uecker

In general, the C standard only requires a diagnostic for constraint violations.

The article is a boring rant with no substance. His main issue seems to be the realloc zero change which he claims breaks idiomatic code. But this is certainly not idiomatic code as it never worked …

auto is not allowed for a function declaration with block scope without the GCC extension.

We made VLA types and derived types (variably modified types) mandatory in C23. (but not VLAs on the stack as automatic variables which are still optional)

I do not think VLA are anymore poorly defined then most other stuff in the C standard. It generally allows a wide range of implementations. As a language features, it is has excellent properties. (aut…

C++ had this forever (I assume), but for C this would be a breaking change which we try very hard to avoid.

It is Sisyphean, but there also many synergies (I work on real-time computational imaging systems). And the specific things you mention were mostly not my work (I made typeof in GCC more coherent, whi…

So you want Vec to refer to struct Vec but only if there is no other type Vec defined before or until one is defined later? That would work, but might be a bit confusing.

Sorry, it was on my list of things to propose, but I did not have enough time (due to a job change). Others were more interested in lambdas.

Because it would break a lot of existing code.

I am exploring way on how to implement this in C (with some extensions) as a library: https://github.com/uecker/noplate Certainly not production ready.…

My software and Debian package uses nested functions. I use it because code quality improves a lot with nested functions. But yes, the executable stack is a problem. I had a patch for GCC to use fu…

I agree, this is one of the more important common extensions we are still missing.

VLA are exactly an array type that knows its length, i.e. a dependent type. VLAs on the stack had some issues, but pointers to VLAs, i.e. variably modified types are quite powerful. Language and comp…

If you have larger fixed size array you can get an error when you overflow the larger array. But this then does not necessarily prevent invalid accesses to the parts of the array which go beyond the a…

Yes this is something we need to work on: Some way to detect stack overflow or prevent it from happening in C. And obviously you need to understand the resource consumption of your algorithm, but this…

Stack allocation is much faster than heap allocation, and compared to fixed-size arrays VLAs save stack space. For example, a recursive divide-by-conquer algorithm that allocates arrays on the stack m…

Not only this, but also out of bounds accesses using UBSan: https://godbolt.org/z/q9qsax7qY (also compiler support is still improving)…

And I am part of WG14 (so a hapless goldbrick). The reason VLA were made optional to make implementing C easier, as C99 was not adopted quickly. Although the reason for the slow adoption were others. …

Maybe you did not realize this, but I somewhat helped with this effort. In the kernel it may make (some) sense. The overall idea that VLA are always bad is incorrect.

VLAs can enable precise bounds checking with the undefined behavior sanitizer. This is useful and you do not have precise bounds checking anymore when you replace it with a larger fixed size array. Al…

In my opinion the improved code quality and bounds checking you can get with VLAs are worth it. Yes, the an attacker should not control the size and one should use -fstack-clash-protection and when th…

The prices in summer were so high mainly because half of France nuclear plants were offline. Look, even the article you cite mentions this: "The largest Nordic nation became the region’s top expo…

The grid is for trade, so I am not sure what sense this complaint makes. Also France relies on imports sometimes. Electricity prices changing with production and demand is also exactly what market is …

So what? You are complaining that Germany still uses coal. This is a fair complaint (and one should complain about this), but Germany is in the middle of the transition to renewables and that in the…

Sorry, I am not interested what a nuclear shill posts on twitter. Here is the source for my numbers (which are the official ones). Sorry, in German but I assume you can guess the labels: https:/…

Germany is exiting both nuclear and coal. In the time from 2010 to 2022 where 14/17 of nuclear plants were shut down generation from coal was reduced from 263 TWh per year to 181 TWh. Renewables …

I use this technique a lot and it is very powerful.

Wind and solar are far from marginal: 50% renewables in 2022: https://www.energy-charts.info/charts/energy_pie/chart.htm?l... Prices are also lower than in France, but not…

See my comment to parent. There is an important lesson about not being misled by looking at the wrong data.