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authorpommicket <pommicket@gmail.com>2021-11-17 22:37:31 -0500
committerpommicket <pommicket@gmail.com>2021-11-17 22:37:31 -0500
commit3922fc11cde176e41c98a73f88e5552736b13e2f (patch)
tree09fdbd834af1614456c3fdfc06cf8a038cc741fe
parentb48712f9c9d7a380fe6a494db7ec9580f9314558 (diff)
simple preprocessor
-rw-r--r--04a/.gitignore1
-rw-r--r--04a/in03252
-rw-r--r--04a/in04a10
3 files changed, 258 insertions, 5 deletions
diff --git a/04a/.gitignore b/04a/.gitignore
new file mode 100644
index 0000000..fe70990
--- /dev/null
+++ b/04a/.gitignore
@@ -0,0 +1 @@
+out*
diff --git a/04a/in03 b/04a/in03
index acd18ab..e4771f3 100644
--- a/04a/in03
+++ b/04a/in03
@@ -20,8 +20,182 @@ A=d3
syscall x2
J=A
?J<0:output_file_error
-J=d0
-syscall x3c
+; initialize :definitions_end
+J=:definitions_end
+D=:definitions
+8J=D
+
+:read_line
+; use rbp to store line pointer
+R=:line
+:read_line_loop
+ ; read 1 byte into rbp
+ J=d3
+ I=R
+ D=d1
+ syscall x0
+ D=A
+ ?D=0:eof
+
+ ; check if the character was a newline:
+ C=1R
+ D=xa
+ ?C=D:read_line_loop_end
+ R+=d1
+ !:read_line_loop
+:read_line_loop_end
+
+; check if line = "#define " up to a terminator of ' '.
+C=x20
+I=:#define
+J=:line
+call :string=
+D=A
+?D!0:handle_#define
+
+; handle a normal line
+; R will store a pointer to the current character
+R=:line
+:process_line_loop
+ C=1R
+ B=C
+ call :isident
+ ?A!0:process_ident
+ ; if *R is not an identifier character, just output it to the file.
+ J=d4
+ B=C
+ call :fputc
+ ; check if we reached the end of the line
+ C=1R
+ D=xa
+ ?C=A:read_line
+ ; increment R, keep looping
+ R+=d1
+ !:process_line_loop
+ :process_ident
+ ; if *R is an ident char. look up this identifier in :definitions.
+ ; use C to keep pointer to definition
+ C=:definitions
+ :lookup_loop
+ D=1C
+ ; check if we reached end of definition table
+ ?D=0:lookup_loop_end
+ ; check if this entry matches our identifier
+ I=R
+ J=C
+ call :ident=
+ ?A!0:perform_substitution
+ ; if not, skip over this entry
+ :skip_definition_loop
+ D=1C
+ I=xa
+ C+=d1
+ ?I!D:skip_definition_loop
+ !:lookup_loop
+ :lookup_loop_end
+ ; this identifier doesn't match anything in the definitions table; just write it.
+ ; first, figure out how long it is
+ J=R
+ :length_loop
+ C=1J
+ B=C
+ call :isident
+ ?A=0:length_loop_end
+ J+=d1
+ !:length_loop
+ :length_loop_end
+ ; now write it.
+ I=R
+ R=J
+ J-=I
+ D=J
+ J=d4
+ syscall x1
+ ; keep looping
+ !:process_line_loop
+
+:perform_substitution
+ ; right now, I is a pointer to the end of the identifier in :line,
+ ; and J is a pointer to the end of the identifier in :definitions.
+
+ ; advance :line pointer for next loop iteration
+ R=I
+
+ J+=d1
+ ; J now points to the definition. let's write it
+ I=J
+ :definition_end_loop
+ C=1I
+ D=xa
+ ?C=D:definition_end_loop_end
+ I+=d1
+ !:definition_end_loop
+ :definition_end_loop_end
+ D=I
+ D-=J
+ I=J
+ J=d4
+ syscall x1
+ ; process the rest of this line
+ !:process_line_loop
+
+:eof
+ J=d0
+ syscall x3c
+
+; can the character in rbx appear in an identifier?
+:isident
+ A='0
+ ?B<A:return_0
+ ; note: 58 = '9' + 1
+ A=d58
+ ?B<A:return_1
+ A='A
+ ?B<A:return_0
+ ; note: 91 = 'z' + 1
+ A=d91
+ ?B<A:return_1
+ A='z
+ ?B>A:return_0
+ ; 96 = 'a' - 1
+ A=d96
+ ?B>A:return_1
+ A='_
+ ?B=A:return_1
+ !:return_0
+
+
+:handle_#define
+ J=:definitions_end
+ J=8J
+ ; start copy from after "#define"
+ I=:line
+ I+=d8
+
+ :#define_copy_loop
+ D=1I
+ 1J=D
+ I+=d1
+ J+=d1
+ A=xa
+ ?D=A:#define_copy_loop_end
+ !:#define_copy_loop
+ :#define_copy_loop_end
+
+ ; update end of definitions
+ D=:definitions_end
+ 8D=J
+ ; emit newline so we don't screw up line numbers
+ J=d4
+ I=:newline
+ D=d1
+ syscall x1
+
+ !:read_line
+
+:newline
+ xa
+
:usage_error
B=:usage_error_message
@@ -72,3 +246,77 @@ syscall x3c
I-=D
A=I
return
+
+:#define
+ str #define
+ x20
+ x0
+
+; check if strings in rdi and rsi are equal, up to terminator in rcx
+:string=
+ D=1I
+ A=1J
+ ?D!A:return_0
+ ?D=C:return_1
+ I+=d1
+ J+=d1
+ !:string=
+
+; check if strings in rdi and rsi are equal, up to the first non-identifier character
+:ident=
+ D=1I
+ B=D
+ call :isident
+ ; I ended
+ ?A=0:ident=_I_end
+
+ D=1J
+ B=D
+ call :isident
+ ; J ended, but I didn't
+ ?A=0:return_0
+
+ ; we haven't reached the end of either
+ D=1I
+ A=1J
+ ?D!A:return_0
+ I+=d1
+ J+=d1
+ !:ident=
+:ident=_I_end
+ D=1J
+ B=D
+ call :isident
+ ; check if J also ended
+ ?A=0:return_1
+ ; J didn't end
+ !:return_0
+
+:return_0
+ A=d0
+ return
+:return_1
+ A=d1
+ return
+
+; write the character in rbx to the file in rdi.
+:fputc
+ C=B
+ I=S
+ I-=d1
+ 1I=C
+ D=d1
+ syscall x1
+ return
+
+
+align
+:definitions_end
+ reserve d8
+:line
+ reserve d1000
+:definitions
+ reserve d200000
+
+; we shouldn't end the file with a reserve; we don't handle that properly
+x00
diff --git a/04a/in04a b/04a/in04a
index c08c184..9798c24 100644
--- a/04a/in04a
+++ b/04a/in04a
@@ -1,3 +1,7 @@
-#define A 777
-#define B 226
-A+B
+A+B=hello A adfhsakjfhjksah+B
+#define COLON d1
+#define SEMICOLON d2
+#define COMMA d3
+
+A=COLON
+1B=A