This document describes changes between tagged Emscripten SDK versions.

Note that in the compiler, version numbering is used as the mechanism to invalidate internal compiler caches,
so version numbers do not necessarily reflect the amount of changes between versions.

To browse or download snapshots of old tagged versions, visit https://github.com/kripken/emscripten/releases .

Not all changes are documented here. In particular, new features, user-oriented fixes, options, command-line parameters, usage changes, deprecations, significant internal modifications and optimizations etc. generally deserve a mention. To examine the full set of changes between versions, visit the link to full changeset diff at the end of each section.

Current trunk code
------------------
 - To see a list of commits in the active development branch 'incoming', which have not yet been packaged in a release, see
    https://github.com/kripken/emscripten/compare/1.7.8...incoming

v1.7.8: 11/19/2013
------------------
 - Fixed an issue with -MMD compilation parameter.
 - Added EM_ASM_INT() and EM_ASM_DOUBLE() macros. For more information, read https://groups.google.com/forum/#!topic/emscripten-discuss/BFGTJPCgO6Y .
 - Fixed --split parameter to also work on Windows.
 - Fixed issues with BSD sockets accept() call.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.7.7...1.7.8

v1.7.7: 11/16/2013
------------------
 - Improve SDL audio buffer queue timing support.
 - Improved default precision of clock_gettime even when not using CLOCK_REALTIME.
 - Optimize and fix issues with LLVM IR processing.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.7.6...1.7.7

v1.7.6: 11/15/2013
------------------
 - Added regex implementation from musl libc.
 - The command line parameter -s DEAD_FUNCTIONS=[] can now be used to explicitly kill functions coming from built-in library_xx.js.
 - Improved EGL support and GLES2 spec conformance.
 - Reverted -s TOTAL_MEMORY=x to require pow2 values, instead of the relaxed 'multiples of 16MB'. This is because the relaxed rule is released only in Firefox 26 which which is currently in Beta and ships on the week of December 10th (currently in Beta). As of writing, current stable Firefox 25 does not yet support these.
 - Adjusted the default linker behavior to warn about all missing symbols, instead of silently ignoring them. Use -s WARN_ON_UNDEFINED_SYMBOLS=0 to suppress these warnings if necessary.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.7.5...1.7.6

v1.7.5: 11/13/2013
------------------
 - Fix issues with the built-in C++ function name demangler.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.7.4...1.7.5

v1.7.4: 11/12/2013
------------------
 - Fixed issues with BSD sockets code and SDL joystick implementation.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.7.3...1.7.4

v1.7.3: 11/12/2013
------------------
 - Added support for generating single-precision floating point instructions.
    - For more information, read https://blog.mozilla.org/javascript/2013/11/07/efficient-float32-arithmetic-in-javascript/
 - Made GLES2 support library more spec-conformant by throwing fewer exceptions on errors. Be sure to build with -s GL_ASSERTIONS=1, remember to use glGetError() and check the browser console to best detect WebGL rendering errors.
 - Converted return value of emscripten_get_now() from float to double, to not lose precision in the function call.
 - Added support for joysticks in SDL via the Gamepad API
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.7.2...1.7.3
 
v1.7.2: 11/9/2013
------------------
 - The compiler now always generates a .js file that contains the generated source code even when compiling to a .html file.
    - Read https://groups.google.com/forum/#!topic/emscripten-discuss/EuHMwqdSsEs
 - Implemented depth+stencil buffer choosing behavior in GLUT, SDL and GLFW.
 - Fixed memory leaks generated by glGetString and eglGetString.
 - Greatly optimized startup times when virtual filesystems with a large amount of files in them.
 - Added some support for SIMD generated by LLVM.
 - Fixed some mappings with SDL keyboard codes.
 - Added a new command line parameter --no-heap-copy to compiler and file packager that can be used to optimize VFS memory usage at startup.
 - Updated libcxx to revision 194185, 2013-11-07.
 - Improvements to various library support. 
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.7.1...1.7.2

v1.7.1: 10/24/2013
------------------
 - Remove old call to Runtime.warn in file packager code
 - Fix bug with parsing of empty types.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.7.0...1.7.1

v1.7.0: 10/23/2013
------------------
 - Adds mouse wheel events support in GLUT library.
 - Adds support for a new link parameter -s CASE_INSENSITIVE_VFS=1 to enable Emscripten virtual filesystem to search files ignoring case.
 - *Numerous* optimizations in both compilation and runtime stages.
 - Remove unnecessary whitespace, compact postSets function, and other optimizations in compilation output to save on generated file size.
 - Fixes float parsing from negative zero.
 - Removes the -s EMIT_GENERATED_FUNCTIONS link parameter as unneeded.
 - Fixes an issue where updating subranges of GL uniform arrays was not possible.
 - asm.js heap size (-s TOTAL_MEMORY=x) no longer needs to be a power of 2. As a relaxed rule, choosing any multiple of 16MB is now possible.
 - O1 optimization no longer runs the 'simplifyExpressions' optimization pass. This is to improve build iteration times when using -O1. Use -O2 to run that pass.
 - EM_ASM() can now be used even when compiling to asm.js.
 - All currently specified non-debugging-related WebGL 1 extensions are now enabled by default on startup, no need to ctx.getExtension() manually to enable them.
 - Improve readability of uncaught JavaScript exceptions that are thrown all the way up to the web console by printing out the stack trace of where the throw occurred.
 - Fix an issue when renaming a directory to a subdirectory.
 - Several compiler stability fixes.
 - Adds a JavaScript implementation of cxa_demangle function for demangling call stack traces at runtime for easier debugging.
 - GL context MSAA antialising is now DISABLED by default, to make the GL behavior consistent with desktop usage.
 - Added support to SDL, GLUT and GLFW libraries to specify MSAA on/off at startup.
 - Implemented glColor4ubv in GL emulation mode.
 - Fix an issue with LLVM keyword __attribute__ ((__constructor__)) (#1155).
 - Fix an issue with va_args and -s UNALIGNED_MEMORY=1 (#1705).
 - Add initial support code for LLVM SIMD constructs and a JavaScript SIMD polyfill implementation from https://github.com/johnmccutchan/ecmascript_simd/ .
 - Fixed support for node.js native filesystem API NODEFS on Windows.
 - Optimize application startup times of Emscripten-compiled programs by enabling the virtual filesystem XHR and asm.js compilation to proceed in parallel when opening a page.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.6.4...1.7.0

v1.6.4: 9/30/2013
------------------
 - Implements a new preprocessor tool for preparsing C struct definitions (#1554), useful for Emscripten support library implementors.
 - Fix parsing issue with sscanf (#1668).
 - Improved the responsiveness of compiler print output on Windows.
 - Improved compilation times at link stage.
 - Added support for new "NODEFS" filesystem that directly accesses files on the native filesystem. Only usable with node.js when compiling to JS.
 - Added support for new IDBFS filesystem for accessing files in IndexedDB storage (#1601.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.6.3...1.6.4

v1.6.3: 9/26/2013
------------------
 - Emscripten CMake toolchain now generates archive files with .a suffix when project target type is static library, instead of generatic .bc files (#1648).
 - Adds iconv library from the musl project to implement wide functions in C library (#1670).
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.6.2...1.6.3

v1.6.2: 9/25/2013
------------------
 - Added support for dprintf() function (#1250).
 - Fixes several compiler stability issues (#1637, #1166, #1661, #1651 and more).
 - Enables support for WEBGL_depth_texture.
 - Adds support for new link flag -s GL_ASSERTIONS=1 which can be used to add extra validation layer to the Emscripten GL library to catch code issues.
 - Adds support to Web Audio API in SDL audio backend so that SDL audio now works in Chrome and new Opera as well.
 - Fixes an alpha blending issue with SDL_SetAlpha.
 - Implemented locale-related code in C library.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.6.1...1.6.2

v1.6.1: 9/22/2013
------------------
 - Several optimizations to compiler link stage.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.6.0...1.6.1

v1.6.0: 9/21/2013
------------------
 - Enable support for %[] pattern in scanf.
 - Added dependency tracking support to linked .js files in CMake toolchain.
 - The hex prefix 0x is now properly handled in sscanf (#1632).
 - Simplify internal compiler operations by removing the internal framework.js. 
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.5.9...1.6.0

v1.5.9: 9/15/2013
------------------
 - Add support for SDL_Delay in web workers.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.5.8...1.5.9

v1.5.8: 9/14/2013
------------------
 - Add support for the GCC -E compiler flag.
 - Update Emscripten libc headers to musl-0.9.13.
 - Added new utility function emscripten_async_load_script() to asynchronously load a new .js script URL.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.5.7...1.5.8

v1.5.7: 8/30/2013
------------------
 - The script tag in default shell.html is now marked 'async', which enables loading the JS script code asynchronously in Firefox without making the main thread unresponsive.
 - Implemented new utility function emscripten_get_canvas_size() which returns the current Module <canvas> element size in pixels.
 - Optimize code size in compiled side modules.
 - Optimize startup memory usage by avoiding unnecessary copying of VFS data at startup.
 - Add support for SDL_WM_ToggleFullScreen().
 - Add support for emscripten_get_now() when running in SpiderMonkey shell.
 - Added new environment variable EM_BUILD_VERBOSE=0,1,2,3 to set an extra compiler output verbosity level for debugging.
 - Added better support for dlopen() to simulate dynamic library loading in JavaScript.
 - Improved support for BSD sockets and networking.
 - Added new SOCKFS filesystem, which reads files via a network connection.
 - Avoid issues with long command line limitations in CMake toolchain by using response files.
 - Fix issues with client-side vertex data rendering in GL emulation mode.
 - Improved precision of clock_gettime().
 - Improve function outlining support.
 - Added support for using NMake generator with CMake toolchain.
 - Improved support for flexible arrays in structs (#1602).
 - Added ability to marshal UTF16 and UTF32 strings between C++ <-> JS code.
 - Added a new commandline tool validate_asms.py to help automating asm.js validation testing.
 - Improved stability with inline asm() syntax.
 - Updated libc headers to new version.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.5.6...1.5.7

v1.5.6: 8/17/2013
------------------
 - Improved BSD sockets support.
 - Added touch events support to GLUT library.
 - Added new --js-opts=0/1 command line option to control whether JS optimizer is run or not.
 - Improved OpenAL support.
 - Added new command line tool tools/find_bigvars.py which can be used on a output file to detect large functions and needs for outlining.
 - Merged link flags -s FORCE_GL_EMULATION and -s DISABLE_GL_EMULATION to a single opt-in flag -s LEGACY_GL_EMULATION=0/1 to control whether GL emulation is active.
 - Improved SDL input support.
 - Several stability-related compiler fixes.
 - Fixed source mapping generation support on Windows.
 - Added back the EMSCRIPTEN_KEEPALIVE attribute qualifier to help prevent inlining and to retain symbols in output without dead code elimination occurring.
 - Fix issues when marshalling UTF8 strings between C<->JS.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.5.5...1.5.6

v1.5.5: 8/9/2013
------------------
 - Update libcxx to revision 187959, 2013-08-08.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.5.4...1.5.5

v1.5.4: 8/9/2013
------------------
 - Fixed multiple issues with C stdlib support.
 - Fix audio buffer queueing issues with OpenAL.
 - Improved BSD sockets support.
 - Added a new compile+link time command line option -Wno-warn-absolute-paths to hide the emscripten compiler warning when absolute paths are passed into the compiler.
 - Added new link flag -s STB_IMAGE=0/1 and integrate it to SDL image loading to enable synchronous image loading support with SDL.
 - Several improvements on function outlining support.
 - Fix issues with GLES2 interop support.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.5.3...1.5.4

v1.5.3: 6/28/2013
------------------
 - Added new optimization level --llvm-lto 3 to run even more aggressive LTO optimizations.
 - Improve optimizations for libc and other libraries.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.5.2...1.5.3

v1.5.2: 6/27/2013
------------------
 - Added support for generating source maps along the built application when -g is specified. This lets the browser show original .cpp sources when debugging.
 - GLUT and SDL improvements.
 - Added new link option -g<level> where level=0-4, which allows controlling various levels of debuggability added to the output.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.5.1...1.5.2

v1.5.1: 6/22/2013
------------------
 - File packager now skips all directories and files starting with '.', and hidden files on Windows.
 - Fix issues with strnlen, memmove, LDBL_ constants, va_args, float.h, and others.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.5.0...1.5.1

v1.5.0: 6/17/2013
------------------
 - Several compiler optimizations.
 - Improve SDL key events support.
 - Increase debug logging when specifying emcc -v.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.4.9...1.5.0

v1.4.9: 6/8/2013
------------------
 - Several compiler optimizations.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.4.8...1.4.9

v1.4.8: 6/6/2013
------------------
 - Add support for webrtc-based sockets.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.4.7...1.4.8

v1.4.7: 6/2/2013
------------------
 - Remove more unneeded break and continue statements in relooper.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.4.6...1.4.7

v1.4.6: 6/2/2013
------------------
 - Improve relooper code.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.4.5...1.4.6

v1.4.5: 6/1/2013
------------------
 - Improve relooper code.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.4.4...1.4.5

v1.4.4: 6/1/2013
------------------
 - Add support for symlinks in source files.
 - Fix various issues with SDL.
 - Added -s FORCE_ALIGNED_MEMORY=0/1 link time flag to control whether all loads and stores are assumed to be aligned.
 - Fix file packager to work with closure.
 - Major improvements to embind support, and optimizations.
 - Improve GL emulation.
 - Optimize VFS usage.
 - Allow emscripten to compile .m and .mm files.
 - Added new syntax --preload-file src@dst to file packager command line to allow placing source files to custom destinations in the FS.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.4.3...1.4.4

v1.4.3: 5/8/2013
------------------
 - Fix issue with strcat.
 - Major embind improvements.
 - Switch to le32-unknown-nacl LLVM target triple as default build option instead of the old i386-pc-linux-gnu target triple.
 - Improve compiler logging behavior.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.4.2...1.4.3

v1.4.2: 5/3/2013
------------------
 - Fix issues with le32-unknown-nacl LLVM target triple.
 - Add some GLEW support.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.4.1...1.4.2

v1.4.1: 4/28/2013
------------------
 - Implement support for le32-unknown-nacl LLVM target triple.
 - Added new cmdline option -s ERROR_ON_UNDEFINED_SYMBOLS=0/1 to give compile-time error on undefined symbols at link time. Default off.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.3.8...1.4.1

v1.3.8: 4/29/2013
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 - Improved 64-bit integer ops codegen.
 - Added Indexed DB support to vfs.
 - Improve warning message on dangerous function pointer casts when compiling in asm.js mode.
 - Added --use-preload-cache command line option to emcc, to be used with the file packager.
 - Fixes to libcextra.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.3.7...1.3.8

v1.3.7: 4/24/2013
------------------
 - Merge IMVU implementation of embind to emscripten trunk. Embind allows high-level C++ <-> JS types interop.
 - Enable asm.js compilation in -O1 and higher by default. Fix issues when compiling to asm.js.
 - Improve libc support with Emscripten with the musl libc headers.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.3.6...1.3.7

v1.3.6: 4/2/2013
------------------
 - Fix hang issue with strtof.
 - Update libcxx to upstream r178253 from March 29, 2013.
 - Fix issues with GL emulation.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.3.5...1.3.6

v1.3.5: 3/25/2013
------------------
 - Get exceptions working as they did before.
 - Remove symbol removing hack.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.3.4...1.3.5

v1.3.4: 3/24/2013
------------------
 - Update to new libcxx and libcxxabi versions from upstream.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.3.3...1.3.4

v1.3.3: 3/23/2013
------------------
 - Remove unneeded check from relooper.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.3.2...1.3.3

v1.3.2: 3/22/2013
------------------
 - Fix issues with fgets. 
 - Add support for non-fullscreen pointer lock.
 - Improve OpenAL support.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.3.1...1.3.2

v1.3.1: 3/19/2013
------------------
 - Improve SDL audio and mixer support.
 - Add GLES2 emulation features when -s FULL_ES2=1 is specified.
 - Add support for OpenAL.
 - Add new -s OPENAL_DEBUG=0/1 link command line option.
 - Fixed an issue with mouse coordinate being offset with canvas.
 - Removed -s UTF_STRING_SUPPORT=0 parameter, this is now always on.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.3.0...1.3.1

v1.3.0: 3/11/2013
------------------
 - Improve GLES2 emulation with -s FULL_ES2=1.
 - Deprecated -s USE_TYPED_ARRAYS=1 and -s QUANTUM_SIZE=1.
 - Implement a minifier infrastructure when compiling for asm.js.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.2.9...1.3.0

v1.2.9: 3/7/2013
------------------
 - Improved canvas behavior when transitioning between fullscreen.
 - Added support for getopt().
 - Fixed several libc issues.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.2.8...1.2.9

v1.2.8: 3/6/2013
------------------
 - Remove unnecessary recursion in relooper RemoveUnneededFlows.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.2.7...1.2.8

v1.2.7: 3/6/2013
------------------
 - Added SDL_Mixer support.
 - Implemented stubs for several Unix and threading-related functions.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.2.6...1.2.7

v1.2.6: 3/5/2013
------------------
 - Relooper updates.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.2.5...1.2.6

v1.2.5: 3/5/2013
------------------
 - Greatly improve GL emulation support.
 - Handle %c in sscanf.
 - Improve compilation times by optimizing parallel execution in the linker.
 - Improve several compiler stability issues detected from fuzzing tests.
 - Implemented emscripten_jcache_printf.
 - Allow running emscripten.py outside emcc itself.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.2.4...1.2.5

v1.2.4: 2/2/2013
------------------
 - Work on adding support for asm.js compilation.
 - Improve EGL support.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.2.3...1.2.4

v1.2.3: 1/9/2013
------------------
 - Work on adding support for asm.js compilation.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.2.2...1.2.3

v1.2.2: 1/8/2013
------------------
 - Work on adding support for asm.js compilation.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.2.1...1.2.2

v1.2.1: 1/8/2013
------------------
 - Improvements to GLUT, SDL and BSD sockets headers.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.2.0...1.2.1

v1.2.0: 1/1/2013
------------------
 - Work on adding support for asm.js compilation.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.1.0...1.2.0

v1.1.0: 12/12/2012
------------------
 - Fix several issues with Windows support.
 - Added a standalone toolchain for CMake.
 - Added emscripten_run_script_string().
 - Optimize compilation times via threading.
 - Update to requiring Clang 3.2. Older versions may no longer work.
 - Several improvements to emscripten library support headers.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.0.1a...1.1.0

v1.0.1a: 11/11/2012
------------------
 - Add relooper code to repository.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.0.1...1.0.1a

v1.0.1: 11/11/2012
------------------
 - First commit that introduced versioning to the Emscripten compiler.