WIP

src/common/output.rs

@@ -4,8 +4,6 @@ use super::Section;
 use crate::error::Error;
 
 pub trait Output<'data> {
-    fn allocate(&mut self, size: u64) -> Result<u64, 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>;
@@ -16,11 +14,6 @@ pub trait Output<'data> {
 pub struct 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<'data>) -> Result<(), Error> {
         eprintln!("Appending section: {}", section);
         Ok(())

src/common/section.rs

@@ -4,21 +4,22 @@ use std::{
     fmt::{Display, Formatter},
 };
 
-pub trait CBI<'data, T>: Iterator<Item = T> {
-    fn clone_to_box(&self) -> Box<dyn CBI<'data, T> + 'data>;
-}
+// pub trait CBI<'data, T>: Iterator<Item = T> {
+//     fn clone_to_box(&self) -> Box<dyn CBI<'data, T> + 'data>;
+// }
 
-impl<'data, T, X: 'data + Iterator<Item = T> + Clone> CBI<'data, T> for X {
-    fn clone_to_box(&self) -> Box<dyn CBI<'data, T> + 'data> {
-        Box::new(self.clone())
-    }
-}
+// impl<'data, T, X: 'data + Iterator<Item = T> + Clone> CBI<'data, T> for X {
+//     fn clone_to_box(&self) -> Box<dyn CBI<'data, T> + 'data> {
+//         Box::new(self.clone())
+//     }
+// }
 
-pub type SectionDataIterator<'data> = Box<dyn CBI<'data, u8> + 'data>;
+// pub type SectionDataIterator<'data> = Box<dyn CBI<'data, u8> + 'data>;
 
+#[derive(Clone)]
 pub struct SectionInfo<'data> {
     pub size: u64,
-    pub data: Option<SectionDataIterator<'data>>,
+    pub data: Option<&'data [u8]>,
     pub offset: u64,
 }
 
@@ -29,19 +30,6 @@ pub enum Section<'data> {
     Bss(SectionInfo<'data>),
 }
 
-impl<'data> Clone for SectionInfo<'data> {
-    fn clone(&self) -> Self {
-        Self {
-            size: self.size,
-            data: match self.data.as_ref() {
-                Some(iter) => Some(iter.clone_to_box()),
-                None => None,
-            },
-            offset: self.offset,
-        }
-    }
-}
-
 impl Section<'_> {
     pub fn size(&self) -> Result<u64, Error> {
         match self {

src/formats/elf/object.rs

@@ -52,12 +52,12 @@ impl Relocatable for ElfObject {
                 Type::ProgBits => {
                     if s.header.sh_size > 0 {
                         if let Some(di) = match &s.contents {
-                            Contents64::Raw(v) => Some(v.iter()),
+                            Contents64::Raw(v) => Some(v),
                             _ => None,
                         } {
                             let si = SectionInfo {
                                 size: s.header.sh_size,
-                                data: Some(Box::new(di.copied())),
+                                data: Some(di),
                                 offset: s.header.sh_offset,
                             };
                             let s_name: &str = &s.name;

src/formats/elf/output.rs

@@ -25,7 +25,7 @@ use super::ElfObject;
 pub struct ElfOutput<'data> {
     destination: PathBuf,
     file: ELF64,
-    segment_data: SegmentData<'data>,
+    input_data: InputData<'data>,
 }
 
 impl<'data> ElfOutput<'data> {
@@ -44,7 +44,7 @@ impl<'data> ElfOutput<'data> {
         Self {
             destination,
             file: elf,
-            segment_data: SegmentData::new(),
+            input_data: InputData::new(),
         }
     }
 
@@ -54,34 +54,32 @@ impl<'data> ElfOutput<'data> {
         Self {
             destination,
             file: elf_bin_from_object(other),
-            segment_data: SegmentData::new(),
+            input_data: InputData::new(),
         }
     }
 
-    fn populate_sections(&mut self) -> Result<u64, Error> {
+    fn populate_sections(&mut self) -> Result<(), Error> {
         let mut names = Vec::new();
         let mut name_idx = 0usize;
-        let mut result = 0u64;
 
-        for (name, sections) in self.segment_data.sections_mut() {
-            let mut data = Vec::new();
+        for (name, sections) in self.input_data.sections_mut() {
+            let mut data_size = 0;
 
-            for t in sections.iter_mut() {
-                if let Some(iter) = &mut t.data {
-                    data.extend(iter.as_mut());
+            for t in sections.iter() {
+                if let Some(bytes) = t.data {
+                    data_size += bytes.len();
                 }
             }
 
-            if data.is_empty() {
+            if data_size == 0{
                 continue;
             }
 
-            result += data.len() as u64;
             names.push(name);
             let section = Section64 {
                 name: name.into(),
-                header: make_section_header(name_idx, ShType::ProgBits, data.len()),
-                contents: Contents64::Raw(data),
+                header: make_section_header(name_idx, ShType::ProgBits, data_size),
+                contents: Contents64::Raw(Vec::new()), // placeholder only
             };
             name_idx += name.len() + 1;
             self.file.add_section(section);
@@ -90,7 +88,6 @@ impl<'data> ElfOutput<'data> {
         let name = ".shstrtab";
         names.push(name);
         let string_table = build_string_table(names, true);
-        result += string_table.len() as u64;
         let section = Section64 {
             name: name.into(),
             header: make_section_header(name_idx, ShType::StrTab, string_table.len()),
@@ -98,7 +95,7 @@ impl<'data> ElfOutput<'data> {
         };
         self.file.add_section(section);
 
-        Ok(result)
+        Ok(())
     }
 
     fn populate_segment(&mut self, offset: &mut u64, size: u64, which: SegmentType) {
@@ -114,12 +111,15 @@ impl<'data> ElfOutput<'data> {
         segment.header.p_memsz = size;
         segment.header.p_offset = *offset;
 
+        let mut page_size = next_page(size);
+
         match which {
             SegmentType::Text => segment.header.p_flags = PF_R | PF_X,
             SegmentType::Data => segment.header.p_flags = PF_R | PF_W,
             SegmentType::Bss => {
                 segment.header.p_flags = PF_R;
                 segment.header.p_memsz = 0;
+                page_size = 0;
             }
         }
 
@@ -127,7 +127,7 @@ impl<'data> ElfOutput<'data> {
         self.file.ehdr.e_phnum += 1;
         self.file.ehdr.e_phentsize = size_of::<Phdr64>() as u16;
 
-        *offset += next_page(size);
+        *offset += page_size;
     }
 
     fn populate_segments(&mut self) -> Result<u64, Error> {
@@ -136,29 +136,25 @@ impl<'data> ElfOutput<'data> {
         // contains .text + .rodata as one segment
         self.populate_segment(
             &mut offset,
-            self.segment_data.program_size(),
+            self.input_data.program_size(),
             SegmentType::Text,
         );
         // contains .data as one segment
         self.populate_segment(
             &mut offset,
-            self.segment_data.data_size(),
+            self.input_data.data_size(),
             SegmentType::Data,
         );
         // contains .bss as one segment
-        self.populate_segment(&mut offset, self.segment_data.bss_size(), SegmentType::Bss);
+        self.populate_segment(&mut offset, self.input_data.bss_size(), SegmentType::Bss);
 
         Ok(offset)
     }
 }
 
 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> {
-        self.segment_data.append_section(section)
+        self.input_data.append_section(section)
     }
 
     fn finalize(mut self) -> Result<PathBuf, Error> {
@@ -169,20 +165,19 @@ impl<'data> Output<'data> for ElfOutput<'data> {
         self.populate_sections()?;
         let page_size = self.populate_segments()?;
 
+        self.file.ehdr.e_shnum = self.file.sections.len() as u16;
+        self.file.ehdr.e_entry = 4096; // TODO
         self.file.ehdr.e_phentsize = PHS;
         self.file.ehdr.e_shentsize = SHS;
-        self.file.ehdr.e_phoff = EHS; // TODO: align
-        self.file.ehdr.e_shoff = self.file.ehdr.e_phoff
-            + u64::from(self.file.ehdr.e_phnum * self.file.ehdr.e_phentsize)
-            + page_size;
-        self.file.ehdr.e_shnum = self.file.sections.len() as u16;
-        self.file.ehdr.e_entry = 0x100; // TODO
+        self.file.ehdr.e_phoff = EHS;
+        self.file.ehdr.e_shoff = self.file.ehdr.e_phoff + (usize::from(self.file.ehdr.e_phentsize) * self.file.segments.len()) as u64;
 
         let str_path = expand_path(&self.destination)?;
 
         let mut writer = file_writer(str_path, 0o755)?;
         let mut offset = 0;
 
+        // write ELF header
         offset += writer.write(&self.file.ehdr.to_le_bytes())?;
 
         // write program header table
@@ -191,17 +186,32 @@ impl<'data> Output<'data> for ElfOutput<'data> {
             offset += writer.write(&seg.header.to_le_bytes())?;
         }
 
-        // write section/segment data
+        eprintln!("SH start: {}", offset);
+        // write section header table
         for sec in self.file.sections.iter_mut() {
-            sec.header.sh_offset = offset as u64;
-            offset += write_padded(&mut writer, offset, &sec.to_le_bytes())?;
+            if sec.header.get_type() == ShType::StrTab {
+                sec.header.sh_offset = offset as u64 + u64::from(SHS);
+            }
+            offset += writer.write(&sec.header.to_le_bytes())?;
+            if sec.header.get_type() == ShType::StrTab {
+                offset += writer.write(&sec.to_le_bytes())?;
+            }
         }
 
-        eprintln!("SHT: {}", offset);
-        // write section header table
-        for sec in self.file.sections.iter() {
-            offset += writer.write(&sec.header.to_le_bytes())?;
+        // program data (segments)
+        offset += pad_to_next_page(&mut writer, offset)?;
+        eprintln!("Prog start: {}", offset);
+        // write section/segment data
+        for bytes in self.input_data.program_bytes() {
+            offset += writer.write(bytes)?;
+        }
+        offset += pad_to_next_page(&mut writer, offset)?;
+
+        eprintln!("Data start: {}", offset);
+        for bytes in self.input_data.data_bytes() {
+            offset += writer.write(bytes)?;
         }
+
         writer.flush()?;
 
         Ok(self.destination)
@@ -213,7 +223,7 @@ fn file_writer(output_filename: &str, permission: u32) -> Result<BufWriter<File>
 
     let file = std::fs::OpenOptions::new()
         .create(true)
-        .read(true)
+        .truncate(true)
         .write(true)
         .mode(permission)
         .open(output_filename)?;
@@ -271,14 +281,13 @@ fn next_page(size: u64) -> u64 {
     page_size * pages_needed
 }
 
-fn write_padded(writer: &mut BufWriter<File>, offset: usize, data: &[u8]) -> Result<usize, Error> {
+fn pad_to_next_page(writer: &mut BufWriter<File>, offset: usize) -> Result<usize, Error> {
     let page_size = page_size::get();
-    let mut written = 0usize;
 
-    written += writer.write(data)?;
-    let padding = page_size - (page_size % offset);
+    let padding = page_size - (offset % page_size);
 
-    written += writer.get_mut().seek(SeekFrom::Current(padding as i64))? as usize;
+    eprintln!("Padding from: {} with: {}", offset, padding);
+    writer.seek(SeekFrom::Current(padding.try_into()?))?;
 
-    Ok(written)
+    Ok(padding)
 }

src/formats/elf/segment.rs

@@ -1,5 +1,5 @@
 use crate::common::SectionInfo;
-use crate::common::{Section, SectionDataIterator};
+use crate::common::{Section};
 use crate::error::Error;
 
 const SI_TEXT: usize = 0;
@@ -15,9 +15,9 @@ pub enum SegmentType {
 
 const SEGMENT_NAMES: [&str; 4] = [".text", ".rodata", ".data", ".bss"];
 
-pub struct SegmentData<'data>([Vec<SectionInfo<'data>>; 4]);
+pub struct InputData<'data>([Vec<SectionInfo<'data>>; 4]);
 
-impl<'data> SegmentData<'data> {
+impl<'data> InputData<'data> {
     pub fn new() -> Self {
         Self([Vec::new(), Vec::new(), Vec::new(), Vec::new()])
     }
@@ -42,20 +42,18 @@ impl<'data> SegmentData<'data> {
             .map(|(i, s)| (SEGMENT_NAMES[i], s))
     }
 
-    pub fn program_data<'local>(&'local self) -> Box<dyn Iterator<Item = u8> + 'local> {
+    pub fn program_bytes<'local>(&'local self) -> impl Iterator<Item = &'local [u8]> {
         let text_iter = self.0[SI_TEXT].iter();
         let rodata_iter = self.0[SI_RODATA].iter();
 
-        let data1 = text_iter.filter_map(|si| match si.data.as_ref() {
-            Some(iter) => Some(iter.clone_to_box()),
-            None => None,
-        });
-        let data2 = rodata_iter.filter_map(|si| match si.data.as_ref() {
-            Some(iter) => Some(iter.clone_to_box()),
-            None => None,
-        });
+        let data1 = text_iter.filter_map(|si| si.data);
+        let data2 = rodata_iter.filter_map(|si| si.data);
 
-        Box::new(data1.chain(data2).flatten())
+        data1.chain(data2)
+    }
+
+    pub fn data_bytes<'local>(&'local self) -> impl Iterator<Item = &'local [u8]> {
+        self.0[SI_DATA].iter().filter_map(|si| si.data)
     }
 
     // .text + .rodata
@@ -92,7 +90,7 @@ impl<'data> SegmentData<'data> {
     }
 }
 
-impl Default for SegmentData<'_> {
+impl Default for InputData<'_> {
     fn default() -> Self {
         Self::new()
     }

src/linker.rs

@@ -19,27 +19,13 @@ impl<'data> Linker<'data> {
     }
 
     pub fn link(&'data 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?)?;
             }
         }
 
-        Ok(allocated)
-    }
-
-    fn total_size(&self) -> Result<u64, Error> {
-        let mut result = 0u64;
-
-        for o in self.relocatables.iter() {
-            for s in o.sections() {
-                result += s?.size()?;
-            }
-        }
-
-        Ok(result)
+        Ok(0)
     }
 }