From 75a6f9a8ce4b1eda1d47c6e2b22deab626820301 Mon Sep 17 00:00:00 2001
From: Chris Fallin <chris@cfallin.org>
Date: Fri, 10 Feb 2023 21:04:01 -0800
Subject: [PATCH] Add missing ir/debug.rs.

---
 src/ir/debug.rs | 78 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 src/ir/debug.rs

diff --git a/src/ir/debug.rs b/src/ir/debug.rs
new file mode 100644
index 0000000..5602cca
--- /dev/null
+++ b/src/ir/debug.rs
@@ -0,0 +1,78 @@
+//! Debug info (currently, source-location maps).
+
+use crate::declare_entity;
+use crate::entity::EntityVec;
+use addr2line::gimli;
+use std::collections::hash_map::Entry as HashEntry;
+use std::collections::HashMap;
+
+declare_entity!(SourceFile, "file");
+declare_entity!(SourceLoc, "loc");
+
+#[derive(Clone, Debug, Default)]
+pub struct Debug {
+    source_files: EntityVec<SourceFile, String>,
+    source_file_dedup: HashMap<String, SourceFile>,
+    source_locs: EntityVec<SourceLoc, SourceLocData>,
+    source_loc_dedup: HashMap<SourceLocData, SourceLoc>,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct SourceLocData {
+    file: SourceFile,
+    line: u32,
+    col: u32,
+}
+
+impl Debug {
+    pub fn intern_file(&mut self, path: &str) -> SourceFile {
+        if let Some(id) = self.source_file_dedup.get(path) {
+            return *id;
+        }
+        let id = self.source_files.push(path.to_owned());
+        self.source_file_dedup.insert(path.to_owned(), id);
+        id
+    }
+
+    pub fn intern_loc(&mut self, file: SourceFile, line: u32, col: u32) -> SourceLoc {
+        let data = SourceLocData { file, line, col };
+        match self.source_loc_dedup.entry(data) {
+            HashEntry::Vacant(v) => {
+                let id = self.source_locs.push(data);
+                *v.insert(id)
+            }
+            HashEntry::Occupied(o) => *o.get(),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default)]
+pub struct DebugMap {
+    tuples: Vec<(u32, u32, SourceLoc)>,
+}
+
+impl DebugMap {
+    pub(crate) fn from_dwarf<R: gimli::Reader>(
+        dwarf: gimli::Dwarf<R>,
+        debug: &mut Debug,
+    ) -> DebugMap {
+        let ctx = addr2line::Context::from_dwarf(dwarf).unwrap();
+        let mut tuples = vec![];
+
+        let mut locs = ctx.find_location_range(0, u64::MAX).unwrap();
+        while let Some((start, end, loc)) = locs.next() {
+            let file = debug.intern_file(loc.file.unwrap_or(""));
+            let loc = debug.intern_loc(file, loc.line.unwrap_or(0), loc.column.unwrap_or(0));
+            tuples.push((start as u32, end as u32, loc));
+        }
+
+        log::trace!("tuples:");
+        for &(start, end, loc) in &tuples {
+            log::trace!(" {:x} - {:x}: {}", start, end, loc);
+        }
+        log::trace!("files: {:?}", debug.source_files);
+        log::trace!("locs: {:?}", debug.source_locs);
+
+        DebugMap { tuples }
+    }
+}