add xmas-elf support together with elf-utils

Cargo.lock

@@ -67,6 +67,7 @@ version = "0.1.0"
 dependencies = [
  "elf-utilities",
  "page_size",
+ "xmas-elf",
 ]
 
 [[package]]
@@ -147,3 +148,18 @@ name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+
+[[package]]
+name = "xmas-elf"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e74de9a366f6ab8c405fa6b371d9ac24943921fa14b3d64afcb202065c405f11"
+dependencies = [
+ "zero",
+]
+
+[[package]]
+name = "zero"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f1bc8a6b2005884962297587045002d8cfb8dcec9db332f4ca216ddc5de82c5"

Cargo.toml

@@ -7,5 +7,6 @@ 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"

src/common/section.rs

@@ -1,5 +1,8 @@
 use crate::error::Error;
-use std::fmt::{Display, Formatter};
+use std::{
+    convert::TryFrom,
+    fmt::{Display, Formatter},
+};
 
 pub type SectionDataIterator<'data> = Box<dyn Iterator<Item = u8> + 'data>;
 
@@ -25,6 +28,22 @@ impl Section<'_> {
     }
 }
 
+impl<'data> TryFrom<(&str, SectionInfo<'data>)> for Section<'data> {
+    type Error = Error;
+
+    fn try_from(value: (&str, SectionInfo<'data>)) -> Result<Self, Self::Error> {
+        if value.0.starts_with(".text") {
+            Ok(Section::Text(value.1))
+        } else if value.0.starts_with(".rodata") || value.0.starts_with(".data") {
+            Ok(Section::Data(value.1))
+        } else if value.0.starts_with(".bss") {
+            Ok(Section::Bss(value.1))
+        } else {
+            Err(Error::InvalidSectionName)
+        }
+    }
+}
+
 impl Display for SectionInfo<'_> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         write!(

src/error.rs

@@ -7,6 +7,7 @@ use std::{
 pub enum Error {
     IOError(std::io::Error),
     InvalidObjectType(u32),
+    InvalidSectionName,
     MissingSectionHeader(&'static str),
     MissingSectionData(&'static str),
     InvalidSectionData,

src/formats.rs

@@ -1,3 +1,5 @@
 mod elf;
+mod xelf;
 
 pub use elf::*;
+pub use xelf::*;

src/formats/elf/object.rs

@@ -1,4 +1,5 @@
 use std::{
+    convert::TryFrom,
     fmt::Display,
     path::{Path, PathBuf},
 };
@@ -45,20 +46,23 @@ impl Relocatable for ElfObject {
             .iter()
             .filter_map(|s| match s.header.get_type() {
                 Type::ProgBits => {
-                    if s.header.sh_size > 0
-                        && (s.name.starts_with(".text")
-                            || s.name.starts_with(".rodata")
-                            || s.name.starts_with(".data"))
-                    {
+                    if s.header.sh_size > 0 {
                         if let Some(di) = match &s.contents {
                             Contents64::Raw(v) => Some(v.iter()),
                             _ => None,
                         } {
-                            Some(Ok(Section::Text(SectionInfo {
+                            let si = SectionInfo {
                                 size: s.header.sh_size,
                                 data: Some(Box::new(di.copied())),
                                 offset: s.header.sh_offset,
-                            })))
+                            };
+                            let s_name: &str = &s.name;
+
+                            match Section::try_from((s_name, si)) {
+                                Ok(s) => Some(Ok(s)),
+                                Err(Error::InvalidSectionName) => None, // skip
+                                Err(err) => Some(Err(err)),
+                            }
                         } else {
                             Some(Err(Error::InvalidSectionData))
                         }

src/formats/xelf.rs

@@ -0,0 +1,26 @@
+use crate::common::{Lazy, Symbol};
+use crate::error::Error;
+use crate::linker::Linker;
+use xmas_elf::ElfFile;
+
+mod object;
+
+pub use object::XElfObject;
+
+impl Linker<'_> {
+    // shortcut to avoid turbofish
+    pub fn xelf() -> Self {
+        Self::new(Vec::new())
+    }
+}
+
+impl<'data> Lazy<&'data str, ElfFile<'data>> for Symbol<'data> {
+    fn value(&self, src: &ElfFile<'data>) -> Result<&'data str, Error> {
+        src.get_string(self.index)
+            .map_err(|e| Error::MissingSectionData(e))
+    }
+
+    fn resolved(&self) -> bool {
+        self.str_ref.is_some()
+    }
+}

src/formats/xelf/object.rs

@@ -0,0 +1,113 @@
+use std::{
+    convert::TryFrom,
+    fmt::Display,
+    path::{Path, PathBuf},
+};
+
+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};
+
+pub struct XElfObject<'data> {
+    origin: PathBuf,
+    elf: ElfFile<'data>,
+}
+
+impl<'data> XElfObject<'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 = XElfObject { origin, elf };
+
+        Ok(result)
+    }
+
+    fn data(&self, h: &SectionHeader<'data>) -> Result<std::slice::Iter<'data, u8>, Error> {
+        match h.get_data(&self.elf) {
+            Ok(SectionData::Undefined(ba)) => Ok(ba.iter()),
+            Ok(_) => Err(Error::InvalidSectionData),
+            Err(_) => Err(Error::InvalidSectionData),
+        }
+    }
+}
+
+impl Relocatable for XElfObject<'_> {
+    fn origin(&self) -> &Path {
+        &self.origin
+    }
+
+    fn sections(&self) -> BSI<'_> {
+        let iter = self.elf.section_iter().filter_map(move |h| {
+            let h_result = h.get_type().map_err(|e| Error::MissingSectionHeader(e));
+            return match h_result {
+                Ok(h_type) => match h_type {
+                    // text, [ro]data
+                    ShType::ProgBits => {
+                        let s_name = h.get_name(&self.elf).unwrap_or("null");
+                        if h.size() > 0 {
+                            match self.data(&h) {
+                                Ok(data_iter) => {
+                                    let si = SectionInfo {
+                                        size: h.size(),
+                                        data: Some(Box::new(data_iter.copied())),
+                                        offset: h.offset(),
+                                    };
+        
+                                    match Section::try_from((s_name, si)) {
+                                        Ok(s) => Some(Ok(s)),
+                                        Err(Error::InvalidSectionName) => None, // skip
+                                        Err(err) => Some(Err(err)),
+                                    }
+                                }
+                                Err(err) => Some(Err(err)),
+                            }
+                        } else {
+                            None
+                        }
+                    }
+                    // bss
+                    ShType::NoBits => Some(Ok(Section::Bss(SectionInfo {
+                        size: h.size(),
+                        data: None,
+                        offset: h.offset(),
+                    }))),
+                    _ => None,
+                },
+                Err(err) => Some(Err(err)),
+            };
+        });
+
+        Box::new(iter)
+    }
+}
+
+impl Display for XElfObject<'_> {
+    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(())
+}