Add a generic palette to highlight kernel / jitted code

src/bin/flamegraph.rs

@@ -82,7 +82,7 @@ struct Opt {
         short = "c",
         long = "colors",
         default_value = defaults::COLORS,
-        possible_values = &["aqua","blue","green","hot","io","java","js","mem","orange","perl","purple","red","wakeup","yellow"],
+        possible_values = &["annotated","aqua","blue","green","hot","io","java","js","mem","orange","perl","purple","red","wakeup","yellow"],
         value_name = "STRING"
     )]
     colors: Palette,

src/flamegraph/color/mod.rs

@@ -118,6 +118,8 @@ pub enum BasicPalette {
 /// different function names (kernel functions, JIT functions, etc.).
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum MultiPalette {
+    /// Use function annotations with no specific language heuristics to color frames.
+    Annotated,
     /// Use Java semantics to color frames.
     Java,
     /// Use JavaScript semantics to color frames.
@@ -193,6 +195,7 @@ impl FromStr for Palette {
             "mem" => Ok(Palette::Basic(BasicPalette::Mem)),
             "io" => Ok(Palette::Basic(BasicPalette::Io)),
             "wakeup" => Ok(Palette::Multi(MultiPalette::Wakeup)),
+            "annotated" => Ok(Palette::Multi(MultiPalette::Annotated)),
             "java" => Ok(Palette::Multi(MultiPalette::Java)),
             "js" => Ok(Palette::Multi(MultiPalette::Js)),
             "perl" => Ok(Palette::Multi(MultiPalette::Perl)),
@@ -304,6 +307,7 @@ macro_rules! color {
 fn rgb_components_for_palette(palette: Palette, name: &str, v1: f32, v2: f32, v3: f32) -> Color {
     let basic_palette = match palette {
         Palette::Basic(basic) => basic,
+        Palette::Multi(MultiPalette::Annotated) => palettes::annotated::resolve(name),
         Palette::Multi(MultiPalette::Java) => palettes::java::resolve(name),
         Palette::Multi(MultiPalette::Perl) => palettes::perl::resolve(name),
         Palette::Multi(MultiPalette::Js) => palettes::js::resolve(name),

src/flamegraph/color/palettes.rs

@@ -1,3 +1,29 @@
+pub(super) mod annotated {
+    use crate::flamegraph::color::BasicPalette;
+
+    /// Handle annotations (_[j], _[i], ...; which are
+    /// accurate) in a generic way.
+    pub fn resolve(name: &str) -> BasicPalette {
+        if name.ends_with(']') {
+            if let Some(ai) = name.rfind("_[") {
+                if name[ai..].len() == 4 {
+                    match &name[ai + 2..ai + 3] {
+                        // kernel annotation
+                        "k" => return BasicPalette::Orange,
+                        // inline annotation
+                        "i" => return BasicPalette::Aqua,
+                        // jit annotation
+                        "j" => return BasicPalette::Green,
+                        _ => {}
+                    }
+                }
+            }
+        }
+
+        BasicPalette::Red
+    }
+}
+
 pub(super) mod java {
     use crate::flamegraph::color::BasicPalette;