summaryrefslogtreecommitdiff
path: root/boot/stage2.elna
diff options
context:
space:
mode:
Diffstat (limited to 'boot/stage2.elna')
-rw-r--r--boot/stage2.elna643
1 files changed, 487 insertions, 156 deletions
diff --git a/boot/stage2.elna b/boot/stage2.elna
index e37b3e6..4e87e89 100644
--- a/boot/stage2.elna
+++ b/boot/stage2.elna
@@ -1,73 +1,221 @@
program
# s1 - Contains the current position in the source text.
+import dummy
+
const
- SOURCE_BUFFER_SIZE := 20480
+ SOURCE_BUFFER_SIZE := 40960
var
- source_code: [20480]Byte
+ source_code: [40960]Byte
+
+# Ignores the import.
+proc _compile_import()
+var loca0: Word
+begin
+ _advance(6)
+ _skip_spaces()
+ loca0 := _read_token()
+ _advance(loca0) # Skip the imported module name.
+end
+
+proc _build_binary_expression()
+begin
+ _build_expression(0)
+
+ _skip_spaces()
+ call _read_token
+ sw a0, 20(sp)
+
+ li t0, 0x26 # &
+ sw t0, 16(sp)
+ mv a0, s1
+ lw a1, 20(sp)
+ addi a2, sp, 16
+ call _token_compare
+ beqz a0, .L_build_binary_expression_and
+
+ li t0, 0x3d # =
+ sw t0, 16(sp)
+ mv a0, s1
+ lw a1, 20(sp)
+ addi a2, sp, 16
+ call _token_compare
+ beqz a0, .L_build_binary_expression_equal
-.section .text
+ /* DEBUG
+ mv a0, s1
+ li a1, 8
+ call _write_error */
+
+ j .Lbuild_binary_expression_end
+
+.L_build_binary_expression_equal:
+ addi s1, s1, 1 # Skip =.
+ _build_expression(1)
+ li t0, 0x0a3161 # a1\n
+ sw t0, 16(sp)
+ li t0, 0x202c3061 # a0,_
+ sw t0, 12(sp)
+ li t0, 0x202c3061 # a0,_
+ sw t0, 8(sp)
+ li t0, 0x20627573 # sub_
+ sw t0, 4(sp)
+ addi a0, sp, 4
+ li a1, 15
+ call _write_out
+
+ li t0, 0x0a306120 # _a0\n
+ sw t0, 16(sp)
+ li t0, 0x2c306120 # _a0,
+ sw t0, 12(sp)
+ li t0, 0x7a716573 # seqz
+ sw t0, 8(sp)
+ addi a0, sp, 8
+ li a1, 12
+ call _write_out
+
+ j .Lbuild_binary_expression_end
+
+.L_build_binary_expression_and:
+ addi s1, s1, 1 # Skip &.
+ _build_expression(1)
+ li t0, 0x0a3161 # a1\n
+ sw t0, 16(sp)
+ li t0, 0x202c3061 # a0,_
+ sw t0, 12(sp)
+ li t0, 0x202c3061 # a0,_
+ sw t0, 8(sp)
+ li t0, 0x20646e61 # and_
+ sw t0, 4(sp)
+ addi a0, sp, 4
+ li a1, 15
+ call _write_out
+
+ j .Lbuild_binary_expression_end
+
+.Lbuild_binary_expression_end:
+end
# Evalutes an expression and saves the result in a0.
+#
+# a0 - X in aX, the register number to save the result.
proc _build_expression()
begin
+ addi a0, a0, '0' # Make the register number to a character.
+ sw a0, 20(sp) # And save it.
+
_skip_spaces()
call _read_token
- sw s1, 20(sp)
- sw a0, 16(sp)
+ sw s1, 16(sp)
+ sw a0, 12(sp)
# Integer literal.
addi a0, s1, 0
- lb a0, (a0)
+ lbu a0, (a0)
call _is_digit
- bnez a0, .Lbuild_expression_number_literal
+ bnez a0, .Lbuild_expression_literal
+
+ addi a0, s1, 0
+ lbu a0, (a0)
+ li t0, 0x5f # _
+ beq a0, t0, .Lbuild_expression_call
+
+ li t0, 0x61636f6c # loca
+ sw t0, 8(sp)
+ mv a0, s1
+ addi a1, sp, 8
+ li a2, 4
+ call _memcmp
+ beqz a0, .Lbuild_expression_identifier
# Named identifier.
- li t0, 0x202c30 # 0,_
- sw t0, 12(sp)
+ lw t1, 20(sp)
+ li t0, 0x00202c00 # \0,_
+ or t0, t0, t1
+ sw t0, 8(sp)
li t0, 0x6120616c # la a
+ sw t0, 4(sp)
+ addi a0, sp, 4
+ li a1, 7
+ call _write_out
+
+ lw a0, 16(sp)
+ lw a1, 12(sp)
+ call _write_out
+
+ li t0, 0x0a # \n
sw t0, 8(sp)
addi a0, sp, 8
+ li a1, 1
+ call _write_out
+
+ goto .Lbuild_expression_advance
+
+ .Lbuild_expression_identifier
+ lw t1, 20(sp)
+ li t0, 0x00202c00 # \0,_
+ or t0, t0, t1
+ sw t0, 8(sp)
+ li t0, 0x6120776c # lw a
+ sw t0, 4(sp)
+ addi a0, sp, 4
li a1, 7
call _write_out
- lw a0, 20(sp)
- lw a1, 16(sp)
+ lw a0, 16(sp)
+ lw a1, 12(sp)
+ addi a0, a0, 4 # Skip the "loca" variable prefix.
+ addi a1, a1, -4 # Skip the "loca" variable prefix.
call _write_out
li t0, 0x0a # \n
- sw t0, 12(sp)
- addi a0, sp, 12
- li a1, 1
+ sw t0, 8(sp)
+ li t0, 0x29707328 # (sp)
+ sw t0, 4(sp)
+ addi a0, sp, 4
+ li a1, 5
call _write_out
- j .Lbuild_expression_end
+ goto .Lbuild_expression_advance
-.Lbuild_expression_number_literal:
- li t0, 0x202c30 # 0,_
- sw t0, 12(sp)
- li t0, 0x6120696c # li a
+ .Lbuild_expression_call
+ lw a0, 16(sp)
+ lw a1, 12(sp)
+ add s1, s1, a1
+ addi s1, s1, 1
+ call _compile_call
+
+ goto .Lbuild_expression_end
+
+ .Lbuild_expression_literal
+ lw t1, 20(sp)
+ li t0, 0x00202c00 # \0,_
+ or t0, t0, t1
sw t0, 8(sp)
- addi a0, sp, 8
+ li t0, 0x6120696c # li a
+ sw t0, 4(sp)
+ addi a0, sp, 4
li a1, 7
call _write_out
- lw a0, 20(sp)
- lw a1, 16(sp)
+ lw a0, 16(sp)
+ lw a1, 12(sp)
call _write_out
li t0, 0x0a # \n
- sw t0, 12(sp)
- addi a0, sp, 12
+ sw t0, 8(sp)
+ addi a0, sp, 8
li a1, 1
call _write_out
- j .Lbuild_expression_end
+ goto .Lbuild_expression_advance
-.Lbuild_expression_end:
- lw a0, 16(sp)
+ .Lbuild_expression_advance
+ lw a0, 12(sp)
add s1, s1, a0
+
+ .Lbuild_expression_end
end
# Compiles a statement beginning with an identifier.
@@ -101,27 +249,22 @@ begin
call _token_compare
beqz a0, .Lcompile_identifier_assign
- /* DEBUG
- mv a0, s1
- li a1, 4
- call _write_error */
-
lw t0, 12(sp)
lbu t0, (t0)
li t1, 0x28 # (
beq t0, t1, .Lcompile_identifier_call
- j .Lcompile_identifier_end
+ goto .Lcompile_identifier_end
-.Lcompile_identifier_call:
+ .Lcompile_identifier_call
lw a0, 20(sp)
lw a1, 16(sp)
call _compile_call
- j .Lcompile_identifier_end
+ goto .Lcompile_identifier_end
-.Lcompile_identifier_assign:
- call _build_expression
+ .Lcompile_identifier_assign
+ _build_binary_expression()
li t0, 0x202c30 # 0,_
sw t0, 12(sp)
@@ -145,9 +288,9 @@ begin
li a1, 5
call _write_out
- j .Lcompile_identifier_end
+ goto .Lcompile_identifier_end
-.Lcompile_identifier_end:
+ .Lcompile_identifier_end
end
# Compiles a procedure call. Expects s1 to point to the first argument.
@@ -161,15 +304,15 @@ begin
sw a1, 16(sp)
sw zero, 12(sp) # Argument count for a procedure call.
-.Lcompile_call_paren:
+ .Lcompile_call_paren
_skip_spaces()
call _read_token
lbu t0, (s1)
li t1, 0x29 # )
beq t0, t1, .Lcompile_call_complete
-.Lcompile_call_argument:
- call _build_expression
+ .Lcompile_call_argument
+ _build_expression(0)
li t0, 0x202c30 # 0,_
sw t0, 8(sp)
@@ -181,12 +324,12 @@ begin
lw t0, 12(sp) # Argument count for a procedure call.
- # Only 8 arguments are supported with a0-a7.
+ # Only 6 arguments are supported with a0-a5.
# Save all arguments on the stack so they aren't overriden afterwards.
# The offset on the stack always has two digits in this case.
li t1, -4
mul t1, t0, t1
- addi t1, t1, 84
+ addi t1, t1, 60
li t2, 10
div t3, t1, t2
rem t4, t1, t2
@@ -223,16 +366,16 @@ begin
sw t0, 12(sp)
_advance(1) # Skip the comma between the arguments.
- j .Lcompile_call_argument
+ goto .Lcompile_call_argument
-.Lcompile_call_complete:
+ .Lcompile_call_complete
sw zero, 12(sp)
-.Lcompile_call_restore:
- # Just go through all a0-a7 registers and read them from stack.
+ .Lcompile_call_restore
+ # Just go through all a0-a5 registers and read them from stack.
# If this stack value contains garbage, the procedure just shouldn't use it.
lw t0, 12(sp)
- li t1, 7
+ li t1, 5
bgt t0, t1, .Lcompile_call_perform
li t0, 0x6120776c # lw a
@@ -245,7 +388,7 @@ begin
li t1, -4
mul t1, t0, t1
- addi t1, t1, 84
+ addi t1, t1, 60
li t2, 10
div t3, t1, t2
rem t4, t1, t2
@@ -271,9 +414,9 @@ begin
addi t0, t0, 1
sw t0, 12(sp)
- j .Lcompile_call_restore
+ goto .Lcompile_call_restore
-.Lcompile_call_perform:
+ .Lcompile_call_perform
li t0, 0x20
sw t0, 8(sp)
li t0, 0x6c6c6163
@@ -327,7 +470,16 @@ begin
li t1, ']'
beq t0, t1, .Ltoken_character_single
-.Ltoken_character_loop_do: # Expect an identifier or a number.
+ li t1, '^'
+ beq t0, t1, .Ltoken_character_single
+
+ li t1, '&'
+ beq t0, t1, .Ltoken_character_single
+
+ li t1, '='
+ beq t0, t1, .Ltoken_character_single
+ # Expect an identifier or a number.
+ .Ltoken_character_loop_do
lw t6, 4(sp)
add t1, s1, t6
lbu a0, (t1) # a0 = Current character.
@@ -338,15 +490,15 @@ begin
lw t6, 4(sp)
addi t6, t6, 1
sw t6, 4(sp)
- j .Ltoken_character_loop_do
+ goto .Ltoken_character_loop_do
-.Ltoken_character_single:
+ .Ltoken_character_single
lw t6, 4(sp)
addi t6, t6, 1
sw t6, 4(sp)
- j .Ltoken_character_end
+ goto .Ltoken_character_end
-.Ltoken_character_colon:
+ .Ltoken_character_colon
lbu t0, 1(s1) # t0 = The character after the colon.
lw t6, 4(sp)
addi t6, t6, 1
@@ -354,16 +506,16 @@ begin
li t1, '='
beq t0, t1, .Ltoken_character_single
- j .Ltoken_character_end
+ goto .Ltoken_character_end
-.Ltoken_character_end:
+ .Ltoken_character_end
lw a0, 4(sp)
end
# Skips the spaces till the next non space character.
proc _skip_spaces()
begin
-.Lspace_loop_do:
+ .Lspace_loop_do
lbu t0, (s1) # t0 = Current character.
li t1, ' '
@@ -375,53 +527,50 @@ begin
li t1, '\r'
beq t0, t1, .Lspace_loop_repeat
- j .Lspace_loop_end
-.Lspace_loop_repeat:
+ goto .Lspace_loop_end
+ .Lspace_loop_repeat
_advance(1)
- j .Lspace_loop_do
+ goto .Lspace_loop_do
-.Lspace_loop_end:
+ .Lspace_loop_end
end
# Skips tabs at the line beginning.
proc _skip_indentation()
begin
-.Lskip_indentation_do:
+ .Lskip_indentation_do
lbu t0, (s1)
li t1, '\t'
beq t0, t1, .Lskip_indentation_skip
- j .Lskip_indentation_end
+ goto .Lskip_indentation_end
-.Lskip_indentation_skip:
+ .Lskip_indentation_skip
_advance(1)
- j .Lskip_indentation_do
+ goto .Lskip_indentation_do
-.Lskip_indentation_end:
+ .Lskip_indentation_end
end
# Parameters:
# a0 - Line length.
-proc _skip_comment()
+proc _skip_comment(loca84: Word)
begin
- add s1, s1, a0
+ _advance(loca84)
_advance(1) # Skip the new line.
end
# Parameters:
# a0 - Line length.
-proc _compile_assembly()
+proc _compile_assembly(loca84: Word)
+var loca0: ^Byte
begin
- sw a0, 4(sp) # a0 - Line length.
-
# Write the source to the standard output.
- mv a0, s1
- lw a1, 4(sp)
- call _write_out
+ loca0 := _current()
- lw t0, 4(sp)
- add s1, s1, t0
+ _write_out(loca0, loca84)
+ _advance(loca84)
li t0, '\n'
sb t0, 0(sp)
@@ -471,16 +620,16 @@ begin
_advance(6) # const\n.
-.Lcompile_constant_section_item:
+ .Lcompile_constant_section_item
_skip_spaces()
lbu a0, (s1)
call _is_upper
beqz a0, .Lcompile_constant_section_end
- call _compile_constant
- j .Lcompile_constant_section_item
+ _compile_constant()
+ goto .Lcompile_constant_section_item
-.Lcompile_constant_section_end:
+ .Lcompile_constant_section_end
end
proc _compile_constant()
@@ -538,16 +687,16 @@ begin
_advance(4) # var\n.
-.Lcompile_variable_section_item:
+ .Lcompile_variable_section_item
_skip_spaces()
lbu a0, (s1)
call _is_lower
beqz a0, .Lcompile_variable_section_end
- call _compile_variable
- j .Lcompile_variable_section_item
+ _compile_variable()
+ goto .Lcompile_variable_section_item
-.Lcompile_variable_section_end:
+ .Lcompile_variable_section_end
end
proc _compile_variable()
@@ -708,7 +857,7 @@ begin
# Skip all declarations until we find the "begin" keyword, denoting the
# beginning of the procedure body.
-.Lcompile_procedure_begin:
+ .Lcompile_procedure_begin
_skip_spaces()
call _read_token
@@ -758,7 +907,7 @@ begin
li t0, 0x0a29 # )\n
sw t0, 12(sp)
- li t0, 0x70732838 # 2(sp
+ li t0, 0x70732838 # 8(sp
sw t0, 8(sp)
li t0, 0x38202c30 # 0, 8
sw t0, 4(sp)
@@ -780,8 +929,61 @@ begin
li a1, 16
call _write_out
+ # Save passed arguments on the stack.
+ li t0, 0x0a29 # )\n
+ sw t0, 12(sp)
+ li t0, 0x70732834 # 4(sp
+ sw t0, 8(sp)
+ li t0, 0x38202c30 # 0, 8
+ sw t0, 4(sp)
+ li t0, 0x61207773 # sw a
+ sw t0, 0(sp)
+ addi a0, sp, 0
+ li a1, 14
+ call _write_out
+
+ li t0, '0'
+ sb t0, 8(sp)
+ li t0, 0x38202c31 # 1, 8
+ sw t0, 4(sp)
+ addi a0, sp, 0
+ li a1, 14
+ call _write_out
+
+ li t0, '6'
+ sb t0, 8(sp)
+ li t0, 0x37202c32 # 2, 7
+ sw t0, 4(sp)
+ addi a0, sp, 0
+ li a1, 14
+ call _write_out
+
+ li t0, '2'
+ sb t0, 8(sp)
+ li t0, 0x37202c33 # 3, 7
+ sw t0, 4(sp)
+ addi a0, sp, 0
+ li a1, 14
+ call _write_out
+
+ li t0, '8'
+ sb t0, 8(sp)
+ li t0, 0x36202c34 # 4, 6
+ sw t0, 4(sp)
+ addi a0, sp, 0
+ li a1, 14
+ call _write_out
+
+ li t0, '4'
+ sb t0, 8(sp)
+ li t0, 0x36202c35 # 5, 6
+ sw t0, 4(sp)
+ addi a0, sp, 0
+ li a1, 14
+ call _write_out
+
# Generate the body of the procedure.
-.Lcompile_procedure_body:
+ .Lcompile_procedure_body
_skip_indentation()
call _read_line
sw a0, 12(sp)
@@ -796,9 +998,9 @@ begin
lw a0, 12(sp)
call _compile_line
- j .Lcompile_procedure_body
+ goto .Lcompile_procedure_body
-.Lcompile_procedure_end:
+ .Lcompile_procedure_end
add s1, s1, 4 # Skip end\n.
# Generate the procedure epilogue with a predefined stack size.
@@ -816,7 +1018,7 @@ begin
li t0, 0x0a29 # )\n
sw t0, 12(sp)
- li t0, 0x70732838 # 2(sp
+ li t0, 0x70732838 # 8(sp
sw t0, 8(sp)
li t0, 0x38202c30 # 0, 8
sw t0, 4(sp)
@@ -869,7 +1071,7 @@ begin
addi t1, a1, 0
addi t2, a2, 0
-.Ltoken_compare_loop:
+ .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
@@ -886,25 +1088,97 @@ begin
addi t0, t0, 1
addi t1, t1, -1
addi t2, t2, 1
- j .Ltoken_compare_loop
+ goto .Ltoken_compare_loop
-.Ltoken_compare_not_equal:
+ .Ltoken_compare_not_equal
li a0, 1
- j .Ltoken_compare_end
+ goto .Ltoken_compare_end
-.Ltoken_compare_equal:
+ .Ltoken_compare_equal
li a0, 0
-.Ltoken_compare_end:
+ .Ltoken_compare_end
+end
+
+proc _compile_goto()
+begin
+ addi s1, s1, 4 # Skip the goto keyword.
+
+ li t0, 0x206a # j_
+ sw t0, 8(sp)
+ addi a0, sp, 8
+ li a1, 2
+ call _write_out
+
+ _skip_spaces()
+ sw s1, 8(sp) # We should be on dot the label is beginning with.
+ _advance(1)
+
+ call _read_token
+ add s1, s1, a0
+ addi a1, a0, 1 # Label length and the dot.
+ lw a0, 8(sp) # Saved dot position.
+ call _write_out
+
+ _advance(1) # Skip the new line.
+
+ li t0, 0x0a # \n
+ sw t0, 8(sp)
+ addi a0, sp, 8
+ li a1, 1
+ call _write_out
+end
+
+# a0 - Line length.
+proc _compile_label()
+begin
+ sw a0, 0(sp) # Save the line length.
+
+ # Write the whole line as is.
+ mv a0, s1
+ lw a1, 0(sp)
+ call _write_out
+
+ lw t0, 0(sp) # Line length.
+ mv t1, s1 # Line start.
+
+ add t1, t1, t0
+ addi t1, t1, -1 # Last character on the line.
+
+ lbu t1, (t1)
+ li t2, ':'
+ beq t1, t2, .Lcompile_label_colon
+
+ li t0, 0x3a # :
+ sw t0, 4(sp)
+ addi a0, sp, 4
+ li a1, 1
+ call _write_out
+
+ .Lcompile_label_colon
+ li t0, 0x0a # \n
+ sw t0, 4(sp)
+ addi a0, sp, 4
+ li a1, 1
+ call _write_out
+
+ lw a0, 0(sp)
+ addi a0, a0, 1 # Skip the new line as well.
+ add s1, s1, a0 # Skip the line.
end
# Parameters:
# a0 - Line length.
+# a1 - Whether the section header was already emitted. If not it should be
+# emitted before any code is written.
+#
# 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.
proc _compile_line()
begin
- sw a0, 20(sp) # a0 - Line length.
+ # Preserve passed arguments.
+ sw a0, 20(sp)
+ sw a1, 16(sp)
beqz a0, .Lcompile_line_empty # Skip an empty line.
@@ -913,125 +1187,167 @@ begin
beq t0, t1, .Lcompile_line_comment
li t0, 0x0a6d6172 # ram\n
- sw t0, 16(sp)
- li t0, 0x676f7270 # prog
sw t0, 12(sp)
+ li t0, 0x676f7270 # prog
+ sw t0, 8(sp)
mv a0, s1
- addi a1, sp, 12
+ addi a1, sp, 8
li a2, 8
call _memcmp
beqz a0, .Lcompile_line_program
li t0, 0x0a74 # t\n
- sw t0, 16(sp)
- li t0, 0x736e6f63 # cons
sw t0, 12(sp)
+ li t0, 0x736e6f63 # cons
+ sw t0, 8(sp)
mv a0, s1
- addi a1, sp, 12
+ addi a1, sp, 8
li a2, 6
call _memcmp
beqz a0, .Lcompile_line_const
li t0, 0x0a726176 # var\n
- sw t0, 16(sp)
+ sw t0, 12(sp)
mv a0, s1
- addi a1, sp, 16
+ addi a1, sp, 12
li a2, 4
- call _memcmp;
+ call _memcmp
beqz a0, .Lcompile_line_var
li t0, 0x20 # _
- sw t0, 16(sp)
- li t0, 0x636f7270 # proc
sw t0, 12(sp)
+ li t0, 0x636f7270 # proc
+ sw t0, 8(sp)
mv a0, s1
- addi a1, sp, 12
+ addi a1, sp, 8
li a2, 5
call _memcmp
beqz a0, .Lcompile_line_procedure
li t0, 0x0a6e # n\n
- sw t0, 16(sp)
- li t0, 0x69676562 # begi
sw t0, 12(sp)
+ li t0, 0x69676562 # begi
+ sw t0, 8(sp)
mv a0, s1
- addi a1, sp, 12
+ addi a1, sp, 8
li a2, 6
call _memcmp
beqz a0, .Lcompile_line_begin
li t0, 0x2e646e65 # end.
- sw t0, 16(sp)
+ sw t0, 12(sp)
mv a0, s1
- addi a1, sp, 16
+ addi a1, sp, 12
li a2, 4
call _memcmp
beqz a0, .Lcompile_line_exit
li t0, 0x61636f6c # loca
- sw t0, 16(sp)
+ sw t0, 12(sp)
mv a0, s1
- addi a1, sp, 16
+ addi a1, sp, 12
li a2, 4
call _memcmp
beqz a0, .Lcompile_line_identifier
+ li t0, 0x7472 # rt
+ sw t0, 12(sp)
+ li t0, 0x6f706d69 # impo
+ sw t0, 8(sp)
+ mv a0, s1
+ addi a1, sp, 8
+ li a2, 6
+ call _memcmp
+ beqz a0, .Lcompile_line_import
+
+ li t0, 0x6f746f67 # goto
+ sw t0, 12(sp)
+ mv a0, s1
+ addi a1, sp, 12
+ li a2, 4
+ call _memcmp
+ beqz a0, .Lcompile_line_goto
+
lbu t0, (s1)
+ li t1, '.'
+ beq t0, t1, .Lcompile_line_label
li t1, '_'
beq t0, t1, .Lcompile_line_identifier
- j .Lcompile_line_unchanged # Else.
+ goto .Lcompile_line_unchanged # Else.
+
+ .Lcompile_line_label
+ lw a0, 20(sp)
+ call _compile_label
+ goto .Lcompile_line_section
+
+ .Lcompile_line_goto
+ _compile_goto()
+ goto .Lcompile_line_section
-.Lcompile_line_identifier:
- call _compile_identifier
- j .Lcompile_line_section
+ .Lcompile_line_import
+ _compile_import()
+ goto .Lcompile_line_section
-.Lcompile_line_exit:
- call _compile_exit
- j .Lcompile_line_section
+ .Lcompile_line_identifier
+ _compile_identifier()
+ goto .Lcompile_line_section
-.Lcompile_line_begin:
- call _compile_entry_point
+ .Lcompile_line_exit
+ _compile_exit()
+ goto .Lcompile_line_section
+
+ .Lcompile_line_begin
+ lw a1, 16(sp)
+ bnez a1, .Lcompile_line_compile_entry
+ _compile_text_section()
+ .Lcompile_line_compile_entry
+ _compile_entry_point()
li a0, 1
- j .Lcompile_line_end
+ goto .Lcompile_line_end
-.Lcompile_line_const:
- call _compile_constant_section
- j .Lcompile_line_section
+ .Lcompile_line_const
+ _compile_constant_section()
+ goto .Lcompile_line_section
-.Lcompile_line_procedure:
- call _compile_procedure
+ .Lcompile_line_procedure
+ lw a1, 16(sp)
+ bnez a1, .Lcompile_line_compile_procedure
+ _compile_text_section()
+ .Lcompile_line_compile_procedure
+ _compile_procedure()
li a0, 1
- j .Lcompile_line_end
+ goto .Lcompile_line_end
-.Lcompile_line_var:
- call _compile_variable_section
- j .Lcompile_line_section
+ .Lcompile_line_var
+ _compile_variable_section()
+ goto .Lcompile_line_section
-.Lcompile_line_program:
- call _compile_program
- j .Lcompile_line_section
+ .Lcompile_line_program
+ _compile_program()
+ goto .Lcompile_line_section
-.Lcompile_line_comment:
+ .Lcompile_line_comment
lw a0, 20(sp)
call _skip_comment
- j .Lcompile_line_section
+ goto .Lcompile_line_section
-.Lcompile_line_empty:
+ .Lcompile_line_empty
_advance(1)
- j .Lcompile_line_section
+ goto .Lcompile_line_section
-.Lcompile_line_unchanged:
+ .Lcompile_line_unchanged
lw a0, 20(sp)
call _compile_assembly
- j .Lcompile_line_section
+ goto .Lcompile_line_section
-.Lcompile_line_section:
+ .Lcompile_line_section
mv a0, zero
-.Lcompile_line_end:
+ .Lcompile_line_end
end
+# Prints ".section .text" and exits.
proc _compile_text_section()
begin
# .section .text
@@ -1107,31 +1423,40 @@ proc _read_line()
begin
mv t0, s1 # Local position in the source text.
-.Lread_line_do:
+ .Lread_line_do
lbu t1, (t0) # t1 = Current character.
beqz t1, .Lread_line_end # Exit the loop on the NUL character.
li t2, '\n'
beq t1, t2, .Lread_line_end # Exit the loop on the new line.
addi t0, t0, 1
- j .Lread_line_do
+ goto .Lread_line_do
-.Lread_line_end:
+ .Lread_line_end
sub a0, t0, s1 # Return the line length.
end
proc _compile()
begin
-.Lcompile_do:
+ sw zero, 4(sp) # Whether the text section header was already emitted.
+
+ .Lcompile_do
lbu t0, (s1) # t0 = Current character.
beqz t0, .Lcompile_end # Exit the loop on the NUL character.
_skip_indentation()
call _read_line
+ lw a1, 4(sp)
call _compile_line
- j .Lcompile_do
-.Lcompile_end:
+ beqz a0, .Lcompile_do
+ # Update whether the text section header was already emitted.
+ lw t0, 4(sp)
+ or t0, t0, a0
+ sw t0, 4(sp)
+
+ goto .Lcompile_do
+ .Lcompile_end
end
# Returns the pointer to the current position in the source text in a0.
@@ -1146,6 +1471,12 @@ begin
add s1, s1, a0
end
+# Returns the first character in the remaining source text.
+proc _front()
+begin
+ lbu a0, (s1)
+end
+
# Entry point.
begin
# Read the source from the standard input.
@@ -1155,5 +1486,5 @@ begin
call _read_file
la s1, source_code # s1 = Source code position.
- call _compile
+ _compile()
end.
generated by cgit v1.2.3 (git 2.26.2) at 2026-06-27 04:19:42 +0000