refactoring

src/common.rs

@@ -3,9 +3,11 @@ mod relocatable;
 mod section;
 mod storage;
 mod symbol;
+mod output;
 
 pub use lazy::*;
 pub use relocatable::*;
 pub use section::*;
 pub use storage::*;
 pub use symbol::*;
+pub use output::*;

src/common/output.rs

@@ -0,0 +1,24 @@
+use crate::error::Error;
+use super::Section;
+
+pub trait Output {
+    fn allocate(&mut self, size: u64) -> Result<u64, Error>;
+
+    fn append_section(&mut self, section: &Section) -> Result<(), Error>;
+
+    // fn prepare_symbol<V, S>(&mut self, symbol: impl Lazy<V, S>) -> Result<&mut Self, Error>;
+}
+
+pub struct DummyOutput;
+
+impl Output for DummyOutput {
+    fn allocate(&mut self, size: u64) -> Result<u64, Error> {
+        eprintln!("Allocating: {}", size);
+        Ok(size)
+    }
+
+    fn append_section(&mut self, section: &Section) -> Result<(), Error> {
+        eprintln!("Appending section: {}", section);
+        Ok(())
+    }
+}

src/formats/elf.rs

@@ -1,72 +1,20 @@
-use std::{
-    fmt::Display,
-    path::{Path, PathBuf},
-};
 
-use crate::common::{Lazy, Relocatable, Storage, Symbol};
-use crate::linker::LinkState;
-use crate::{common::BSI, error::Error};
-use xmas_elf::header::Type as ElfType;
+use crate::common::{Lazy, Symbol};
+use crate::linker::Linker;
+use crate::error::Error;
 use xmas_elf::ElfFile;
 
+mod object;
 mod section;
 mod section_iter;
 
 use section_iter::SectionIter;
+pub use object::ElfObject;
 
-pub struct ElfObject<'data> {
-    origin: PathBuf,
-    elf: ElfFile<'data>,
-}
-
-impl<'data> ElfObject<'data> {
-    pub fn new(storage: &'data mut Storage) -> Result<Self, Error> {
-        let origin = storage.origin()?;
-        let elf = ElfFile::new(storage.bytes()?).map_err(|_| Error::InvalidObjectType(0))?;
-
-        is_relocatable(&elf)?;
-        let result = ElfObject { origin, elf };
-
-        Ok(result)
-    }
-}
-
-impl Relocatable for ElfObject<'_> {
-    fn origin(&self) -> &Path {
-        &self.origin
-    }
-
-    fn sections(&self) -> BSI<'_> {
-        Box::new(SectionIter {
-            elf: &self.elf,
-            iter: self.elf.section_iter(),
-        })
-    }
-}
-
-impl Display for ElfObject<'_> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(
-            f,
-            "==={:?}===\n>Symbols:\n{}\n>Sections:\n",
-            self.origin().file_name().unwrap(),
-            "TODO"
-        )?;
-
-        for section in self.sections() {
-            let u = section.unwrap();
-            write!(f, "{}", u)?;
-        }
-
-        Ok(())
-    }
-}
-
-impl LinkState<'_> {
-    pub fn new() -> Self {
-        LinkState {
-            relocatables: Vec::new(), // it's a trait thing
-        }
+impl Linker<'_> {
+    // shortcut to avoid turbofish
+    pub fn elf() -> Self {
+        Self::new(Vec::new())
     }
 }
 
@@ -80,13 +28,3 @@ impl<'data> Lazy<&'data str, ElfFile<'data>> for Symbol<'data> {
         self.str_ref.is_some()
     }
 }
-
-fn is_relocatable(elf: &ElfFile) -> Result<(), Error> {
-    let raw_type = elf.header.pt2.type_();
-    let elf_type: ElfType = raw_type.as_type();
-    if elf_type != ElfType::Relocatable {
-        return Err(Error::InvalidObjectType(raw_type.0.into()));
-    }
-
-    Ok(())
-}

src/formats/elf/object.rs

@@ -0,0 +1,69 @@
+use std::{
+    fmt::Display,
+    path::{Path, PathBuf},
+};
+
+use crate::common::{Relocatable, Storage};
+use crate::{common::BSI, error::Error};
+use xmas_elf::header::Type as ElfType;
+use xmas_elf::ElfFile;
+
+use super::SectionIter;
+
+pub struct ElfObject<'data> {
+    origin: PathBuf,
+    elf: ElfFile<'data>,
+}
+
+impl<'data> ElfObject<'data> {
+    pub fn new(storage: &'data mut Storage) -> Result<Self, Error> {
+        let origin = storage.origin()?;
+        let elf = ElfFile::new(storage.bytes()?).map_err(|_| Error::InvalidObjectType(0))?;
+
+        is_relocatable(&elf)?;
+        let result = ElfObject { origin, elf };
+
+        Ok(result)
+    }
+}
+
+impl Relocatable for ElfObject<'_> {
+    fn origin(&self) -> &Path {
+        &self.origin
+    }
+
+    fn sections(&self) -> BSI<'_> {
+        Box::new(SectionIter {
+            elf: &self.elf,
+            iter: self.elf.section_iter(),
+        })
+    }
+}
+
+impl Display for ElfObject<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "==={:?}===\n>Symbols:\n{}\n>Sections:\n",
+            self.origin().file_name().unwrap(),
+            "TODO"
+        )?;
+
+        for section in self.sections() {
+            let u = section.unwrap();
+            write!(f, "{}", u)?;
+        }
+
+        Ok(())
+    }
+}
+
+fn is_relocatable(elf: &ElfFile) -> Result<(), Error> {
+    let raw_type = elf.header.pt2.type_();
+    let elf_type: ElfType = raw_type.as_type();
+    if elf_type != ElfType::Relocatable {
+        return Err(Error::InvalidObjectType(raw_type.0.into()));
+    }
+
+    Ok(())
+}

src/linker.rs

@@ -1,22 +1,38 @@
 use std::fmt::Display;
 
-use crate::{common::Relocatable, error::Error};
+use crate::{common::{Output, Relocatable}, error::Error};
 
-pub struct LinkState<'data> {
-    pub relocatables: Vec<Box<dyn Relocatable + 'data>>,
+pub struct Linker<'data> {
+    relocatables: Vec<Box<dyn Relocatable + 'data>>,
 }
 
-impl<'data> LinkState<'data> {
+impl<'data> Linker<'data> {
+    pub fn new(relocatables: Vec<Box<dyn Relocatable + 'data>>) -> Self {
+        Self {
+            relocatables,
+        }
+    }
+
     pub fn add_relocatable(
         &mut self,
         relocatable: Box<dyn Relocatable + 'data>,
-    ) -> Result<(), Error> {
+    ) {
         self.relocatables.push(relocatable);
+    }
 
-        Ok(())
+    pub fn link(&self, output: &mut dyn Output) -> Result<u64, Error> {
+        let allocated = output.allocate(self.total_size()?)?;
+
+        for r in self.relocatables.iter() {
+            for s in r.sections() {
+                output.append_section(&s?)?;
+            }
+        }
+
+        Ok(allocated)
     }
 
-    pub fn total_size(&self) -> Result<u64, Error> {
+    fn total_size(&self) -> Result<u64, Error> {
         let mut result = 0u64;
 
         for o in self.relocatables.iter() {
@@ -29,11 +45,11 @@ impl<'data> LinkState<'data> {
     }
 }
 
-impl Display for LinkState<'_> {
+impl Display for Linker<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         writeln!(f, "===Relocatables===")?;
 
-        for r in &self.relocatables {
+        for r in self.relocatables.iter() {
             write!(f, "{}", r)?;
         }
 

src/main.rs

@@ -3,9 +3,9 @@ mod error;
 mod formats;
 mod linker;
 
-use common::Storage;
+use common::{Storage, DummyOutput};
 use formats::ElfObject;
-use linker::LinkState;
+use linker::Linker;
 
 fn main() {
     let mut args = std::env::args().peekable();
@@ -14,7 +14,8 @@ fn main() {
     args.next().unwrap();
 
     let mut contents: Vec<Storage> = Vec::new();
-    let mut linker = LinkState::new();
+    let mut linker = Linker::elf();
+    let mut output = DummyOutput;
 
     while args.peek().is_some() {
         let fpath = args.next().expect("Unexpected peek-a-boo");
@@ -23,12 +24,9 @@ fn main() {
     }
 
     for storage in contents.iter_mut() {
-        let relocatable = ElfObject::new(storage).unwrap();
-        linker.add_relocatable(Box::new(relocatable)).unwrap();
+        let relocatable = ElfObject::new(storage).expect("Parsing ELF");
+        linker.add_relocatable(Box::new(relocatable));
     }
 
-    let total_size = linker.total_size().expect("Size to be known");
-    println!("to allocate: {}", total_size);
-
-    println!("all: \n{}", linker);
+    linker.link(&mut output).expect("Linking");
 }