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# This Source Code Form is subject to the terms of the Mozilla Public License,
# v. 2.0. If a copy of the MPL was not distributed with this file, You can
# obtain one at https://mozilla.org/MPL/2.0/.
.global symbol_table_build, symbol_table_find
.include "boot/definitions.inc"
.equ SYMBOL_PRIME, 1543
.section .rodata
.type symbol_builtin_name_int, @object
symbol_builtin_name_int: .ascii "Int"
.type symbol_builtin_name_word, @object
symbol_builtin_name_word: .ascii "Word"
.type symbol_builtin_name_byte, @object
symbol_builtin_name_byte: .ascii "Byte"
.type symbol_builtin_name_char, @object
symbol_builtin_name_char: .ascii "Char"
# Every type info starts with a word describing what type it is.
# Primitive types have only type size.
.type symbol_builtin_type_int, @object
symbol_builtin_type_int: .word TYPE_PRIMITIVE
.word 4
.type symbol_builtin_type_word, @object
symbol_builtin_type_word: .word TYPE_PRIMITIVE
.word 4
.type symbol_builtin_type_byte, @object
symbol_builtin_type_byte: .word TYPE_PRIMITIVE
.word 1
.type symbol_builtin_type_char, @object
symbol_builtin_type_char: .word TYPE_PRIMITIVE
.word 1
.section .bss
# The first word of the symbol table is its length.
# Then a list of type infos follows:
#
# record
# name: String
# info: ^TypeInfo
# end
.type symbol_table, @object
symbol_table: .zero SYMBOL_PRIME
.section .text
# Searches for a symbol by name.
#
# Parameters:
# a0 - Local symbol table or 0.
# a1 - Length of the symbol to search.
# a2 - Pointer to the symbol name.
#
# Sets a0 to the symbol info.
.type symbol_table_find, @function
symbol_table_find:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
sw s1, 20(sp) # Current symbol in the table.
sw s2, 16(sp) # Symbol table length.
sw s3, 12(sp) # Length of the symbol to search.
sw s4, 8(sp) # Pointer to the symbol to search.
mv s3, a1
mv s4, a2
la s1, symbol_table
lw s2, 0(s1)
addi s1, s1, 4 # Advance to the first symbol in the table.
.Lsymbol_table_find_loop:
beqz s2, .Lsymbol_table_find_not_found
# Compare string lengths.
lw a2, 0(s1)
bne s3, a2, .Lsymbol_table_find_continue
# If lengths match, compare the content.
mv a0, s4
lw a1, 4(s1)
call _memcmp
bnez a0, .Lsymbol_table_find_continue
lw a0, 8(s1) # Pointer to the symbol.
j .Lsymbol_table_end
.Lsymbol_table_find_continue:
addi s2, s2, -1
j .Lsymbol_table_find_loop
.Lsymbol_table_find_not_found:
li a0, 0
.Lsymbol_table_end:
lw s1, 20(sp)
lw s2, 16(sp)
lw s3, 12(sp)
lw s4, 8(sp)
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
# Build the initial symbols.
#
# Sets a0 to the pointer to the global symbol table.
.type symbol_build, @function
symbol_table_build:
la a0, symbol_table
addi t0, a0, 4
li t1, 3 # Length of the word "Int".
sw t1, 0(t0)
la t1, symbol_builtin_name_int
sw t1, 4(t0)
la t1, symbol_builtin_type_int
sw t1, 8(t0)
lw t1, 0(a0)
addi t1, t1, 1
sw t1, 0(a0)
addi t0, t0, 12
li t1, 4 # Length of the word "Word".
sw t1, 0(t0)
la t1, symbol_builtin_name_word
sw t1, 4(t0)
la t1, symbol_builtin_type_word
sw t1, 8(t0)
lw t1, 0(a0)
addi t1, t1, 1
sw t1, 0(a0)
addi t0, t0, 12
li t1, 4 # Length of the word "Byte".
sw t1, 0(t0)
la t1, symbol_builtin_name_byte
sw t1, 4(t0)
la t1, symbol_builtin_type_byte
sw t1, 8(t0)
lw t1, 0(a0)
addi t1, t1, 1
sw t1, 0(a0)
addi t0, t0, 12
li t1, 4 # Length of the word "Char".
sw t1, 0(t0)
la t1, symbol_builtin_name_char
sw t1, 4(t0)
la t1, symbol_builtin_type_char
sw t1, 8(t0)
lw t1, 0(a0)
addi t1, t1, 1
sw t1, 0(a0)
addi t0, t0, 12
ret
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