From af663ae39c1c5da37303f6f1d956908e12d18716 Mon Sep 17 00:00:00 2001
From: Ted Kremenek <kremenek@apple.com>
Date: Thu, 27 Feb 2014 21:56:44 +0000
Subject: [PATCH] [CFG] record the original (now unreachable) block of 'case:'
 and 'default:' cases.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@202435 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/CFG.cpp  | 31 +++++++++++++++++++++----------
 test/Analysis/cfg.cpp |  7 ++++---
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
index 180a01289b..c28513324b 100644
--- a/lib/Analysis/CFG.cpp
+++ b/lib/Analysis/CFG.cpp
@@ -2742,8 +2742,8 @@ CFGBlock *CFGBuilder::VisitSwitchStmt(SwitchStmt *Terminator) {
   SwitchAlwaysHasSuccessor |= switchExclusivelyCovered;
   SwitchAlwaysHasSuccessor |= Terminator->isAllEnumCasesCovered() &&
                               Terminator->getSwitchCaseList();
-  addSuccessor(SwitchTerminatedBlock,
-               SwitchAlwaysHasSuccessor ? 0 : DefaultCaseBlock);
+  addSuccessor(SwitchTerminatedBlock, DefaultCaseBlock,
+               !SwitchAlwaysHasSuccessor);
 
   // Add the terminator and condition in the switch block.
   SwitchTerminatedBlock->setTerminator(Terminator);
@@ -2844,10 +2844,9 @@ CFGBlock *CFGBuilder::VisitCaseStmt(CaseStmt *CS) {
   // Add this block to the list of successors for the block with the switch
   // statement.
   assert(SwitchTerminatedBlock);
-  addSuccessor(SwitchTerminatedBlock,
+  addSuccessor(SwitchTerminatedBlock, CaseBlock,
                shouldAddCase(switchExclusivelyCovered, switchCond,
-                             CS, *Context)
-               ? CaseBlock : 0);
+                             CS, *Context));
 
   // We set Block to NULL to allow lazy creation of a new block (if necessary)
   Block = NULL;
@@ -4034,12 +4033,24 @@ static void print_block(raw_ostream &OS, const CFG* cfg,
         if (i % 10 == 8)
           OS << "\n    ";
 
-        if (*I)
-          OS << " B" << (*I)->getBlockID();
-        else
-          OS  << " NULL";
+        CFGBlock *B = *I;
+
+        bool Reachable = true;
+        if (!B) {
+          Reachable = false;
+          B = I->getPossiblyUnreachableBlock();
+        }
+
+        if (B) {
+          OS << " B" << B->getBlockID();
+          if (!Reachable)
+            OS << "(Unreachable)";
+        }
+        else {
+          OS << " NULL";
+        }
       }
-      
+
       if (ShowColors)
         OS.resetColor();
       OS << '\n';
diff --git a/test/Analysis/cfg.cpp b/test/Analysis/cfg.cpp
index c465acb356..1f3bfac2c3 100644
--- a/test/Analysis/cfg.cpp
+++ b/test/Analysis/cfg.cpp
@@ -199,7 +199,7 @@ namespace NoReturnSingleSuccessor {
 // CHECK-NEXT:    1: x
 // CHECK-NEXT:    2: [B1.1] (ImplicitCastExpr, LValueToRValue, int)
 // CHECK-NEXT:    3: return [B1.2];
-// CHECK-NEXT:    Preds (4): B3 B4 B5 B6
+// CHECK-NEXT:    Preds (5): B3 B4 B5 B6 B2(Unreachable)
 // CHECK-NEXT:    Succs (1): B0
 // CHECK:  [B2]
 // CHECK-NEXT:    1: 0
@@ -209,7 +209,7 @@ namespace NoReturnSingleSuccessor {
 // CHECK-NEXT:    5: [B2.4] (ImplicitCastExpr, IntegralCast, int)
 // CHECK-NEXT:    T: switch [B2.5]
 // CHECK-NEXT:    Preds (1): B7
-// CHECK-NEXT:    Succs (5): B3 B4 B5 B6 NULL
+// CHECK-NEXT:    Succs (5): B3 B4 B5 B6 B1(Unreachable)
 // CHECK:  [B3]
 // CHECK-NEXT:   case D:
 // CHECK-NEXT:    1: 4
@@ -275,13 +275,14 @@ int test_enum_with_extension(enum MyEnum value) {
 // CHECK-NEXT:    5: [B2.4] (ImplicitCastExpr, IntegralCast, int)
 // CHECK-NEXT:    T: switch [B2.5]
 // CHECK-NEXT:    Preds (1): B7
-// CHECK-NEXT:    Succs (4): B4 B5 B6 NULL
+// CHECK-NEXT:    Succs (4): B4 B5 B6 B3(Unreachable)
 // CHECK:  [B3]
 // CHECK-NEXT:   default:
 // CHECK-NEXT:    1: 4
 // CHECK-NEXT:    2: x
 // CHECK-NEXT:    3: [B3.2] = [B3.1]
 // CHECK-NEXT:    T: break;
+// CHECK-NEXT:    Preds (1): B2(Unreachable)
 // CHECK-NEXT:    Succs (1): B1
 // CHECK:  [B4]
 // CHECK-NEXT:   case C:
-- 
2.40.0