1 Some notes on multi-platform support of Isabelle
2 ================================================
7 The general programming model is that of a stylized ML + Scala + POSIX
8 environment, with as little system-specific code in user-space tools
11 The basic Isabelle system infrastructure provides some facilities to
12 make this work, e.g. see the ML and Scala modules File and Path, or
13 functions like Isabelle_System.bash. The settings environment also
14 provides some means for portability, e.g. the bash function "jvmpath"
15 to keep the impression that Java on Windows/Cygwin adheres to
16 Isabelle/POSIX standards, although inside the JVM itself there are
17 many Windows-specific things.
19 When producing add-on tools, it is important to stay within this clean
20 room of Isabelle, and refrain from overly ambitious system hacking.
21 The existing Isabelle scripts follow a peculiar style that reflects
22 long years of experience in getting system plumbing right.
28 The following hardware and operating system platforms are officially
29 supported by the Isabelle distribution (and bundled tools), with the
30 following reference versions (which have been selected to be neither
33 x86-linux Ubuntu 10.04 LTS
34 x86_64-linux Ubuntu 10.04 LTS
36 x86_64-darwin Mac OS X 10.7 Lion (macbroy6)
37 Mac OS X 10.8 Mountain Lion (macbroy30)
38 Mac OS X 10.9 Mavericks (macbroy2)
39 Mac OS X 10.10 Yosemite (macbroy31)
41 x86-cygwin Cygwin 1.7 (vmbroy9)
43 All of the above platforms are 100% supported by Isabelle -- end-users
44 should not have to care about the differences (at least in theory).
46 Fringe platforms like BSD or Solaris are unsupported.
49 32 bit vs. 64 bit platforms
50 ---------------------------
52 Most users have 64 bit hardware and are running a 64 bit operating
53 system by default. For Linux this usually means missing 32 bit shared
54 libraries, so native x86_64-linux needs to be used by default, despite
55 its doubled space requirements for Poly/ML heaps. For Mac OS X, the
56 x86-darwin personality usually works seamlessly for C/C++ programs,
57 but the Java 7 platform is only available for x86_64-darwin.
59 Add-on executables are expected to work without manual user
60 configuration. Each component settings script needs to determine the
61 platform details appropriately.
63 The Isabelle settings environment provides the following variables to
64 help configuring platform-dependent tools:
66 ISABELLE_PLATFORM64 (potentially empty)
70 The ISABELLE_PLATFORM setting variable refers to the 32 bit version of
71 the platform, even on 64 bit hardware. Using regular bash notation,
72 tools may express their preference for 64 bit with a fall-back for 32
75 "${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM32}"
77 Moreover note that ML and JVM usually have a different idea of the
78 platform, depending on the respective binaries that are actually run.
79 Poly/ML 5.5.x performs best in 32 bit mode, even for large
80 applications, thanks to its sophisticated heap management. The JVM
81 usually works better in 64 bit mode, which allows its heap to grow
84 The traditional "uname" Unix tool usually only tells about its own
85 executable format, not the underlying platform!
88 Dependable system tools
89 -----------------------
91 The following portable system tools can be taken for granted:
93 * GNU bash as uniform shell on all platforms. The POSIX "standard"
94 shell /bin/sh is *not* appropriate, because there are too many
95 non-standard implementations of it.
97 * Perl as largely portable system programming language, with its
98 fairly robust support for processes, signals, sockets etc.
100 * Scala with Java 1.7. Isabelle/Scala irons out many oddities and
101 portability issues of the Java platform.
107 * Mac OS X: If MacPorts is installed there is some danger that
108 accidental references to its shared libraries are created
109 (e.g. libgmp). Use otool -L to check if compiled binaries also work
112 * Mac OS X: If MacPorts is installed and its version of Perl takes
113 precedence over /usr/bin/perl in the PATH, then the end-user needs
114 to take care of installing extra modules, e.g. for HTTP support.
115 Such add-ons are usually included in Apple's /usr/bin/perl by
118 * The Java runtime has its own idea about the underlying platform,
119 which affects Java native libraries in particular. In
120 Isabelle/Scala the function isabelle.Platform.jvm_platform
121 identifies the JVM platform. Since a particular Java version is
122 always bundled with Isabelle, the resulting settings also provide
123 some clues about its platform, without running it.
125 * Common Unix tools like /bin/sh, /bin/kill, sed, ulimit are
126 notoriously non-portable an should be avoided.