Implement sections_allowlist

Fixes #14
decompals · Feb 27, 2024 · 6aec53d · 6aec53d
1 parent f749bcc
commit 6aec53d
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diff --git a/docs/file_format/settings.md b/docs/file_format/settings.md
@@ -100,6 +100,27 @@ A positive integer or `null`.
 
 `null`
 
+## `sections_allowlist`
+
+A list of sections to that should be preserved during linking.
+
+Usually used for keeping debugging sections.
+
+### Example
+
+```yaml
+settings:
+  sections_allowlist: [.mdebug, .note, .comment]
+```
+
+### Valid values
+
+List of strings.
+
+### Default value
+
+`[]`
+
 ## `sections_denylist`
 
 List of sections to be discarded.

diff --git a/slinky/src/linker_writer.rs b/slinky/src/linker_writer.rs
@@ -45,7 +45,28 @@ impl<'a> LinkerWriter<'a> {
     }
 
     pub fn end_sections(&mut self) {
+        let mut need_ln = false;
+
+        if !self.settings.sections_allowlist.is_empty() {
+            let address = " 0";
+
+            for sect in &self.settings.sections_allowlist {
+                self.writeln(&format!("{}{} :", sect, address));
+                self.begin_block();
+
+                self.writeln(&format!("*({});", sect));
+
+                self.end_block();
+            }
+
+            need_ln = true;
+        }
+
         if self.settings.discard_wildcard_section || !self.settings.sections_denylist.is_empty() {
+            if need_ln {
+                self.writeln("");
+            }
+
             self.writeln("/DISCARD/ :");
             self.begin_block();
 

diff --git a/slinky/src/settings.rs b/slinky/src/settings.rs
@@ -15,6 +15,7 @@ pub struct Settings {
 
     pub hardcoded_gp_value: Option<u32>,
 
+    pub sections_allowlist: Vec<String>,
     pub sections_denylist: Vec<String>,
     pub discard_wildcard_section: bool,
 
@@ -43,6 +44,10 @@ fn settings_default_hardcoded_gp_value() -> Option<u32> {
     None
 }
 
+fn settings_default_sections_allowlist() -> Vec<String> {
+    vec![]
+}
+
 fn settings_default_section_denylist() -> Vec<String> {
     vec![
         ".reginfo".into(),
@@ -96,6 +101,7 @@ impl Default for Settings {
 
             hardcoded_gp_value: settings_default_hardcoded_gp_value(),
 
+            sections_allowlist: settings_default_sections_allowlist(),
             sections_denylist: settings_default_section_denylist(),
             discard_wildcard_section: settings_default_discard_wildcard_section(),
 
@@ -122,6 +128,8 @@ pub(crate) struct SettingsSerial {
     #[serde(default)]
     pub hardcoded_gp_value: AbsentNullable<u32>,
 
+    #[serde(default)]
+    pub sections_allowlist: AbsentNullable<Vec<String>>,
     #[serde(default)]
     pub sections_denylist: AbsentNullable<Vec<String>>,
     #[serde(default)]
@@ -157,6 +165,9 @@ impl SettingsSerial {
             .hardcoded_gp_value
             .get_optional_nullable("hardcoded_gp_value", settings_default_hardcoded_gp_value)?;
 
+        let sections_allowlist = self
+            .sections_allowlist
+            .get_non_null("sections_allowlist", settings_default_sections_allowlist)?;
         let sections_denylist = self
             .sections_denylist
             .get_non_null("sections_denylist", settings_default_section_denylist)?;
@@ -188,6 +199,7 @@ impl SettingsSerial {
             base_path,
             linker_symbols_style,
             hardcoded_gp_value,
+            sections_allowlist,
             sections_denylist,
             discard_wildcard_section,
             alloc_sections,

diff --git a/tests/input_files/drmario64.yaml b/tests/input_files/drmario64.yaml
@@ -1,6 +1,68 @@
 settings:
   base_path: build/us
 
+  sections_allowlist:
+    # Basic sections.
+    # lld complains if .shstrtab is not explictly mentioned on the linker script when using a wildcard discard, so here we are
+    - .strtab
+    - .symtab
+    - .shstrtab
+    # mips debug sections
+    - .pdr
+    - .mdebug
+    - .mdebug.abi32
+    # DWARF debug sections
+    # Symbols in the DWARF debugging sections are relative to the beginning of the section so we begin them at 0.
+    # DWARF 1
+    - .debug
+    - .line
+    # GNU DWARF 1 extensions
+    - .debug_srcinfo
+    - .debug_sfnames
+    # DWARF 1.1 and DWARF 2
+    - .debug_aranges
+    - .debug_pubnames
+    # DWARF 2
+    - .debug_info
+    # - .gnu.linkonce.wi.*
+    - .debug_abbrev
+    - .debug_line
+    # - .debug_line.*
+    - .debug_line_end
+    - .debug_frame
+    - .debug_str
+    - .debug_loc
+    - .debug_macinfo
+    # SGI/MIPS DWARF 2 extensions
+    - .debug_weaknames
+    - .debug_funcnames
+    - .debug_typenames
+    - .debug_varnames
+    # DWARF 3
+    - .debug_pubtypes
+    - .debug_ranges
+    # DWARF 5
+    - .debug_addr
+    - .debug_line_str
+    - .debug_loclists
+    - .debug_macro
+    - .debug_names
+    - .debug_rnglists
+    - .debug_str_offsets
+    - .debug_sup
+    # gnu attributes
+    - .gnu.attributes
+    # misc
+    - .note
+    - .comment
+  sections_denylist:
+    - .reginfo
+    - .MIPS.abiflags
+    - .MIPS.options
+    - .note.gnu.build-id
+    - .interp
+    - .eh_frame
+
 segments:
   - name: header
     fixed_vram: 0x8F000000

diff --git a/tests/linker_scripts/drmario64.ld b/tests/linker_scripts/drmario64.ld
@@ -7475,6 +7475,155 @@ SECTIONS
     segment_tutorial_data_ROM_END = __romPos;
     segment_tutorial_data_ROM_SIZE = ABSOLUTE(segment_tutorial_data_ROM_END - segment_tutorial_data_ROM_START);
 
+    .strtab 0 :
+    {
+        *(.strtab);
+    }
+    .symtab 0 :
+    {
+        *(.symtab);
+    }
+    .shstrtab 0 :
+    {
+        *(.shstrtab);
+    }
+    .pdr 0 :
+    {
+        *(.pdr);
+    }
+    .mdebug 0 :
+    {
+        *(.mdebug);
+    }
+    .mdebug.abi32 0 :
+    {
+        *(.mdebug.abi32);
+    }
+    .debug 0 :
+    {
+        *(.debug);
+    }
+    .line 0 :
+    {
+        *(.line);
+    }
+    .debug_srcinfo 0 :
+    {
+        *(.debug_srcinfo);
+    }
+    .debug_sfnames 0 :
+    {
+        *(.debug_sfnames);
+    }
+    .debug_aranges 0 :
+    {
+        *(.debug_aranges);
+    }
+    .debug_pubnames 0 :
+    {
+        *(.debug_pubnames);
+    }
+    .debug_info 0 :
+    {
+        *(.debug_info);
+    }
+    .debug_abbrev 0 :
+    {
+        *(.debug_abbrev);
+    }
+    .debug_line 0 :
+    {
+        *(.debug_line);
+    }
+    .debug_line_end 0 :
+    {
+        *(.debug_line_end);
+    }
+    .debug_frame 0 :
+    {
+        *(.debug_frame);
+    }
+    .debug_str 0 :
+    {
+        *(.debug_str);
+    }
+    .debug_loc 0 :
+    {
+        *(.debug_loc);
+    }
+    .debug_macinfo 0 :
+    {
+        *(.debug_macinfo);
+    }
+    .debug_weaknames 0 :
+    {
+        *(.debug_weaknames);
+    }
+    .debug_funcnames 0 :
+    {
+        *(.debug_funcnames);
+    }
+    .debug_typenames 0 :
+    {
+        *(.debug_typenames);
+    }
+    .debug_varnames 0 :
+    {
+        *(.debug_varnames);
+    }
+    .debug_pubtypes 0 :
+    {
+        *(.debug_pubtypes);
+    }
+    .debug_ranges 0 :
+    {
+        *(.debug_ranges);
+    }
+    .debug_addr 0 :
+    {
+        *(.debug_addr);
+    }
+    .debug_line_str 0 :
+    {
+        *(.debug_line_str);
+    }
+    .debug_loclists 0 :
+    {
+        *(.debug_loclists);
+    }
+    .debug_macro 0 :
+    {
+        *(.debug_macro);
+    }
+    .debug_names 0 :
+    {
+        *(.debug_names);
+    }
+    .debug_rnglists 0 :
+    {
+        *(.debug_rnglists);
+    }
+    .debug_str_offsets 0 :
+    {
+        *(.debug_str_offsets);
+    }
+    .debug_sup 0 :
+    {
+        *(.debug_sup);
+    }
+    .gnu.attributes 0 :
+    {
+        *(.gnu.attributes);
+    }
+    .note 0 :
+    {
+        *(.note);
+    }
+    .comment 0 :
+    {
+        *(.comment);
+    }
+
     /DISCARD/ :
     {
         *(.reginfo);