Fixes missing overflow lint for i64 rust-lang#14269

The `type_overflow` lint, doesn't catch the overflow for `i64` because the overflow happens earlier in the parse phase when the `u64` as biggest possible int gets casted to `i64` , without checking the for overflows. We can't lint in the parse phase, so a refactoring of the `LitInt` type was necessary. The types `LitInt`, `LitUint` and `LitIntUnsuffixed` where merged to one type `LitInt` which stores it's value as `u64`. An additional parameter was added which indicate the signedness of the type and the sign of the value.
hirschenberger · Jul 24, 2014 · 8ff2f09 · 8ff2f09
1 parent 9e2bb9d
commit 8ff2f09
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Showing 17 changed files with 141 additions and 98 deletions.
diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
@@ -135,7 +135,7 @@ impl LintPass for TypeLimits {
                 match expr.node  {
                     ast::ExprLit(lit) => {
                         match lit.node {
-                            ast::LitUint(..) => {
+                            ast::LitInt(_, ast::UnsignedIntLit(_)) => {
                                 cx.span_lint(UNSIGNED_NEGATE, e.span,
                                              "negation of unsigned int literal may \
                                              be unintentional");
@@ -177,15 +177,25 @@ impl LintPass for TypeLimits {
                         } else { t };
                         let (min, max) = int_ty_range(int_type);
                         let mut lit_val: i64 = match lit.node {
-                            ast::LitInt(v, _) => v,
-                            ast::LitUint(v, _) => v as i64,
-                            ast::LitIntUnsuffixed(v) => v,
+                            ast::LitInt(v, ast::SignedIntLit(_, ast::Plus)) |
+                            ast::LitInt(v, ast::UnsuffixedIntLit(ast::Plus)) => {
+                                if v > i64::MAX as u64{
+                                    cx.span_lint(TYPE_OVERFLOW, e.span,
+                                                 "literal out of range for its type");
+                                    return;
+                                }
+                                v as i64
+                            }
+                            ast::LitInt(v, ast::SignedIntLit(_, ast::Minus)) |
+                            ast::LitInt(v, ast::UnsuffixedIntLit(ast::Minus)) => {
+                                -(v as i64)
+                            }
                             _ => fail!()
                         };
                         if self.negated_expr_id == e.id {
                             lit_val *= -1;
                         }
-                        if  lit_val < min || lit_val > max {
+                        if lit_val < min || lit_val > max {
                             cx.span_lint(TYPE_OVERFLOW, e.span,
                                          "literal out of range for its type");
                         }
@@ -197,9 +207,7 @@ impl LintPass for TypeLimits {
                         let (min, max) = uint_ty_range(uint_type);
                         let lit_val: u64 = match lit.node {
                             ast::LitByte(_v) => return,  // _v is u8, within range by definition
-                            ast::LitInt(v, _) => v as u64,
-                            ast::LitUint(v, _) => v,
-                            ast::LitIntUnsuffixed(v) => v as u64,
+                            ast::LitInt(v, _) => v,
                             _ => fail!()
                         };
                         if  lit_val < min || lit_val > max {
@@ -294,9 +302,10 @@ impl LintPass for TypeLimits {
                     let (min, max) = int_ty_range(int_ty);
                     let lit_val: i64 = match lit.node {
                         ast::ExprLit(li) => match li.node {
-                            ast::LitInt(v, _) => v,
-                            ast::LitUint(v, _) => v as i64,
-                            ast::LitIntUnsuffixed(v) => v,
+                            ast::LitInt(v, ast::SignedIntLit(_, ast::Plus)) |
+                            ast::LitInt(v, ast::UnsuffixedIntLit(ast::Plus)) => v as i64,
+                            ast::LitInt(v, ast::SignedIntLit(_, ast::Minus)) |
+                            ast::LitInt(v, ast::UnsuffixedIntLit(ast::Minus)) => -(v as i64),
                             _ => return true
                         },
                         _ => fail!()
@@ -307,9 +316,7 @@ impl LintPass for TypeLimits {
                     let (min, max): (u64, u64) = uint_ty_range(uint_ty);
                     let lit_val: u64 = match lit.node {
                         ast::ExprLit(li) => match li.node {
-                            ast::LitInt(v, _) => v as u64,
-                            ast::LitUint(v, _) => v,
-                            ast::LitIntUnsuffixed(v) => v as u64,
+                            ast::LitInt(v, _) => v,
                             _ => return true
                         },
                         _ => fail!()

diff --git a/src/librustc/middle/const_eval.rs b/src/librustc/middle/const_eval.rs
@@ -560,10 +560,13 @@ pub fn lit_to_const(lit: &Lit) -> const_val {
         }
         LitByte(n) => const_uint(n as u64),
         LitChar(n) => const_uint(n as u64),
-        LitInt(n, _) => const_int(n),
-        LitUint(n, _) => const_uint(n),
-        LitIntUnsuffixed(n) => const_int(n),
-        LitFloat(ref n, _) | LitFloatUnsuffixed(ref n) => {
+        LitInt(n, ast::SignedIntLit(_, ast::Plus)) |
+        LitInt(n, ast::UnsuffixedIntLit(ast::Plus)) => const_int(n as i64),
+        LitInt(n, ast::SignedIntLit(_, ast::Minus)) |
+        LitInt(n, ast::UnsuffixedIntLit(ast::Minus)) => const_int(-(n as i64)),
+        LitInt(n, ast::UnsignedIntLit(_)) => const_uint(n),
+        LitFloat(ref n, _) |
+        LitFloatUnsuffixed(ref n) => {
             const_float(from_str::<f64>(n.get()).unwrap() as f64)
         }
         LitNil => const_nil,

diff --git a/src/librustc/middle/trans/consts.rs b/src/librustc/middle/trans/consts.rs
@@ -47,9 +47,13 @@ pub fn const_lit(cx: &CrateContext, e: &ast::Expr, lit: ast::Lit)
     match lit.node {
         ast::LitByte(b) => C_integral(Type::uint_from_ty(cx, ast::TyU8), b as u64, false),
         ast::LitChar(i) => C_integral(Type::char(cx), i as u64, false),
-        ast::LitInt(i, t) => C_integral(Type::int_from_ty(cx, t), i as u64, true),
-        ast::LitUint(u, t) => C_integral(Type::uint_from_ty(cx, t), u, false),
-        ast::LitIntUnsuffixed(i) => {
+        ast::LitInt(i, ast::SignedIntLit(t, _)) => {
+            C_integral(Type::int_from_ty(cx, t), i, true)
+        }
+        ast::LitInt(u, ast::UnsignedIntLit(t)) => {
+            C_integral(Type::uint_from_ty(cx, t), u, false)
+        }
+        ast::LitInt(i, ast::UnsuffixedIntLit(_)) => {
             let lit_int_ty = ty::node_id_to_type(cx.tcx(), e.id);
             match ty::get(lit_int_ty).sty {
                 ty::ty_int(t) => {

diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
@@ -1959,9 +1959,9 @@ fn check_lit(fcx: &FnCtxt,
         }
         ast::LitByte(_) => ty::mk_u8(),
         ast::LitChar(_) => ty::mk_char(),
-        ast::LitInt(_, t) => ty::mk_mach_int(t),
-        ast::LitUint(_, t) => ty::mk_mach_uint(t),
-        ast::LitIntUnsuffixed(_) => {
+        ast::LitInt(_, ast::SignedIntLit(t, _)) => ty::mk_mach_int(t),
+        ast::LitInt(_, ast::UnsignedIntLit(t)) => ty::mk_mach_uint(t),
+        ast::LitInt(_, ast::UnsuffixedIntLit(_)) => {
             let opt_ty = expected.map_to_option(fcx, |sty| {
                 match *sty {
                     ty::ty_int(i) => Some(ty::mk_mach_int(i)),

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
@@ -1953,8 +1953,6 @@ fn lit_to_string(lit: &ast::Lit) -> String {
         },
         ast::LitChar(c) => format!("'{}'", c),
         ast::LitInt(i, _t) => i.to_string(),
-        ast::LitUint(u, _t) => u.to_string(),
-        ast::LitIntUnsuffixed(i) => i.to_string(),
         ast::LitFloat(ref f, _t) => f.get().to_string(),
         ast::LitFloatUnsuffixed(ref f) => f.get().to_string(),
         ast::LitBool(b) => b.to_string(),

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
@@ -18,6 +18,7 @@ use parse::token::{InternedString, str_to_ident};
 use parse::token;
 
 use std::fmt;
+use std::num::Zero;
 use std::fmt::Show;
 use std::option::Option;
 use std::rc::Rc;
@@ -654,15 +655,46 @@ pub enum StrStyle {
 
 pub type Lit = Spanned<Lit_>;
 
+#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+pub enum Sign {
+    Minus,
+    Plus
+}
+
+impl<T: PartialOrd+Zero> Sign {
+    pub fn new(n: T) -> Sign {
+        if n < Zero::zero() {
+            Minus
+        } else {
+            Plus
+        }
+    }
+}
+
+#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+pub enum LitIntType {
+    SignedIntLit(IntTy, Sign),
+    UnsignedIntLit(UintTy),
+    UnsuffixedIntLit(Sign)
+}
+
+impl LitIntType {
+    pub fn suffix_len(&self) -> uint {
+        match *self {
+            UnsuffixedIntLit(_) => 0,
+            SignedIntLit(s, _) => s.suffix_len(),
+            UnsignedIntLit(u) => u.suffix_len()
+        }
+    }
+}
+
 #[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
 pub enum Lit_ {
     LitStr(InternedString, StrStyle),
     LitBinary(Rc<Vec<u8> >),
     LitByte(u8),
     LitChar(char),
-    LitInt(i64, IntTy),
-    LitUint(u64, UintTy),
-    LitIntUnsuffixed(i64),
+    LitInt(u64, LitIntType),
     LitFloat(InternedString, FloatTy),
     LitFloatUnsuffixed(InternedString),
     LitNil,

diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
@@ -618,13 +618,13 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
         self.expr(sp, ast::ExprLit(box(GC) respan(sp, lit)))
     }
     fn expr_uint(&self, span: Span, i: uint) -> Gc<ast::Expr> {
-        self.expr_lit(span, ast::LitUint(i as u64, ast::TyU))
+        self.expr_lit(span, ast::LitInt(i as u64, ast::UnsignedIntLit(ast::TyU)))
     }
     fn expr_int(&self, sp: Span, i: int) -> Gc<ast::Expr> {
-        self.expr_lit(sp, ast::LitInt(i as i64, ast::TyI))
+        self.expr_lit(sp, ast::LitInt(i as u64, ast::SignedIntLit(ast::TyI, ast::Sign::new(i))))
     }
     fn expr_u8(&self, sp: Span, u: u8) -> Gc<ast::Expr> {
-        self.expr_lit(sp, ast::LitUint(u as u64, ast::TyU8))
+        self.expr_lit(sp, ast::LitInt(u as u64, ast::UnsignedIntLit(ast::TyU8)))
     }
     fn expr_bool(&self, sp: Span, value: bool) -> Gc<ast::Expr> {
         self.expr_lit(sp, ast::LitBool(value))

diff --git a/src/libsyntax/ext/bytes.rs b/src/libsyntax/ext/bytes.rs
@@ -47,7 +47,7 @@ pub fn expand_syntax_ext(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                 }
 
                 // u8 literal, push to vector expression
-                ast::LitUint(v, ast::TyU8) => {
+                ast::LitInt(v, ast::UnsignedIntLit(ast::TyU8)) => {
                     if v > 0xFF {
                         cx.span_err(expr.span, "too large u8 literal in bytes!");
                         err = true;
@@ -57,13 +57,14 @@ pub fn expand_syntax_ext(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                 }
 
                 // integer literal, push to vector expression
-                ast::LitIntUnsuffixed(v) => {
+                ast::LitInt(_, ast::UnsuffixedIntLit(ast::Minus)) => {
+                    cx.span_err(expr.span, "negative integer literal in bytes!");
+                    err = true;
+                }
+                ast::LitInt(v, ast::UnsuffixedIntLit(ast::Plus)) => {
                     if v > 0xFF {
                         cx.span_err(expr.span, "too large integer literal in bytes!");
                         err = true;
-                    } else if v < 0 {
-                        cx.span_err(expr.span, "negative integer literal in bytes!");
-                        err = true;
                     } else {
                         bytes.push(cx.expr_u8(expr.span, v as u8));
                     }

diff --git a/src/libsyntax/ext/concat.rs b/src/libsyntax/ext/concat.rs
@@ -37,11 +37,14 @@ pub fn expand_syntax_ext(cx: &mut base::ExtCtxt,
                     ast::LitChar(c) => {
                         accumulator.push_char(c);
                     }
-                    ast::LitInt(i, _) | ast::LitIntUnsuffixed(i) => {
+                    ast::LitInt(i, ast::UnsignedIntLit(_)) |
+                    ast::LitInt(i, ast::SignedIntLit(_, ast::Plus)) |
+                    ast::LitInt(i, ast::UnsuffixedIntLit(ast::Plus)) => {
                         accumulator.push_str(format!("{}", i).as_slice());
                     }
-                    ast::LitUint(u, _) => {
-                        accumulator.push_str(format!("{}", u).as_slice());
+                    ast::LitInt(i, ast::SignedIntLit(_, ast::Minus)) |
+                    ast::LitInt(i, ast::UnsuffixedIntLit(ast::Minus)) => {
+                        accumulator.push_str(format!("-{}", i).as_slice());
                     }
                     ast::LitNil => {}
                     ast::LitBool(b) => {

diff --git a/src/libsyntax/ext/deriving/generic/mod.rs b/src/libsyntax/ext/deriving/generic/mod.rs
@@ -996,7 +996,7 @@ impl<'a> MethodDef<'a> {
             let arms : Vec<ast::Arm> = variants.iter().enumerate()
                 .map(|(index, &variant)| {
                     let pat = variant_to_pat(cx, sp, &*variant);
-                    let lit = ast::LitUint(index as u64, ast::TyU);
+                    let lit = ast::LitInt(index as u64, ast::UnsignedIntLit(ast::TyU));
                     cx.arm(sp, vec![pat], cx.expr_lit(sp, lit))
                 }).collect();
 

diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
@@ -187,16 +187,17 @@ pub mod rt {
         (signed, $t:ty, $tag:ident) => (
             impl ToSource for $t {
                 fn to_source(&self) -> String {
-                    let lit = dummy_spanned(ast::LitInt(*self as i64, ast::$tag));
-                    pprust::lit_to_string(&lit)
+                    let lit = ast::LitInt(*self as u64, ast::SignedIntLit(ast::$tag,
+                                                                          ast::Sign::new(*self)));
+                    pprust::lit_to_string(&dummy_spanned(lit))
                 }
             }
         );
         (unsigned, $t:ty, $tag:ident) => (
             impl ToSource for $t {
                 fn to_source(&self) -> String {
-                    let lit = dummy_spanned(ast::LitUint(*self as u64, ast::$tag));
-                    pprust::lit_to_string(&lit)
+                    let lit = ast::LitInt(*self as u64, ast::UnsignedIntLit(ast::$tag));
+                    pprust::lit_to_string(&dummy_spanned(lit))
                 }
             }
         );

diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
@@ -515,31 +515,13 @@ pub fn integer_lit(s: &str, sd: &SpanHandler, sp: Span) -> ast::Lit_ {
     debug!("parse_integer_lit: {}", s);
 
     if s.len() == 1 {
-        return ast::LitIntUnsuffixed((s.char_at(0)).to_digit(10).unwrap() as i64);
+        let n = (s.char_at(0)).to_digit(10).unwrap();
+        return ast::LitInt(n as u64, ast::UnsuffixedIntLit(ast::Sign::new(n)));
     }
 
     let mut base = 10;
     let orig = s;
-
-    #[deriving(Show)]
-    enum Result {
-        Nothing,
-        Signed(ast::IntTy),
-        Unsigned(ast::UintTy)
-    }
-
-    impl Result {
-        fn suffix_len(&self) -> uint {
-            match *self {
-                Nothing => 0,
-                Signed(s) => s.suffix_len(),
-                Unsigned(u) => u.suffix_len()
-            }
-        }
-    }
-
-    let mut ty = Nothing;
-
+    let mut ty = ast::UnsuffixedIntLit(ast::Plus);
 
     if s.char_at(0) == '0' {
         match s.char_at(1) {
@@ -556,62 +538,63 @@ pub fn integer_lit(s: &str, sd: &SpanHandler, sp: Span) -> ast::Lit_ {
 
     let last = s.len() - 1;
     match s.char_at(last) {
-        'i' => ty = Signed(ast::TyI),
-        'u' => ty = Unsigned(ast::TyU),
+        'i' => ty = ast::SignedIntLit(ast::TyI, ast::Plus),
+        'u' => ty = ast::UnsignedIntLit(ast::TyU),
         '8' => {
             if s.len() > 2 {
                 match s.char_at(last - 1) {
-                    'i' => ty = Signed(ast::TyI8),
-                    'u' => ty = Unsigned(ast::TyU8),
+                    'i' => ty = ast::SignedIntLit(ast::TyI8, ast::Plus),
+                    'u' => ty = ast::UnsignedIntLit(ast::TyU8),
                     _ => { }
                 }
             }
         },
         '6' => {
             if s.len() > 3 && s.char_at(last - 1) == '1' {
                 match s.char_at(last - 2) {
-                    'i' => ty = Signed(ast::TyI16),
-                    'u' => ty = Unsigned(ast::TyU16),
+                    'i' => ty = ast::SignedIntLit(ast::TyI16, ast::Plus),
+                    'u' => ty = ast::UnsignedIntLit(ast::TyU16),
                     _ => { }
                 }
             }
         },
         '2' => {
             if s.len() > 3 && s.char_at(last - 1) == '3' {
                 match s.char_at(last - 2) {
-                    'i' => ty = Signed(ast::TyI32),
-                    'u' => ty = Unsigned(ast::TyU32),
+                    'i' => ty = ast::SignedIntLit(ast::TyI32, ast::Plus),
+                    'u' => ty = ast::UnsignedIntLit(ast::TyU32),
                     _ => { }
                 }
             }
         },
         '4' => {
             if s.len() > 3 && s.char_at(last - 1) == '6' {
                 match s.char_at(last - 2) {
-                    'i' => ty = Signed(ast::TyI64),
-                    'u' => ty = Unsigned(ast::TyU64),
+                    'i' => ty = ast::SignedIntLit(ast::TyI64, ast::Plus),
+                    'u' => ty = ast::UnsignedIntLit(ast::TyU64),
                     _ => { }
                 }
             }
         },
         _ => { }
     }
 
-
-    s = s.slice_to(s.len() - ty.suffix_len());
-
     debug!("The suffix is {}, base {}, the new string is {}, the original \
            string was {}", ty, base, s, orig);
 
+    s = s.slice_to(s.len() - ty.suffix_len());
+
     let res: u64 = match ::std::num::from_str_radix(s, base) {
         Some(r) => r,
         None => { sd.span_err(sp, "int literal is too large"); 0 }
     };
 
+    // adjust the sign
+    let sign = ast::Sign::new(res);
     match ty {
-        Nothing => ast::LitIntUnsuffixed(res as i64),
-        Signed(t) => ast::LitInt(res as i64, t),
-        Unsigned(t) => ast::LitUint(res, t)
+        ast::SignedIntLit(t, _) => ast::LitInt(res, ast::SignedIntLit(t, sign)),
+        ast::UnsuffixedIntLit(_) => ast::LitInt(res, ast::UnsuffixedIntLit(sign)),
+        us@ast::UnsignedIntLit(_) => ast::LitInt(res, us)
     }
 }