[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- removed all the unit tests (most were outdated)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

1 files changed, 50 insertions, 0 deletions

diff --git a/src/backend/ast/ir.scm b/src/backend/ast/ir.scm
new file mode 100644
index 0000000..102739c
--- /dev/null
+++ b/src/backend/ast/ir.scm
@@ -0,0 +1,50 @@
+(define-module (backend ast ir)
+  #:export (prog
+            srout
+            neg
+            not
+            mov
+            stack
+            reg
+            imm
+            tmp
+            ret))
+
+;;; Commentary:
+;;;
+;;; Nodes which exist to do nothing when evaluated.
+;;;
+;;; Code:
+
+(define (ir-node type . args)
+  (cons type args))
+
+(define (prog func)
+  (ir-node 'prog func))
+
+(define (srout label instrs)
+  (ir-node 'srout label instrs))
+
+(define (neg dst)
+  (ir-node 'neg dst))
+
+(define (not dst)
+  (ir-node 'not dst))
+
+(define (mov src dst)
+  (ir-node 'mov src dst))
+
+(define (stack val)
+  (ir-node 'stack val))
+
+(define (reg val)
+  (ir-node 'reg val))
+
+(define (imm val)
+  (ir-node 'imm val))
+
+(define (tmp num)
+  (ir-node 'tmp num))
+
+(define (ret)
+  (ir-node 'ret))