Added Makefile

5 files changed, 163 insertions, 19 deletions

diff --git a/.gitignore b/.gitignore
index 445d02b..d37163e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 *.o
 a.out
-*.asm
+bin/*
+asm/*
+bfc
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..b405f94
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,53 @@
+CC = gcc
+CCFLAGS = -Wall -Wextra
+NASM = nasm
+
+ifeq ($(shell uname),Linux)
+	NASMFLAGS = -f elf64
+endif
+ifeq ($(shell uname),Darwin)
+	NASMFLAGS = -f macho64
+endif
+ifeq ($(NASMFLAGS),)
+	$(error architecture: $(shell uname) not recognized)
+endif
+
+SRC = bfc.c
+NAME = bfc
+
+ASMDIR = asm
+BINDIR = bin
+
+EXAMPLESDIR = examples
+EXAMPLES = $(shell find $(EXAMPLESDIR) -name '*.bf' -type f)
+EXAMPLES_ASM = $(EXAMPLES:$(EXAMPLESDIR)/%.bf=$(ASMDIR)/%.asm)
+EXAMPLES_NAME = $(EXAMPLES:$(EXAMPLESDIR)/%.bf=$(BINDIR)/%)
+
+all: $(NAME) $(EXAMPLES_NAME)
+
+$(NAME): bfc.c
+	$(CC) $(CCFLAGS) -o $@ $<
+
+$(BINDIR)/%: $(ASMDIR)/%.asm $(BINDIR)
+	$(NASM) $(NASMFLAGS) -o $@.o $<
+	ld -o $@ $@.o
+
+$(ASMDIR)/%.asm: $(EXAMPLESDIR)/%.bf $(ASMDIR)
+	./$(NAME) < $< > $@
+
+$(BINDIR):
+	mkdir -pv $@
+
+$(ASMDIR):
+	mkdir -pv $@
+
+clean:
+	- rm -rv $(ASMDIR)
+	- rm -rv $(BINDIR)
+	- rm $(NAME)
+
+re: clean all
+
+# weird GNU make behavior where it rm's every asm files at the end
+# (https://stackoverflow.com/questions/47447369)
+.PRECIOUS: $(EXAMPLES_ASM)
diff --git a/bfc.c b/bfc.c
index 25c2859..ee4b699 100644
--- a/bfc.c
+++ b/bfc.c
@@ -1,3 +1,4 @@
+#include <getopt.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -11,6 +12,23 @@ static size_t label_stack_frame = 0;
 
 int main(int argc, char *argv[])
 {
+    int option;
+
+    /* while ((option = getopt(argc, argv, "So:b:")) != -1) */
+    /* { */
+    /*     switch (option) */
+    /*     { */
+    /*         case 'S': */
+    /*             assembly = true; */
+    /*         case 'o': */
+    /*             output_filename = optstring */
+    /*         case 'b': */
+    /*             buffer_length = atoi(optstring); */
+    /*         case 'e': */
+    /*             // byte, word, dword or qword */
+    /*             buffer_elem = x; */
+    /*     } */
+    /* } */
     FILE *input_file = NULL;
     if (argc == 2)
         input_file = fopen(argv[1], "r");
@@ -21,10 +39,10 @@ int main(int argc, char *argv[])
     FILE *output_file = stdout;
     fprintf(
         output_file,
+        "global _start\n\n"
         "section .bss\n"
         "\tbuffer: resb %zu\n\n"
         "section .text\n"
-        "global _start\n"
         "_start:\n"
         "\tmov rbx, buffer\n",
         buffer_size
@@ -37,35 +55,35 @@ int main(int argc, char *argv[])
         switch (c)
         {
         case '>':
-            fprintf(output_file, "    inc rbx              ; >\n");
+            fprintf(output_file, "    inc rbx                  ; >\n");
             break;
         case '<':
-            fprintf(output_file, "    dec rbx              ; <\n");
+            fprintf(output_file, "    dec rbx                  ; <\n");
             break;
         case '+':
-            fprintf(output_file, "    inc byte [rbx]       ; +\n");
+            fprintf(output_file, "    inc byte [rbx]           ; +\n");
             break;
         case '-':
-            fprintf(output_file, "    dec byte [rbx]       ; -\n");
+            fprintf(output_file, "    dec byte [rbx]           ; -\n");
             break;
         case '.':
-            fprintf(output_file, "    mov rdi, 1           ; .\n");
-            fprintf(output_file, "    mov rsi, rbx         ; .\n");
-            fprintf(output_file, "    mov rdx, 1           ; .\n");
-            fprintf(output_file, "    mov rax, 1           ; .\n");
-            fprintf(output_file, "    syscall              ; .\n");
+            fprintf(output_file, "    mov rdi, 1               ; .\n");
+            fprintf(output_file, "    mov rsi, rbx             ; .\n");
+            fprintf(output_file, "    mov rdx, 1               ; .\n");
+            fprintf(output_file, "    mov rax, 1               ; .\n");
+            fprintf(output_file, "    syscall                  ; .\n");
             break;
         case ',':
-            fprintf(output_file, "    mov rdi, 0           ; ,\n");
-            fprintf(output_file, "    mov rsi, rbx         ; ,\n");
-            fprintf(output_file, "    mov rdx, 1           ; ,\n");
-            fprintf(output_file, "    mov rax, 0           ; ,\n");
-            fprintf(output_file, "    syscall              ; ,\n");
+            fprintf(output_file, "    mov rdi, 0               ; ,\n");
+            fprintf(output_file, "    mov rsi, rbx             ; ,\n");
+            fprintf(output_file, "    mov rdx, 1               ; ,\n");
+            fprintf(output_file, "    mov rax, 0               ; ,\n");
+            fprintf(output_file, "    syscall                  ; ,\n");
             break;
         case '[':
             label_frame_id = label_stack[label_stack_frame];
             fprintf(output_file, "label_open_%03zu_%03zu:          ; [\n", label_stack_frame, label_frame_id);
-            fprintf(output_file, "    cmp byte [rbx], 0    ; [\n");
+            fprintf(output_file, "    cmp byte [rbx], 0        ; [\n");
             fprintf(output_file, "    je  label_close_%03zu_%03zu  ; [\n", label_stack_frame, label_frame_id);
             label_stack_frame++;
             break;
@@ -73,7 +91,7 @@ int main(int argc, char *argv[])
             label_stack_frame--;
             label_frame_id = label_stack[label_stack_frame];
             fprintf(output_file, "label_close_%03zu_%03zu:         ; ]\n", label_stack_frame, label_frame_id);
-            fprintf(output_file, "    cmp byte [rbx], 0    ; ]\n");
+            fprintf(output_file, "    cmp byte [rbx], 0        ; ]\n");
             fprintf(output_file, "    jne label_open_%03zu_%03zu   ; ]\n", label_stack_frame, label_frame_id);
             label_stack[label_stack_frame]++;
             break;
@@ -85,10 +103,10 @@ int main(int argc, char *argv[])
             // error
         }
     }
+    fprintf(output_file, "\n");
     fprintf(output_file, "    mov rdi, 0   ; exit\n");
     fprintf(output_file, "    mov rax, 60  ; exit\n");
     fprintf(output_file, "    syscall      ; exit\n");
 
-
     return 0;
 }
diff --git a/examples/hello_world.bf b/examples/hello_world.bf
new file mode 100644
index 0000000..2a5b338
--- /dev/null
+++ b/examples/hello_world.bf
@@ -0,0 +1,43 @@
+[ ; This program prints "Hello World!" and a newline to the screen, its
+  ; length is 106 active command characters. [It is not the shortest.]
+
+  ; This loop is an "initial comment loop", a simple way of adding a comment
+  ; to a BF program such that you don't have to worry about any command
+  ; characters. Any ".", ",", "+", "-", "<" and ">" characters are simply
+  ; ignored, the "[" and "]" characters just have to be balanced. This
+  ; loop and the commands it contains are ignored because the current cell
+  ; defaults to a value of 0; the 0 value causes this loop to be skipped.
+]
+++++++++                ; Set Cell #0 to 8
+[
+    >++++               ; Add 4 to Cell #1; this will always set Cell #1 to 4
+    [                   ; as the cell will be cleared by the loop
+        >++             ; Add 2 to Cell #2
+        >+++            ; Add 3 to Cell #3
+        >+++            ; Add 3 to Cell #4
+        >+              ; Add 1 to Cell #5
+        <<<<-           ; Decrement the loop counter in Cell #1
+    ]                   ; Loop until Cell #1 is zero; number of iterations is 4
+    >+                  ; Add 1 to Cell #2
+    >+                  ; Add 1 to Cell #3
+    >-                  ; Subtract 1 from Cell #4
+    >>+                 ; Add 1 to Cell #6
+    [<]                 ; Move back to the first zero cell you find; this will
+                        ; be Cell #1 which was cleared by the previous loop
+    <-                  ; Decrement the loop Counter in Cell #0
+]                       ; Loop until Cell #0 is zero; number of iterations is 8
+
+; The result of this is:
+; Cell no :   0   1   2   3   4   5   6
+; Contents:   0   0  72 104  88  32   8
+; Pointer :   ^
+
+>>.                     ; Cell #2 has value 72 which is 'H'
+>---.                   ; Subtract 3 from Cell #3 to get 101 which is 'e'
++++++++..+++.           ; Likewise for 'llo' from Cell #3
+>>.                     ; Cell #5 is 32 for the space
+<-.                     ; Subtract 1 from Cell #4 for 87 to give a 'W'
+<.                      ; Cell #3 was set to 'o' from the end of 'Hello'
++++.------.--------.    ; Cell #3 for 'rl' and 'd'
+>>+.                    ; Add 1 to Cell #5 gives us an exclamation point
+>++.                    ; And finally a newline from Cell #6
diff --git a/examples/rot13.bf b/examples/rot13.bf
new file mode 100644
index 0000000..3ce3faf
--- /dev/null
+++ b/examples/rot13.bf
@@ -0,0 +1,28 @@
+-,+[                          ; Read first character and start outer character reading loop
+    -[                        ; Skip forward if character is 0
+        >>++++[>++++++++<-]   ; Set up divisor (32) for division loop
+                              ;   (MEMORY LAYOUT: dividend copy remainder divisor quotient zero zero)
+        <+<-[                 ; Set up dividend (x minus 1) and enter division loop
+            >+>+>-[>>>]       ; Increase copy and remainder / reduce divisor / Normal case: skip forward
+            <[[>+<-]>>+>]     ; Special case: move remainder back to divisor and increase quotient
+            <<<<<-            ; Decrement dividend
+        ]                     ; End division loop
+    ]>>>[-]+                  ; End skip loop; zero former divisor and reuse space for a flag
+    >--[-[<->+++[-]]]<[       ;    Zero that flag unless quotient was 2 or 3; zero quotient; check flag
+        ++++++++++++<[        ; If flag then set up divisor (13) for second division loop
+                              ;   (MEMORY LAYOUT: zero copy dividend divisor remainder quotient zero zero)
+            >-[>+>>]          ; Reduce divisor; Normal case: increase remainder
+            >[+[<+>-]>+>>]    ; Special case: increase remainder / move it back to divisor / increase quotient
+            <<<<<-            ; Decrease dividend
+        ]                     ; End division loop
+        >>[<+>-]              ; Add remainder back to divisor to get a useful 13
+        >[                    ; Skip forward if quotient was 0
+            -[                ; Decrement quotient and skip forward if quotient was 1
+                -<<[-]>>      ; Zero quotient and divisor if quotient was 2
+            ]<<[<<->>-]>>     ; Zero divisor and subtract 13 from copy if quotient was 1
+        ]<<[<<+>>-]           ; Zero divisor and add 13 to copy if quotient was 0
+    ]                         ; End outer skip loop (jump to here if ((character minus 1)/32) was not 2 or 3)
+    <[-]                      ; Clear remainder from first division if second division was skipped
+    <.[-]                     ; Output ROT13ed character from copy and clear it
+    <-,+                      ; Read next character
+]                             ; End character reading loop