[PATCH] D24759: [RFC][StaticAnalyser] fix unreachable code false positives when block numbers mismatch

[Daniel Marjamäki via cfe-commits]

danielmarjamaki updated this revision to Diff 72461.
danielmarjamaki marked 2 inline comments as done.
danielmarjamaki added a comment.

Fixed review comments by Devin. It works better now!


https://reviews.llvm.org/D24759

Files:
  lib/Analysis/CFG.cpp
  test/Analysis/unreachable-code-path.c

Index: test/Analysis/unreachable-code-path.c
===================================================================
--- test/Analysis/unreachable-code-path.c
+++ test/Analysis/unreachable-code-path.c
@@ -158,3 +158,14 @@
     }
   }
 }
+
+// Ensure that ExplodedGraph and unoptimized CFG match.
+void test12(int x) {
+  switch (x) {
+  case 1:
+    break; // not unreachable
+  case 2:
+    do { } while (0);
+    break;
+  }
+}
Index: lib/Analysis/CFG.cpp
===================================================================
--- lib/Analysis/CFG.cpp
+++ lib/Analysis/CFG.cpp
@@ -2983,20 +2983,19 @@
         return nullptr;
     }
 
-    if (!KnownVal.isFalse()) {
-      // Add an intermediate block between the BodyBlock and the
-      // ExitConditionBlock to represent the "loop back" transition.  Create an
-      // empty block to represent the transition block for looping back to the
-      // head of the loop.
-      // FIXME: Can we do this more efficiently without adding another block?
-      Block = nullptr;
-      Succ = BodyBlock;
-      CFGBlock *LoopBackBlock = createBlock();
-      LoopBackBlock->setLoopTarget(D);
+    // Add an intermediate block between the BodyBlock and the
+    // ExitConditionBlock to represent the "loop back" transition.  Create an
+    // empty block to represent the transition block for looping back to the
+    // head of the loop.
+    // FIXME: Can we do this more efficiently without adding another block?
+    Block = nullptr;
+    Succ = BodyBlock;
+    CFGBlock *LoopBackBlock = createBlock();
+    LoopBackBlock->setLoopTarget(D);
 
+    if (!KnownVal.isFalse())
       // Add the loop body entry as a successor to the condition.
       addSuccessor(ExitConditionBlock, LoopBackBlock);
-    }
     else
       addSuccessor(ExitConditionBlock, nullptr);
   }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D24759.72461.patch
Type: text/x-patch
Size: 1813 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20160926/6228fbea/attachment.bin>