https://github.com/tasemulators/mednafen
a manual copy of mednafen code, because mednafen is too cool for git
https://github.com/tasemulators/mednafen
Last synced: 3 months ago
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a manual copy of mednafen code, because mednafen is too cool for git
- Host: GitHub
- URL: https://github.com/tasemulators/mednafen
- Owner: TASEmulators
- License: gpl-2.0
- Created: 2020-05-25T16:02:06.000Z (about 5 years ago)
- Default Branch: master
- Last Pushed: 2024-11-15T03:36:55.000Z (8 months ago)
- Last Synced: 2025-04-13T13:15:44.111Z (3 months ago)
- Language: Objective-C
- Size: 6.65 MB
- Stars: 8
- Watchers: 7
- Forks: 2
- Open Issues: 0
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Metadata Files:
- Readme: README
- Changelog: ChangeLog
- License: COPYING
- Authors: AUTHORS
Awesome Lists containing this project
README
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Compilation Notes:
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gcc or LLVM clang is required for compiling Mednafen. Intel's C compiler may work, but is untested.
Probably doesn't need to be said, but the compilers optionally specified via CC and CXX *must* be the same version.
clang: 3.5.0 or newer is required, though gcc 4.9.x is preferable for performance reasons.
gcc: 4.8(4.8.4+), or 4.9(4.9.2+) or newer is required. gcc 4.9 is recommended; gcc 5.x and gcc 6.x tend to produce
slower executables, at least with Mednafen on x86_64.
Reportedly, passing: --build=x86_64-apple-darwin`uname -r`
to the configure script is necessary for building on Mac OS X to work properly.
Compiling at -O3 or higher, or with other custom optimization flags, is discouraged.
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Some notes(and reminders) on the source code:
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Check "mednafen/src/types.h" for standard C and C++ library header includes, and avoid #include'ing the same files redundantly elsewhere.
Avoid %= in save state load variable sanitizing code unless the variable is unsigned.
malloc(), realloc(), calloc()'ing 0 bytes of memory may return a NULL pointer.
memcpy()/memmove()/etc. with NULL pointers is undefined and bad even when length is 0.
Careful to not do something like: void somefunc(int something[16]); [...] sizeof(something)
Try to avoid writing new code that violates strict overflow(even though we compile with -fwrapv), especially be mindful
of stuff like what's described at http://kqueue.org/blog/2013/09/17/cltq/
Order of operations != Operator precedence. Remember sequence point rules, and don't do stuff like:
value = FuncWithSideEffects() | (FuncWithSideEffects() << 8); // BAD BAD
See: http://en.cppreference.com/w/cpp/language/eval_order
Avoid writing new code that shifts left signed integers or negative values to avoid technically undefined behavior; use
ugly typecasting, or multiply by powers of 2 instead(remotely modern compilers can optimize it to a shift internally).
Vanishing temporaries: https://gcc.gnu.org/onlinedocs/gcc/Temporaries.html#Temporaries
Do not place a period before the field width for "s" and "[" conversion specifiers in *scanf() format strings; perhaps a bad
habit picked up long ago from working with a buggy libc or trio?
Avoid compiling different C++ files with different compiler flags in regards to instruction set used(like -mmmx, -msse, -mfpmath, -march),
or else there may be (template-)function ODR violations that could cause compatibility problems.
GPLv3-incompatible code:
WonderSwan emulation code from Cygne.
QuickLZ(old version used)
Don't do greater-than and less-than comparisons between pointers unless they're pointers to members of the same array/struct/etc.
Avoid using a pointer into a nested array of a multidimensional array to access elements of the multidimensional array that lie outside of that specific
nested array, as such behavior is probably undefined.
Pointer provenance, DR260.
Don't create temporarily-invalid pointers via careless pointer arithmetic; restructure the expressions if possible, or utilize uintptr_t instead.
x86_64 inline assembly, stack red zone.
https://gcc.gnu.org/onlinedocs/gccint/Memory-model.html#Memory-model
Don't use memcmp() on class/struct objects unless they're initialized with memset() and copied around with only memcpy()(or equivalent).
Don't rely on malloc(), realloc(), and calloc() setting errno to ENOMEM on a memory allocation error.
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Code contributions:
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To keep things simpler for commercial licensing, any patches or new code offered for emulation modules "apple2", "psx", "snes_faust", and "ss",
along with contributions to core Mednafen functionality with code that is not self-contained(e.g. support for a new CD image format), will be ignored.
Distributing a separate patch set or an outright fork(with branding that clearly conveys the forkiness) is recommended.