Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 251 insertions, 0 deletions

diff --git a/library/stdarch/crates/assert-instr-macro/src/lib.rs b/library/stdarch/crates/assert-instr-macro/src/lib.rs
new file mode 100644
index 000000000..9fa411df3
--- /dev/null
+++ b/library/stdarch/crates/assert-instr-macro/src/lib.rs
@@ -0,0 +1,251 @@
+//! Implementation of the `#[assert_instr]` macro
+//!
+//! This macro is used when testing the `stdarch` crate and is used to generate
+//! test cases to assert that functions do indeed contain the instructions that
+//! we're expecting them to contain.
+//!
+//! The procedural macro here is relatively simple, it simply appends a
+//! `#[test]` function to the original token stream which asserts that the
+//! function itself contains the relevant instruction.
+#![deny(rust_2018_idioms)]
+
+#[macro_use]
+extern crate quote;
+
+use proc_macro2::TokenStream;
+use quote::ToTokens;
+
+#[proc_macro_attribute]
+pub fn assert_instr(
+    attr: proc_macro::TokenStream,
+    item: proc_macro::TokenStream,
+) -> proc_macro::TokenStream {
+    let invoc = match syn::parse::<Invoc>(attr) {
+        Ok(s) => s,
+        Err(e) => return e.to_compile_error().into(),
+    };
+    let item = match syn::parse::<syn::Item>(item) {
+        Ok(s) => s,
+        Err(e) => return e.to_compile_error().into(),
+    };
+    let func = match item {
+        syn::Item::Fn(ref f) => f,
+        _ => panic!("must be attached to a function"),
+    };
+
+    let instr = &invoc.instr;
+    let name = &func.sig.ident;
+
+    // Disable assert_instr for x86 targets compiled with avx enabled, which
+    // causes LLVM to generate different intrinsics that the ones we are
+    // testing for.
+    let disable_assert_instr = std::env::var("STDARCH_DISABLE_ASSERT_INSTR").is_ok();
+
+    // Disable dedup guard. Only works if the LLVM MergeFunctions pass is disabled, e.g.
+    // with `-Z merge-functions=disabled` in RUSTFLAGS.
+    let disable_dedup_guard = std::env::var("STDARCH_DISABLE_DEDUP_GUARD").is_ok();
+
+    // If instruction tests are disabled avoid emitting this shim at all, just
+    // return the original item without our attribute.
+    if !cfg!(optimized) || disable_assert_instr {
+        return (quote! { #item }).into();
+    }
+
+    let instr_str = instr
+        .replace('.', "_")
+        .replace('/', "_")
+        .replace(':', "_")
+        .replace(char::is_whitespace, "");
+    let assert_name = syn::Ident::new(&format!("assert_{}_{}", name, instr_str), name.span());
+    // These name has to be unique enough for us to find it in the disassembly later on:
+    let shim_name = syn::Ident::new(
+        &format!("stdarch_test_shim_{}_{}", name, instr_str),
+        name.span(),
+    );
+    let shim_name_ptr = syn::Ident::new(
+        &format!("stdarch_test_shim_{}_{}_ptr", name, instr_str).to_ascii_uppercase(),
+        name.span(),
+    );
+    let mut inputs = Vec::new();
+    let mut input_vals = Vec::new();
+    let mut const_vals = Vec::new();
+    let ret = &func.sig.output;
+    for arg in func.sig.inputs.iter() {
+        let capture = match *arg {
+            syn::FnArg::Typed(ref c) => c,
+            ref v => panic!(
+                "arguments must not have patterns: `{:?}`",
+                v.clone().into_token_stream()
+            ),
+        };
+        let ident = match *capture.pat {
+            syn::Pat::Ident(ref i) => &i.ident,
+            _ => panic!("must have bare arguments"),
+        };
+        if let Some(&(_, ref tokens)) = invoc.args.iter().find(|a| *ident == a.0) {
+            input_vals.push(quote! { #tokens });
+        } else {
+            inputs.push(capture);
+            input_vals.push(quote! { #ident });
+        }
+    }
+    for arg in func.sig.generics.params.iter() {
+        let c = match *arg {
+            syn::GenericParam::Const(ref c) => c,
+            ref v => panic!(
+                "only const generics are allowed: `{:?}`",
+                v.clone().into_token_stream()
+            ),
+        };
+        if let Some(&(_, ref tokens)) = invoc.args.iter().find(|a| c.ident == a.0) {
+            const_vals.push(quote! { #tokens });
+        } else {
+            panic!("const generics must have a value for tests");
+        }
+    }
+
+    let attrs = func
+        .attrs
+        .iter()
+        .filter(|attr| {
+            attr.path
+                .segments
+                .first()
+                .expect("attr.path.segments.first() failed")
+                .ident
+                .to_string()
+                .starts_with("target")
+        })
+        .collect::<Vec<_>>();
+    let attrs = Append(&attrs);
+
+    // Use an ABI on Windows that passes SIMD values in registers, like what
+    // happens on Unix (I think?) by default.
+    let abi = if cfg!(windows) {
+        let target = std::env::var("TARGET").unwrap();
+        if target.contains("x86_64") {
+            syn::LitStr::new("sysv64", proc_macro2::Span::call_site())
+        } else {
+            syn::LitStr::new("vectorcall", proc_macro2::Span::call_site())
+        }
+    } else {
+        syn::LitStr::new("C", proc_macro2::Span::call_site())
+    };
+    let shim_name_str = format!("{}{}", shim_name, assert_name);
+    let to_test = if disable_dedup_guard {
+        quote! {
+            #attrs
+            #[no_mangle]
+            #[inline(never)]
+            pub unsafe extern #abi fn #shim_name(#(#inputs),*) #ret {
+                #name::<#(#const_vals),*>(#(#input_vals),*)
+            }
+        }
+    } else {
+        quote! {
+
+            const #shim_name_ptr : *const u8 = #shim_name_str.as_ptr();
+
+            #attrs
+            #[no_mangle]
+            #[inline(never)]
+            pub unsafe extern #abi fn #shim_name(#(#inputs),*) #ret {
+                // The compiler in optimized mode by default runs a pass called
+                // "mergefunc" where it'll merge functions that look identical.
+                // Turns out some intrinsics produce identical code and they're
+                // folded together, meaning that one just jumps to another. This
+                // messes up our inspection of the disassembly of this function and
+                // we're not a huge fan of that.
+                //
+                // To thwart this pass and prevent functions from being merged we
+                // generate some code that's hopefully very tight in terms of
+                // codegen but is otherwise unique to prevent code from being
+                // folded.
+                ::stdarch_test::_DONT_DEDUP = #shim_name_ptr;
+                #name::<#(#const_vals),*>(#(#input_vals),*)
+            }
+        }
+    };
+
+    let tokens: TokenStream = quote! {
+        #[test]
+        #[allow(non_snake_case)]
+        fn #assert_name() {
+            #to_test
+
+            ::stdarch_test::assert(#shim_name as usize,
+                                   stringify!(#shim_name),
+                                   #instr);
+        }
+    };
+
+    let tokens: TokenStream = quote! {
+        #item
+        #tokens
+    };
+    tokens.into()
+}
+
+struct Invoc {
+    instr: String,
+    args: Vec<(syn::Ident, syn::Expr)>,
+}
+
+impl syn::parse::Parse for Invoc {
+    fn parse(input: syn::parse::ParseStream<'_>) -> syn::Result<Self> {
+        use syn::{ext::IdentExt, Token};
+
+        let mut instr = String::new();
+        while !input.is_empty() {
+            if input.parse::<Token![,]>().is_ok() {
+                break;
+            }
+            if let Ok(ident) = syn::Ident::parse_any(input) {
+                instr.push_str(&ident.to_string());
+                continue;
+            }
+            if input.parse::<Token![.]>().is_ok() {
+                instr.push('.');
+                continue;
+            }
+            if let Ok(s) = input.parse::<syn::LitStr>() {
+                instr.push_str(&s.value());
+                continue;
+            }
+            println!("{:?}", input.cursor().token_stream());
+            return Err(input.error("expected an instruction"));
+        }
+        if instr.is_empty() {
+            return Err(input.error("expected an instruction before comma"));
+        }
+        let mut args = Vec::new();
+        while !input.is_empty() {
+            let name = input.parse::<syn::Ident>()?;
+            input.parse::<Token![=]>()?;
+            let expr = input.parse::<syn::Expr>()?;
+            args.push((name, expr));
+
+            if input.parse::<Token![,]>().is_err() {
+                if !input.is_empty() {
+                    return Err(input.error("extra tokens at end"));
+                }
+                break;
+            }
+        }
+        Ok(Self { instr, args })
+    }
+}
+
+struct Append<T>(T);
+
+impl<T> quote::ToTokens for Append<T>
+where
+    T: Clone + IntoIterator,
+    T::Item: quote::ToTokens,
+{
+    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
+        for item in self.0.clone() {
+            item.to_tokens(tokens);
+        }
+    }
+}