DebugCheckArrayBounds¶
Checks at run time that the shapes in an array assignment conform.
Declaration¶
Syntax¶
DebugCheckArrayBounds(expr target, expr* components,
array_extent_check* checks, bool move_allocation)
Arguments¶
Argument |
Описание |
|---|---|
|
the array being assigned to. |
|
the array operands of the right hand side, whose shapes must match |
|
the extents compared at run time, in order (see array_extent_check). |
|
|
Return values¶
None.
Описание¶
This node is inserted by the array_op pass ahead of an array assignment when
bounds checking is enabled, and it is never produced by a frontend. It fails
at run time with a diagnostic naming the mismatching extents rather than
writing out of bounds. It is omitted when the extents of the target and of
all operands are compile-time constants and equal, since it cannot fail then.
The extents of a section are compile-time constants when the start, end and
stride of each of its subscript triplets are, as for a(:, i) with a of
constant bounds.
After it, every operand has the extent of the target in every dimension. The element references of the loop that implements the assignment rely on that and are marked in_bounds.
Each element of components must itself be an array: the check compares the
extents of the target against the extents of the operands the assignment
reads.
The pass that inserts the node also decides what it compares, and records it
in checks, so that a code generator only evaluates and compares the
extents it is given. Each operand is compared with the next one, when both
have the same rank, and then the first operand with target, in every
dimension the two arrays have. A dimension in which both extents are
compile-time constants and equal is left out, since its comparison cannot
fail. A comparison of two operands reports a mismatch in a binary operation,
one with target a mismatch in the assignment. When target is an
allocatable array that is not allocated, its unallocated state is reported
instead of its extents.
Examples¶
(DebugCheckArrayBounds
:target (Var
:v (SymbolRef 1 "a")
)
:components [
(Var
:v (SymbolRef 1 "b")
)
]
:checks [
(array_extent_check
:left 0
:right 1
:dim 1
:left_extent (ArraySize
:v (Var
:v (SymbolRef 1 "a")
)
:dim (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (Integer
:kind 4
)
:value nil
)
:right_extent (ArraySize
:v (Var
:v (SymbolRef 1 "b")
)
:dim (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (Integer
:kind 4
)
:value nil
)
)
]
:move_allocation false
)
It comes from this complete ASR text document:
(TranslationUnit
:symtab (SymbolTable
:id 0
:symbols {
"main" (Program
:symtab (SymbolTable
:id 1
:symbols {
"a" (Variable
:parent_symtab 1
:name "a"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (Array
:type (Integer
:kind 4
)
:dims [
(dimension
:start (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:length (IntegerConstant
:n 3
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
)
]
:physical_type :FixedSizeArray
:memory_space :Global
)
:type_declaration nil
:abi :Source
:access :Public
:presence :Required
:value_attr false
:target_attr false
:contiguous_attr false
:bindc_name nil
:is_volatile false
:is_protected false
:pass_attr :NotMethod
:self_argument nil
:codims []
:common_block nil
)
"b" (Variable
:parent_symtab 1
:name "b"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (Allocatable
:type (Array
:type (Integer
:kind 4
)
:dims [
(dimension
:start nil
:length nil
)
]
:physical_type :DescriptorArray
:memory_space :Global
)
)
:type_declaration nil
:abi :Source
:access :Public
:presence :Required
:value_attr false
:target_attr false
:contiguous_attr false
:bindc_name nil
:is_volatile false
:is_protected false
:pass_attr :NotMethod
:self_argument nil
:codims []
:common_block nil
)
}
)
:name "main"
:dependencies []
:body [
(DebugCheckArrayBounds
:target (Var
:v (SymbolRef 1 "a")
)
:components [
(Var
:v (SymbolRef 1 "b")
)
]
:checks [
(array_extent_check
:left 0
:right 1
:dim 1
:left_extent (ArraySize
:v (Var
:v (SymbolRef 1 "a")
)
:dim (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (Integer
:kind 4
)
:value nil
)
:right_extent (ArraySize
:v (Var
:v (SymbolRef 1 "b")
)
:dim (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (Integer
:kind 4
)
:value nil
)
)
]
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "a")
)
:value (Var
:v (SymbolRef 1 "b")
)
:overloaded nil
:realloc_lhs false
:move_allocation false
:new_target false
)
]
:global_init nil
)
}
)
:items []
:global_init nil
)