mirror of https://github.com/japl-lang/japl.git
92 lines
3.9 KiB
Nim
92 lines
3.9 KiB
Nim
# Copyright 2020 Mattia Giambirtone
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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## This module handles all memory allocation and deallocation for the entire
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## JAPL runtime. Forcing the entire language to route memory management
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## into a single module makes it easy to track how much memory we have allocated
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## and simplifies the implementation of a garbage collector.
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## To also make our life as language implementers easier, the internals of the
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## interpreter (which means the tokenizer, the compiler, the debugger
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## and some minor parts of the Virtual Machine) will use nim's GC
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import segfaults
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import config
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when DEBUG_TRACE_ALLOCATION:
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import strformat
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proc reallocate*(pointr: pointer, oldSize: int, newSize: int): pointer =
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## Wrapper around realloc/dealloc
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try:
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if newSize == 0 and pointr != nil: # pointr is awful, but clashing with builtins is even more awful
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when DEBUG_TRACE_ALLOCATION:
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if oldSize > 1:
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echo &"DEBUG - Memory manager: Deallocating {oldSize} bytes"
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else:
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echo "DEBUG - Memory manager: Deallocating 1 byte"
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dealloc(pointr)
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return nil
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when DEBUG_TRACE_ALLOCATION:
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if pointr == nil and newSize == 0:
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echo &"DEBUG - Memory manager: Warning, asked to dealloc() nil pointer from {oldSize} to {newSize} bytes, ignoring request"
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if oldSize > 0 and pointr != nil or oldSize == 0:
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when DEBUG_TRACE_ALLOCATION:
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if oldSize == 0:
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if newSize > 1:
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echo &"DEBUG - Memory manager: Allocating {newSize} bytes of memory"
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else:
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echo "DEBUG - Memory manager: Allocating 1 byte of memory"
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else:
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echo &"DEBUG - Memory manager: Resizing {oldSize} bytes of memory to {newSize} bytes"
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result = realloc(pointr, newSize)
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when DEBUG_TRACE_ALLOCATION:
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if oldSize > 0 and pointr == nil:
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echo &"DEBUG - Memory manager: Warning, asked to realloc() nil pointer from {oldSize} to {newSize} bytes, ignoring request"
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except NilAccessDefect:
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stderr.write("A fatal error occurred -> could not manage memory, segmentation fault\n")
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quit(71) # For now, there's not much we can do if we can't get the memory we need
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template resizeArray*(kind: untyped, pointr: pointer, oldCount, newCount: int): untyped =
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## Handy macro (in the C sense of macro, not nim's) to resize a dynamic array
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cast[ptr UncheckedArray[kind]](reallocate(pointr, sizeof(kind) * oldCount, sizeof(kind) * newCount))
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template freeArray*(kind: untyped, pointr: pointer, oldCount: int): untyped =
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## Frees a dynamic array
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reallocate(pointr, sizeof(kind) * oldCount, 0)
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template free*(kind: untyped, pointr: pointer): untyped =
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## Frees a pointer by reallocating its
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## size to 0
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reallocate(pointr, sizeof(kind), 0)
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template growCapacity*(capacity: int): untyped =
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## Handy macro used to calculate how much
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## more memory is needed when reallocating
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## dynamic arrays
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if capacity < 8:
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8
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else:
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capacity * ARRAY_GROW_FACTOR
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template allocate*(castTo: untyped, sizeTo: untyped, count: int): untyped =
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## Allocates an object and casts its pointer to the specified type
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cast[ptr castTo](reallocate(nil, 0, sizeof(sizeTo) * count))
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