Admin/components/PLATFORMS

update platforms: discontinue macOS 10.13 High Sierra, macOS 10.14 Mojave, macOS 10.15 Catalina;

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−Multi-platform support of Isabelle
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−==================================
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−
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−Preamble
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−--------
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−
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−The general programming model is that of a stylized ML + Scala + POSIX
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−environment, with a minimum of system-specific code in user-space
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−tools.
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−
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−The Isabelle system infrastructure provides some facilities to make
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−this work, e.g. see the ML and Scala modules File and Path, or
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−functions like Isabelle_System.bash.  The settings environment also
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−provides some means for portability, e.g. the bash function
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−"platform_path" to keep the impression that Windows/Cygwin adheres to
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−Isabelle/POSIX standards, although many executables are native on
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−Windows (notably Poly/ML and Java).
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−
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−When producing add-on tools, it is important to stay within this clean
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−room of Isabelle, and refrain from non-portable access to operating
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−system functions. The Isabelle environment uses GNU bash and
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−Isabelle/Scala as portable system infrastructure, using somewhat
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−peculiar implementation techniques.
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−
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−
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−Supported platforms
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−-------------------
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−
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−A broad range of hardware and operating system platforms are supported
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−by building executables on base-line versions that are neither too old
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−nor too new. Common OS families should work: Linux, macOS,
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−Windows. More exotic platforms are unsupported: NixOS, BSD, Solaris.
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−
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−Official platforms:
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−
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−  x86_64-linux      Ubuntu 18.04 LTS
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−
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−  x86_64-darwin     macOS 11 Big Sur (mini1 Macmini8,1)
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−                    macOS 12 Monterey (???)
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−                    macOS 13 Ventura (mini3 Mac14,12 -- MacMini M2 Pro, 6+4 cores)
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−                    macOS 14 Sonoma (mini2 Macmini8,1)
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−
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−  arm64-darwin      macOS 11 Big Sur (assur Macmini9,1 -- MacMini M1, 4+4 cores)
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−                    macOS 12 Monterey (???)
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−                    macOS 13 Ventura (mini3 Mac14,12 -- MacMini M2 Pro, 6+4 cores)
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−                    macOS 14 Sonoma (studio1 Mac13,2 M1 Ultra, 16+4 cores)
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−
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−  x86_64-windows    Windows 10
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−  x86_64-cygwin     Cygwin 3.4.x https://isabelle.sketis.net/cygwin_2023 (x86_64/release)
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−
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−Experimental platforms:
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−
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−  arm64-linux       Raspberry Pi OS 64bit beta (Debian 10 / Buster)
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−
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−
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−64 bit vs. 32 bit platform personality
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−--------------------------------------
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−
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−Isabelle requires 64 bit hardware running a 64 bit operating
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−system. Only Windows still supports native x86 executables, but the
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−POSIX emulation on Windows via Cygwin64 works exclusively for x86_64.
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−
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−The Isabelle settings environment provides variable
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−ISABELLE_PLATFORM64 to refer to the standard platform personality. On
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−Windows this is for Cygwin64, but the following native platform
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−identifiers are available as well:
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−
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−  ISABELLE_WINDOWS_PLATFORM64
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−  ISABELLE_WINDOWS_PLATFORM32
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−
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−These are always empty on Linux and macOS, and non-empty on
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−Windows. For example, this is how to refer to native Windows and
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−fall-back on Unix (always 64 bit):
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−
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−  "${ISABELLE_WINDOWS_PLATFORM64:-$ISABELLE_PLATFORM64}"
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−
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−And this is for old 32 bit executables on Windows, but still 64 bit on
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−Unix:
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−
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−  "${ISABELLE_WINDOWS_PLATFORM32:-$ISABELLE_PLATFORM64}"
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−
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−For Apple Silicon the native platform is "$ISABELLE_APPLE_PLATFORM64"
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−(arm64-darwin), but thanks to Rosetta 2 "$ISABELLE_PLATFORM64"
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−(x64_64-darwin) works routinely with fairly good performance.
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−
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−
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−Dependable system tools
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−-----------------------
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−
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−The following portable system tools can be taken for granted:
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−
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−* Scala on top of Java.  Isabelle/Scala irons out many fine points of
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−  the Java platform to make it fully portable as described above.
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−
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−* GNU bash as uniform shell on all platforms. The POSIX "standard"
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−  shell /bin/sh does *not* work portably -- there are too many
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−  non-standard implementations of it. On Debian and Ubuntu /bin/sh is
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−  actually /bin/dash and introduces many oddities.
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−
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−
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−Known problems
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−--------------
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−
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−* macOS: If Homebrew or MacPorts is installed, there is some danger
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−  that accidental references to its shared libraries are created
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−  (e.g. libgmp).  Use otool -L to check if compiled binaries also work
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−  without MacPorts.
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−
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−* Common Unix tools like /bin/sh, /bin/kill, sed, ulimit are
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−  notoriously non-portable an should be avoided.
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−
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−* The traditional "uname" Unix tool only tells about its own
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−  executable format, not the underlying platform!