Add support for MwOverlayBranch (#24)

* Add support for MwOverlayBranch

* Make clippy happy

* cargo fmt

src/cmd/dwarf.rs

@@ -15,8 +15,8 @@ use syntect::{
 
 use crate::util::{
     dwarf::{
-        process_cu_tag, process_root_tag, read_debug_section, should_skip_tag, tag_type_string,
-        AttributeKind, TagKind,
+        process_compile_unit, process_cu_tag, process_overlay_branch, read_debug_section,
+        should_skip_tag, tag_type_string, AttributeKind, TagKind,
     },
     file::{buf_writer, map_file},
 };
@@ -163,7 +163,33 @@ where
     let mut units = Vec::<String>::new();
     if let Some((_, mut tag)) = info.tags.first_key_value() {
         loop {
-            let unit = process_root_tag(tag)?;
+            match tag.kind {
+                TagKind::Padding => {
+                    // TODO
+                }
+                TagKind::MwOverlayBranch => {
+                    let branch = process_overlay_branch(tag)?;
+                    writeln!(w, "\n/*\n    Overlay: {}", branch.name)?;
+                    writeln!(w, "    Overlay ID: {}", branch.id)?;
+                    writeln!(
+                        w,
+                        "    Code range: {:#010X} -> {:#010X}",
+                        branch.start_address, branch.end_address
+                    )?;
+
+                    if let Some(unit_addr) = branch.compile_unit {
+                        let tag = info
+                            .tags
+                            .get(&unit_addr)
+                            .ok_or_else(|| anyhow!("Failed to get CompileUnit"))?;
+                        let unit = process_compile_unit(tag)?;
+                        writeln!(w, "    Compile unit: {}", unit.name)?;
+                    }
+
+                    writeln!(w, "*/")?;
+                }
+                TagKind::CompileUnit => {
+                    let unit = process_compile_unit(tag)?;
                     if units.contains(&unit.name) {
                         // log::warn!("Duplicate unit '{}'", unit.name);
                     } else {
@@ -207,7 +233,12 @@ where
                         match tag_type_string(&info, &typedefs, &tag_type) {
                             Ok(s) => writeln!(w, "{}", s)?,
                             Err(e) => {
-                        log::error!("Failed to emit tag {} (unit {}): {}", child.key, unit.name, e);
+                                log::error!(
+                                    "Failed to emit tag {} (unit {}): {}",
+                                    child.key,
+                                    unit.name,
+                                    e
+                                );
                                 writeln!(
                                     w,
                                     "// ERROR: Failed to emit tag {} ({:?})",
@@ -219,7 +250,8 @@ where
 
                         if let TagKind::Typedef = child.kind {
                             // TODO fundamental typedefs?
-                    if let Some(ud_type_ref) = child.reference_attribute(AttributeKind::UserDefType)
+                            if let Some(ud_type_ref) =
+                                child.reference_attribute(AttributeKind::UserDefType)
                             {
                                 match typedefs.entry(ud_type_ref) {
                                     btree_map::Entry::Vacant(e) => {
@@ -232,6 +264,9 @@ where
                             }
                         }
                     }
+                }
+                kind => bail!("Unhandled root tag type {:?}", kind),
+            }
 
             if let Some(next) = tag.next_sibling(&info.tags) {
                 tag = next;

src/util/dwarf.rs

@@ -799,6 +799,15 @@ pub struct CompileUnit {
     pub end_address: Option<u32>,
 }
 
+#[derive(Debug, Clone)]
+pub struct OverlayBranch {
+    pub name: String,
+    pub id: u32,
+    pub start_address: u32,
+    pub end_address: u32,
+    pub compile_unit: Option<u32>,
+}
+
 impl UserDefinedType {
     pub fn name(&self) -> Option<String> {
         match self {
@@ -2343,7 +2352,7 @@ pub fn process_type(attr: &Attribute, e: Endian) -> Result<Type> {
     }
 }
 
-pub fn process_root_tag(tag: &Tag) -> Result<CompileUnit> {
+pub fn process_compile_unit(tag: &Tag) -> Result<CompileUnit> {
     ensure!(tag.kind == TagKind::CompileUnit, "{:?} is not a CompileUnit tag", tag.kind);
 
     let mut name = None;
@@ -2374,6 +2383,35 @@ pub fn process_root_tag(tag: &Tag) -> Result<CompileUnit> {
     Ok(CompileUnit { name, producer, language, start_address, end_address })
 }
 
+pub fn process_overlay_branch(tag: &Tag) -> Result<OverlayBranch> {
+    ensure!(tag.kind == TagKind::MwOverlayBranch, "{:?} is not an OverlayBranch tag", tag.kind);
+
+    let mut name = None;
+    let mut id = None;
+    let mut start_address = None;
+    let mut end_address = None;
+    let mut compile_unit = None;
+    for attr in &tag.attributes {
+        match (attr.kind, &attr.value) {
+            (AttributeKind::Sibling, _) => {}
+            (AttributeKind::Member, AttributeValue::Reference(addr)) => compile_unit = Some(*addr),
+            (AttributeKind::MwOverlayName, AttributeValue::String(s)) => name = Some(s.clone()),
+            (AttributeKind::MwOverlayId, AttributeValue::Data4(value)) => id = Some(*value),
+            (AttributeKind::LowPc, &AttributeValue::Address(addr)) => start_address = Some(addr),
+            (AttributeKind::HighPc, &AttributeValue::Address(addr)) => end_address = Some(addr),
+            _ => bail!("Unhandled OverlayBranch attribute {:?}", attr),
+        }
+    }
+
+    let name = name.ok_or_else(|| anyhow!("OverlayBranch without Name: {:?}", tag))?;
+    let id = id.ok_or_else(|| anyhow!("OverlayBranch without Id: {:?}", tag))?;
+    let start_address =
+        start_address.ok_or_else(|| anyhow!("OverlayBranch without LowPc: {:?}", tag))?;
+    let end_address =
+        end_address.ok_or_else(|| anyhow!("OverlayBranch without HighPc: {:?}", tag))?;
+    Ok(OverlayBranch { name, id, start_address, end_address, compile_unit })
+}
+
 pub fn process_cu_tag(info: &DwarfInfo, tag: &Tag) -> Result<TagType> {
     match tag.kind {
         TagKind::Typedef => Ok(TagType::Typedef(process_typedef_tag(info, tag)?)),