Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide/src/view_memory_layout.rs')
| -rw-r--r-- | crates/ide/src/view_memory_layout.rs | 409 |
1 files changed, 409 insertions, 0 deletions
diff --git a/crates/ide/src/view_memory_layout.rs b/crates/ide/src/view_memory_layout.rs new file mode 100644 index 0000000000..2f6332abd2 --- /dev/null +++ b/crates/ide/src/view_memory_layout.rs @@ -0,0 +1,409 @@ +use std::fmt; + +use hir::{Field, HirDisplay, Layout, Semantics, Type}; +use ide_db::{ + defs::Definition, + helpers::{get_definition, pick_best_token}, + RootDatabase, +}; +use syntax::{AstNode, SyntaxKind}; + +use crate::FilePosition; + +pub struct MemoryLayoutNode { + pub item_name: String, + pub typename: String, + pub size: u64, + pub alignment: u64, + pub offset: u64, + pub parent_idx: i64, + pub children_start: i64, + pub children_len: u64, +} + +pub struct RecursiveMemoryLayout { + pub nodes: Vec<MemoryLayoutNode>, +} + +// NOTE: this is currently strictly for testing and so isn't super useful as a visualization tool, however it could be adapted to become one? +impl fmt::Display for RecursiveMemoryLayout { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fn process( + fmt: &mut fmt::Formatter<'_>, + nodes: &Vec<MemoryLayoutNode>, + idx: usize, + depth: usize, + ) -> fmt::Result { + let mut out = "\t".repeat(depth); + let node = &nodes[idx]; + out += &format!( + "{}: {} (size: {}, align: {}, field offset: {})\n", + node.item_name, node.typename, node.size, node.alignment, node.offset + ); + write!(fmt, "{}", out)?; + if node.children_start != -1 { + for j in nodes[idx].children_start + ..(nodes[idx].children_start + nodes[idx].children_len as i64) + { + process(fmt, nodes, j as usize, depth + 1)?; + } + } + Ok(()) + } + + process(fmt, &self.nodes, 0, 0) + } +} + +enum FieldOrTupleIdx { + Field(Field), + TupleIdx(usize), +} + +impl FieldOrTupleIdx { + fn name(&self, db: &RootDatabase) -> String { + match *self { + FieldOrTupleIdx::Field(f) => f + .name(db) + .as_str() + .map(|s| s.to_owned()) + .unwrap_or_else(|| format!(".{}", f.name(db).as_tuple_index().unwrap())), + FieldOrTupleIdx::TupleIdx(i) => format!(".{i}").to_owned(), + } + } + + fn index(&self) -> usize { + match *self { + FieldOrTupleIdx::Field(f) => f.index(), + FieldOrTupleIdx::TupleIdx(i) => i, + } + } +} + +// Feature: View Memory Layout +// +// Displays the recursive memory layout of a datatype. +// +// |=== +// | Editor | Action Name +// +// | VS Code | **rust-analyzer: View Memory Layout** +// |=== +pub(crate) fn view_memory_layout( + db: &RootDatabase, + position: FilePosition, +) -> Option<RecursiveMemoryLayout> { + let sema = Semantics::new(db); + let file = sema.parse(position.file_id); + let token = + pick_best_token(file.syntax().token_at_offset(position.offset), |kind| match kind { + SyntaxKind::IDENT => 3, + _ => 0, + })?; + + let def = get_definition(&sema, token)?; + + let ty = match def { + Definition::Adt(it) => it.ty(db), + Definition::TypeAlias(it) => it.ty(db), + Definition::BuiltinType(it) => it.ty(db), + Definition::SelfType(it) => it.self_ty(db), + Definition::Local(it) => it.ty(db), + Definition::Field(it) => it.ty(db), + Definition::Const(it) => it.ty(db), + Definition::Static(it) => it.ty(db), + _ => return None, + }; + + fn read_layout( + nodes: &mut Vec<MemoryLayoutNode>, + db: &RootDatabase, + ty: &Type, + layout: &Layout, + parent_idx: usize, + ) { + let mut fields = ty + .fields(db) + .into_iter() + .map(|(f, ty)| (FieldOrTupleIdx::Field(f), ty)) + .chain( + ty.tuple_fields(db) + .into_iter() + .enumerate() + .map(|(i, ty)| (FieldOrTupleIdx::TupleIdx(i), ty)), + ) + .collect::<Vec<_>>(); + + if fields.len() == 0 { + return; + } + + fields.sort_by_key(|(f, _)| layout.field_offset(f.index()).unwrap()); + + let children_start = nodes.len(); + nodes[parent_idx].children_start = children_start as i64; + nodes[parent_idx].children_len = fields.len() as u64; + + for (field, child_ty) in fields.iter() { + if let Ok(child_layout) = child_ty.layout(db) { + nodes.push(MemoryLayoutNode { + item_name: field.name(db), + typename: child_ty.display(db).to_string(), + size: child_layout.size(), + alignment: child_layout.align(), + offset: layout.field_offset(field.index()).unwrap_or(0), + parent_idx: parent_idx as i64, + children_start: -1, + children_len: 0, + }); + } else { + nodes.push(MemoryLayoutNode { + item_name: field.name(db) + + format!("(no layout data: {:?})", child_ty.layout(db).unwrap_err()) + .as_ref(), + typename: child_ty.display(db).to_string(), + size: 0, + offset: 0, + alignment: 0, + parent_idx: parent_idx as i64, + children_start: -1, + children_len: 0, + }); + } + } + + for (i, (_, child_ty)) in fields.iter().enumerate() { + if let Ok(child_layout) = child_ty.layout(db) { + read_layout(nodes, db, &child_ty, &child_layout, children_start + i); + } + } + } + + ty.layout(db) + .map(|layout| { + let item_name = match def { + // def is a datatype + Definition::Adt(_) + | Definition::TypeAlias(_) + | Definition::BuiltinType(_) + | Definition::SelfType(_) => "[ROOT]".to_owned(), + + // def is an item + def => def + .name(db) + .map(|n| { + n.as_str() + .map(|s| s.to_owned()) + .unwrap_or_else(|| format!(".{}", n.as_tuple_index().unwrap())) + }) + .unwrap_or("[ROOT]".to_owned()), + }; + + let typename = ty.display(db).to_string(); + + let mut nodes = vec![MemoryLayoutNode { + item_name, + typename: typename.clone(), + size: layout.size(), + offset: 0, + alignment: layout.align(), + parent_idx: -1, + children_start: -1, + children_len: 0, + }]; + read_layout(&mut nodes, db, &ty, &layout, 0); + + RecursiveMemoryLayout { nodes } + }) + .ok() +} + +#[cfg(test)] +mod tests { + use super::*; + + use crate::fixture; + use expect_test::expect; + + fn make_memory_layout(ra_fixture: &str) -> Option<RecursiveMemoryLayout> { + let (analysis, position, _) = fixture::annotations(ra_fixture); + + view_memory_layout(&analysis.db, position) + } + + #[test] + fn view_memory_layout_none() { + assert!(make_memory_layout(r#"$0"#).is_none()); + assert!(make_memory_layout(r#"stru$0ct Blah {}"#).is_none()); + } + + #[test] + fn view_memory_layout_primitive() { + expect![[r#" + foo: i32 (size: 4, align: 4, field offset: 0) + "#]] + .assert_eq( + &make_memory_layout( + r#" +fn main() { + let foo$0 = 109; // default i32 +} +"#, + ) + .unwrap() + .to_string(), + ); + } + + #[test] + fn view_memory_layout_constant() { + expect![[r#" + BLAH: bool (size: 1, align: 1, field offset: 0) + "#]] + .assert_eq( + &make_memory_layout( + r#" +const BLAH$0: bool = 0; +"#, + ) + .unwrap() + .to_string(), + ); + } + + #[test] + fn view_memory_layout_static() { + expect![[r#" + BLAH: bool (size: 1, align: 1, field offset: 0) + "#]] + .assert_eq( + &make_memory_layout( + r#" +static BLAH$0: bool = 0; +"#, + ) + .unwrap() + .to_string(), + ); + } + + #[test] + fn view_memory_layout_tuple() { + expect![[r#" + x: (f64, u8, i64) (size: 24, align: 8, field offset: 0) + .0: f64 (size: 8, align: 8, field offset: 0) + .1: u8 (size: 1, align: 1, field offset: 8) + .2: i64 (size: 8, align: 8, field offset: 16) + "#]] + .assert_eq( + &make_memory_layout( + r#" +fn main() { + let x$0 = (101.0, 111u8, 119i64); +} +"#, + ) + .unwrap() + .to_string(), + ); + } + + #[test] + fn view_memory_layout_c_struct() { + expect![[r#" + [ROOT]: Blah (size: 16, align: 4, field offset: 0) + a: u32 (size: 4, align: 4, field offset: 0) + b: (i32, u8) (size: 8, align: 4, field offset: 4) + .0: i32 (size: 4, align: 4, field offset: 0) + .1: u8 (size: 1, align: 1, field offset: 4) + c: i8 (size: 1, align: 1, field offset: 12) + "#]] + .assert_eq( + &make_memory_layout( + r#" +#[repr(C)] +struct Blah$0 { + a: u32, + b: (i32, u8), + c: i8, +} +"#, + ) + .unwrap() + .to_string(), + ); + } + + #[test] + fn view_memory_layout_struct() { + expect![[r#" + [ROOT]: Blah (size: 16, align: 4, field offset: 0) + b: (i32, u8) (size: 8, align: 4, field offset: 0) + .0: i32 (size: 4, align: 4, field offset: 0) + .1: u8 (size: 1, align: 1, field offset: 4) + a: u32 (size: 4, align: 4, field offset: 8) + c: i8 (size: 1, align: 1, field offset: 12) + "#]] + .assert_eq( + &make_memory_layout( + r#" +struct Blah$0 { + a: u32, + b: (i32, u8), + c: i8, +} +"#, + ) + .unwrap() + .to_string(), + ); + } + + #[test] + fn view_memory_layout_member() { + expect![[r#" + a: bool (size: 1, align: 1, field offset: 0) + "#]] + .assert_eq( + &make_memory_layout( + r#" +#[repr(C)] +struct Oof { + a$0: bool, +} +"#, + ) + .unwrap() + .to_string(), + ); + } + + #[test] + fn view_memory_layout_alias() { + let ml_a = make_memory_layout( + r#" +struct X { + a: u32, + b: i8, + c: (f32, f32), +} + +type Foo$0 = X; +"#, + ) + .unwrap(); + + let ml_b = make_memory_layout( + r#" +struct X$0 { + a: u32, + b: i8, + c: (f32, f32), +} +"#, + ) + .unwrap(); + + assert_eq!(ml_a.to_string(), ml_b.to_string()); + } +} |