auto merge of #15371 : pnkfelix/rust/fsk-render-dataflow-on-dot, r=alexcrichton

Use one or more of the following `-Z` flag options to tell the
graphviz renderer to include the corresponding dataflow sets (after
the iterative constraint propagation reaches a fixed-point solution):

  * `-Z flowgraph-print-loans` : loans computed via middle::borrowck
  * `-Z flowgraph-print-moves` : moves computed via middle::borrowck::move_data
  * `-Z flowgraph-print-assigns` : assignments, via middle::borrowck::move_data
  * `-Z flowgraph-print-all` : all of the available sets are included.

Fix #15016.

Author: bors

Diff for: src/libgraphviz/lib.rs

@@ -434,10 +434,37 @@ impl<'a> LabelText<'a> {
     /// Renders text as string suitable for a label in a .dot file.
     pub fn escape(&self) -> String {
         match self {
-            &LabelStr(ref s) => s.as_slice().escape_default().to_string(),
-            &EscStr(ref s) => LabelText::escape_str(s.as_slice()).to_string(),
+            &LabelStr(ref s) => s.as_slice().escape_default(),
+            &EscStr(ref s) => LabelText::escape_str(s.as_slice()),
         }
     }
+
+    /// Decomposes content into string suitable for making EscStr that
+    /// yields same content as self.  The result obeys the law
+    /// render(`lt`) == render(`EscStr(lt.pre_escaped_content())`) for
+    /// all `lt: LabelText`.
+    fn pre_escaped_content(self) -> str::MaybeOwned<'a> {
+        match self {
+            EscStr(s) => s,
+            LabelStr(s) => if s.as_slice().contains_char('\\') {
+                str::Owned(s.as_slice().escape_default())
+            } else {
+                s
+            },
+        }
+    }
+
+    /// Puts `prefix` on a line above this label, with a blank line separator.
+    pub fn prefix_line(self, prefix: LabelText) -> LabelText {
+        prefix.suffix_line(self)
+    }
+
+    /// Puts `suffix` on a line below this label, with a blank line separator.
+    pub fn suffix_line(self, suffix: LabelText) -> LabelText {
+        let prefix = self.pre_escaped_content().into_string();
+        let suffix = suffix.pre_escaped_content();
+        EscStr(str::Owned(prefix.append(r"\n\n").append(suffix.as_slice())))
+    }
 }
 
 pub type Nodes<'a,N> = MaybeOwnedVector<'a,N>;
@@ -664,10 +691,7 @@ mod tests {
         let mut writer = MemWriter::new();
         render(&g, &mut writer).unwrap();
         let mut r = BufReader::new(writer.get_ref());
-        match r.read_to_string() {
-            Ok(string) => Ok(string.to_string()),
-            Err(err) => Err(err),
-        }
+        r.read_to_string()
     }
 
     // All of the tests use raw-strings as the format for the expected outputs,

Diff for: src/librustc/driver/config.rs

@@ -179,7 +179,11 @@ debugging_opts!(
         AST_JSON,
         AST_JSON_NOEXPAND,
         LS,
-        SAVE_ANALYSIS
+        SAVE_ANALYSIS,
+        FLOWGRAPH_PRINT_LOANS,
+        FLOWGRAPH_PRINT_MOVES,
+        FLOWGRAPH_PRINT_ASSIGNS,
+        FLOWGRAPH_PRINT_ALL
     ]
     0
 )
@@ -215,7 +219,15 @@ pub fn debugging_opts_map() -> Vec<(&'static str, &'static str, u64)> {
      ("ast-json-noexpand", "Print the pre-expansion AST as JSON and halt", AST_JSON_NOEXPAND),
      ("ls", "List the symbols defined by a library crate", LS),
      ("save-analysis", "Write syntax and type analysis information \
-                        in addition to normal output", SAVE_ANALYSIS))
+                        in addition to normal output", SAVE_ANALYSIS),
+     ("flowgraph-print-loans", "Include loan analysis data in \
+                       --pretty flowgraph output", FLOWGRAPH_PRINT_LOANS),
+     ("flowgraph-print-moves", "Include move analysis data in \
+                       --pretty flowgraph output", FLOWGRAPH_PRINT_MOVES),
+     ("flowgraph-print-assigns", "Include assignment analysis data in \
+                       --pretty flowgraph output", FLOWGRAPH_PRINT_ASSIGNS),
+     ("flowgraph-print-all", "Include all dataflow analysis data in \
+                       --pretty flowgraph output", FLOWGRAPH_PRINT_ALL))
 }
 
 /// Declare a macro that will define all CodegenOptions fields and parsers all

Diff for: src/librustc/driver/driver.rs

@@ -19,6 +19,9 @@ use lint;
 use llvm::{ContextRef, ModuleRef};
 use metadata::common::LinkMeta;
 use metadata::creader;
+use middle::borrowck::{FnPartsWithCFG};
+use middle::borrowck;
+use borrowck_dot = middle::borrowck::graphviz;
 use middle::cfg;
 use middle::cfg::graphviz::LabelledCFG;
 use middle::{trans, freevars, stability, kind, ty, typeck, reachable};
@@ -40,6 +43,7 @@ use std::io;
 use std::io::fs;
 use std::io::MemReader;
 use syntax::ast;
+use syntax::ast_map::blocks;
 use syntax::attr;
 use syntax::attr::{AttrMetaMethods};
 use syntax::diagnostics;
@@ -662,6 +666,25 @@ impl pprust::PpAnn for TypedAnnotation {
     }
 }
 
+fn gather_flowgraph_variants(sess: &Session) -> Vec<borrowck_dot::Variant> {
+    let print_loans   = config::FLOWGRAPH_PRINT_LOANS;
+    let print_moves   = config::FLOWGRAPH_PRINT_MOVES;
+    let print_assigns = config::FLOWGRAPH_PRINT_ASSIGNS;
+    let print_all     = config::FLOWGRAPH_PRINT_ALL;
+    let opt = |print_which| sess.debugging_opt(print_which);
+    let mut variants = Vec::new();
+    if opt(print_all) || opt(print_loans) {
+        variants.push(borrowck_dot::Loans);
+    }
+    if opt(print_all) || opt(print_moves) {
+        variants.push(borrowck_dot::Moves);
+    }
+    if opt(print_all) || opt(print_assigns) {
+        variants.push(borrowck_dot::Assigns);
+    }
+    variants
+}
+
 pub fn pretty_print_input(sess: Session,
                           cfg: ast::CrateConfig,
                           input: &Input,
@@ -733,10 +756,17 @@ pub fn pretty_print_input(sess: Session,
                 sess.fatal(format!("--pretty flowgraph couldn't find id: {}",
                                    nodeid).as_slice())
             });
-            let block = match node {
-                syntax::ast_map::NodeBlock(block) => block,
-                _ => {
-                    let message = format!("--pretty=flowgraph needs block, got {:?}",
+            let code = blocks::Code::from_node(node);
+            match code {
+                Some(code) => {
+                    let variants = gather_flowgraph_variants(&sess);
+                    let analysis = phase_3_run_analysis_passes(sess, &krate,
+                                                               ast_map, id);
+                    print_flowgraph(variants, analysis, code, out)
+                }
+                None => {
+                    let message = format!("--pretty=flowgraph needs \
+                                           block, fn, or method; got {:?}",
                                           node);
 
                     // point to what was found, if there's an
@@ -746,10 +776,7 @@ pub fn pretty_print_input(sess: Session,
                         None => sess.fatal(message.as_slice())
                     }
                 }
-            };
-            let analysis = phase_3_run_analysis_passes(sess, &krate,
-                                                       ast_map, id);
-            print_flowgraph(analysis, block, out)
+            }
         }
         _ => {
             pprust::print_crate(sess.codemap(),
@@ -765,17 +792,52 @@ pub fn pretty_print_input(sess: Session,
 
 }
 
-fn print_flowgraph<W:io::Writer>(analysis: CrateAnalysis,
-                                 block: ast::P<ast::Block>,
+fn print_flowgraph<W:io::Writer>(variants: Vec<borrowck_dot::Variant>,
+                                 analysis: CrateAnalysis,
+                                 code: blocks::Code,
                                  mut out: W) -> io::IoResult<()> {
     let ty_cx = &analysis.ty_cx;
-    let cfg = cfg::CFG::new(ty_cx, &*block);
-    let lcfg = LabelledCFG { ast_map: &ty_cx.map,
-                             cfg: &cfg,
-                             name: format!("block{}", block.id), };
+    let cfg = match code {
+        blocks::BlockCode(block) => cfg::CFG::new(ty_cx, &*block),
+        blocks::FnLikeCode(fn_like) => cfg::CFG::new(ty_cx, fn_like.body()),
+    };
     debug!("cfg: {:?}", cfg);
-    let r = dot::render(&lcfg, &mut out);
-    return expand_err_details(r);
+
+    match code {
+        _ if variants.len() == 0 => {
+            let lcfg = LabelledCFG {
+                ast_map: &ty_cx.map,
+                cfg: &cfg,
+                name: format!("node_{}", code.id()),
+            };
+            let r = dot::render(&lcfg, &mut out);
+            return expand_err_details(r);
+        }
+        blocks::BlockCode(_) => {
+            ty_cx.sess.err("--pretty flowgraph with -Z flowgraph-print \
+                            annotations requires fn-like node id.");
+            return Ok(())
+        }
+        blocks::FnLikeCode(fn_like) => {
+            let fn_parts = FnPartsWithCFG::from_fn_like(&fn_like, &cfg);
+            let (bccx, analysis_data) =
+                borrowck::build_borrowck_dataflow_data_for_fn(ty_cx, fn_parts);
+
+            let lcfg = LabelledCFG {
+                ast_map: &ty_cx.map,
+                cfg: &cfg,
+                name: format!("node_{}", code.id()),
+            };
+            let lcfg = borrowck_dot::DataflowLabeller {
+                inner: lcfg,
+                variants: variants,
+                borrowck_ctxt: &bccx,
+                analysis_data: &analysis_data,
+            };
+            let r = dot::render(&lcfg, &mut out);
+            return expand_err_details(r);
+        }
+    }
 
     fn expand_err_details(r: io::IoResult<()>) -> io::IoResult<()> {
         r.map_err(|ioerr| {

Diff for: src/librustc/middle/borrowck/graphviz.rs

@@ -0,0 +1,148 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! This module provides linkage between rustc::middle::graph and
+//! libgraphviz traits, specialized to attaching borrowck analysis
+//! data to rendered labels.
+
+/// For clarity, rename the graphviz crate locally to dot.
+use dot = graphviz;
+pub use middle::cfg::graphviz::{Node, Edge};
+use cfg_dot = middle::cfg::graphviz;
+
+use middle::borrowck;
+use middle::borrowck::{BorrowckCtxt, LoanPath};
+use middle::cfg::{CFGIndex};
+use middle::dataflow::{DataFlowOperator, DataFlowContext, EntryOrExit};
+use middle::dataflow;
+
+use std::rc::Rc;
+use std::str;
+
+#[deriving(Show)]
+pub enum Variant {
+    Loans,
+    Moves,
+    Assigns,
+}
+
+impl Variant {
+    pub fn short_name(&self) -> &'static str {
+        match *self {
+            Loans   => "loans",
+            Moves   => "moves",
+            Assigns => "assigns",
+        }
+    }
+}
+
+pub struct DataflowLabeller<'a> {
+    pub inner: cfg_dot::LabelledCFG<'a>,
+    pub variants: Vec<Variant>,
+    pub borrowck_ctxt: &'a BorrowckCtxt<'a>,
+    pub analysis_data: &'a borrowck::AnalysisData<'a>,
+}
+
+impl<'a> DataflowLabeller<'a> {
+    fn dataflow_for(&self, e: EntryOrExit, n: &Node<'a>) -> String {
+        let id = n.val1().data.id;
+        debug!("dataflow_for({}, id={}) {}", e, id, self.variants);
+        let mut sets = "".to_string();
+        let mut seen_one = false;
+        for &variant in self.variants.iter() {
+            if seen_one { sets.push_str(" "); } else { seen_one = true; }
+            sets.push_str(variant.short_name());
+            sets.push_str(": ");
+            sets.push_str(self.dataflow_for_variant(e, n, variant).as_slice());
+        }
+        sets
+    }
+
+    fn dataflow_for_variant(&self, e: EntryOrExit, n: &Node, v: Variant) -> String {
+        let cfgidx = n.val0();
+        match v {
+            Loans   => self.dataflow_loans_for(e, cfgidx),
+            Moves   => self.dataflow_moves_for(e, cfgidx),
+            Assigns => self.dataflow_assigns_for(e, cfgidx),
+        }
+    }
+
+    fn build_set<O:DataFlowOperator>(&self,
+                                     e: EntryOrExit,
+                                     cfgidx: CFGIndex,
+                                     dfcx: &DataFlowContext<'a, O>,
+                                     to_lp: |uint| -> Rc<LoanPath>) -> String {
+        let mut saw_some = false;
+        let mut set = "{".to_string();
+        dfcx.each_bit_for_node(e, cfgidx, |index| {
+            let lp = to_lp(index);
+            if saw_some {
+                set.push_str(", ");
+            }
+            let loan_str = self.borrowck_ctxt.loan_path_to_string(&*lp);
+            set.push_str(loan_str.as_slice());
+            saw_some = true;
+            true
+        });
+        set.append("}")
+    }
+
+    fn dataflow_loans_for(&self, e: EntryOrExit, cfgidx: CFGIndex) -> String {
+        let dfcx = &self.analysis_data.loans;
+        let loan_index_to_path = |loan_index| {
+            let all_loans = &self.analysis_data.all_loans;
+            all_loans.get(loan_index).loan_path()
+        };
+        self.build_set(e, cfgidx, dfcx, loan_index_to_path)
+    }
+
+    fn dataflow_moves_for(&self, e: EntryOrExit, cfgidx: CFGIndex) -> String {
+        let dfcx = &self.analysis_data.move_data.dfcx_moves;
+        let move_index_to_path = |move_index| {
+            let move_data = &self.analysis_data.move_data.move_data;
+            let moves = move_data.moves.borrow();
+            let move = moves.get(move_index);
+            move_data.path_loan_path(move.path)
+        };
+        self.build_set(e, cfgidx, dfcx, move_index_to_path)
+    }
+
+    fn dataflow_assigns_for(&self, e: EntryOrExit, cfgidx: CFGIndex) -> String {
+        let dfcx = &self.analysis_data.move_data.dfcx_assign;
+        let assign_index_to_path = |assign_index| {
+            let move_data = &self.analysis_data.move_data.move_data;
+            let assignments = move_data.var_assignments.borrow();
+            let assignment = assignments.get(assign_index);
+            move_data.path_loan_path(assignment.path)
+        };
+        self.build_set(e, cfgidx, dfcx, assign_index_to_path)
+    }
+}
+
+impl<'a> dot::Labeller<'a, Node<'a>, Edge<'a>> for DataflowLabeller<'a> {
+    fn graph_id(&'a self) -> dot::Id<'a> { self.inner.graph_id() }
+    fn node_id(&'a self, n: &Node<'a>) -> dot::Id<'a> { self.inner.node_id(n) }
+    fn node_label(&'a self, n: &Node<'a>) -> dot::LabelText<'a> {
+        let prefix = self.dataflow_for(dataflow::Entry, n);
+        let suffix = self.dataflow_for(dataflow::Exit, n);
+        let inner_label = self.inner.node_label(n);
+        inner_label
+            .prefix_line(dot::LabelStr(str::Owned(prefix)))
+            .suffix_line(dot::LabelStr(str::Owned(suffix)))
+    }
+    fn edge_label(&'a self, e: &Edge<'a>) -> dot::LabelText<'a> { self.inner.edge_label(e) }
+}
+
+impl<'a> dot::GraphWalk<'a, Node<'a>, Edge<'a>> for DataflowLabeller<'a> {
+    fn nodes(&self) -> dot::Nodes<'a, Node<'a>> { self.inner.nodes() }
+    fn edges(&self) -> dot::Edges<'a, Edge<'a>> { self.inner.edges() }
+    fn source(&self, edge: &Edge<'a>) -> Node<'a> { self.inner.source(edge) }
+    fn target(&self, edge: &Edge<'a>) -> Node<'a> { self.inner.target(edge) }
+}