Propertly simulate DWARF information when imports present (#1452)

* Ignore complex LLVM10 expressions.

* Propery function name when imports are present

crates/debug/src/read_debuginfo.rs

@@ -26,6 +26,7 @@ pub struct FunctionMetadata {
 pub struct WasmFileInfo {
     pub path: Option<PathBuf>,
     pub code_section_offset: u64,
+    pub imported_func_count: u32,
     pub funcs: Box<[FunctionMetadata]>,
 }
 
@@ -164,6 +165,7 @@ pub fn read_debuginfo(data: &[u8]) -> Result<DebugInfoData> {
     let mut sections = HashMap::new();
     let mut name_section = None;
     let mut code_section_offset = 0;
+    let mut imported_func_count = 0;
 
     let mut signatures_params: Vec<Box<[WasmType]>> = Vec::new();
     let mut func_params_refs: Vec<usize> = Vec::new();
@@ -193,6 +195,13 @@ pub fn read_debuginfo(data: &[u8]) -> Result<DebugInfoData> {
                     .map(|ft| Ok(ft?.params))
                     .collect::<Result<Vec<_>>>()?;
             }
+            SectionCode::Import => {
+                for i in section.get_import_section_reader()? {
+                    if let wasmparser::ImportSectionEntryType::Function(_) = i?.ty {
+                        imported_func_count += 1;
+                    }
+                }
+            }
             SectionCode::Function => {
                 func_params_refs = section
                     .get_function_section_reader()?
@@ -234,6 +243,7 @@ pub fn read_debuginfo(data: &[u8]) -> Result<DebugInfoData> {
         wasm_file: WasmFileInfo {
             path: None,
             code_section_offset,
+            imported_func_count,
             funcs: func_meta.into_boxed_slice(),
         },
     })

crates/debug/src/transform/address_transform.rs

@@ -737,6 +737,7 @@ mod tests {
             &WasmFileInfo {
                 path: None,
                 code_section_offset: 1,
+                imported_func_count: 0,
                 funcs: Box::new([]),
             },
         );

crates/debug/src/transform/expression.rs

@@ -333,7 +333,14 @@ where
                 return Ok(None);
             }
             let index = pc.read_sleb128()?;
-            pc.read_u8()?; // consume 159
+            if pc.read_u8()? != 159 {
+                // FIXME The following operator is not DW_OP_stack_value, e.g. :
+                // DW_AT_location  (0x00000ea5:
+                //   [0x00001e19, 0x00001e26): DW_OP_WASM_location 0x0 +1, DW_OP_plus_uconst 0x10, DW_OP_stack_value
+                //   [0x00001e5a, 0x00001e72): DW_OP_WASM_location 0x0 +20, DW_OP_stack_value
+                // )
+                return Ok(None);
+            }
             if !code_chunk.is_empty() {
                 parts.push(CompiledExpressionPart::Code(code_chunk));
                 code_chunk = Vec::new();

crates/debug/src/transform/simulate.rs

@@ -8,7 +8,7 @@ use gimli::{self, LineEncoding};
 use std::collections::{HashMap, HashSet};
 use std::path::PathBuf;
 use wasmtime_environ::entity::EntityRef;
-use wasmtime_environ::wasm::get_vmctx_value_label;
+use wasmtime_environ::wasm::{get_vmctx_value_label, DefinedFuncIndex};
 use wasmtime_environ::{ModuleVmctxInfo, ValueLabelsRanges};
 
 pub use crate::read_debuginfo::{DebugInfoData, FunctionMetadata, WasmType};
@@ -18,7 +18,7 @@ const PRODUCER_NAME: &str = "wasmtime";
 
 fn generate_line_info(
     addr_tr: &AddressTransform,
-    translated: &HashSet<u32>,
+    translated: &HashSet<DefinedFuncIndex>,
     out_encoding: gimli::Encoding,
     w: &WasmFileInfo,
     comp_dir_id: write::StringId,
@@ -46,7 +46,7 @@ fn generate_line_info(
 
     for (i, map) in addr_tr.map() {
         let symbol = i.index();
-        if translated.contains(&(symbol as u32)) {
+        if translated.contains(&i) {
             continue;
         }
 
@@ -257,7 +257,7 @@ pub fn generate_simulated_dwarf(
     di: &DebugInfoData,
     vmctx_info: &ModuleVmctxInfo,
     ranges: &ValueLabelsRanges,
-    translated: &HashSet<u32>,
+    translated: &HashSet<DefinedFuncIndex>,
     out_encoding: gimli::Encoding,
     out_units: &mut write::UnitTable,
     out_strings: &mut write::StringTable,
@@ -277,6 +277,7 @@ pub fn generate_simulated_dwarf(
     } else {
         (None, None)
     };
+    let imported_func_count = di.wasm_file.imported_func_count;
 
     let (unit, root_id, name_id) = {
         let comp_dir_id = out_strings.add(
@@ -326,7 +327,7 @@ pub fn generate_simulated_dwarf(
 
     for (i, map) in addr_tr.map().iter() {
         let index = i.index();
-        if translated.contains(&(index as u32)) {
+        if translated.contains(&i) {
             continue;
         }
 
@@ -346,9 +347,10 @@ pub fn generate_simulated_dwarf(
             write::AttributeValue::Udata((end - start) as u64),
         );
 
-        let id = match func_names.and_then(|m| m.get(&(index as u32))) {
+        let func_index = imported_func_count + (index as u32);
+        let id = match func_names.and_then(|m| m.get(&func_index)) {
             Some(n) => out_strings.add(n.to_owned()),
-            None => out_strings.add(format!("wasm-function[{}]", index)),
+            None => out_strings.add(format!("wasm-function[{}]", func_index)),
         };
 
         die.set(gimli::DW_AT_name, write::AttributeValue::StringRef(id));

crates/debug/src/transform/unit.rs

@@ -10,8 +10,8 @@ use anyhow::{Context, Error};
 use gimli::write;
 use gimli::{AttributeValue, DebuggingInformationEntry, Unit};
 use std::collections::HashSet;
-use wasmtime_environ::entity::EntityRef;
 use wasmtime_environ::isa::TargetIsa;
+use wasmtime_environ::wasm::DefinedFuncIndex;
 use wasmtime_environ::{ModuleVmctxInfo, ValueLabelsRanges};
 
 struct InheritedAttr<T> {
@@ -148,7 +148,7 @@ pub(crate) fn clone_unit<'a, R>(
     module_info: &ModuleVmctxInfo,
     out_units: &mut write::UnitTable,
     out_strings: &mut write::StringTable,
-    translated: &mut HashSet<u32>,
+    translated: &mut HashSet<DefinedFuncIndex>,
     isa: &dyn TargetIsa,
 ) -> Result<Option<(write::UnitId, UnitRefsMap, PendingDebugInfoRefs)>, Error>
 where
@@ -270,7 +270,7 @@ where
                 {
                     current_value_range.push(new_stack_len, frame_info);
                 }
-                translated.insert(func_index.index() as u32);
+                translated.insert(func_index);
                 current_scope_ranges.push(new_stack_len, range_builder.get_ranges(addr_tr));
                 Some(range_builder)
             } else {

tests/debug/simulate.rs

@@ -54,3 +54,24 @@ fn test_debug_dwarf_simulate_simple_x86_64() -> Result<()> {
 )"#,
     )
 }
+
+#[test]
+#[ignore]
+#[cfg(all(
+    any(target_os = "linux", target_os = "macos"),
+    target_pointer_width = "64"
+))]
+fn test_debug_dwarf_simulate_with_imports_x86_64() -> Result<()> {
+    check_wat(
+        r#"
+;; check: DW_TAG_compile_unit 
+(module
+;; check: DW_TAG_subprogram 
+;; check: DW_AT_name	("func1")
+    (import "foo" "bar" (func $import1) )
+    (func $func1 (result i32)
+        i32.const 1
+    )
+)"#,
+    )
+}