64' in os.environ.get('LIB', '')
     arch = 'x64' if vc_x64 else 'x86'
     inno_source_dir = source_dir / 'contrib' / 'packaging' / 'inno'
     inno_build_dir = build_dir / ('inno-%s' % arch)
 
     requirements_txt = (
         source_dir / 'contrib' / 'packaging' / 'inno' / 'requirements.txt'
     )
 
     inno_build_dir.mkdir(parents=True, exist_ok=True)
 
     build_py2exe(
         source_dir,
         build_dir,
         python_exe,
         'inno',
         requirements_txt,
         extra_packages=EXTRA_PACKAGES,
     )
 
     # hg.exe depends on VC9 runtime DLLs. Copy those into place.
     for f in find_vc_runtime_files(vc_x64):
         if f.name.endswith('.manifest'):
             basename = 'Microsoft.VC90.CRT.manifest'
         else:
             basename = f.name
 
         dest_path = source_dir / 'dist' / basename
 
         print('copying %s to %s' % (f, dest_path))
         shutil.copyfile(f, dest_path)
 
     print('creating installer')
 
-    # Copy Inno files into place.
-    for p in ('mercurial.iss', 'modpath.iss'):
-        shutil.copyfile(inno_source_dir / p, inno_build_dir / p)
+    # Install Inno files by rendering a template.
+    jinja_env = jinja2.Environment(
+        loader=jinja2.FileSystemLoader(str(inno_source_dir)),
+        # Need to change these to prevent conflict with Inno Setup.
+        comment_start_string='{##',
+        comment_end_string='##}',
+    )
+
+    try:
+        template = jinja_env.get_template('mercurial.iss')
+    except jinja2.TemplateSyntaxError as e:
+        raise Exception(
+            'template syntax error at %s:%d: %s'
+            % (e.name, e.lineno, e.message,)
+        )
+
+    content = template.render()
+
+    with (inno_build_dir / 'mercurial.iss').open('w', encoding='utf-8') as fh:
+        fh.write(content)
 
     args = [str(iscc_exe)]
 
     if vc_x64:
         args.append('/dARCH=x64')
 
     if version:
         args.append('/dVERSION=%s' % version)
 
     args.append('/Odist')
     args.append(str(inno_build_dir / 'mercurial.iss'))
 
     subprocess.run(args, cwd=str(source_dir), check=True)

contrib/packaging/inno/mercurial.iss

@@ -1,124 +1,125 b''
 ; Script generated by the Inno Setup Script Wizard.
 ; SEE THE DOCUMENTATION FOR DETAILS ON CREATING INNO SETUP SCRIPT FILES!
 
 #ifndef VERSION
 #define FileHandle
 #define FileLine
 #define VERSION = "unknown"
 #if FileHandle = FileOpen(SourcePath + "\..\..\mercurial\__version__.py")
   #expr FileLine = FileRead(FileHandle)
   #expr FileLine = FileRead(FileHandle)
   #define VERSION = Copy(FileLine, Pos('"', FileLine)+1, Len(FileLine)-Pos('"', FileLine)-1)
 #endif
 #if FileHandle
   #expr FileClose(FileHandle)
 #endif
 #pragma message "Detected Version: " + VERSION
 #endif
 
 #ifndef ARCH
 #define ARCH = "x86"
 #endif
 
 [Setup]
 AppCopyright=Copyright 2005-2019 Matt Mackall and others
 AppName=Mercurial
 AppVersion={#VERSION}
 #if ARCH == "x64"
 AppVerName=Mercurial {#VERSION} (64-bit)
 OutputBaseFilename=Mercurial-{#VERSION}-x64
 ArchitecturesAllowed=x64
 ArchitecturesInstallIn64BitMode=x64
 #else
 AppVerName=Mercurial {#VERSION}
 OutputBaseFilename=Mercurial-{#VERSION}
 #endif
 InfoAfterFile=contrib/win32/postinstall.txt
 LicenseFile=COPYING
 ShowLanguageDialog=yes
 AppPublisher=Matt Mackall and others
 AppPublisherURL=https://mercurial-scm.org/
 AppSupportURL=https://mercurial-scm.org/
 AppUpdatesURL=https://mercurial-scm.org/
-AppID={{4B95A5F1-EF59-4B08-BED8-C891C46121B3}
+{{ 'AppID={{4B95A5F1-EF59-4B08-BED8-C891C46121B3}' }}
 AppContact=[e-mail]
 DefaultDirName={pf}\Mercurial
 SourceDir=..\..
 VersionInfoDescription=Mercurial distributed SCM (version {#VERSION})
 VersionInfoCopyright=Copyright 2005-2019 Matt Mackall and others
 VersionInfoCompany=Matt Mackall and others
 InternalCompressLevel=max
 SolidCompression=true
 SetupIconFile=contrib\win32\mercurial.ico
 AllowNoIcons=true
 DefaultGroupName=Mercurial
 PrivilegesRequired=none
 ChangesEnvironment=true
 
 [Files]
 Source: contrib\mercurial.el; DestDir: {app}/Contrib
 Source: contrib\vim\*.*; DestDir: {app}/Contrib/Vim
 Source: contrib\zsh_completion; DestDir: {app}/Contrib
 Source: contrib\bash_completion; DestDir: {app}/Contrib
 Source: contrib\tcsh_completion; DestDir: {app}/Contrib
 Source: contrib\tcsh_completion_build.sh; DestDir: {app}/Contrib
 Source: contrib\hgk; DestDir: {app}/Contrib; DestName: hgk.tcl
 Source: contrib\xml.rnc; DestDir: {app}/Contrib
 Source: contrib\mercurial.el; DestDir: {app}/Contrib
 Source: contrib\mq.el; DestDir: {app}/Contrib
 Source: contrib\hgweb.fcgi; DestDir: {app}/Contrib
 Source: contrib\hgweb.wsgi; DestDir: {app}/Contrib
 Source: contrib\win32\ReadMe.html; DestDir: {app}; Flags: isreadme
 Source: contrib\win32\postinstall.txt; DestDir: {app}; DestName: ReleaseNotes.txt
 Source: dist\hg.exe; DestDir: {app}; AfterInstall: Touch('{app}\hg.exe.local')
 Source: dist\lib\*.dll; Destdir: {app}\lib
 Source: dist\lib\*.pyd; Destdir: {app}\lib
 Source: dist\python*.dll; Destdir: {app}; Flags: skipifsourcedoesntexist
 Source: dist\msvc*.dll; DestDir: {app}; Flags: skipifsourcedoesntexist
 Source: dist\Microsoft.VC*.CRT.manifest; DestDir: {app}; Flags: skipifsourcedoesntexist
 Source: dist\lib\library.zip; DestDir: {app}\lib
 Source: doc\*.html; DestDir: {app}\Docs
 Source: doc\style.css; DestDir: {app}\Docs
 Source: mercurial\help\*.txt; DestDir: {app}\help
 Source: mercurial\help\internals\*.txt; DestDir: {app}\help\internals
 Source: mercurial\default.d\*.rc; DestDir: {app}\default.d
 Source: mercurial\locale\*.*; DestDir: {app}\locale; Flags: recursesubdirs createallsubdirs skipifsourcedoesntexist
 Source: mercurial\templates\*.*; DestDir: {app}\Templates; Flags: recursesubdirs createallsubdirs
 Source: CONTRIBUTORS; DestDir: {app}; DestName: Contributors.txt
 Source: COPYING; DestDir: {app}; DestName: Copying.txt
 
 [INI]
 Filename: {app}\Mercurial.url; Section: InternetShortcut; Key: URL; String: https://mercurial-scm.org/
 Filename: {app}\default.d\editor.rc; Section: ui; Key: editor; String: notepad
 
 [UninstallDelete]
 Type: files; Name: {app}\Mercurial.url
 Type: filesandordirs; Name: {app}\default.d
 Type: files; Name: "{app}\hg.exe.local"
 
 [Icons]
 Name: {group}\Uninstall Mercurial; Filename: {uninstallexe}
 Name: {group}\Mercurial Command Reference; Filename: {app}\Docs\hg.1.html
 Name: {group}\Mercurial Configuration Files; Filename: {app}\Docs\hgrc.5.html
 Name: {group}\Mercurial Ignore Files; Filename: {app}\Docs\hgignore.5.html
 Name: {group}\Mercurial Web Site; Filename: {app}\Mercurial.url
 
 [Tasks]
 Name: modifypath; Description: Add the installation path to the search path; Flags: unchecked
 
 [Code]
 procedure Touch(fn: String);
 begin
   SaveStringToFile(ExpandConstant(fn), '', False);
 end;
 
 const
     ModPathName = 'modifypath';
     ModPathType = 'user';
 
 function ModPathDir(): TArrayOfString;
 begin
     setArrayLength(Result, 1)
     Result[0] := ExpandConstant('{app}');
 end;
-#include "modpath.iss"
+
+{% include 'modpath.iss' %}