[Ongoing] Rewrite frontend to use Flex/Bison

This is a merge of another experiment, so the changes are large:

- separated "modules" directory into frontend/backend
  - adjusted module names and moved files for this to happen
- removed modules lexer & parser
- removed all the unit tests (most were outdated)
- added Bison, flex, and C development tools to manifest.scm
- added lexer.l, a source file used by the flex utility with a functioning lexing implementation
- added parser.y, a source file used by the bison utility with a functioning parser implementation
- added node.c and node.h, which parser.y uses to construct an AST of a C source file (up to binary ops)
- added driver.c, a Guile-C interface that provides a module to scheme programs
- added a Makefile to make all of this
- added stuff to .gitignore

3 files changed, 0 insertions, 138 deletions

diff --git a/src/unit-tests/lexer/lexer.test.scm b/src/unit-tests/lexer/lexer.test.scm
deleted file mode 100644
index ce3520d..0000000
--- a/src/unit-tests/lexer/lexer.test.scm
+++ /dev/null
@@ -1,89 +0,0 @@
-;; -*- compile-command: "guile -L ./src/modules ./src/unit-tests/lexer/lexer.test.scm"; -*-
-(use-modules (srfi srfi-64)
-             (lexer lexer))
-
-(define (read-this str)
-  (set-current-input-port
-   (open-input-string str))
-  str)
-
-
-(test-begin "lexer-harness")
-
-
-(test-equal (read-this "")
-  '()
-  (read-tokens))
-
-(test-equal (read-this "(")
-  '(left-paren)
-  (read-tokens))
-
-(test-equal (read-this "((")
-  '(left-paren left-paren)
-  (read-tokens))
-
-(test-equal (read-this "( )")
-  '(left-paren right-paren)
-  (read-tokens))
-
-(test-equal (read-this "( {;} {((};})")
-  '(left-paren open-brace semi-colon close-brace open-brace left-paren left-paren close-brace semi-colon close-brace right-paren)
-  (read-tokens))
-
-(test-equal (read-this "1")
-  '(1)
-  (read-tokens))
-
-(test-equal (read-this "~+-")
-  '(complement add sub)
-  (read-tokens))
-
-(test-equal (read-this "---")
-  '(decrement sub)
-  (read-tokens))
-
-(test-equal (read-this "+--")
-  '(add decrement)
-  (read-tokens))
-
-(test-equal (read-this "0")
-  '(0)
-  (read-tokens))
-
-(test-equal (read-this "0011001")
-  '(11001)
-  (read-tokens))
-
-(test-equal (read-this "12 {34")
-  '(12 open-brace 34)
-  (read-tokens))
-
-(test-equal (read-this "34;")
-  '(34 semi-colon)
-  (read-tokens))
-
-(test-error (read-this "3.4")
-            (read-tokens))
-
-(test-equal (read-this "a")
-  '("a")
-  (read-tokens))
-
-(test-equal (read-this "a_2")
-  '("a_2")
-  (read-tokens))
-
-(test-error (read-this "1foo")
-            (read-tokens))
-
-(test-equal (read-this "void")
-  '(void)
-  (read-tokens))
-
-(test-equal (read-this "int main(void) {return 2;}")
-  '(int "main" left-paren void right-paren open-brace return 2 semi-colon close-brace)
-  (read-tokens))
-
-
-(test-end "lexer-harness")
diff --git a/src/unit-tests/parser/parser.test.scm b/src/unit-tests/parser/parser.test.scm
deleted file mode 100644
index 32e1e6c..0000000
--- a/src/unit-tests/parser/parser.test.scm
+++ /dev/null
@@ -1,30 +0,0 @@
-;; -*- compile-command: "guile -L ./src/modules ./src/unit-tests/parser/parser.test.scm"; -*-
-(use-modules (srfi srfi-64)
-             (parser parser))
-
-
-(test-begin "parser-harness")
-
-
-(test-equal "trivial function main 2"
-  '(program (function (identifier "main") (return (constant 2))))
-  (p-program '(int "main" left-paren void right-paren open-brace return 2 semi-colon close-brace)))
-
-(test-equal "trivial function foo 4"
-  '(program (function (identifier "foo") (return (constant 4))))
-  (p-program '(int "foo" left-paren void right-paren open-brace return 4 semi-colon close-brace)))
-
-(test-error "trivial function bad double return"
-            (p-program '(int "foo" left-paren void right-paren open-brace return return 4 semi-colon close-brace)))
-
-(test-error "trivial function bad parens"
-            (p-program '(int "foo" right-paren void left-paren open-brace return 4 semi-colon close-brace)))
-
-(test-error "trivial function bad int parameter"
-            (p-program '(int "foo" left-paren int right-paren open-brace return 4 semi-colon close-brace)))
-
-(test-error "trivial function incomplete function"
-            (p-program '(int "foo" left-paren void right-paren open-brace return)))
-
-
-(test-end "parser-harness")
diff --git a/src/unit-tests/utils/t-factory.test.scm b/src/unit-tests/utils/t-factory.test.scm
deleted file mode 100644
index d780c17..0000000
--- a/src/unit-tests/utils/t-factory.test.scm
+++ /dev/null
@@ -1,19 +0,0 @@
-;; -*- compile-command: "guile -L ./src/modules ./src/unit-tests/utils/t-factory.test.scm"; -*-
-(use-modules (srfi srfi-64)
-             (ast assembly-tree)
-             (utils t-factory))
-
-
-(test-begin "t-factory-harness")
-
-
-(test-equal "make first temporary"
-  't.101
-  (temporary-name (make-t)))
-
-(test-equal "make second temporary"
-  't.102
-  (temporary-name (make-t)))
-
-
-(test-end "t-factory-harness")