From 2ab1084ed44284e4f1d44c2a5b4e982a5539d37d Mon Sep 17 00:00:00 2001
From: bjorn3 <bjorn3@users.noreply.github.com>
Date: Sun, 12 Jul 2020 20:27:45 +0200
Subject: [PATCH] Add simple profile filter rust script (#1065)

---
 filter_profile.rs | 124 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100755 filter_profile.rs

diff --git a/filter_profile.rs b/filter_profile.rs
new file mode 100755
index 00000000000..82bf53934b8
--- /dev/null
+++ b/filter_profile.rs
@@ -0,0 +1,124 @@
+#!/bin/bash
+#![forbid(unsafe_code)]/* This line is ignored by bash
+# This block is ignored by rustc
+CHANNEL="release"
+source ./config.sh
+CG_CLIF_JIT=1 PROFILE=$1 OUTPUT=$2 exec $RUSTC $0 --crate-type bin -Cprefer-dynamic
+#*/
+
+//! This program filters away uninteresting samples and trims uninteresting frames for stackcollapse
+//! profiles.
+//!
+//! Usage: ./filter_profile.rs <profile in stackcollapse format> <output file>
+//!
+//! This file is specially crafted to be both a valid bash script and valid rust source file. If
+//! executed as bash script this will run the rust source using cg_clif in JIT mode.
+
+use std::io::Write;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let profile_name = std::env::var("PROFILE").unwrap();
+    let output_name = std::env::var("OUTPUT").unwrap();
+    if profile_name.is_empty() || output_name.is_empty() {
+        println!("Usage: ./filter_profile.rs <profile in stackcollapse format> <output file>");
+        std::process::exit(1);
+    }
+    let profile = std::fs::read_to_string(profile_name)
+        .map_err(|err| format!("Failed to read profile {}", err))?;
+    let mut output = std::fs::OpenOptions::new()
+        .create(true)
+        .write(true)
+        .truncate(true)
+        .open(output_name)?;
+
+    for line in profile.lines() {
+        let mut stack = &line[..line.rfind(" ").unwrap()];
+        let count = &line[line.rfind(" ").unwrap() + 1..];
+
+        // Filter away uninteresting samples
+        if !stack.contains("rustc_codegen_cranelift") {
+            continue;
+        }
+
+        if stack.contains("rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items")
+            || stack.contains("rustc_incremental::assert_dep_graph::assert_dep_graph")
+            || stack.contains("rustc_symbol_mangling::test::report_symbol_names")
+        {
+            continue;
+        }
+
+        // Trim start
+        if let Some(index) = stack.find("rustc_interface::passes::configure_and_expand") {
+            stack = &stack[index..];
+        } else if let Some(index) = stack.find("rustc_interface::passes::analysis") {
+            stack = &stack[index..];
+        } else if let Some(index) = stack.find("rustc_interface::passes::start_codegen") {
+            stack = &stack[index..];
+        } else if let Some(index) = stack.find("rustc_interface::queries::Linker::link") {
+            stack = &stack[index..];
+        }
+
+        if let Some(index) = stack.find("rustc_codegen_cranelift::driver::aot::module_codegen") {
+            stack = &stack[index..];
+        }
+
+        // Trim end
+        const MALLOC: &str = "malloc";
+        if let Some(index) = stack.find(MALLOC) {
+            stack = &stack[..index + MALLOC.len()];
+        }
+
+        const FREE: &str = "free";
+        if let Some(index) = stack.find(FREE) {
+            stack = &stack[..index + FREE.len()];
+        }
+
+        const TYPECK_ITEM_BODIES: &str = "rustc_typeck::check::typeck_item_bodies";
+        if let Some(index) = stack.find(TYPECK_ITEM_BODIES) {
+            stack = &stack[..index + TYPECK_ITEM_BODIES.len()];
+        }
+
+        const COLLECT_AND_PARTITION_MONO_ITEMS: &str =
+            "rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items";
+        if let Some(index) = stack.find(COLLECT_AND_PARTITION_MONO_ITEMS) {
+            stack = &stack[..index + COLLECT_AND_PARTITION_MONO_ITEMS.len()];
+        }
+
+        const ASSERT_DEP_GRAPH: &str = "rustc_incremental::assert_dep_graph::assert_dep_graph";
+        if let Some(index) = stack.find(ASSERT_DEP_GRAPH) {
+            stack = &stack[..index + ASSERT_DEP_GRAPH.len()];
+        }
+
+        const REPORT_SYMBOL_NAMES: &str = "rustc_symbol_mangling::test::report_symbol_names";
+        if let Some(index) = stack.find(REPORT_SYMBOL_NAMES) {
+            stack = &stack[..index + REPORT_SYMBOL_NAMES.len()];
+        }
+
+        const ENCODE_METADATA: &str = "rustc_middle::ty::context::TyCtxt::encode_metadata";
+        if let Some(index) = stack.find(ENCODE_METADATA) {
+            stack = &stack[..index + ENCODE_METADATA.len()];
+        }
+
+        const SUBST_AND_NORMALIZE_ERASING_REGIONS: &str = "rustc_middle::ty::normalize_erasing_regions::<impl rustc_middle::ty::context::TyCtxt>::subst_and_normalize_erasing_regions";
+        if let Some(index) = stack.find(SUBST_AND_NORMALIZE_ERASING_REGIONS) {
+            stack = &stack[..index + SUBST_AND_NORMALIZE_ERASING_REGIONS.len()];
+        }
+
+        const NORMALIZE_ERASING_LATE_BOUND_REGIONS: &str = "rustc_middle::ty::normalize_erasing_regions::<impl rustc_middle::ty::context::TyCtxt>::normalize_erasing_late_bound_regions";
+        if let Some(index) = stack.find(NORMALIZE_ERASING_LATE_BOUND_REGIONS) {
+            stack = &stack[..index + NORMALIZE_ERASING_LATE_BOUND_REGIONS.len()];
+        }
+
+        const INST_BUILD: &str = "<cranelift_frontend::frontend::FuncInstBuilder as cranelift_codegen::ir::builder::InstBuilderBase>::build";
+        if let Some(index) = stack.find(INST_BUILD) {
+            stack = &stack[..index + INST_BUILD.len()];
+        }
+
+        output.write_all(stack.as_bytes())?;
+        output.write_all(&*b" ")?;
+        output.write_all(count.as_bytes())?;
+        output.write_all(&*b"\n")?;
+    }
+
+    Ok(())
+}