first file output

Cargo.toml

@@ -7,6 +7,11 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-xmas-elf = "0.7.0"
-elf-utilities = "0.2.8"
 page_size = "0.4.2"
+elf-utilities = { version = "0.2.8", optional = true }
+xmas-elf = { version = "0.7.0", optional = true }
+
+[features]
+default = ["elf"]
+elf = ["elf-utilities"]
+xelf = ["xmas-elf"]

src/common/output.rs

@@ -1,24 +1,32 @@
+use std::path::PathBuf;
+
 use super::Section;
 use crate::error::Error;
 
-pub trait Output {
+pub trait Output<'data> {
     fn allocate(&mut self, size: u64) -> Result<u64, Error>;
 
-    fn append_section(&mut self, section: &Section) -> Result<(), Error>;
+    fn append_section(&mut self, section: Section<'data>) -> Result<(), Error>;
 
     // fn prepare_symbol<V, S>(&mut self, symbol: impl Lazy<V, S>) -> Result<&mut Self, Error>;
+
+    fn finalize(self) -> Result<PathBuf, Error>;
 }
 
 pub struct DummyOutput;
 
-impl Output for DummyOutput {
+impl<'data> Output<'data> 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> {
+    fn append_section(&mut self, section: Section<'data>) -> Result<(), Error> {
         eprintln!("Appending section: {}", section);
         Ok(())
     }
+
+    fn finalize(self) -> Result<PathBuf, Error> {
+        todo!();
+    }
 }

src/common/storage.rs

@@ -1,4 +1,5 @@
 use std::path::PathBuf;
+use std::{fs::canonicalize, io::ErrorKind};
 
 use crate::error::Error;
 
@@ -16,7 +17,18 @@ impl Storage {
     }
 
     pub fn origin(&self) -> Result<PathBuf, Error> {
-        std::fs::canonicalize(&self.origin).map_err(|e| e.into())
+        canonicalize(&self.origin).map_err(|e| e.into())
+    }
+
+    pub fn destination(&self) -> Result<PathBuf, Error> {
+        let mut dest = canonicalize(&self.origin).map_err(|e| Error::from(e))?;
+        if !dest.pop() {
+            let err = std::io::Error::new(ErrorKind::Other, "Destination path invalid");
+            Err(Error::IOError(Box::new(err)))
+        } else {
+            dest.push("rld.out");
+            Ok(dest)
+        }
     }
 
     pub fn iter(&mut self) -> Result<impl Iterator<Item = &u8>, Error> {

src/error.rs

@@ -5,11 +5,9 @@ use std::{
 
 #[derive(Debug)]
 pub enum Error {
-    IOError(std::io::Error),
+    IOError(Box<dyn std::error::Error>),
     InvalidObjectType(u32),
     InvalidSectionName,
-    MissingSectionHeader(&'static str),
-    MissingSectionData(&'static str),
     InvalidSectionData,
     ParseError(Box<dyn std::error::Error>),
     LinkingError(Trace),
@@ -31,7 +29,7 @@ pub trait SourceInfo: Debug + Display {
 
 impl From<std::io::Error> for Error {
     fn from(err: std::io::Error) -> Self {
-        Self::IOError(err)
+        Self::IOError(Box::new(err))
     }
 }
 

src/formats.rs

@@ -1,5 +1,9 @@
+#[cfg(feature = "elf")]
 mod elf;
+#[cfg(feature = "xelf")]
 mod xelf;
 
+#[cfg(feature = "elf")]
 pub use elf::*;
+#[cfg(feature = "xelf")]
 pub use xelf::*;

src/formats/elf.rs

@@ -3,9 +3,11 @@ use crate::error::Error;
 use crate::linker::Linker;
 
 mod object;
+mod output;
 
 use elf_utilities::file::ELF64;
-pub use object::ElfObject;
+pub use object::*;
+pub use output::*;
 
 impl Linker<'_> {
     // shortcut to avoid turbofish

src/formats/elf/object.rs

@@ -30,6 +30,10 @@ impl ElfObject {
 
         Ok(result)
     }
+
+    pub fn elf(&self) -> &ELF64 {
+        &self.elf
+    }
 }
 
 impl Relocatable for ElfObject {

src/formats/elf/output.rs

@@ -0,0 +1,128 @@
+use std::path::PathBuf;
+
+use elf_utilities::{
+    file::{ELF64Dumper, ELF64},
+    section::Section64,
+    segment::{Segment64, Type},
+};
+
+use crate::{
+    common::{Output, Section, SectionInfo},
+    error::Error,
+};
+
+use super::ElfObject;
+
+pub struct ElfOutput<'data> {
+    destination: PathBuf,
+    dump: ELF64Dumper,
+    text: Vec<SectionInfo<'data>>,
+    data: Vec<SectionInfo<'data>>,
+    bss: Vec<SectionInfo<'data>>,
+}
+
+impl ElfOutput<'_> {
+    pub fn new(destination: PathBuf) -> Self {
+        use elf_utilities::header::{Class, Data, Machine, Type, Version, OSABI};
+
+        let mut elf = ELF64::default();
+        elf.ehdr.set_elf_type(Type::Exec);
+        elf.ehdr.set_class(Class::Bit64);
+        elf.ehdr.set_machine(Machine::Intel386);
+        elf.ehdr.set_object_version(Version::Current);
+        elf.ehdr.set_file_version(Version::Current);
+        elf.ehdr.set_osabi(OSABI::Linux);
+        elf.ehdr.set_data(Data::LSB2);
+
+        Self {
+            destination,
+            dump: ELF64Dumper::new(elf),
+            text: Vec::new(),
+            data: Vec::new(),
+            bss: Vec::new(),
+        }
+    }
+
+    pub fn from_object(object: &ElfObject, destination: PathBuf) -> Self {
+        use elf_utilities::header::Type;
+
+        let other = object.elf();
+
+        let mut elf = ELF64::default();
+        elf.ehdr = other.ehdr.clone();
+        elf.ehdr.set_elf_type(Type::Exec);
+
+        Self {
+            destination,
+            dump: ELF64Dumper::new(elf),
+            text: Vec::new(),
+            data: Vec::new(),
+            bss: Vec::new(),
+        }
+    }
+
+    fn populate_section_data(&mut self) -> Result<u64, Error> {
+        use elf_utilities::section::{Contents64, Shdr64, Type};
+
+        let mut data = Vec::new();
+
+        for t in self.text.iter_mut() {
+            if let Some(iter) = &mut t.data {
+                data.extend(iter.as_mut());
+            }
+        }
+
+        let mut header = Shdr64::default();
+        header.set_type(Type::ProgBits);
+        header.sh_entsize = data.len() as u64;
+
+        let sec64 = Section64 {
+            name: ".text".into(),
+            header,
+            contents: Contents64::Raw(data),
+        };
+
+        self.dump.file.add_section(sec64);
+
+        Ok(0)
+    }
+}
+
+impl<'data> Output<'data> for ElfOutput<'data> {
+    fn allocate(&mut self, size: u64) -> Result<u64, Error> {
+        Ok(size)
+    }
+
+    fn append_section(&mut self, section: Section<'data>) -> Result<(), Error> {
+        match section {
+            Section::Text(si) => self.text.push(si),
+            Section::Data(si) => self.data.push(si),
+            Section::Bss(si) => self.bss.push(si),
+        }
+
+        Ok(())
+    }
+
+    fn finalize(mut self) -> Result<PathBuf, Error> {
+        use std::io::Error as IOError;
+        use std::io::ErrorKind;
+
+        self.populate_section_data()?;
+        let mut segment = Segment64::default();
+        segment.header.set_type(Type::Load);
+        self.dump.file.segments.push(segment);
+        self.dump.file.finalize();
+
+        let str_path = self.destination.to_str().ok_or_else(|| {
+            let ioe = IOError::new(ErrorKind::Other, "Path expansion fail");
+            let boxed = Box::new(ioe);
+            Error::IOError(boxed)
+        })?;
+
+        self.dump
+            .generate_elf_file(str_path, 0o755)
+            .map_err(|e| Error::IOError(e))?;
+
+        Ok(self.destination)
+    }
+}

src/formats/xelf/object.rs

@@ -6,8 +6,11 @@ use std::{
 
 use crate::common::{Relocatable, Section, SectionInfo, Storage};
 use crate::{common::BSI, error::Error};
-use xmas_elf::{ElfFile, sections::{SectionData, SectionHeader}};
 use xmas_elf::{header::Type as ElfType, sections::ShType};
+use xmas_elf::{
+    sections::{SectionData, SectionHeader},
+    ElfFile,
+};
 
 pub struct XElfObject<'data> {
     origin: PathBuf,

src/linker.rs

@@ -18,12 +18,12 @@ impl<'data> Linker<'data> {
         self.relocatables.push(relocatable);
     }
 
-    pub fn link(&self, output: &mut dyn Output) -> Result<u64, Error> {
+    pub fn link<'l: 'data>(&'l self, output: &mut dyn Output<'data>) -> 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?)?;
+                output.append_section(s?)?;
             }
         }
 

src/main.rs

@@ -3,8 +3,8 @@ mod error;
 mod formats;
 mod linker;
 
-use common::{DummyOutput, Storage};
+use common::{Output, Storage};
-use formats::ElfObject;
+use formats::{ElfObject, ElfOutput};
 use linker::Linker;
 
 fn main() {
@@ -15,7 +15,7 @@ fn main() {
 
     let mut contents: Vec<Storage> = Vec::new();
     let mut linker = Linker::elf();
-    let mut output = DummyOutput;
+    let mut maybe_out = None;
 
     while args.peek().is_some() {
         let fpath = args.next().expect("Unexpected peek-a-boo");
@@ -25,8 +25,19 @@ fn main() {
 
     for storage in contents.iter_mut() {
         let relocatable = ElfObject::new(storage).expect("Parsing ELF");
+
+        if maybe_out.is_none() {
+            let dest = storage.destination().expect("Path resolution");
+            maybe_out = Some(ElfOutput::from_object(&relocatable, dest));
+        }
         linker.add_relocatable(Box::new(relocatable));
     }
 
-    linker.link(&mut output).expect("Linking");
+    if let Some(mut output) = maybe_out {
+        let linked = linker.link(&mut output).expect("Linking");
+        let outpath = output.finalize().expect("Finalization");
+        eprintln!("Done {:?}, linked {} bytes", outpath, linked);
+    } else {
+        eprintln!("Nothing to do");
+    }
 }