From 9366750a5a97c8aeae1df4898ea849b087865195 Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Sun, 22 Jan 2012 02:31:55 +0000
Subject: [PATCH] Fix -Wswitch to warn about out of bounds enum cases even when
 there's a default

For consistency with GCC & reasonable sanity. The FIXME suggests that the
original author was perhaps using the default check for some other purpose,
not realizing the more obvious limitation/false-negatives it creates, but this
doesn't seem to produce any regressions & fixes the included test.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148649 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaStmt.cpp | 60 ++++++++++++++++++++-----------------------
 test/Sema/switch.c    |  8 ++++++
 2 files changed, 36 insertions(+), 32 deletions(-)

diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 0be3e43b5a..b9b5b212c3 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -862,39 +862,35 @@ Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch,
         std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
 
       // See which case values aren't in enum.
-      // TODO: we might want to check whether case values are out of the
-      // enum even if we don't want to check whether all cases are handled.
-      if (!TheDefaultStmt) {
-        EnumValsTy::const_iterator EI = EnumVals.begin();
-        for (CaseValsTy::const_iterator CI = CaseVals.begin();
-             CI != CaseVals.end(); CI++) {
-          while (EI != EIend && EI->first < CI->first)
-            EI++;
-          if (EI == EIend || EI->first > CI->first)
-            Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum)
-              << ED->getDeclName();
+      EnumValsTy::const_iterator EI = EnumVals.begin();
+      for (CaseValsTy::const_iterator CI = CaseVals.begin();
+           CI != CaseVals.end(); CI++) {
+        while (EI != EIend && EI->first < CI->first)
+          EI++;
+        if (EI == EIend || EI->first > CI->first)
+          Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum)
+            << ED->getDeclName();
+      }
+      // See which of case ranges aren't in enum
+      EI = EnumVals.begin();
+      for (CaseRangesTy::const_iterator RI = CaseRanges.begin();
+           RI != CaseRanges.end() && EI != EIend; RI++) {
+        while (EI != EIend && EI->first < RI->first)
+          EI++;
+
+        if (EI == EIend || EI->first != RI->first) {
+          Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum)
+            << ED->getDeclName();
         }
-        // See which of case ranges aren't in enum
-        EI = EnumVals.begin();
-        for (CaseRangesTy::const_iterator RI = CaseRanges.begin();
-             RI != CaseRanges.end() && EI != EIend; RI++) {
-          while (EI != EIend && EI->first < RI->first)
-            EI++;
-
-          if (EI == EIend || EI->first != RI->first) {
-            Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum)
-              << ED->getDeclName();
-          }
 
-          llvm::APSInt Hi = 
-            RI->second->getRHS()->EvaluateKnownConstInt(Context);
-          AdjustAPSInt(Hi, CondWidth, CondIsSigned);
-          while (EI != EIend && EI->first < Hi)
-            EI++;
-          if (EI == EIend || EI->first != Hi)
-            Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum)
-              << ED->getDeclName();
-        }
+        llvm::APSInt Hi = 
+          RI->second->getRHS()->EvaluateKnownConstInt(Context);
+        AdjustAPSInt(Hi, CondWidth, CondIsSigned);
+        while (EI != EIend && EI->first < Hi)
+          EI++;
+        if (EI == EIend || EI->first != Hi)
+          Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum)
+            << ED->getDeclName();
       }
 
       // Check which enum vals aren't in switch
@@ -904,7 +900,7 @@ Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch,
 
       SmallVector<DeclarationName,8> UnhandledNames;
 
-      for (EnumValsTy::const_iterator EI = EnumVals.begin(); EI != EIend; EI++){
+      for (EI = EnumVals.begin(); EI != EIend; EI++){
         // Drop unneeded case values
         llvm::APSInt CIVal;
         while (CI != CaseVals.end() && CI->first < EI->first)
diff --git a/test/Sema/switch.c b/test/Sema/switch.c
index 63ffed18e3..f36ecb255f 100644
--- a/test/Sema/switch.c
+++ b/test/Sema/switch.c
@@ -297,3 +297,11 @@ int test18() {
   default: return 2; // expected-warning {{default is unreachable as all enumeration values are accounted for}}
   }
 }
+
+int test19() {
+  enum { A, B } a;
+  switch (a) {
+  case 7: return 1; // expected-warning {{case value not in enumerated type}}
+  default: return 3;
+  }
+}
-- 
2.40.0