diff --git a/src/ir.cpp b/src/ir.cpp index 98ed53d83..a450b6d14 100644 --- a/src/ir.cpp +++ b/src/ir.cpp @@ -11432,6 +11432,26 @@ static TypeTableEntry *ir_analyze_bit_shift(IrAnalyze *ira, IrInstructionBinOp * } else { TypeTableEntry *shift_amt_type = get_smallest_unsigned_int_type(ira->codegen, op1->value.type->data.integral.bit_count - 1); + if (bin_op_instruction->op_id == IrBinOpBitShiftLeftLossy && + op2->value.type->id == TypeTableEntryIdComptimeInt) { + if (!bigint_fits_in_bits(&op2->value.data.x_bigint, + shift_amt_type->data.integral.bit_count, + op2->value.data.x_bigint.is_negative)) { + Buf *val_buf = buf_alloc(); + bigint_append_buf(val_buf, &op2->value.data.x_bigint, 10); + ErrorMsg* msg = ir_add_error(ira, + &bin_op_instruction->base, + buf_sprintf("RHS of shift is too large for LHS type")); + add_error_note( + ira->codegen, + msg, + op2->source_node, + buf_sprintf("value %s cannot fit into type %s", + buf_ptr(val_buf), + buf_ptr(&shift_amt_type->name))); + return ira->codegen->builtin_types.entry_invalid; + } + } casted_op2 = ir_implicit_cast(ira, op2, shift_amt_type); if (casted_op2 == ira->codegen->invalid_instruction) diff --git a/test/compile_errors.zig b/test/compile_errors.zig index 2247f0af9..cfe4a2ef5 100644 --- a/test/compile_errors.zig +++ b/test/compile_errors.zig @@ -1677,6 +1677,18 @@ pub fn addCases(cases: *tests.CompileErrorContext) void { ".tmp_source.zig:1:16: error: integer value 300 cannot be implicitly casted to type 'u8'", ); + cases.add( + "invalid shift amount error", + \\const x : u8 = 2; + \\fn f() u16 { + \\ return x << 8; + \\} + \\export fn entry() u16 { return f(); } + , + ".tmp_source.zig:3:14: error: RHS of shift is too large for LHS type", + ".tmp_source.zig:3:17: note: value 8 cannot fit into type u3", + ); + cases.add( "incompatible number literals", \\const x = 2 == 2.0;