Fix incorrect if/elseif/else code generation

Fix the incorrect tests that passed erroneously Prevent a missing else from generating an empty else statement in code Move the offset pointing to within else to the correct position
adituv · Dec 18, 2016 · 39f3efd · 39f3efd
1 parent f93e5b2
commit 39f3efd
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/src/Compiler/QbScript/CodeGen.hs b/src/Compiler/QbScript/CodeGen.hs
@@ -161,13 +161,14 @@ putElseIfs = mapM_ putElseIf
       modify $ updateHoles nh' lh'
 
 putElse :: [Instruction] -> StateT BranchState Packing ()
+putElse [] = pure ()
 putElse body = do
   BranchState nh lastHoles <- get
   h' <- lift $ do
     putWord8 0x01
-    fillOffsetHole nh
     putWord8 0x48
     nextHole <- putOffsetHole
+    fillOffsetHole nh
     mapM_ putInstr body
     return nextHole
 

diff --git a/test/Compiler/QbScript/CodeGen/Tests.hs b/test/Compiler/QbScript/CodeGen/Tests.hs
@@ -30,12 +30,22 @@ instrTests =
     it "generates an assignment correctly" $
       testPacking (putInstr (Assign (NonLocal . QbName $ "x") (ELit . SmallLit . LitN $ 2)))
          `shouldBe` [0x01, 0x16, 0x7C, 0xE9, 0x23, 0x73, 0x07, 0x17, 0x02, 0x00, 0x00, 0x00]
+    it "generates an if with no else branches correctly" $
+      testPacking (putInstr (IfElse (ELit LitPassthrough, [BareExpr $ ELit LitPassthrough])
+                                    [] []))
+        `shouldBe` [ 0x01, 0x47, 0x07, 0x00, 0x2C, 0x01, 0x2C, 0x01, 0x28 ]
+    it "generates an if/else correctly" $
+      testPacking (putInstr (IfElse (ELit LitPassthrough, [BareExpr $ ELit LitPassthrough])
+                                    []
+                                    [BareExpr $ ELit LitPassthrough]))
+        `shouldBe` [ 0x01, 0x47, 0x09, 0x00, 0x2C, 0x01, 0x2C
+                   , 0x01, 0x48, 0x06, 0x00, 0x01, 0x2C, 0x01, 0x28]
     it "generates an if/elseif/else correctly" $
       testPacking (putInstr (IfElse (ELit LitPassthrough, [BareExpr $ ELit LitPassthrough])
                                    [(ELit LitPassthrough, [BareExpr $ ELit LitPassthrough])]
                                     [BareExpr $ ELit LitPassthrough]))
         `shouldBe` [ 0x01, 0x47, 0x06, 0x00, 0x2C, 0x01, 0x2C
-                   , 0x01, 0x27, 0x08, 0x00, 0x0D, 0x00, 0x2C, 0x01, 0x2C
+                   , 0x01, 0x27, 0x0B, 0x00, 0x0D, 0x00, 0x2C, 0x01, 0x2C
                    , 0x01, 0x48, 0x06, 0x00, 0x01, 0x2C, 0x01, 0x28 ]
     it "generates a repeat correctly" $
       testPacking (putInstr (Repeat (ELit . SmallLit . LitN $ 4) [BareExpr $ ELit LitPassthrough]))