Compile procedure headers

1 files changed, 345 insertions, 14 deletions

diff --git a/boot/echo-boot.s b/boot/echo-boot.s
index a8faecb..22d59d0 100644
--- a/boot/echo-boot.s
+++ b/boot/echo-boot.s
@@ -188,7 +188,7 @@ _compile_program:
 	sw t0, 8(sp)
 
 	addi a0, sp, 8
-	li a1, 16
+	li a1, 15
 	call write_out
 
 	addi s1, s1, 8 # program\n.
@@ -496,7 +496,160 @@ _compile_procedure:
 	addi s1, s1, 1 # Skip opening argument paren.
 	call _skip_spaces
 	addi s1, s1, 1 # Skip closing argument paren.
+
+	li t0, 0x6e # n
+	sw t0, 12(sp)
+	li t0, 0x69676562 # begi
+	sw t0, 8(sp)
+
+	# Skip all declarations until we find the "begin" keyword, denoting the
+	# beginning of the procedure body.
+.Lcompile_procedure_begin:
 	call _skip_spaces
+	call _read_token
+
+	mv a1, a0
+	mv a0, s1
+	addi a2, sp, 8
+	add s1, s1, a1
+	call _token_compare
+
+	bnez a0, .Lcompile_procedure_begin
+
+	# Generate the procedure prologue with a predefined stack size.
+	li t0, 0x69646461 # addi
+	sw t0, 12(sp)
+	addi a0, sp, 12
+	li a1, 4
+	call write_out
+
+	li t0, 0x2c707320 # _sp,
+	sw t0, 12(sp)
+
+	addi a0, sp, 12
+	li a1, 4
+	call write_out
+
+	addi a0, sp, 12
+	li a1, 4
+	call write_out
+
+	li t0, 0x0a36392d # -96\n
+	sw t0, 12(sp)
+	addi a0, sp, 12
+	li a1, 4
+	call write_out
+
+	li t0, 0x0a29 # )\n
+	sw t0, 12(sp)
+	li t0, 0x70732832 # 2(sp
+	sw t0, 8(sp)
+	li t0, 0x39202c61 # a, 9
+	sw t0, 4(sp)
+	li t0, 0x72207773 # sw r
+	sw t0, 0(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call write_out
+
+	li t0, 0x0a29 # )\n
+	sw t0, 12(sp)
+	li t0, 0x70732838 # 2(sp
+	sw t0, 8(sp)
+	li t0, 0x38202c30 # 0, 8
+	sw t0, 4(sp)
+	li t0, 0x73207773 # sw s
+	sw t0, 0(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call write_out
+
+	li t0, 0x0a363920 # _96\n
+	sw t0, 12(sp)
+	li t0, 0x2c707320 # _sp,
+	sw t0, 8(sp)
+	li t0, 0x2c307320 # _s0,
+	sw t0, 4(sp)
+	li t0, 0x69646461 # addi
+	sw t0, 0(sp)
+	addi a0, sp, 0
+	li a1, 16
+	call write_out
+
+	# Generate the body of the procedure.
+.Lcompile_procedure_body:
+	call _skip_indentation
+	call _read_line
+	sw a0, 12(sp)
+	li t0, 0x0a646e65 # end\n
+	sw t0, 8(sp)
+	mv a0, s1
+	addi a1, sp, 8
+	li a2, 4
+	call memcmp
+
+	beqz a0, .Lcompile_procedure_end
+
+	lw a0, 12(sp)
+	call _compile_line
+	j .Lcompile_procedure_body
+
+.Lcompile_procedure_end:
+	add s1, s1, 4 # Skip end\n.
+
+	# Generate the procedure epilogue with a predefined stack size.
+	li t0, 0x0a29 # )\n
+	sw t0, 12(sp)
+	li t0, 0x70732832 # 2(sp
+	sw t0, 8(sp)
+	li t0, 0x39202c61 # a, 9
+	sw t0, 4(sp)
+	li t0, 0x7220776c # lw r
+	sw t0, 0(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call write_out
+
+	li t0, 0x0a29 # )\n
+	sw t0, 12(sp)
+	li t0, 0x70732838 # 2(sp
+	sw t0, 8(sp)
+	li t0, 0x38202c30 # 0, 8
+	sw t0, 4(sp)
+	li t0, 0x7320776c # lw s
+	sw t0, 0(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call write_out
+
+	li t0, 0x69646461 # addi
+	sw t0, 12(sp)
+	addi a0, sp, 12
+	li a1, 4
+	call write_out
+
+	li t0, 0x2c707320 # _sp,
+	sw t0, 12(sp)
+
+	addi a0, sp, 12
+	li a1, 4
+	call write_out
+
+	addi a0, sp, 12
+	li a1, 4
+	call write_out
+
+	li t0, 0x0a3639 # 96\n
+	sw t0, 12(sp)
+	addi a0, sp, 12
+	li a1, 3
+	call write_out
+
+	li t0, 0x0a746572 # ret\n
+	sw t0, 12(sp)
+	addi a0, sp, 12
+	li a1, 4
+	call write_out
 
 	# Epilogue.
 	lw ra, 28(sp)
@@ -504,8 +657,52 @@ _compile_procedure:
 	addi sp, sp, 32
 	ret
 
+# Compares two string, which of one has a length, the other one is null-terminated.
+#
+# a0 - The address of the token string.
+# a1 - The length of the string in a0.
+# a2 - The address of the null-terminated string.
+#
+# If the strings match sets a0 to 0, otherwise sets it to 1.
+.type _token_compare, @function
+_token_compare:
+	addi t0, a0, 0
+	addi t1, a1, 0
+	addi t2, a2, 0
+
+.Ltoken_compare_loop:
+	lbu t3, (t2)
+
+	# Will only be 0 if the current character in the null terminated string is \0 and the remaining length of the
+	# another string is 0.
+	or t4, t3, t1
+	beqz t4, .Ltoken_compare_equal
+
+	beqz t1, .Ltoken_compare_not_equal
+	beqz t3, .Ltoken_compare_not_equal
+
+	lbu t4, (t0)
+	bne t3, t4, .Ltoken_compare_not_equal
+
+	addi t0, t0, 1
+	addi t1, t1, -1
+	addi t2, t2, 1
+	j .Ltoken_compare_loop
+
+.Ltoken_compare_not_equal:
+	li a0, 1
+	j .Ltoken_compare_end
+
+.Ltoken_compare_equal:
+	li a0, 0
+
+.Ltoken_compare_end:
+	ret
+
 # Parameters:
 # a0 - Line length.
+# Returns 1 in a0 if the parsed line contained a text section element such a
+# procedure or the program entry point. Otherwise sets a0 to 0.
 .type _compile_line, @function
 _compile_line:
 	# Prologue.
@@ -560,14 +757,42 @@ _compile_line:
 	call memcmp
 	beqz a0, .Lcompile_line_procedure
 
+	li t0, 0x0a6e # n\n
+	sw t0, 16(sp)
+	li t0, 0x69676562 # begi
+	sw t0, 12(sp)
+	mv a0, s1
+	addi a1, sp, 12
+	li a2, 6
+	call memcmp
+	beqz a0, .Lcompile_line_begin
+
+	li t0, 0x2e646e65 # end.
+	sw t0, 16(sp)
+	mv a0, s1
+	addi a1, sp, 16
+	li a2, 4
+	call memcmp
+	beqz a0, .Lcompile_line_exit
+
 	j .Lcompile_line_unchanged # Else.
 
+.Lcompile_line_exit:
+	call _compile_exit
+	j .Lcompile_line_section
+
+.Lcompile_line_begin:
+	call _compile_entry_point
+	li a0, 1
+	j .Lcompile_line_end
+
 .Lcompile_line_const:
 	call _compile_constant_section
-	j .Lcompile_line_end
+	j .Lcompile_line_section
 
 .Lcompile_line_procedure:
 	call _compile_procedure
+	li a0, 1
 	j .Lcompile_line_end
 
 .Lcompile_line_var:
@@ -578,25 +803,28 @@ _compile_line:
 	call write_error */
 
 	call _compile_variable_section
-	j .Lcompile_line_end
+	j .Lcompile_line_section
 
 .Lcompile_line_program:
 	call _compile_program
-	j .Lcompile_line_end
+	j .Lcompile_line_section
 
 .Lcompile_line_comment:
 	lw a0, 20(sp)
 	call _skip_comment
-	j .Lcompile_line_end
+	j .Lcompile_line_section
 
 .Lcompile_line_empty:
 	addi s1, s1, 1
-	j .Lcompile_line_end
+	j .Lcompile_line_section
 
 .Lcompile_line_unchanged:
 	lw a0, 20(sp)
 	call _compile_assembly
-	j .Lcompile_line_end
+	j .Lcompile_line_section
+
+.Lcompile_line_section:
+	mv a0, zero
 
 .Lcompile_line_end:
 	# Epilogue.
@@ -605,6 +833,109 @@ _compile_line:
 	addi sp, sp, 32
 	ret
 
+.type _compile_text_section, @function
+_compile_text_section:
+	# Prologue.
+	addi sp, sp, -24
+	sw ra, 20(sp)
+	sw s0, 16(sp)
+	addi s0, sp, 24
+
+	# .section .text
+	li t0, 0x0a7478 # xt\n
+	sw t0, 12(sp)
+	li t0, 0x65742e20 # _.te
+	sw t0, 8(sp)
+	li t0, 0x6e6f6974 # tion
+	sw t0, 4(sp)
+	li t0, 0x6365732e # .sec
+	sw t0, 0(sp)
+
+	addi a0, sp, 0
+	li a1, 15
+	call write_out
+
+	# Epilogue.
+	lw ra, 20(sp)
+	lw s0, 16(sp)
+	addi sp, sp, 24
+	ret
+
+.type _compile_entry_point, @function
+_compile_entry_point:
+	# Prologue.
+	addi sp, sp, -64
+	sw ra, 60(sp)
+	sw s0, 56(sp)
+	addi s0, sp, 64
+
+	# .type _start, @function
+	li t0, 0x0a3a7472 # rt:\n
+	sw t0, 52(sp)
+	li t0, 0x6174735f # _sta
+	sw t0, 48(sp)
+	li t0, 0x0a6e6f69 # ion\n
+	sw t0, 44(sp)
+	li t0, 0x74636e75 # unct
+	sw t0, 40(sp)
+	li t0, 0x6640202c # , @f
+	sw t0, 36(sp)
+	li t0, 0x74726174 # tart
+	sw t0, 32(sp)
+	li t0, 0x735f2065 # e _s
+	sw t0, 28(sp)
+	li t0, 0x7079742e # .typ
+	sw t0, 24(sp)
+	addi a0, sp, 24
+	li a1, 32
+	call write_out
+
+	addi s1, s1, 6 # Skip begin\n.
+
+	# Epilogue.
+	lw ra, 60(sp)
+	lw s0, 56(sp)
+	addi sp, sp, 64
+	ret
+
+.type _compile_exit, @function
+_compile_exit:
+	# Prologue.
+	addi sp, sp, -64
+	sw ra, 60(sp)
+	sw s0, 56(sp)
+	addi s0, sp, 64
+
+	# li a0, 0
+	# li a7, SYS_EXIT
+	# ecall
+	li t0, 0x0a # \n
+	sw t0, 52(sp)
+	li t0, 0x6c6c6163 # call
+	sw t0, 48(sp)
+	li t0, 0x650a3339 # 93\ne
+	sw t0, 44(sp)
+	li t0, 0x202c3761 # a7,_
+	sw t0, 40(sp)
+	li t0, 0x20696c0a # \nli_
+	sw t0, 36(sp)
+	li t0, 0x30202c30 # 0, 0
+	sw t0, 32(sp)
+	li t0, 0x6120696c # li a
+	sw t0, 28(sp)
+	addi a0, sp, 28
+	li a1, 25
+	call write_out
+
+	addi s1, s1, 4 # Skip end.
+	call _skip_spaces # Read the possible new line at the end of the file.
+
+	# Epilogue.
+	lw ra, 60(sp)
+	lw s0, 56(sp)
+	addi sp, sp, 64
+	ret
+
 # Finds the end of the line and returns its length in a0.
 .type _read_line, @function
 _read_line:
@@ -626,10 +957,10 @@ _read_line:
 .type _compile, @function
 _compile:
 	# Prologue.
-	addi sp, sp, -8
-	sw ra, 4(sp)
-	sw s0, 0(sp)
-	addi s0, sp, 8
+	addi sp, sp, -16
+	sw ra, 12(sp)
+	sw s0, 8(sp)
+	addi s0, sp, 16
 
 .Lcompile_do:
 	lbu t0, (s1) # t0 = Current character.
@@ -643,9 +974,9 @@ _compile:
 .Lcompile_end:
 
 	# Epilogue.
-	lw ra, 4(sp)
-	lw s0, 0(sp)
-	addi sp, sp, 8
+	lw ra, 12(sp)
+	lw s0, 8(sp)
+	addi sp, sp, 16
 	ret
 
 # Entry point.