Improve error handling in libsyntax

src/librustc/session/config.rs

@@ -657,15 +657,15 @@ pub fn build_target_config(opts: &Options, sp: &SpanHandler) -> Config {
     let target = match Target::search(&opts.target_triple) {
         Ok(t) => t,
         Err(e) => {
-            sp.handler().fatal(&format!("Error loading target specification: {}", e));
+            panic!(sp.handler().fatal(&format!("Error loading target specification: {}", e)));
         }
     };
 
     let (int_type, uint_type) = match &target.target_pointer_width[..] {
         "32" => (ast::TyI32, ast::TyU32),
         "64" => (ast::TyI64, ast::TyU64),
-        w    => sp.handler().fatal(&format!("target specification was invalid: unrecognized \
-                                             target-pointer-width {}", w))
+        w    => panic!(sp.handler().fatal(&format!("target specification was invalid: \
+                                                    unrecognized target-pointer-width {}", w))),
     };
 
     Config {

src/librustc/session/mod.rs

@@ -94,7 +94,7 @@ impl Session {
         if self.opts.treat_err_as_bug {
             self.bug(msg);
         }
-        self.diagnostic().handler().fatal(msg)
+        panic!(self.diagnostic().handler().fatal(msg))
     }
     pub fn span_err_or_warn(&self, is_warning: bool, sp: Span, msg: &str) {
         if is_warning {
@@ -415,8 +415,8 @@ pub fn build_session_(sopts: config::Options,
     let host = match Target::search(config::host_triple()) {
         Ok(t) => t,
         Err(e) => {
-            span_diagnostic.handler()
-                .fatal(&format!("Error loading host specification: {}", e));
+            panic!(span_diagnostic.handler()
+                                  .fatal(&format!("Error loading host specification: {}", e)));
     }
     };
     let target_cfg = config::build_target_config(&sopts, &span_diagnostic);

src/librustc_back/target/mod.rs

@@ -257,8 +257,10 @@ impl Target {
                      .map(|s| s.as_string())
                      .and_then(|os| os.map(|s| s.to_string())) {
                 Some(val) => val,
-                None =>
-                    handler.fatal(&format!("Field {} in target specification is required", name))
+                None => {
+                    panic!(handler.fatal(&format!("Field {} in target specification is required",
+                                                  name)))
+                }
             }
         };
 

src/librustc_trans/back/write.rs

@@ -38,14 +38,12 @@ pub fn llvm_err(handler: &diagnostic::Handler, msg: String) -> ! {
     unsafe {
         let cstr = llvm::LLVMRustGetLastError();
         if cstr == ptr::null() {
-            handler.fatal(&msg[..]);
+            panic!(handler.fatal(&msg[..]));
         } else {
             let err = CStr::from_ptr(cstr).to_bytes();
             let err = String::from_utf8_lossy(err).to_string();
             libc::free(cstr as *mut _);
-            handler.fatal(&format!("{}: {}",
-                                  &msg[..],
-                                  &err[..]));
+            panic!(handler.fatal(&format!("{}: {}", &msg[..], &err[..])));
         }
     }
 }

src/libsyntax/diagnostic.rs

@@ -206,13 +206,9 @@ impl Handler {
             can_emit_warnings: can_emit_warnings
         }
     }
-    pub fn fatal(&self, msg: &str) -> ! {
+    pub fn fatal(&self, msg: &str) -> FatalError {
         self.emit.borrow_mut().emit(None, msg, None, Fatal);
-
-        // Suppress the fatal error message from the panic below as we've
-        // already terminated in our own "legitimate" fashion.
-        io::set_panic(Box::new(io::sink()));
-        panic!(FatalError);
+        FatalError
     }
     pub fn err(&self, msg: &str) {
         self.emit.borrow_mut().emit(None, msg, None, Error);
@@ -230,14 +226,15 @@ impl Handler {
     pub fn abort_if_errors(&self) {
         let s;
         match self.err_count.get() {
-          0 => return,
-          1 => s = "aborting due to previous error".to_string(),
-          _   => {
-            s = format!("aborting due to {} previous errors",
-                        self.err_count.get());
-          }
+            0 => return,
+            1 => s = "aborting due to previous error".to_string(),
+            _  => {
+                s = format!("aborting due to {} previous errors",
+                            self.err_count.get());
+            }
         }
-        self.fatal(&s[..]);
+
+        panic!(self.fatal(&s[..]));
     }
     pub fn warn(&self, msg: &str) {
         self.emit.borrow_mut().emit(None, msg, None, Warning);

src/libsyntax/ext/asm.rs

@@ -79,7 +79,7 @@ pub fn expand_asm<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                     cx.span_err(sp, "malformed inline assembly");
                     return DummyResult::expr(sp);
                 }
-                let (s, style) = match expr_to_string(cx, p.parse_expr(),
+                let (s, style) = match expr_to_string(cx, panictry!(p.parse_expr_nopanic()),
                                                    "inline assembly must be a string literal") {
                     Some((s, st)) => (s, st),
                     // let compilation continue
@@ -102,7 +102,7 @@ pub fn expand_asm<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                     let span = p.last_span;
 
                     panictry!(p.expect(&token::OpenDelim(token::Paren)));
-                    let out = p.parse_expr();
+                    let out = panictry!(p.parse_expr_nopanic());
                     panictry!(p.expect(&token::CloseDelim(token::Paren)));
 
                     // Expands a read+write operand into two operands.
@@ -146,7 +146,7 @@ pub fn expand_asm<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                     }
 
                     panictry!(p.expect(&token::OpenDelim(token::Paren)));
-                    let input = p.parse_expr();
+                    let input = panictry!(p.parse_expr_nopanic());
                     panictry!(p.expect(&token::CloseDelim(token::Paren)));
 
                     inputs.push((constraint, input));

src/libsyntax/ext/base.rs

@@ -809,7 +809,7 @@ pub fn get_single_str_from_tts(cx: &mut ExtCtxt,
         cx.span_err(sp, &format!("{} takes 1 argument", name));
         return None
     }
-    let ret = cx.expander().fold_expr(p.parse_expr());
+    let ret = cx.expander().fold_expr(panictry!(p.parse_expr_nopanic()));
     if p.token != token::Eof {
         cx.span_err(sp, &format!("{} takes 1 argument", name));
     }
@@ -826,7 +826,7 @@ pub fn get_exprs_from_tts(cx: &mut ExtCtxt,
     let mut p = cx.new_parser_from_tts(tts);
     let mut es = Vec::new();
     while p.token != token::Eof {
-        es.push(cx.expander().fold_expr(p.parse_expr()));
+        es.push(cx.expander().fold_expr(panictry!(p.parse_expr_nopanic())));
         if panictry!(p.eat(&token::Comma)){
             continue;
         }

src/libsyntax/ext/cfg.rs

@@ -19,15 +19,14 @@ use ext::base;
 use ext::build::AstBuilder;
 use attr;
 use attr::*;
-use parse::attr::ParserAttr;
 use parse::token;
 
 pub fn expand_cfg<'cx>(cx: &mut ExtCtxt,
                        sp: Span,
                        tts: &[ast::TokenTree])
                        -> Box<base::MacResult+'static> {
     let mut p = cx.new_parser_from_tts(tts);
-    let cfg = p.parse_meta_item();
+    let cfg = panictry!(p.parse_meta_item());
 
     if !panictry!(p.eat(&token::Eof)){
         cx.span_err(sp, "expected 1 cfg-pattern");

src/libsyntax/ext/format.rs

@@ -93,7 +93,7 @@ fn parse_args(ecx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
         ecx.span_err(sp, "requires at least a format string argument");
         return None;
     }
-    let fmtstr = p.parse_expr();
+    let fmtstr = panictry!(p.parse_expr_nopanic());
     let mut named = false;
     while p.token != token::Eof {
         if !panictry!(p.eat(&token::Comma)) {
@@ -124,7 +124,7 @@ fn parse_args(ecx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
             let name: &str = &ident.name.as_str();
 
             panictry!(p.expect(&token::Eq));
-            let e = p.parse_expr();
+            let e = panictry!(p.parse_expr_nopanic());
             match names.get(name) {
                 None => {}
                 Some(prev) => {
@@ -138,7 +138,7 @@ fn parse_args(ecx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
             order.push(name.to_string());
             names.insert(name.to_string(), e);
         } else {
-            args.push(p.parse_expr());
+            args.push(panictry!(p.parse_expr_nopanic()));
         }
     }
     Some((fmtstr, args, order, names))

src/libsyntax/ext/quote.rs

@@ -327,55 +327,55 @@ pub fn expand_quote_expr<'cx>(cx: &'cx mut ExtCtxt,
                               sp: Span,
                               tts: &[ast::TokenTree])
                               -> Box<base::MacResult+'cx> {
-    let expanded = expand_parse_call(cx, sp, "parse_expr", vec!(), tts);
+    let expanded = expand_parse_call(cx, sp, "parse_expr_panic", vec!(), tts);
     base::MacEager::expr(expanded)
 }
 
 pub fn expand_quote_item<'cx>(cx: &mut ExtCtxt,
                               sp: Span,
                               tts: &[ast::TokenTree])
                               -> Box<base::MacResult+'cx> {
-    let expanded = expand_parse_call(cx, sp, "parse_item", vec!(), tts);
+    let expanded = expand_parse_call(cx, sp, "parse_item_panic", vec!(), tts);
     base::MacEager::expr(expanded)
 }
 
 pub fn expand_quote_pat<'cx>(cx: &'cx mut ExtCtxt,
                              sp: Span,
                              tts: &[ast::TokenTree])
                              -> Box<base::MacResult+'cx> {
-    let expanded = expand_parse_call(cx, sp, "parse_pat", vec!(), tts);
+    let expanded = expand_parse_call(cx, sp, "parse_pat_panic", vec!(), tts);
     base::MacEager::expr(expanded)
 }
 
 pub fn expand_quote_arm(cx: &mut ExtCtxt,
                         sp: Span,
                         tts: &[ast::TokenTree])
                         -> Box<base::MacResult+'static> {
-    let expanded = expand_parse_call(cx, sp, "parse_arm", vec!(), tts);
+    let expanded = expand_parse_call(cx, sp, "parse_arm_panic", vec!(), tts);
     base::MacEager::expr(expanded)
 }
 
 pub fn expand_quote_ty(cx: &mut ExtCtxt,
                        sp: Span,
                        tts: &[ast::TokenTree])
                        -> Box<base::MacResult+'static> {
-    let expanded = expand_parse_call(cx, sp, "parse_ty", vec!(), tts);
+    let expanded = expand_parse_call(cx, sp, "parse_ty_panic", vec!(), tts);
     base::MacEager::expr(expanded)
 }
 
 pub fn expand_quote_stmt(cx: &mut ExtCtxt,
                          sp: Span,
                          tts: &[ast::TokenTree])
                          -> Box<base::MacResult+'static> {
-    let expanded = expand_parse_call(cx, sp, "parse_stmt", vec!(), tts);
+    let expanded = expand_parse_call(cx, sp, "parse_stmt_panic", vec!(), tts);
     base::MacEager::expr(expanded)
 }
 
 pub fn expand_quote_attr(cx: &mut ExtCtxt,
                          sp: Span,
                          tts: &[ast::TokenTree])
                          -> Box<base::MacResult+'static> {
-    let expanded = expand_parse_call(cx, sp, "parse_attribute",
+    let expanded = expand_parse_call(cx, sp, "parse_attribute_panic",
                                     vec!(cx.expr_bool(sp, true)), tts);
 
     base::MacEager::expr(expanded)
@@ -694,7 +694,7 @@ fn parse_arguments_to_quote(cx: &ExtCtxt, tts: &[ast::TokenTree])
     let mut p = cx.new_parser_from_tts(tts);
     p.quote_depth += 1;
 
-    let cx_expr = p.parse_expr();
+    let cx_expr = panictry!(p.parse_expr_nopanic());
     if !panictry!(p.eat(&token::Comma)) {
         panic!(p.fatal("expected token `,`"));
     }

src/libsyntax/ext/source_util.rs

@@ -109,13 +109,13 @@ pub fn expand_include<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree
     }
     impl<'a> base::MacResult for ExpandResult<'a> {
         fn make_expr(mut self: Box<ExpandResult<'a>>) -> Option<P<ast::Expr>> {
-            Some(self.p.parse_expr())
+            Some(panictry!(self.p.parse_expr_nopanic()))
         }
         fn make_items(mut self: Box<ExpandResult<'a>>)
                       -> Option<SmallVector<P<ast::Item>>> {
             let mut ret = SmallVector::zero();
             while self.p.token != token::Eof {
-                match self.p.parse_item() {
+                match panictry!(self.p.parse_item_nopanic()) {
                     Some(item) => ret.push(item),
                     None => panic!(self.p.span_fatal(
                         self.p.span,

src/libsyntax/ext/tt/macro_parser.rs

@@ -85,7 +85,6 @@ use codemap::{BytePos, mk_sp, Span};
 use codemap;
 use parse::lexer::*; //resolve bug?
 use parse::ParseSess;
-use parse::attr::ParserAttr;
 use parse::parser::{LifetimeAndTypesWithoutColons, Parser};
 use parse::token::{Eof, DocComment, MatchNt, SubstNt};
 use parse::token::{Token, Nonterminal};
@@ -503,18 +502,18 @@ pub fn parse_nt(p: &mut Parser, sp: Span, name: &str) -> Nonterminal {
     // check at the beginning and the parser checks after each bump
     panictry!(p.check_unknown_macro_variable());
     match name {
-        "item" => match p.parse_item() {
+        "item" => match panictry!(p.parse_item_nopanic()) {
             Some(i) => token::NtItem(i),
             None => panic!(p.fatal("expected an item keyword"))
         },
         "block" => token::NtBlock(panictry!(p.parse_block())),
-        "stmt" => match p.parse_stmt() {
+        "stmt" => match panictry!(p.parse_stmt_nopanic()) {
             Some(s) => token::NtStmt(s),
             None => panic!(p.fatal("expected a statement"))
         },
-        "pat" => token::NtPat(p.parse_pat()),
-        "expr" => token::NtExpr(p.parse_expr()),
-        "ty" => token::NtTy(p.parse_ty()),
+        "pat" => token::NtPat(panictry!(p.parse_pat_nopanic())),
+        "expr" => token::NtExpr(panictry!(p.parse_expr_nopanic())),
+        "ty" => token::NtTy(panictry!(p.parse_ty_nopanic())),
         // this could be handled like a token, since it is one
         "ident" => match p.token {
             token::Ident(sn,b) => { panictry!(p.bump()); token::NtIdent(Box::new(sn),b) }
@@ -527,7 +526,7 @@ pub fn parse_nt(p: &mut Parser, sp: Span, name: &str) -> Nonterminal {
         "path" => {
             token::NtPath(Box::new(panictry!(p.parse_path(LifetimeAndTypesWithoutColons))))
         },
-        "meta" => token::NtMeta(p.parse_meta_item()),
+        "meta" => token::NtMeta(panictry!(p.parse_meta_item())),
         _ => {
             panic!(p.span_fatal_help(sp,
                             &format!("invalid fragment specifier `{}`", name),

src/libsyntax/ext/tt/macro_rules.rs

@@ -66,18 +66,18 @@ impl<'a> ParserAnyMacro<'a> {
 
 impl<'a> MacResult for ParserAnyMacro<'a> {
     fn make_expr(self: Box<ParserAnyMacro<'a>>) -> Option<P<ast::Expr>> {
-        let ret = self.parser.borrow_mut().parse_expr();
+        let ret = panictry!(self.parser.borrow_mut().parse_expr_nopanic());
         self.ensure_complete_parse(true);
         Some(ret)
     }
     fn make_pat(self: Box<ParserAnyMacro<'a>>) -> Option<P<ast::Pat>> {
-        let ret = self.parser.borrow_mut().parse_pat();
+        let ret = panictry!(self.parser.borrow_mut().parse_pat_nopanic());
         self.ensure_complete_parse(false);
         Some(ret)
     }
     fn make_items(self: Box<ParserAnyMacro<'a>>) -> Option<SmallVector<P<ast::Item>>> {
         let mut ret = SmallVector::zero();
-        while let Some(item) = self.parser.borrow_mut().parse_item() {
+        while let Some(item) = panictry!(self.parser.borrow_mut().parse_item_nopanic()) {
             ret.push(item);
         }
         self.ensure_complete_parse(false);
@@ -119,7 +119,7 @@ impl<'a> MacResult for ParserAnyMacro<'a> {
     }
 
     fn make_ty(self: Box<ParserAnyMacro<'a>>) -> Option<P<ast::Ty>> {
-        let ret = self.parser.borrow_mut().parse_ty();
+        let ret = panictry!(self.parser.borrow_mut().parse_ty_nopanic());
         self.ensure_complete_parse(true);
         Some(ret)
     }

src/libsyntax/lib.rs

@@ -30,7 +30,6 @@
 #![feature(filling_drop)]
 #![feature(libc)]
 #![feature(rustc_private)]
-#![feature(set_stdio)]
 #![feature(staged_api)]
 #![feature(str_char)]
 #![feature(str_escape)]