From 130d3eb32eedce78bfd5e596c5c90d7fbe9d495b Mon Sep 17 00:00:00 2001
From: Halid Odat <halidodat@gmail.com>
Date: Thu, 10 Nov 2022 17:04:21 +0100
Subject: [PATCH] Add CLI option for generating flowgraphs

---
 boa_cli/src/main.rs             | 42 ++++++++++++++++++++++++++++++++-
 boa_engine/src/vm/code_block.rs |  6 +----
 boa_engine/src/vm/graph.rs      |  3 +--
 3 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/boa_cli/src/main.rs b/boa_cli/src/main.rs
index 82da7c5cf8c..d128a6ed7df 100644
--- a/boa_cli/src/main.rs
+++ b/boa_cli/src/main.rs
@@ -60,7 +60,12 @@
 )]
 
 use boa_ast::StatementList;
-use boa_engine::Context;
+use boa_engine::{
+    vm::{
+        graph::{Direction, Graph},
+    },
+    Context, JsResult,
+};
 use clap::{Parser, ValueEnum, ValueHint};
 use colored::{Color, Colorize};
 use rustyline::{config::Config, error::ReadlineError, EditMode, Editor};
@@ -104,6 +109,10 @@ struct Opt {
     #[arg(long, short)]
     trace: bool,
 
+    /// Generate instruction flowgraph. Default is Graphviz.
+    #[arg(long, value_name = "FORMAT", ignore_case = true, value_enum)]
+    flowgraph: Option<Option<FlowgraphFormat>>,
+
     /// Use vi mode in the REPL
     #[arg(long = "vi")]
     vi_mode: bool,
@@ -136,6 +145,14 @@ enum DumpFormat {
     JsonPretty,
 }
 
+#[derive(Debug, Clone, Copy, ValueEnum)]
+enum FlowgraphFormat {
+    /// Generates in graphviz format.
+    Graphviz,
+    /// Generates in mermaid format.
+    Mermaid,
+}
+
 /// Parses the the token stream into an AST and returns it.
 ///
 /// Returns a error of type String with a message,
@@ -184,6 +201,19 @@ where
     Ok(())
 }
 
+fn generate_flowgraph(context: &mut Context, src: &[u8], flowgraph: FlowgraphFormat) -> JsResult<String> {
+    let ast = context.parse(src)?;
+    let code = context.compile(&ast)?;
+
+    let mut graph = Graph::new(Direction::TopToBottom);
+    code.to_graph(context.interner(), graph.subgraph(String::default()));
+    let result = match flowgraph {
+        FlowgraphFormat::Graphviz => graph.to_graphviz_format(),
+        FlowgraphFormat::Mermaid => graph.to_mermaid_format(),
+    };
+    Ok(result)
+}
+
 pub fn main() -> Result<(), io::Error> {
     let args = Opt::parse();
 
@@ -199,6 +229,11 @@ pub fn main() -> Result<(), io::Error> {
             if let Err(e) = dump(&buffer, &args, &mut context) {
                 eprintln!("{e}");
             }
+        } else if let Some(flowgraph) = args.flowgraph {
+            match generate_flowgraph(&mut context, &buffer, flowgraph.unwrap_or(FlowgraphFormat::Graphviz)) {
+                Ok(v) => println!("{}", v),
+                Err(v) => eprintln!("Uncaught {v}"),
+            }
         } else {
             match context.eval(&buffer) {
                 Ok(v) => println!("{}", v.display()),
@@ -245,6 +280,11 @@ pub fn main() -> Result<(), io::Error> {
                         if let Err(e) = dump(&line, &args, &mut context) {
                             eprintln!("{e}");
                         }
+                    } else if let Some(flowgraph) = args.flowgraph {
+                        match generate_flowgraph(&mut context, line.trim_end().as_bytes(), flowgraph.unwrap_or(FlowgraphFormat::Graphviz)) {
+                            Ok(v) => println!("{}", v),
+                            Err(v) => eprintln!("Uncaught {v}"),
+                        }
                     } else {
                         match context.eval(line.trim_end()) {
                             Ok(v) => println!("{}", v.display()),
diff --git a/boa_engine/src/vm/code_block.rs b/boa_engine/src/vm/code_block.rs
index 5c0741d5a13..a8444e20725 100644
--- a/boa_engine/src/vm/code_block.rs
+++ b/boa_engine/src/vm/code_block.rs
@@ -20,7 +20,7 @@ use crate::{
     },
     property::PropertyDescriptor,
     vm::call_frame::GeneratorResumeKind,
-    vm::{call_frame::FinallyReturn, graph::Graph, CallFrame, Opcode},
+    vm::{call_frame::FinallyReturn, CallFrame, Opcode},
     Context, JsResult, JsString, JsValue,
 };
 use boa_ast::{expression::Identifier, function::FormalParameterList};
@@ -465,10 +465,6 @@ impl ToInternedString for CodeBlock {
             }
         }
 
-        let mut graph = Graph::new(crate::vm::graph::Direction::TopToBottom);
-        self.to_graph(interner, graph.subgraph(String::default()));
-        println!("\n{}\n", graph.to_mermaid_format());
-
         f
     }
 }
diff --git a/boa_engine/src/vm/graph.rs b/boa_engine/src/vm/graph.rs
index 678eb589651..40cfb9ab742 100644
--- a/boa_engine/src/vm/graph.rs
+++ b/boa_engine/src/vm/graph.rs
@@ -236,8 +236,7 @@ impl SubGraph {
             };
             let style = match edge.style {
                 EdgeStyle::Line => "-->",
-                EdgeStyle::Dotted => "-.->",
-                EdgeStyle::Dashed => "-.->",
+                EdgeStyle::Dotted | EdgeStyle::Dashed => "-.->",
             };
             result.push_str(&format!(
                 "  {}_i_{} {style}| {}| {}_i_{}\n",