From 0f46e4f1f23368f4615a9847671e3a91b2ebaf18 Mon Sep 17 00:00:00 2001 From: Ryan Prichard Date: Fri, 3 Apr 2015 01:27:04 -0700 Subject: Propagate macro backtraces more often, improve formatting diagnostics * In noop_fold_expr, call new_span in these cases: - ExprMethodCall's identifier - ExprField's identifier - ExprTupField's integer Calling new_span for ExprMethodCall's identifier is necessary to print an acceptable diagnostic for write!(&2, ""). We see this error: :2:20: 2:66 error: type `&mut _` does not implement any method in scope named `write_fmt` :2 ( & mut * $ dst ) . write_fmt ( format_args ! ( $ ( $ arg ) * ) ) ) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ With this change, we also see a macro expansion backtrace leading to the write!(&2, "") call site. * After fully expanding a macro, we replace the expansion expression's span with the original span. Call fld.new_span to add a backtrace to this span. (Note that I'm call new_span after bt.pop(), so the macro just expanded isn't on the backtrace.) The motivating example for this change is println!("{}"). The format string literal is concat!($fmt, "arg") and is inside the libstd macro. We need to see the backtrace to find the println! call site. * Add a backtrace to the format_args! format expression span. Addresses #23459 --- src/libsyntax/ext/expand.rs | 2 +- src/libsyntax/ext/format.rs | 8 ++++++-- src/libsyntax/fold.rs | 8 +++++--- 3 files changed, 12 insertions(+), 6 deletions(-) (limited to 'src/libsyntax') diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs index 5f4ec01791c..b65798b8a49 100644 --- a/src/libsyntax/ext/expand.rs +++ b/src/libsyntax/ext/expand.rs @@ -55,7 +55,7 @@ pub fn expand_expr(e: P, fld: &mut MacroExpander) -> P { fully_expanded.map(|e| ast::Expr { id: ast::DUMMY_NODE_ID, node: e.node, - span: span, + span: fld.new_span(span), }) } diff --git a/src/libsyntax/ext/format.rs b/src/libsyntax/ext/format.rs index 1d99a475b32..513bbf6c77b 100644 --- a/src/libsyntax/ext/format.rs +++ b/src/libsyntax/ext/format.rs @@ -17,6 +17,7 @@ use ext::base::*; use ext::base; use ext::build::AstBuilder; use fmt_macros as parse; +use fold::Folder; use parse::token::special_idents; use parse::token; use ptr::P; @@ -649,6 +650,10 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt, sp: Span, names: HashMap>) -> P { let arg_types: Vec<_> = (0..args.len()).map(|_| None).collect(); + // Expand the format literal so that efmt.span will have a backtrace. This + // is essential for locating a bug when the format literal is generated in + // a macro. (e.g. println!("{}"), which uses concat!($fmt, "\n")). + let efmt = ecx.expander().fold_expr(efmt); let mut cx = Context { ecx: ecx, args: args, @@ -663,9 +668,8 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt, sp: Span, pieces: Vec::new(), str_pieces: Vec::new(), all_pieces_simple: true, - fmtsp: sp, + fmtsp: efmt.span, }; - cx.fmtsp = efmt.span; let fmt = match expr_to_string(cx.ecx, efmt, "format argument must be a string literal.") { diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs index d4451cc7b71..d7033ce7e48 100644 --- a/src/libsyntax/fold.rs +++ b/src/libsyntax/fold.rs @@ -1176,7 +1176,7 @@ pub fn noop_fold_expr(Expr {id, node, span}: Expr, folder: &mut T) -> } ExprMethodCall(i, tps, args) => { ExprMethodCall( - respan(i.span, folder.fold_ident(i.node)), + respan(folder.new_span(i.span), folder.fold_ident(i.node)), tps.move_map(|x| folder.fold_ty(x)), args.move_map(|x| folder.fold_expr(x))) } @@ -1246,11 +1246,13 @@ pub fn noop_fold_expr(Expr {id, node, span}: Expr, folder: &mut T) -> } ExprField(el, ident) => { ExprField(folder.fold_expr(el), - respan(ident.span, folder.fold_ident(ident.node))) + respan(folder.new_span(ident.span), + folder.fold_ident(ident.node))) } ExprTupField(el, ident) => { ExprTupField(folder.fold_expr(el), - respan(ident.span, folder.fold_usize(ident.node))) + respan(folder.new_span(ident.span), + folder.fold_usize(ident.node))) } ExprIndex(el, er) => { ExprIndex(folder.fold_expr(el), folder.fold_expr(er)) -- cgit 1.4.1-3-g733a5 From fab3295cba64a8e4245374c5eb8f2478029d13db Mon Sep 17 00:00:00 2001 From: Ryan Prichard Date: Sun, 5 Apr 2015 18:07:11 -0700 Subject: Suppress the macro backtrace for `fileline_note` and `fileline_help`. --- src/libsyntax/codemap.rs | 2 +- src/libsyntax/diagnostic.rs | 7 +++---- 2 files changed, 4 insertions(+), 5 deletions(-) (limited to 'src/libsyntax') diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs index 7635c8eadc2..5bbf79d0477 100644 --- a/src/libsyntax/codemap.rs +++ b/src/libsyntax/codemap.rs @@ -871,7 +871,7 @@ impl CodeMap { F: FnOnce(Option<&ExpnInfo>) -> T, { match id { - NO_EXPANSION => f(None), + NO_EXPANSION | COMMAND_LINE_EXPN => f(None), ExpnId(i) => f(Some(&(*self.expansions.borrow())[i as usize])) } } diff --git a/src/libsyntax/diagnostic.rs b/src/libsyntax/diagnostic.rs index ed7bdcd898e..f3715d765e3 100644 --- a/src/libsyntax/diagnostic.rs +++ b/src/libsyntax/diagnostic.rs @@ -465,22 +465,21 @@ fn emit(dst: &mut EmitterWriter, cm: &codemap::CodeMap, rsp: RenderSpan, match rsp { FullSpan(_) => { try!(highlight_lines(dst, cm, sp, lvl, cm.span_to_lines(sp))); + try!(print_macro_backtrace(dst, cm, sp)); } EndSpan(_) => { try!(end_highlight_lines(dst, cm, sp, lvl, cm.span_to_lines(sp))); + try!(print_macro_backtrace(dst, cm, sp)); } Suggestion(_, ref suggestion) => { try!(highlight_suggestion(dst, cm, sp, suggestion)); + try!(print_macro_backtrace(dst, cm, sp)); } FileLine(..) => { // no source text in this case! } } - if sp != COMMAND_LINE_SP { - try!(print_macro_backtrace(dst, cm, sp)); - } - match code { Some(code) => match dst.registry.as_ref().and_then(|registry| registry.find_description(code)) { -- cgit 1.4.1-3-g733a5 From ddbdf51f394226bcae162ed2d5348126b32e7dbd Mon Sep 17 00:00:00 2001 From: Ryan Prichard Date: Thu, 9 Apr 2015 22:42:59 -0700 Subject: Remove the vestigial ExtCtxt::print_backtrace function. It was added in 2011-08-05 and reduced to a no-op ten days later. --- src/libsyntax/ext/base.rs | 10 ---------- src/libsyntax/ext/log_syntax.rs | 2 -- 2 files changed, 12 deletions(-) (limited to 'src/libsyntax') diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs index 346fb3580e1..9994fad3e31 100644 --- a/src/libsyntax/ext/base.rs +++ b/src/libsyntax/ext/base.rs @@ -605,7 +605,6 @@ impl<'a> ExtCtxt<'a> { None => self.bug("missing top span") }) } - pub fn print_backtrace(&self) { } pub fn backtrace(&self) -> ExpnId { self.backtrace } pub fn original_span(&self) -> Span { let mut expn_id = self.backtrace; @@ -700,7 +699,6 @@ impl<'a> ExtCtxt<'a> { /// substitute; we never hit resolve/type-checking so the dummy /// value doesn't have to match anything) pub fn span_fatal(&self, sp: Span, msg: &str) -> ! { - self.print_backtrace(); panic!(self.parse_sess.span_diagnostic.span_fatal(sp, msg)); } @@ -710,35 +708,27 @@ impl<'a> ExtCtxt<'a> { /// Compilation will be stopped in the near future (at the end of /// the macro expansion phase). pub fn span_err(&self, sp: Span, msg: &str) { - self.print_backtrace(); self.parse_sess.span_diagnostic.span_err(sp, msg); } pub fn span_warn(&self, sp: Span, msg: &str) { - self.print_backtrace(); self.parse_sess.span_diagnostic.span_warn(sp, msg); } pub fn span_unimpl(&self, sp: Span, msg: &str) -> ! { - self.print_backtrace(); self.parse_sess.span_diagnostic.span_unimpl(sp, msg); } pub fn span_bug(&self, sp: Span, msg: &str) -> ! { - self.print_backtrace(); self.parse_sess.span_diagnostic.span_bug(sp, msg); } pub fn span_note(&self, sp: Span, msg: &str) { - self.print_backtrace(); self.parse_sess.span_diagnostic.span_note(sp, msg); } pub fn span_help(&self, sp: Span, msg: &str) { - self.print_backtrace(); self.parse_sess.span_diagnostic.span_help(sp, msg); } pub fn fileline_help(&self, sp: Span, msg: &str) { - self.print_backtrace(); self.parse_sess.span_diagnostic.fileline_help(sp, msg); } pub fn bug(&self, msg: &str) -> ! { - self.print_backtrace(); self.parse_sess.span_diagnostic.handler().bug(msg); } pub fn trace_macros(&self) -> bool { diff --git a/src/libsyntax/ext/log_syntax.rs b/src/libsyntax/ext/log_syntax.rs index 8173dd93f74..9869108952c 100644 --- a/src/libsyntax/ext/log_syntax.rs +++ b/src/libsyntax/ext/log_syntax.rs @@ -26,8 +26,6 @@ pub fn expand_syntax_ext<'cx>(cx: &'cx mut base::ExtCtxt, return base::DummyResult::any(sp); } - cx.print_backtrace(); - println!("{}", print::pprust::tts_to_string(tts)); // any so that `log_syntax` can be invoked as an expression and item. -- cgit 1.4.1-3-g733a5