[cfe-commits] r113451 - in /cfe/trunk: lib/Analysis/ReachableCode.cpp test/Sema/warn-unreachable.c

[Ted Kremenek]

Author: kremenek
Date: Wed Sep  8 19:06:10 2010
New Revision: 113451

URL: http://llvm.org/viewvc/llvm-project?rev=113451&view=rev
Log:
Enhance -Wunreachable-code to not consider the 'default:' branch of a switch statement live if a switch on an enum value has
explicit 'case:' statements for each enum value.

Modified:
    cfe/trunk/lib/Analysis/ReachableCode.cpp
    cfe/trunk/test/Sema/warn-unreachable.c

Modified: cfe/trunk/lib/Analysis/ReachableCode.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/ReachableCode.cpp?rev=113451&r1=113450&r2=113451&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/ReachableCode.cpp (original)
+++ cfe/trunk/lib/Analysis/ReachableCode.cpp Wed Sep  8 19:06:10 2010
@@ -131,6 +131,9 @@
   }
 
   // Solve
+  CFGBlock::FilterOptions FO;
+  FO.IgnoreDefaultsWithCoveredEnums = 1;
+
   while (!WL.empty()) {
     const CFGBlock *item = WL.back();
     WL.pop_back();
@@ -147,8 +150,8 @@
         }
 
     reachable.set(item->getBlockID());
-    for (CFGBlock::const_succ_iterator I=item->succ_begin(), E=item->succ_end();
-         I != E; ++I)
+    for (CFGBlock::filtered_succ_iterator I =
+	   item->filtered_succ_start_end(FO); I.hasMore(); ++I)
       if (const CFGBlock *B = *I) {
         unsigned blockID = B->getBlockID();
         if (!reachable[blockID]) {
@@ -190,14 +193,17 @@
   ++count;
   WL.push_back(&Start);
 
-    // Find the reachable blocks from 'Start'.
+  // Find the reachable blocks from 'Start'.
+  CFGBlock::FilterOptions FO;
+  FO.IgnoreDefaultsWithCoveredEnums = 1;
+
   while (!WL.empty()) {
     const CFGBlock *item = WL.back();
     WL.pop_back();
 
       // Look at the successors and mark then reachable.
-    for (CFGBlock::const_succ_iterator I=item->succ_begin(), E=item->succ_end();
-         I != E; ++I)
+    for (CFGBlock::filtered_succ_iterator I= item->filtered_succ_start_end(FO);
+         I.hasMore(); ++I)
       if (const CFGBlock *B = *I) {
         unsigned blockID = B->getBlockID();
         if (!Reachable[blockID]) {

Modified: cfe/trunk/test/Sema/warn-unreachable.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/warn-unreachable.c?rev=113451&r1=113450&r2=113451&view=diff
==============================================================================
--- cfe/trunk/test/Sema/warn-unreachable.c (original)
+++ cfe/trunk/test/Sema/warn-unreachable.c Wed Sep  8 19:06:10 2010
@@ -98,3 +98,19 @@
   }
   }
 }
+
+enum Cases { C1, C2, C3 };
+int test_enum_cases(enum Cases C) {
+  switch (C) {
+    case C1:
+    case C2:
+    case C3:
+      return 1;
+    default: {
+      int i = 0; // expected-warning{{will never be executed}}
+      ++i;
+      return i;
+    }
+  }  
+}
+