Comment by lquidfire
Comment by lquidfire a day ago
Cool project! I take it the goal is that, overhead being acceptable, most C / C++ programmes don't actually "have to be" rewritten in something like Rust?
I wonder how / where Epic Games comes in?
Comment by lquidfire a day ago
Cool project! I take it the goal is that, overhead being acceptable, most C / C++ programmes don't actually "have to be" rewritten in something like Rust?
I wonder how / where Epic Games comes in?
From the topic starter: "I've posted a graph showing nearly 9000 microbenchmarks of Fil-C vs. clang on cryptographic software (each run pinned to 1 core on the same Zen 4). Typically code compiled with Fil-C takes between 1x and 4x as many cycles as the same code compiled with clang"
Thus, Fil-C compiled code is 1 to 4 times as slow as plain C. This is not in the "significantly slower" ballpark, like where most interpreters are. The ROOT C/C++ interpreter is 20+ times slower than binary code, for example.
Cryptographic software is probably close to a best case scenario since there is very little memory management involved and runtime is dominated by computation in tight loops. As long as Fil-C is able to avoid doing anything expensive in the inner loops you get good performance.
> best case scenario since there is very little memory management involved and runtime is dominated by computation in tight loops.
Along with the sibling comment, microbenchmarks should not be used as authoritative data when the use case is full applications. For that matter, highly optimized Java or Go may be "1 to 4 times as slow as plain C". Fil-C has its merits, but they should be described carefully, just with any technology.
What does "significantly" mean to you? To my ear, "significantly" means "statistically significant".
What language do people considering c as an option for a new project consider? Rust is the obvious one we aren't going to discuss because then we won't be able to talk about anything else, Zig is probably almost as well loved and defended, but it isn't actually memory safe, just much easier to be memory safe. As you say, c# and go, also maybe f# and ocaml if we are just writing simple c style stuff none of those would look all that different. Go jhs some ub related to concurrency that people run into, but most of these simple utilities are either single threaded or fine grained parallel which is pretty easy to get right. Julia too maybe?
I keep ignoring nim for some reason. How fast is it with all the checks on? The benchmarks for it julia, and swift typically turn off safety checks, which is not how I would run them.
A GC lang isn't necessarily significantly slower than C. You should qualify your statements. Moreover, this is a variant of C, which means that the programs are likely less liberal with heap allocations. It remains to be seen how much of a slowdown Fil-C imposes under normal operating conditions. Moreover, although it is indeed primarily suited for existing programs, its use in new programs isn't necessarily worse than, e.g., C# or Go. If performance is the deciding factor, probably use Rust, Zig, Nim, D, etc. .
WASM is a sandbox. It doesn't obviate memory safety measures elsewhere. A program with a buffer overflow running in WASM can still be exploited to do anything that program can do within in WASM sandbox, e.g. disclose information it shouldn't. WASM ensures such a program can't escape its container, but memory safety bugs within a container can still be plenty harmful.
You can buffer overflow in fil-c and it won't detect it unless the entire buffer was its own stack or heap allocation with nothing following it (and also it needs to be a multiple of 16 bytes, cause that's padding that fil-c allows you to overflow into). So it arguably isn't much different from wasm.
Quick example:
typedef struct Foo {
int buf[2];
float some_float;
int main(void) {
Foo foo = {0};
for (size_t i = 0; i < 3; ++i) {
foo.buf[i] = 0x3f000000;
printf("foo.buf[%zu]: %d\n", i, foo.buf[i]);
}
printf("foo.some_float: %f\n", foo.some_float);
This overflows into the float, not causing any panics, printing 0.5 for the float.
At least WASM can be added incrementally. Fil-C is all or nothing and it cannot be used without rebuilding everything. In that respect a sandbox ranks lower in comprehensiveness but higher in practicality and that's the main issue with Fil-C. It's extremely impressive but it's not a practical solution for C's memory safety issues.
Note that Fil-C is a garbage-collected language that is significantly slower than C.
It's not a target for writing new code (you'd be better off with C# or golang), but something like sandboxing with WASM, except that Fil-C crashes more precisely.