sembr a few files

ci/sembr/src/main.rs

@@ -315,3 +315,10 @@ html comment closing
 ";
     assert_eq!(expected, lengthen_lines(original, 50));
 }
+
+#[test]
+#[ignore]
+fn should_pass() {
+    let original = "if you see `input isn't interesting! verify interesting-ness test`.";
+    assert_eq!(original, comply(original));
+}

src/attributes.md

@@ -14,8 +14,8 @@ Examples include `#[allow]` and `#[macro_use]`.
 
 These attributes have several important characteristics:
 * They are always in scope, and do not participate in typical path-based resolution.
-* They cannot be renamed. For example, `use allow as foo` will compile, but writing `#[foo]` will
-  produce an error.
+* They cannot be renamed.
+  For example, `use allow as foo` will compile, but writing `#[foo]` will produce an error.
 * They are 'inert', meaning they are left as-is by the macro expansion code.
   As a result, any behavior comes as a result of the compiler explicitly checking for their presence.
   For example, lint-related code explicitly checks for `#[allow]`, `#[warn]`, `#[deny]`, and
@@ -30,26 +30,30 @@ For more information on these attributes, see the chapter about [attribute parsi
 These attributes are defined by a crate - either the standard library, or a proc-macro crate.
 
 **Important**: Many non-builtin attributes, such as `#[derive]`, are still considered part of the
-core Rust language. However, they are **not** called 'builtin attributes', since they have a
+core Rust language.
+However, they are **not** called 'builtin attributes', since they have a
 corresponding definition in the standard library.
 
 Definitions of non-builtin attributes take two forms:
 
 1. Proc-macro attributes, defined via a function annotated with `#[proc_macro_attribute]` in a
    proc-macro crate.
-2. AST-based attributes, defined in the standard library. These attributes have special 'stub'
+2. AST-based attributes, defined in the standard library.
+   These attributes have special 'stub'
    macros defined in places like [`library/core/src/macros/mod.rs`][core_macros].
 
 [core_macros]:  https://github.com/rust-lang/rust/blob/HEAD/library/core/src/macros/mod.rs
 
 These definitions exist to allow the macros to participate in typical path-based resolution - they
-can be imported, re-exported, and renamed just like any other item definition. However, the body of
-the definition is empty. Instead, the macro is annotated with the `#[rustc_builtin_macro]`
+can be imported, re-exported, and renamed just like any other item definition.
+However, the body of the definition is empty.
+Instead, the macro is annotated with the `#[rustc_builtin_macro]`
 attribute, which tells the compiler to run a corresponding function in `rustc_builtin_macros`.
 
 All non-builtin attributes have the following characteristics:
 * Like all other definitions (e.g. structs), they must be brought into scope via an import.
   Many standard library attributes are included in the prelude - this is why writing `#[derive]`
   works without an import.
-* They participate in macro expansion. The implementation of the macro may leave the attribute
+* They participate in macro expansion.
+  The implementation of the macro may leave the attribute
   target unchanged, modify the target, produce new AST nodes, or remove the target entirely.

src/autodiff/debugging.md

@@ -1,92 +1,128 @@
 # Reporting backend crashes
 
-If after a compilation failure you are greeted by a large amount of llvm-ir code, then our enzyme backend likely failed to compile your code. These cases are harder to debug, so your help is highly appreciated. Please also keep in mind that release builds are usually much more likely to work at the moment.
+If after a compilation failure you are greeted by a large amount of llvm-ir code, then our enzyme backend likely failed to compile your code.
+These cases are harder to debug, so your help is highly appreciated.
+Please also keep in mind that release builds are usually much more likely to work at the moment.
 
 The final goal here is to reproduce your bug in the enzyme [compiler explorer](https://enzyme.mit.edu/explorer/), in order to create a bug report in the [Enzyme](https://github.com/enzymead/enzyme/issues) repository.
 
-We have an `autodiff` flag which you can pass to `rustflags` to help with this. it will print the whole llvm-ir module, along with some `__enzyme_fwddiff` or `__enzyme_autodiff` calls. A potential workflow on linux could look like:  
+We have an `autodiff` flag which you can pass to `rustflags` to help with this.
+it will print the whole llvm-ir module, along with some `__enzyme_fwddiff` or `__enzyme_autodiff` calls.
+A potential workflow on linux could look like:
 
 ## Controlling llvm-ir generation
 
 Before generating the llvm-ir, keep in mind two techniques that can help ensure the relevant rust code is visible for debugging:
 
-- **`std::hint::black_box`**: wrap rust variables or expressions in `std::hint::black_box()` to prevent rust and llvm from optimizing them away. This is useful when you need to inspect or manually manipulate specific values in the llvm-ir.
-- **`extern "rust"` or `extern "c"`**: if you want to see how a specific function declaration is lowered to llvm-ir, you can declare it as `extern "rust"` or `extern "c"`. You can also look for existing `__enzyme_autodiff` or similar declarations within the generated module for examples.
+- **`std::hint::black_box`**: wrap rust variables or expressions in `std::hint::black_box()` to prevent rust and llvm from optimizing them away.
+  This is useful when you need to inspect or manually manipulate specific values in the llvm-ir.
+- **`extern "rust"` or `extern "c"`**: if you want to see how a specific function declaration is lowered to llvm-ir, you can declare it as `extern "rust"` or `extern "c"`.
+  You can also look for existing `__enzyme_autodiff` or similar declarations within the generated module for examples.
 
 ## 1) Generate an llvm-ir reproducer
 
 ```sh
-RUSTFLAGS="-Z autodiff=Enable,PrintModBefore" cargo +enzyme build --release &> out.ll 
+RUSTFLAGS="-Z autodiff=Enable,PrintModBefore" cargo +enzyme build --release &> out.ll
 ```
 
 This also captures a few warnings and info messages above and below your module. open out.ll and remove every line above `; moduleid = <somehash>`. Now look at the end of the file and remove everything that's not part of llvm-ir, i.e. remove errors and warnings. The last line of your llvm-ir should now start with `!<somenumber> = `, i.e. `!40831 = !{i32 0, i32 1037508, i32 1037538, i32 1037559}` or `!43760 = !dilocation(line: 297, column: 5, scope: !43746)`.
 
-The actual numbers will depend on your code.  
+The actual numbers will depend on your code.
 
 ## 2) Check your llvm-ir reproducer
 
-To confirm that your previous step worked, we will use llvm's `opt` tool. Find your path to the opt binary, with a path similar to `<some_dir>/rust/build/<x86/arm/...-target-triple>/ci-llvm/bin/opt`. If you build LLVM from source, you'll likely need to replace `ci-llvm` with `build`. Also find `llvmenzyme-21.<so/dll/dylib>` path, similar to `/rust/build/target-triple/enzyme/build/enzyme/llvmenzyme-21`. Please keep in mind that llvm frequently updates it's llvm backend, so the version number might be higher (20, 21, ...). Once you have both, run the following command:
+To confirm that your previous step worked, we will use llvm's `opt` tool.
+Find your path to the opt binary, with a path similar to `<some_dir>/rust/build/<x86/arm/...-target-triple>/ci-llvm/bin/opt`.
+If you build LLVM from source, you'll likely need to replace `ci-llvm` with `build`.
+Also find `llvmenzyme-21.<so/dll/dylib>` path, similar to `/rust/build/target-triple/enzyme/build/enzyme/llvmenzyme-21`.
+Please keep in mind that llvm frequently updates it's llvm backend, so the version number might be higher (20, 21, ...).
+Once you have both, run the following command:
 
 ```sh
 <path/to/opt> out.ll -load-pass-plugin=/path/to/build/<target-triple>/stage1/lib/libEnzyme-21.so -passes="enzyme" -enzyme-strict-aliasing=0  -S
 ```
-This command might fail for future versions or on your system, in which case you should replace libEnzyme-21.so with LLVMEnzyme-21.so. Look at the Enzyme docs for instructions on how to build it. You might need to also adjust how to build your LLVM version.
+This command might fail for future versions or on your system, in which case you should replace libEnzyme-21.so with LLVMEnzyme-21.so.
+Look at the Enzyme docs for instructions on how to build it.
+You might need to also adjust how to build your LLVM version.
 
-If the previous step succeeded, you are going to see the same error that you saw when compiling your rust code with cargo. 
+If the previous step succeeded, you are going to see the same error that you saw when compiling your rust code with cargo.
 
-If you fail to get the same error, please open an issue in the rust repository. If you succeed, congrats! the file is still huge, so let's automatically minimize it.
+If you fail to get the same error, please open an issue in the rust repository.
+If you succeed, congrats!
+The file is still huge, so let's automatically minimize it.
 
 ## 3) Minimize your llvm-ir reproducer
 
-First find your `llvm-extract` binary, it's in the same folder as your opt binary. then run:
+First, find your `llvm-extract` binary;
+it should be in the same folder as your opt binary.
+Then run:
 
 ```sh
 <path/to/llvm-extract> -S --func=<name> --recursive --rfunc="enzyme_autodiff*" --rfunc="enzyme_fwddiff*" --rfunc=<fnc_called_by_enzyme> out.ll -o mwe.ll
 ```
 
 This command creates `mwe.ll`, a minimal working example.
 
-Please adjust the name passed with the last `--func` flag. You can either apply the `#[no_mangle]` attribute to the function you differentiate, then you can replace it with the rust name. otherwise you will need to look up the mangled function name. To do that, open `out.ll` and search for `__enzyme_fwddiff` or `__enzyme_autodiff`. the first string in that function call is the name of your function. example:
+Please adjust the name passed with the last `--func` flag.
+You can either apply the `#[no_mangle]` attribute to the function you differentiate, then you can replace it with the rust name.
+Otherwise you will need to look up the mangled function name.
+To do that, open `out.ll` and search for `__enzyme_fwddiff` or `__enzyme_autodiff`.
+The first string in that function call is the name of your function.
+Example:
 
-```llvm-ir 
+```llvm-ir
 define double @enzyme_opt_helper_0(ptr %0, i64 %1, double %2) {
   %4 = call double (...) @__enzyme_fwddiff(ptr @_zn2ad3_f217h3b3b1800bd39fde3e, metadata !"enzyme_const", ptr %0, metadata !"enzyme_const", i64 %1, metadata !"enzyme_dup", double %2, double %2)
   ret double %4
 }
 ```
 
-Here, `_zn2ad3_f217h3b3b1800bd39fde3e` is the correct name. make sure to not copy the leading `@`. redo step 2) by running the `opt` command again, but this time passing `mwe.ll` as the input file instead of `out.ll`. Check if this minimized example still reproduces the crash.
+Here, `_zn2ad3_f217h3b3b1800bd39fde3e` is the correct name.
+Make sure to not copy the leading `@`.
+Redo step 2) by running the `opt` command again, but this time passing `mwe.ll` as the input file instead of `out.ll`.
+Check if this minimized example still reproduces the crash.
 
 ## 4) (Optional) Minimize your llvm-ir reproducer further.
 
-After the previous step you should have an `mwe.ll` file with ~5k loc. let's try to get it down to 50. find your `llvm-reduce` binary next to `opt` and `llvm-extract`. Copy the first line of your error message, an example could be:
+After the previous step you should have an `mwe.ll` file with ~5k loc.
+Let's try to get it down to 50. find your `llvm-reduce` binary next to `opt` and `llvm-extract`.
+Copy the first line of your error message, an example could be:
 
 ```sh
 opt: /home/manuel/prog/rust/src/llvm-project/llvm/lib/ir/instructions.cpp:686: void llvm::callinst::init(llvm::functiontype*, llvm::value*, llvm::arrayref<llvm::value*>, llvm::arrayref<llvm::operandbundledeft<llvm::value*> >, const llvm::twine&): assertion `(args.size() == fty->getnumparams() || (fty->isvararg() && args.size() > fty->getnumparams())) && "calling a function with bad signature!"' failed.
 ```
 
-If you just get a `segfault` there is no sensible error message and not much to do automatically, so continue to 5).  
-otherwise, create a `script.sh` file containing
+If you just get a `segfault` there is no sensible error message and not much to do automatically, so continue to 5).
+
+Otherwise, create a `script.sh` file containing
 
 ```sh
 #!/bin/bash
 <path/to/your/opt> $1 -load-pass-plugin=/path/to/llvmenzyme-19.so -passes="enzyme" \
     |& grep "/some/path.cpp:686: void llvm::callinst::init"
 ```
 
-Experiment a bit with which error message you pass to grep. it should be long enough to make sure that the error is unique. However, for longer errors including `(` or `)` you will need to escape them correctly which can become annoying. Run
+Experiment a bit with which error message you pass to grep.
+It should be long enough to make sure that the error is unique.
+However, for longer errors including `(` or `)` you will need to escape them correctly which can become annoying.
+Run:
 
-```sh 
-<path/to/llvm-reduce> --test=script.sh mwe.ll 
+```sh
+<path/to/llvm-reduce> --test=script.sh mwe.ll
 ```
 
-If you see `input isn't interesting! verify interesting-ness test`, you got the error message in script.sh wrong, you need to make sure that grep matches your actual error. If all works out, you will see a lot of iterations, ending with a new `reduced.ll` file. Verify with `opt` that you still get the same error.
+If you see `input isn't interesting! verify interesting-ness test`,
+you got the error message in script.sh wrong, and need to make sure that grep matches your actual error.
+If all works out, you will see a lot of iterations, ending with a new `reduced.ll` file.
+Verify with `opt` that you still get the same error.
 
 ### Advanced debugging: manual llvm-ir investigation
 
 Once you have a minimized reproducer (`mwe.ll` or `reduced.ll`), you can delve deeper:
 
-- **manual editing:** try manually rewriting the llvm-ir. for certain issues, like those involving indirect calls, you might investigate enzyme-specific intrinsics like `__enzyme_virtualreverse`. Understanding how to use these might require consulting enzyme's documentation or source code.
+- **manual editing:** try manually rewriting the llvm-ir.
+  For certain issues, like those involving indirect calls, you might investigate enzyme-specific intrinsics like `__enzyme_virtualreverse`.
+  Understanding how to use these might require consulting enzyme's documentation or source code.
 - **enzyme test cases:** look for relevant test cases within the [enzyme repository](https://github.com/enzymead/enzyme/tree/main/enzyme/test) that might demonstrate the correct usage of features or intrinsics related to your problem.
 
 ## 5) Report your bug.
@@ -97,18 +133,27 @@ Afterwards, you should be able to copy and paste your `mwe.ll` (or `reduced.ll`)
 - Replace the field to the right of your compiler with `-passes="enzyme"`, if it is not already set.
 - Hopefully, you will see once again your now familiar error.
 - Please use the share button to copy links to them.
-- Please create an issue on [https://github.com/enzymead/enzyme/issues](https://github.com/enzymead/enzyme/issues) and share `mwe.ll` and (if you have it) `reduced.ll`, as well as links to the compiler explorer. Please feel free to also add your rust code or a link to it.
+- Please create an issue on [https://github.com/enzymead/enzyme/issues](https://github.com/enzymead/enzyme/issues) and share `mwe.ll` and (if you have it) `reduced.ll`, as well as links to the compiler explorer.
+  Please feel free to also add your rust code or a link to it.
 
 #### Documenting findings
 
-some enzyme errors, like `"attempting to call an indirect active function whose runtime value is inactive"`, have historically caused confusion. If you investigate such an issue, even if you don't find a complete solution, please consider documenting your findings. If the insights are general to enzyme and not specific to its rust usage, contributing them to the main [enzyme documentation](https://github.com/enzymead/www) is often the best first step. You can also mention your findings in the relevant enzyme github issue or propose updates to these docs if appropriate. This helps prevent others from starting from scratch.
+Some enzyme errors, like `"attempting to call an indirect active function whose runtime value is inactive"`, have historically caused confusion.
+If you investigate such an issue, even if you don't find a complete solution, please consider documenting your findings.
+If the insights are general to enzyme and not specific to its rust usage, contributing them to the main [enzyme documentation](https://github.com/enzymead/www) is often the best first step.
+You can also mention your findings in the relevant enzyme github issue or propose updates to these docs if appropriate.
+This helps prevent others from starting from scratch.
 
-With a clear reproducer and documentation, hopefully an enzyme developer will be able to fix your bug. Once that happens, the enzyme submodule inside the rust compiler will be updated, which should allow you to differentiate your rust code. Thanks for helping us to improve rust-ad.
+With a clear reproducer and documentation, hopefully an enzyme developer will be able to fix your bug.
+Once that happens, the enzyme submodule inside the rust compiler will be updated, which should allow you to differentiate your rust code.
+Thanks for helping us to improve rust-ad.
 
 # Minimize rust code
 
-Beyond having a minimal llvm-ir reproducer, it is also helpful to have a minimal rust reproducer without dependencies. This allows us to add it as a test case to ci once we fix it, which avoids regressions for the future.
+Beyond having a minimal llvm-ir reproducer, it is also helpful to have a minimal rust reproducer without dependencies.
+This allows us to add it as a test case to ci once we fix it, which avoids regressions for the future.
 
-There are a few solutions to help you with minimizing the rust reproducer. This is probably the most simple automated approach: [cargo-minimize](https://github.com/nilstrieb/cargo-minimize).
+There are a few solutions to help you with minimizing the rust reproducer.
+This is probably the most simple automated approach: [cargo-minimize](https://github.com/nilstrieb/cargo-minimize).
 
 Otherwise we have various alternatives, including [`treereduce`](https://github.com/langston-barrett/treereduce), [`halfempty`](https://github.com/googleprojectzero/halfempty), or [`picireny`](https://github.com/renatahodovan/picireny), potentially also [`creduce`](https://github.com/csmith-project/creduce).

src/autodiff/installation.md

@@ -6,11 +6,13 @@ Most users can enable `std::autodiff` on their latest nightly toolchain by insta
 - **macOS**: with `aarch64-apple-darwin`
 - **Windows**: with `x86_64-llvm-mingw` or `aarch64-llvm-mingw`
 
-As a rustc/enzyme/autodiff contributor, or if you need any other platform, you can build rustc including autodiff from source. Please open an issue if you want help enabling automatic builds for your preferred target.
+As a rustc/enzyme/autodiff contributor, or if you need any other platform, you can build rustc including autodiff from source.
+Please open an issue if you want help enabling automatic builds for your preferred target.
 
 ## Installation guide
 
-If you want to use `std::autodiff` on Linux, macOS, or Windows and don't plan to contribute PR's to the project, then we recommend to just use your existing nightly installation and download the missing component. Please run:
+If you want to use `std::autodiff` on Linux, macOS, or Windows and don't plan to contribute PR's to the project, then we recommend to just use your existing nightly installation and download the missing component.
+Please run:
 
 ```console
 rustup +nightly component add enzyme