The Glulx VM reference interpreter
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.gitignore Added a .gitignore. Mar 22, 2009
LICENSE Switch to MIT license. Oct 25, 2016
Makefile Switch to the default compiler. Jan 31, 2017 Version number bump. Jan 23, 2017
accel.c Full stashing of the acceleration_func table. Feb 27, 2016
debugger.c More variables declared not at the start of a scope block Feb 2, 2017
exec.c Expanded definition of TOLERATE_SUPERGLUS_BUG. Jan 12, 2017
files.c Release 0.4.3. Mar 22, 2009
float.c Added an option to *not* assume IEEE-754 native floats. Aug 2, 2010
funcs.c Setup to put breakpoints on functions. May 30, 2014
gestalt.c Version number bump. Jan 23, 2017
gestalt.h Started adding the floating-point opcodes. Jul 21, 2010
glkop.c Put in some defensive checks for missing Glk objects. I'm not sure this Sep 28, 2014
glulxdump.c Brought the opcode table up to date. However, the disassembler is sti… Jan 15, 2012
glulxe.h Merge branch 'master' into debugger Jan 13, 2017
heap.c Removed a bunch of unused variables that never bothered me before. Apr 30, 2011
iosstart.h Add an object for storing accel entries. Feb 27, 2016
iosstart.m Full stashing of the acceleration_func table. Feb 27, 2016
macstart.c Release 0.3.4. Mar 22, 2009
main.c Put declaration at top. Jan 31, 2017
opcodes.h Started adding the floating-point opcodes. Jul 21, 2010
operand.c Putting arguments on the macros is silly. Sep 24, 2014
osdepend.c Abstracted powf() to an osdepend wrapper. (Needed for Windows.) Aug 24, 2010 More comments. Jul 17, 2016
profile.c @restore and @restoreundo should fail (rather than fatalerror out) Aug 23, 2016
search.c Removed unnecessary include. Jan 4, 2011
serial.c @restore and @restoreundo should fail (rather than fatalerror out) Aug 23, 2016
string.c Removed a bunch of unused variables that never bothered me before. Apr 30, 2011
unixstrt.c Use the standard macro for a blorb chunk ID. Oct 30, 2016
vm.c Merge branch 'master' into debugger Jul 17, 2016
winstart.c Fix line endings Apr 26, 2017

Glulxe: the Glulx VM interpreter


Since this is a Glk program, it must be built with a Glk library. See the Glk home page.

The Unix Makefile that comes with this package is designed to link any of the Unix libraries (CheapGlk, GlkTerm, RemGlk, etc.) You'll have to go into the Makefile and set three variables to find the library. There are instructions at the top of the Makefile. Then just type

make glulxe

That should suffice. When the program is built, type

./glulxe filename.ulx

where "filename.ulx" is a Glulx game file to execute.

To build this program with a Mac or Windows interface, or any other interface, you'll need the appropriate Glk library.

This program supports floating-point operations, which are implemented using the standard C99 math functions. The Makefile uses "-lm" to link these in. If your platform does not support these functions, you can comment out the "#define FLOAT_SUPPORT" line in glulxe.h.

If you define the VM_DEBUGGER symbol (uncomment the "#define VM_DEBUGGER" line in glulxe.h), you must include the libxml2 library. See the XMLLIB definition in the Makefile.


0.5.4 (Jan 23, 2017):

  • Added an internal debugger. Compile with "#define VM_DEBUGGER" (and a debug-supporting Glk library) to use it.
  • Expanded the TOLERATE_SUPERGLUS_BUG behavior to tolerate more Superglus game files.

0.5.3 (Oct 25, 2016):

  • Turn on SERIALIZE_CACHE_RAM in the default build. This speeds up save and save-undo operations.
  • Other tweaks to speed up launch, restart, restore, etc.
  • Fixed a bug where accelerated functions were not being autosaved. (Only relevant for iOS, currently.)
  • When profiling, restore/restore-undo operations will now fail (and the game will continue) instead of causing a fatal error.
  • Added a build option to tolerate the Superglus bug where (very old) game files would try to write to memory address zero. (Not on by default.)
  • Switched from my old ad-hoc license to the MIT license.

0.5.2 (Mar 27, 2014):

  • Added acceleration functions 8 through 13, which work correctly when NUM_ATTR_BYTES is changed.

0.5.1 (Mar 10, 2013):

  • Fixed a bug in glkop.c that prevented get_buffer_stream() from working right.
  • Updated to understand the upcoming, updated I6 debug file format. (See The old format is still supported.

0.5.0 (Oct 18, 2012):

  • Turned on memory-range checking in the default build. (Should have done this years ago.)
  • Fixed a bug where @setmemsize could crash an open char memory stream or char line input request.
  • Updated glkop.c to handle arrays of Glk objects. (This is needed to support glk_schannel_play_multi().)
  • Added hooks for the library to execute at startup and select time.
  • Added a hook which allows the library to get and pass on a game ID string.
  • Clean up all memory allocation when the VM exits.

0.4.7 (Oct 10, 2011):

  • Abstracted powf() to an osdepend wrapper. (Needed for Windows.)
  • Fixed a @ceil bug, for some C math libraries.
  • Improved the profiling system in several ways.
  • Fixed a bug in glkop.c dispatching, to do with optional array arguments.

0.4.6 (Aug 17, 2010):

  • Added floating-point math feature.
  • Updated winstart.c. (Thanks David Kinder.)
  • Fixed @random even more, on Windows.
  • @verify works right on game files with extended memory.
  • @getiosys works right when the two store operands are different variable types. (E.g., one local and one global.)

0.4.5 (Nov 23, 2009):

  • VERIFY_MEMORY_ACCESS now detects writes to the ROM section of memory.
  • Fixed off-by-eight bug in @astorebit and @aloadbit with negative bit numbers.
  • Fixed an obscure bug with division and modulo of $80000000. (Thanks Evin Robertson.)
  • Fixed an extremely obscure problem with changing I/O mode in the middle of printing a number.
  • Glk array/string operations are now checked for memory overflows (though not for ROM writing). This generates a warning at present; in the future, it will be a fatal error.
  • Better fix for the @random bug.

0.4.4 (Mar 11, 2009):

  • Added profiling code, which is turned off by default. To compile it in, define VM_PROFILING in Makefile or in glulxe.h.
  • Added function-accleration feature.
  • Fixed bug where @random 0 was returning only positive numbers.

0.4.3 (Jan 23, 2008):

  • Verify the presence of Unicode calls in the Glk library at runtime. (Thanks Simon Baldwin.)
  • Added a compile-time option to check for invalid memory accesses. (This is slower, but safer. Define VERIFY_MEMORY_ACCESS in Makefile or in glulxe.h. Thanks Evin Robertson.)
  • Fixed a memory leak of undo states. (Thanks Matthew Wightman.)
  • Fixed a linked-list handling error for Glk unicode arrays. (Thanks David Kinder.)

0.4.2 (Feb 15, 2007):

  • Fixed a bug that preventing compiling with old (pre-Unicode) Glk libraries.

0.4.1 (Feb 11, 2007):

  • Added array copy and heap allocation functionality. (Glulx spec 3.1.0.)

0.4.0 (Aug 13, 2006):

  • Added Unicode functionality. (Glulx spec 3.0.0.)

0.3.5 (Aug 24, 2000):

  • Fixed El-Stupido bug in the modulo opcode.

0.3.4 (Jul 11, 2000):

  • Finally supports string arguments to Glk calls.

0.3.3 (Mar 29, 2000):

  • Added setiosys, getiosys opcodes.
  • Fixed bug in binarysearch.

0.3.2 (Feb 21, 2000):

  • Added search, jumpabs, callf, and gestalt opcodes.

0.3.1 (Aug 23, 1999):

  • Startup code now handles Blorb files correctly.

0.3.0 (Aug 17, 1999):

  • Added support for compressed strings.

0.2.2 (Jun 15, 1999):

  • Another pre-release version.

0.2.0 (May 30, 1999):

  • A pre-release version.


The source code in this package is copyright 1999-2016 by Andrew Plotkin. It is distributed under the MIT license; see the "LICENSE" file.