Support vtune profiling of trampolines too (#3687)

* Provide helpers for demangling function names

* Profile trampolines in vtune too

* get rid of mapping

* avoid code duplication with jitdump_linux

* maintain previous default display name for wasm functions

* no dash, grrr

* Remove unused profiling error type

crates/wasmtime/Cargo.toml

@@ -26,8 +26,6 @@ region = "2.2.0"
 libc = "0.2"
 cfg-if = "1.0"
 backtrace = "0.3.61"
-rustc-demangle = "0.1.16"
-cpp_demangle = "0.3.2"
 log = "0.4.8"
 wat = { version = "1.0.36", optional = true }
 serde = { version = "1.0.94", features = ["derive"] }

crates/wasmtime/src/trampoline/func.rs

@@ -6,7 +6,7 @@ use std::any::Any;
 use std::panic::{self, AssertUnwindSafe};
 use std::sync::Arc;
 use wasmtime_environ::{EntityIndex, Module, ModuleType, PrimaryMap, SignatureIndex};
-use wasmtime_jit::{CodeMemory, MmapVec};
+use wasmtime_jit::{CodeMemory, MmapVec, ProfilingAgent};
 use wasmtime_runtime::{
     Imports, InstanceAllocationRequest, InstanceAllocator, InstanceHandle,
     OnDemandInstanceAllocator, StorePtr, VMContext, VMFunctionBody, VMSharedSignatureIndex,
@@ -66,6 +66,39 @@ unsafe extern "C" fn stub_fn<F>(
     }
 }
 
+#[cfg(compiler)]
+fn register_trampolines(profiler: &dyn ProfilingAgent, image: &object::File<'_>) {
+    use object::{Object as _, ObjectSection, ObjectSymbol, SectionKind, SymbolKind};
+    let pid = std::process::id();
+    let tid = pid;
+
+    let text_base = match image.sections().find(|s| s.kind() == SectionKind::Text) {
+        Some(section) => match section.data() {
+            Ok(data) => data.as_ptr() as usize,
+            Err(_) => return,
+        },
+        None => return,
+    };
+
+    for sym in image.symbols() {
+        if !sym.is_definition() {
+            continue;
+        }
+        if sym.kind() != SymbolKind::Text {
+            continue;
+        }
+        let address = sym.address();
+        let size = sym.size();
+        if address == 0 || size == 0 {
+            continue;
+        }
+        if let Ok(name) = sym.name() {
+            let addr = text_base + address as usize;
+            profiler.load_single_trampoline(name, addr as *const u8, size as usize, pid, tid);
+        }
+    }
+}
+
 #[cfg(compiler)]
 pub fn create_function<F>(
     ft: &FuncType,
@@ -87,7 +120,8 @@ where
     // also take care of unwind table registration.
     let mut code_memory = CodeMemory::new(obj);
     let code = code_memory.publish()?;
-    engine.config().profiler.trampoline_load(&code.obj);
+
+    register_trampolines(engine.config().profiler.as_ref(), &code.obj);
 
     // Extract the host/wasm trampolines from the results of compilation since
     // we know their start/length.

crates/wasmtime/src/trap.rs

@@ -4,6 +4,7 @@ use backtrace::Backtrace;
 use std::fmt;
 use std::sync::Arc;
 use wasmtime_environ::TrapCode as EnvTrapCode;
+use wasmtime_jit::{demangle_function_name, demangle_function_name_or_index};
 
 /// A struct representing an aborted instruction execution, with a message
 /// indicating the cause.
@@ -327,17 +328,8 @@ impl fmt::Display for Trap {
                 write!(f, "{:#6x} - ", offset)?;
             }
 
-            let demangle =
-                |f: &mut fmt::Formatter<'_>, name: &str| match rustc_demangle::try_demangle(name) {
-                    Ok(name) => write!(f, "{}", name),
-                    Err(_) => match cpp_demangle::Symbol::new(name) {
-                        Ok(name) => write!(f, "{}", name),
-                        Err(_) => write!(f, "{}", name),
-                    },
-                };
-            let write_raw_func_name = |f: &mut fmt::Formatter<'_>| match frame.func_name() {
-                Some(name) => demangle(f, name),
-                None => write!(f, "<wasm function {}>", frame.func_index()),
+            let write_raw_func_name = |f: &mut fmt::Formatter<'_>| {
+                demangle_function_name_or_index(f, frame.func_name(), frame.func_index() as usize)
             };
             if frame.symbols().is_empty() {
                 write!(f, "{}!", name)?;
@@ -351,7 +343,7 @@ impl fmt::Display for Trap {
                         // ...
                     }
                     match symbol.name() {
-                        Some(name) => demangle(f, name)?,
+                        Some(name) => demangle_function_name(f, name)?,
                         None if i == 0 => write_raw_func_name(f)?,
                         None => write!(f, "<inlined function>")?,
                     }