motiejus/zig
1
Fork 0
Code Releases Activity

add debug safety checks for remainder division

Browse Source 
See #217
This commit is contained in:
Andrew Kelley
2017-03-26 15:06:43 -04:00
parent 6ee63c8f58
commit 8aeea72654
7 changed files with 76 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
doc/langref.md
View File

@@ -165,17 +165,17 @@ ContainerDecl = option("extern" | "packed") ("struct" | "enum" | "union") "{" ma
```
x() x[] x.y
!x -x ~x *x &x ?x %x %%x
!x -x -%x ~x *x &x ?x %x %%x ??x
x{}
* / %
+ - ++
* / % ** *%
+ - ++ +% -%
<< >>
&
^
|
== != < > <= >=
&&
||
and
or
?? %%
= *= /= %= += -= <<= >>= &= ^= |=
```

3
src/all_types.hpp
View File

@@ -1205,6 +1205,7 @@ enum PanicMsgId {
PanicMsgIdIntegerOverflow,
PanicMsgIdShiftOverflowedBits,
PanicMsgIdDivisionByZero,
PanicMsgIdRemainderDivisionByZero,
PanicMsgIdExactDivisionRemainder,
PanicMsgIdSliceWidenRemainder,
PanicMsgIdUnwrapMaybeFail,
@@ -1828,7 +1829,7 @@ enum IrBinOp {
IrBinOpMult,
IrBinOpMultWrap,
IrBinOpDiv,
IrBinOpMod,
IrBinOpRem,
IrBinOpArrayCat,
IrBinOpArrayMult,
};

4
src/bignum.cpp
View File

@@ -212,7 +212,7 @@ bool bignum_div(BigNum *dest, BigNum *op1, BigNum *op2) {
return false;
}
bool bignum_mod(BigNum *dest, BigNum *op1, BigNum *op2) {
bool bignum_rem(BigNum *dest, BigNum *op1, BigNum *op2) {
assert(op1->kind == op2->kind);
dest->kind = op1->kind;
@@ -220,7 +220,7 @@ bool bignum_mod(BigNum *dest, BigNum *op1, BigNum *op2) {
dest->data.x_float = fmod(op1->data.x_float, op2->data.x_float);
} else {
if (op1->is_negative || op2->is_negative) {
zig_panic("TODO handle mod with negative numbers");
zig_panic("TODO handle remainder division with negative numbers");
}
dest->data.x_uint = op1->data.x_uint % op2->data.x_uint;
bignum_normalize(dest);

2
src/bignum.hpp
View File

@@ -37,7 +37,7 @@ bool bignum_add(BigNum *dest, BigNum *op1, BigNum *op2);
bool bignum_sub(BigNum *dest, BigNum *op1, BigNum *op2);
bool bignum_mul(BigNum *dest, BigNum *op1, BigNum *op2);
bool bignum_div(BigNum *dest, BigNum *op1, BigNum *op2);
bool bignum_mod(BigNum *dest, BigNum *op1, BigNum *op2);
bool bignum_rem(BigNum *dest, BigNum *op1, BigNum *op2);
bool bignum_or(BigNum *dest, BigNum *op1, BigNum *op2);
bool bignum_and(BigNum *dest, BigNum *op1, BigNum *op2);

68
src/codegen.cpp
View File

@@ -512,6 +512,8 @@ static Buf *panic_msg_buf(PanicMsgId msg_id) {
return buf_create_from_str("left shift overflowed bits");
case PanicMsgIdDivisionByZero:
return buf_create_from_str("division by zero");
case PanicMsgIdRemainderDivisionByZero:
return buf_create_from_str("remainder division by zero");
case PanicMsgIdExactDivisionRemainder:
return buf_create_from_str("exact division produced remainder");
case PanicMsgIdSliceWidenRemainder:
@@ -956,6 +958,59 @@ static LLVMValueRef gen_div(CodeGen *g, bool want_debug_safety, LLVMValueRef val
}
}
static LLVMValueRef gen_rem(CodeGen *g, bool want_debug_safety, LLVMValueRef val1, LLVMValueRef val2,
TypeTableEntry *type_entry)
{
if (want_debug_safety) {
LLVMValueRef zero = LLVMConstNull(type_entry->type_ref);
LLVMValueRef is_zero_bit;
if (type_entry->id == TypeTableEntryIdInt) {
is_zero_bit = LLVMBuildICmp(g->builder, LLVMIntEQ, val2, zero, "");
} else if (type_entry->id == TypeTableEntryIdFloat) {
is_zero_bit = LLVMBuildFCmp(g->builder, LLVMRealOEQ, val2, zero, "");
} else {
zig_unreachable();
}
LLVMBasicBlockRef rem_zero_ok_block = LLVMAppendBasicBlock(g->cur_fn_val, "RemZeroOk");
LLVMBasicBlockRef rem_zero_fail_block = LLVMAppendBasicBlock(g->cur_fn_val, "RemZeroFail");
LLVMBuildCondBr(g->builder, is_zero_bit, rem_zero_fail_block, rem_zero_ok_block);
LLVMPositionBuilderAtEnd(g->builder, rem_zero_fail_block);
gen_debug_safety_crash(g, PanicMsgIdRemainderDivisionByZero);
LLVMPositionBuilderAtEnd(g->builder, rem_zero_ok_block);
if (type_entry->id == TypeTableEntryIdInt && type_entry->data.integral.is_signed) {
LLVMValueRef neg_1_value = LLVMConstInt(type_entry->type_ref, -1, true);
LLVMValueRef int_min_value = LLVMConstInt(type_entry->type_ref, min_signed_val(type_entry), true);
LLVMBasicBlockRef overflow_ok_block = LLVMAppendBasicBlock(g->cur_fn_val, "RemOverflowOk");
LLVMBasicBlockRef overflow_fail_block = LLVMAppendBasicBlock(g->cur_fn_val, "RemOverflowFail");
LLVMValueRef num_is_int_min = LLVMBuildICmp(g->builder, LLVMIntEQ, val1, int_min_value, "");
LLVMValueRef den_is_neg_1 = LLVMBuildICmp(g->builder, LLVMIntEQ, val2, neg_1_value, "");
LLVMValueRef overflow_fail_bit = LLVMBuildAnd(g->builder, num_is_int_min, den_is_neg_1, "");
LLVMBuildCondBr(g->builder, overflow_fail_bit, overflow_fail_block, overflow_ok_block);
LLVMPositionBuilderAtEnd(g->builder, overflow_fail_block);
gen_debug_safety_crash(g, PanicMsgIdIntegerOverflow);
LLVMPositionBuilderAtEnd(g->builder, overflow_ok_block);
}
}
if (type_entry->id == TypeTableEntryIdFloat) {
return LLVMBuildFRem(g->builder, val1, val2, "");
} else {
assert(type_entry->id == TypeTableEntryIdInt);
if (type_entry->data.integral.is_signed) {
return LLVMBuildSRem(g->builder, val1, val2, "");
} else {
return LLVMBuildURem(g->builder, val1, val2, "");
}
}
}
static LLVMValueRef ir_render_bin_op(CodeGen *g, IrExecutable *executable,
IrInstructionBinOp *bin_op_instruction)
{
@@ -1092,17 +1147,8 @@ static LLVMValueRef ir_render_bin_op(CodeGen *g, IrExecutable *executable,
}
case IrBinOpDiv:
return gen_div(g, want_debug_safety, op1_value, op2_value, canon_type, false);
case IrBinOpMod:
if (canon_type->id == TypeTableEntryIdFloat) {
return LLVMBuildFRem(g->builder, op1_value, op2_value, "");
} else {
assert(canon_type->id == TypeTableEntryIdInt);
if (canon_type->data.integral.is_signed) {
return LLVMBuildSRem(g->builder, op1_value, op2_value, "");
} else {
return LLVMBuildURem(g->builder, op1_value, op2_value, "");
}
}
case IrBinOpRem:
return gen_rem(g, want_debug_safety, op1_value, op2_value, canon_type);
}
zig_unreachable();
}

16
src/ir.cpp
View File

@@ -3487,7 +3487,7 @@ static IrInstruction *ir_gen_bin_op(IrBuilder *irb, Scope *scope, AstNode *node)
case BinOpTypeAssignDiv:
return ir_gen_assign_op(irb, scope, node, IrBinOpDiv);
case BinOpTypeAssignMod:
return ir_gen_assign_op(irb, scope, node, IrBinOpMod);
return ir_gen_assign_op(irb, scope, node, IrBinOpRem);
case BinOpTypeAssignPlus:
return ir_gen_assign_op(irb, scope, node, IrBinOpAdd);
case BinOpTypeAssignPlusWrap:
@@ -3555,7 +3555,7 @@ static IrInstruction *ir_gen_bin_op(IrBuilder *irb, Scope *scope, AstNode *node)
case BinOpTypeDiv:
return ir_gen_bin_op_id(irb, scope, node, IrBinOpDiv);
case BinOpTypeMod:
return ir_gen_bin_op_id(irb, scope, node, IrBinOpMod);
return ir_gen_bin_op_id(irb, scope, node, IrBinOpRem);
case BinOpTypeArrayCat:
return ir_gen_bin_op_id(irb, scope, node, IrBinOpArrayCat);
case BinOpTypeArrayMult:
@@ -7394,7 +7394,7 @@ static int ir_eval_bignum(ConstExprValue *op1_val, ConstExprValue *op2_val,
{
bool is_int = false;
bool is_float = false;
if (bignum_fn == bignum_div || bignum_fn == bignum_mod) {
if (bignum_fn == bignum_div || bignum_fn == bignum_rem) {
if (type->id == TypeTableEntryIdInt ||
type->id == TypeTableEntryIdNumLitInt)
{
@@ -7480,8 +7480,8 @@ static int ir_eval_math_op(TypeTableEntry *canon_type, ConstExprValue *op1_val,
return ir_eval_bignum(op1_val, op2_val, out_val, bignum_mul, canon_type, true);
case IrBinOpDiv:
return ir_eval_bignum(op1_val, op2_val, out_val, bignum_div, canon_type, false);
case IrBinOpMod:
return ir_eval_bignum(op1_val, op2_val, out_val, bignum_mod, canon_type, false);
case IrBinOpRem:
return ir_eval_bignum(op1_val, op2_val, out_val, bignum_rem, canon_type, false);
}
zig_unreachable();
}
@@ -7506,7 +7506,7 @@ static TypeTableEntry *ir_analyze_bin_op_math(IrAnalyze *ira, IrInstructionBinOp
op_id == IrBinOpSub ||
op_id == IrBinOpMult ||
op_id == IrBinOpDiv ||
op_id == IrBinOpMod))
op_id == IrBinOpRem))
{
// float
} else {
@@ -7777,7 +7777,7 @@ static TypeTableEntry *ir_analyze_instruction_bin_op(IrAnalyze *ira, IrInstructi
case IrBinOpMult:
case IrBinOpMultWrap:
case IrBinOpDiv:
case IrBinOpMod:
case IrBinOpRem:
return ir_analyze_bin_op_math(ira, bin_op_instruction);
case IrBinOpArrayCat:
return ir_analyze_array_cat(ira, bin_op_instruction);
@@ -11211,7 +11211,7 @@ static TypeTableEntry *ir_analyze_instruction_div_exact(IrAnalyze *ira, IrInstru
}
BigNum remainder;
if (bignum_mod(&remainder, &op1_val->data.x_bignum, &op2_val->data.x_bignum)) {
if (bignum_rem(&remainder, &op1_val->data.x_bignum, &op2_val->data.x_bignum)) {
ir_add_error(ira, &instruction->base, buf_sprintf("integer overflow"));
return ira->codegen->builtin_types.entry_invalid;
}

2
src/ir_print.cpp
View File

@@ -110,7 +110,7 @@ static const char *ir_bin_op_id_str(IrBinOp op_id) {
return "*%";
case IrBinOpDiv:
return "/";
case IrBinOpMod:
case IrBinOpRem:
return "%";
case IrBinOpArrayCat:
return "++";