From: Jonas Schievink Date: Thu, 12 May 2016 22:20:59 +0000 (+0200) Subject: Some simple improvements to MIR pretty printing X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=96b178b131c63b38aa760381a4a0359fd8a17ed1;p=rust.git Some simple improvements to MIR pretty printing In short, this PR changes the MIR printer so that it: * places an empty line between the MIR for each item * does *not* write an empty line before the first BB when there are no var decls * aligns the "// Scope" comments 50 chars in (makes the output more readable) * prints the scope comments as "// scope N at ..." instead of "// Scope(N) at ..." * prints a prettier scope tree: * no more unbalanced delimiters! * no more "Parent" entry (these convey no useful information) * drop the "Scope()" and just print scope IDs * no braces when the scope is empty --- diff --git a/src/librustc_mir/pretty.rs b/src/librustc_mir/pretty.rs index bf6689de236..46f433ff4c6 100644 --- a/src/librustc_mir/pretty.rs +++ b/src/librustc_mir/pretty.rs @@ -21,6 +21,8 @@ use syntax::codemap::Span; const INDENT: &'static str = " "; +/// Alignment for lining up comments following MIR statements +const ALIGN: usize = 50; /// If the session is properly configured, dumps a human-readable /// representation of the mir into: @@ -79,11 +81,20 @@ pub fn write_mir_pretty<'a, 'b, 'tcx, I>(tcx: TyCtxt<'b, 'tcx, 'tcx>, -> io::Result<()> where I: Iterator)>, 'tcx: 'a { + let mut first = true; for (&id, mir) in iter { + if first { + first = false; + } else { + // Put empty lines between all items + writeln!(w, "")?; + } + let src = MirSource::from_node(tcx, id); write_mir_fn(tcx, src, mir, w, None)?; for (i, mir) in mir.promoted.iter().enumerate() { + writeln!(w, "")?; write_mir_fn(tcx, MirSource::Promoted(id, i), mir, w, None)?; } } @@ -131,6 +142,8 @@ pub fn write_mir_fn<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, .or_insert(vec![]) .push(ScopeId::new(index)); } + + writeln!(w, "{}scope tree:", INDENT)?; write_scope_tree(tcx, mir, auxiliary, &scope_tree, w, None, 1)?; writeln!(w, "}}")?; @@ -147,7 +160,7 @@ fn write_basic_block(tcx: TyCtxt, let data = mir.basic_block_data(block); // Basic block label at the top. - writeln!(w, "\n{}{:?}: {{", INDENT, block)?; + writeln!(w, "{}{:?}: {{", INDENT, block)?; // List of statements in the middle. let mut current_location = Location { block: block, statement_index: 0 }; @@ -165,25 +178,27 @@ fn write_basic_block(tcx: TyCtxt, } } - writeln!(w, "{0}{0}{1:?}; // {2}", - INDENT, - statement, + let indented_mir = format!("{0}{0}{1:?};", INDENT, statement); + writeln!(w, "{0:1$} // {2}", + indented_mir, + ALIGN, comment(tcx, statement.scope, statement.span))?; current_location.statement_index += 1; } // Terminator at the bottom. - writeln!(w, "{0}{0}{1:?}; // {2}", - INDENT, - data.terminator().kind, + let indented_terminator = format!("{0}{0}{1:?};", INDENT, data.terminator().kind); + writeln!(w, "{0:1$} // {2}", + indented_terminator, + ALIGN, comment(tcx, data.terminator().scope, data.terminator().span))?; - writeln!(w, "{}}}", INDENT) + writeln!(w, "{}}}\n", INDENT) } fn comment(tcx: TyCtxt, scope: ScopeId, span: Span) -> String { - format!("Scope({}) at {}", scope.index(), tcx.sess.codemap().span_to_string(span)) + format!("scope {} at {}", scope.index(), tcx.sess.codemap().span_to_string(span)) } fn write_scope_tree(tcx: TyCtxt, @@ -198,12 +213,9 @@ fn write_scope_tree(tcx: TyCtxt, let indent = depth * INDENT.len(); let data = &mir.scopes[child]; assert_eq!(data.parent_scope, parent); - writeln!(w, "{0:1$}Scope({2}) {{", "", indent, child.index())?; + write!(w, "{0:1$}{2}", "", indent, child.index())?; let indent = indent + INDENT.len(); - if let Some(parent) = parent { - writeln!(w, "{0:1$}Parent: Scope({2})", "", indent, parent.index())?; - } if let Some(auxiliary) = auxiliary { let extent = auxiliary[child].extent; @@ -211,9 +223,18 @@ fn write_scope_tree(tcx: TyCtxt, writeln!(w, "{0:1$}Extent: {2:?}", "", indent, data)?; } - write_scope_tree(tcx, mir, auxiliary, scope_tree, w, - Some(child), depth + 1)?; + if scope_tree.get(&Some(child)).map(Vec::is_empty).unwrap_or(true) { + // No child scopes, skip the braces + writeln!(w, "")?; + } else { + writeln!(w, " {{")?; + write_scope_tree(tcx, mir, auxiliary, scope_tree, w, + Some(child), depth + 1)?; + + writeln!(w, "{0:1$}}}", "", indent - INDENT.len())?; + } } + Ok(()) } @@ -261,13 +282,20 @@ fn write_mir_intro<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, // User variable types (including the user's name in a comment). for (i, var) in mir.var_decls.iter().enumerate() { - write!(w, "{}let ", INDENT)?; - if var.mutability == Mutability::Mut { - write!(w, "mut ")?; - } - writeln!(w, "{:?}: {}; // {} in {}", - Lvalue::Var(i as u32), - var.ty, + let mut_str = if var.mutability == Mutability::Mut { + "mut " + } else { + "" + }; + + let indented_var = format!("{}let {}{:?}: {};", + INDENT, + mut_str, + Lvalue::Var(i as u32), + var.ty); + writeln!(w, "{0:1$} // \"{2}\" in {3}", + indented_var, + ALIGN, var.name, comment(tcx, var.scope, var.span))?; } @@ -277,5 +305,10 @@ fn write_mir_intro<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, writeln!(w, "{}let mut {:?}: {};", INDENT, Lvalue::Temp(i as u32), temp.ty)?; } + // Wrote any declaration? Add an empty line before the first block is printed. + if !mir.var_decls.is_empty() || !mir.temp_decls.is_empty() { + writeln!(w, "")?; + } + Ok(()) }