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Only report bitshift lints on bitshift ops

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Oliver Schneider 2018-01-29 19:06:44 +01:00 committed by Oliver Schneider
parent 438139f635
commit 13c0dc56df
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1 changed files with 16 additions and 14 deletions
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30
src/librustc_mir/transform/const_prop.rs
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@ -15,7 +15,7 @@
use rustc::mir::{Constant, Literal, Location, Place, Mir, Operand, Rvalue, Local};
use rustc::mir::{NullOp, StatementKind, Statement, BasicBlock, LocalKind};
use rustc::mir::{TerminatorKind, ClearCrossCrate, SourceInfo};
use rustc::mir::{TerminatorKind, ClearCrossCrate, SourceInfo, BinOp};
use rustc::mir::visit::Visitor;
use rustc::ty::layout::LayoutOf;
use rustc::middle::const_val::ConstVal;
@ -216,19 +216,21 @@ impl<'b, 'a, 'tcx:'b> OptimizationFinder<'b, 'a, 'tcx> {
let ecx = mk_borrowck_eval_cx(self.tcx, instance, self.mir, span).unwrap();
let r = ecx.value_to_primval(ValTy { value: right.0, ty: right.1 }).ok()?;
let param_env = self.tcx.param_env(self.source.def_id);
let bits = (self.tcx, param_env).layout_of(left.1).unwrap().size.bits();
if r.to_bytes().ok()? >= bits as u128 {
let scope_info = match self.mir.visibility_scope_info {
ClearCrossCrate::Set(ref data) => data,
ClearCrossCrate::Clear => return None,
};
let node_id = scope_info[source_info.scope].lint_root;
self.tcx.lint_node(
::rustc::lint::builtin::EXCEEDING_BITSHIFTS,
node_id,
span,
"bitshift exceeds the type's number of bits");
if op == BinOp::Shr || op == BinOp::Shl {
let param_env = self.tcx.param_env(self.source.def_id);
let bits = (self.tcx, param_env).layout_of(left.1).unwrap().size.bits();
if r.to_bytes().ok()? >= bits as u128 {
let scope_info = match self.mir.visibility_scope_info {
ClearCrossCrate::Set(ref data) => data,
ClearCrossCrate::Clear => return None,
};
let node_id = scope_info[source_info.scope].lint_root;
self.tcx.lint_node(
::rustc::lint::builtin::EXCEEDING_BITSHIFTS,
node_id,
span,
"bitshift exceeds the type's number of bits");
}
}
let l = ecx.value_to_primval(ValTy { value: left.0, ty: left.1 }).ok()?;
trace!("const evaluating {:?} for {:?} and {:?}", op, left, right);