Enable dwarf debugging

CHANGELOG.md

@@ -1,3 +1,9 @@
+## wasm_split_cli vfuture
+
+- Experimental support to emit debug sections. By default enabled via environment variable
+  `WASM_SPLIT_CLI_ENABLE_DWARF`. The current setup duplicates the DWARF information into
+  all output modules, which can lead to large split files.
+
 ## wasm_split_helpers v0.2.3
 
 - Propagate `debug_assertions` to the CLI with a new marker in the hidden `#[link_section]`.

crates/wasm_split_cli/Cargo.toml

@@ -19,6 +19,7 @@ wasmparser = "0.252"
 # bin-only depdencies
 clap = { version = "4.5", features = ["derive"], optional = true }
 tracing-subscriber = { version = "0.3", features = ["fmt"], optional = true }
+gimli = { version = "0.34.0", default-features = false, features = ["std", "read", "write"] }
 
 [dev-dependencies]
 tempfile = "3.27.0"

crates/wasm_split_cli/src/dep_graph.rs

@@ -47,6 +47,8 @@ pub fn get_dependencies(module: &InputModule) -> Result<Dependencies> {
                 RelocDetails::TableNumber(details) => Some(DepNode::Table(details.index)),
                 RelocDetails::GlobalIndex(details) => Some(DepNode::Global(details.index)),
                 RelocDetails::TagIndex(details) => Some(DepNode::Tag(details.index)),
+                RelocDetails::FunctionOffset(details) => Some(DepNode::Function(details.index)),
+                RelocDetails::SectionOffset(_) => None,
             };
             if let Some(target) = target {
                 self.add_dep(a, target);
@@ -146,7 +148,7 @@ fn iter_functions_with_relocs<'m>(
     module: &'m InputModule,
 ) -> impl Iterator<Item = Result<(InputFuncId, &'m RelocationEntry)>> {
     let code_relocs = module.reloc_info.iter_code_relocs();
-    let code_section_offset = module.reloc_info.code_section_offset();
+    let code_section_offset = module.reloc_info.code_section_reloc_base();
     let mut function_index = 0;
     code_relocs.map(move |entry| {
         let reloc_file_range = shift_range(entry.relocation_range()?, code_section_offset);
@@ -275,7 +277,7 @@ macro_rules! emit_iter_err {
 fn iter_data_dependencies<'m>(
     module: &'m InputModule,
 ) -> impl Iterator<Item = Result<DataDependency<'m>>> {
-    let data_section_offset = module.reloc_info.data_section_offset();
+    let data_section_offset = module.reloc_info.data_section_reloc_base();
     let mut data_relocs = module.reloc_info.iter_data_relocs().peekable();
     let mut data_symbols = module.reloc_info.data_symbols.iter().peekable();