pe(write): some debug! traces

It can be hard to debug why your writer is not working as intended, here
are some `debug!` traces to help in that endeavor.

src/pe/certificate_table.rs

@@ -3,6 +3,7 @@
 /// https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#the-attribute-certificate-table-image-only
 /// https://learn.microsoft.com/en-us/windows/win32/api/wintrust/ns-wintrust-win_certificate
 use crate::error;
+use crate::pe::debug;
 use scroll::{ctx, Pread, Pwrite};
 
 use alloc::string::ToString;
@@ -132,6 +133,7 @@ impl<'a> AttributeCertificate<'a> {
  bytes: &'a [u8],
  current_offset: &mut usize,
  ) -> Result<AttributeCertificate<'a>, error::Error> {
+ debug!("reading certificate header at {current_offset}");
  // `current_offset` is moved sizeof(AttributeCertificateHeader) = 8 bytes further.
  let header: AttributeCertificateHeader = bytes.gread_with(current_offset, scroll::LE)?;
  let cert_size = usize::try_from(header.length.saturating_sub(CERTIFICATE_DATA_OFFSET))
@@ -141,6 +143,11 @@ impl<'a> AttributeCertificate<'a> {
  )
  })?;
 
+ debug!(
+ "parsing certificate header {:#?}, predicted certificate size: {}",
+ header, cert_size
+ );
+
  if let Some(bytes) = bytes.get(*current_offset..(*current_offset + cert_size)) {
  let attr = Self {
  length: header.length,

src/pe/header.rs

@@ -253,6 +253,7 @@ impl CoffHeader {
  let string_table_offset = self.pointer_to_symbol_table as usize
  + symbol::SymbolTable::size(self.number_of_symbol_table as usize);
  for i in 0..nsections {
+ debug!("parsing section at offset {offset}");
  let section =
  section_table::SectionTable::parse(bytes, offset, string_table_offset as usize)?;
  debug!("({}) {:#?}", i, section);
@@ -342,6 +343,7 @@ impl ctx::TryIntoCtx<scroll::Endian> for Header {
  bytes.gwrite_with(self.dos_stub, offset, ctx)?;
  bytes.gwrite_with(self.signature, offset, scroll::LE)?;
  bytes.gwrite_with(self.coff_header, offset, ctx)?;
+ debug!("Non-optional header written, current offset: {}", offset);
  if let Some(opt_header) = self.optional_header {
  bytes.gwrite_with(opt_header, offset, ctx)?;
  }

src/pe/optional_header.rs

@@ -2,6 +2,7 @@ use crate::container;
 use crate::error;
 
 use crate::pe::data_directories;
+use crate::pe::debug;
 
 use scroll::{ctx, Endian, LE};
 use scroll::{Pread, Pwrite, SizeWith};
@@ -358,12 +359,16 @@ impl ctx::TryIntoCtx<scroll::Endian> for OptionalHeader {
  match self.standard_fields.magic {
  MAGIC_32 => {
  bytes.gwrite_with::<StandardFields32>(self.standard_fields.into(), offset, ctx)?;
+ debug!("Wrote standard fields 32 bits (offset: {})", offset);
  bytes.gwrite_with(WindowsFields32::try_from(self.windows_fields)?, offset, ctx)?;
+ debug!("Wrote windows fields 32 bits (offset: {})", offset);
  bytes.gwrite_with(self.data_directories, offset, ctx)?;
  }
  MAGIC_64 => {
  bytes.gwrite_with::<StandardFields64>(self.standard_fields.into(), offset, ctx)?;
+ debug!("Wrote standard fields 64 bits (offset: {})", offset);
  bytes.gwrite_with(self.windows_fields, offset, ctx)?;
+ debug!("Wrote windows fields 64 bits (offset: {})", offset);
  bytes.gwrite_with(self.data_directories, offset, ctx)?;
  }
  _ => panic!(),