Resolve #ifdef, #ifndef, #else, #endif.

2 files changed, 72 insertions, 18 deletions

diff --git a/module/c/preprocessor2.scm b/module/c/preprocessor2.scm
index 2677c42e..28d11901 100644
--- a/module/c/preprocessor2.scm
+++ b/module/c/preprocessor2.scm
@@ -633,12 +633,18 @@
                                               ((if) resolve-for-if)
                                               ((ifdef)
                                                (lambda (env body)
-                                                 (if (in-environment? env (identifier-token? (car body)))
-                                                     enter-active-if enter-inactive-if)))
+                                                 ((if (in-environment? env (identifier-token? (car body)))
+                                                      enter-active-if enter-inactive-if)
+                                                  env)))
                                               ((ifndef)
                                                (lambda (env body)
-                                                 (if (in-environment? env (identifier-token? (car body)))
-                                                     enter-inactive-if enter-active-if)))
+                                                 ((if (in-environment? env (identifier-token? (car body)))
+                                                      enter-inactive-if enter-active-if)
+                                                  env)))
+                                              ;; NOTE possibly validate that body is empty for endif and else
+                                              ((endif) (lambda (env _) (leave-if env)))
+                                              ((else)  (lambda (env _) (flip-flop-if env)))
+                                              ;; ((elif)  (lambda ))
                                               ((define) resolve-define)
                                               ((undef) (lambda (env body) (remove-identifier env (identifier-token? (car body)))))
                                               ((line) handle-line-directive)
diff --git a/tests/test/cpp/preprocessor2.scm b/tests/test/cpp/preprocessor2.scm
index 5e1bb736..b4825907 100644
--- a/tests/test/cpp/preprocessor2.scm
+++ b/tests/test/cpp/preprocessor2.scm
@@ -592,17 +592,11 @@
         (lex "x"))))))
 
 
+;; TODO
 ;; resolve-h-file
 ;; resolve-q-file
-;; handle-pragma
 ;; include
 
-;; if
-;; else
-;; ifdef
-;; ifndef
-;; elif
-
 
 
 (call-with-values (lambda ()
@@ -803,13 +797,6 @@ LISTING(..\\listing.dir)
 " e))))))
     ))
 
-;; TODO
-;; if
-;; else
-;; ifdef
-;; ifndef
-;; elif
-
 (test-group "Next token matches?"
   (test-assert "Zero tokens never match" (not (next-token-matches? (const #t) '())))
 
@@ -990,3 +977,64 @@ debug(\"X = %d\\n\", x);
 showlist(The first, second, and third items.);
 report(x>y, \"x is %d but y is %d\", x, y);
 "))))
+
+
+
+(test-group "Conditionals"
+  (test-group "ifdef"
+   (test-equal "#ifdef on non-defined"
+     (lex "")
+     (run "
+#ifdef X
+x
+#endif"))
+
+   (test-equal "#ifdef on defined"
+     (lex "x")
+     (run "
+#define X
+#ifdef X
+x
+#endif")))
+
+  (test-group "ifndef"
+   (test-equal "#ifndef on non-defined"
+     (lex "x")
+     (run "
+#ifndef X
+x
+#endif"))
+
+   (test-equal "#ifndef on defined"
+     (lex "")
+     (run "
+#define X
+#ifndef X
+x
+#endif
+")))
+
+  (test-group "else"
+   (test-equal "else from active to inactive"
+     (lex "1")
+     (run "
+#ifndef X
+1
+#else
+2
+#endif"))
+
+   (test-equal "else from inactive to active"
+     (lex "2")
+     (run "
+#ifdef X
+1
+#else
+2
+#endif")))
+
+;; TODO
+;; if
+;; elif
+
+  )