Extend the Stmt AST to make it easier to look through label, default,

and case statements. Use this to make the logic in the CFG builder more
robust at finding the actual statements within a compound statement,
even when there are many layers of labels obscuring it.

Also extend the test cases for a large chunk of PR10063. Still more work
to do here though.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139437 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/AST/Stmt.h b/include/clang/AST/Stmt.h
index 0e696a9781296882ad132bf903c5565f4e99b64f..34b8a12f40e98e918b8eb619b35366e48faa2e31 100644 (file)
--- a/include/clang/AST/Stmt.h
+++ b/include/clang/AST/Stmt.h
@@ -296,6 +296,12 @@ public:
   /// statement, such as ExprWithCleanups or ImplicitCastExpr nodes.
   Stmt *IgnoreImplicit();
 
+  const Stmt *stripLabelLikeStatements() const;
+  Stmt *stripLabelLikeStatements() {
+    return const_cast<Stmt*>(
+      const_cast<const Stmt*>(this)->stripLabelLikeStatements());
+  }
+
   // Implement isa<T> support.
   static bool classof(const Stmt *) { return true; }
 

diff --git a/lib/AST/Stmt.cpp b/lib/AST/Stmt.cpp
index 9e4be940110d4c511f1782fb58c81bf2f39eb721..e7b87e4db6795049e2664e849ef8549f34828337 100644 (file)
--- a/lib/AST/Stmt.cpp
+++ b/lib/AST/Stmt.cpp
@@ -97,6 +97,22 @@ Stmt *Stmt::IgnoreImplicit() {
   return s;
 }
 
+/// \brief Strip off all label-like statements.
+///
+/// This will strip off label statements, case statements, and default
+/// statements recursively.
+const Stmt *Stmt::stripLabelLikeStatements() const {
+  const Stmt *S = this;
+  while (true) {
+    if (const LabelStmt *LS = dyn_cast<LabelStmt>(S))
+      S = LS->getSubStmt();
+    else if (const SwitchCase *SC = dyn_cast<SwitchCase>(S))
+      S = SC->getSubStmt();
+    else
+      return S;
+  }
+}
+
 namespace {
   struct good {};
   struct bad {};

diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
index 393feffdadad9b9684badcfd98e75e748ff93926..d385420a56770e3211df6461996995646bea2c7a 100644 (file)
--- a/lib/Analysis/CFG.cpp
+++ b/lib/Analysis/CFG.cpp
@@ -723,9 +723,7 @@ void CFGBuilder::addLocalScopeForStmt(Stmt *S) {
   if (CompoundStmt *CS = dyn_cast<CompoundStmt>(S)) {
     for (CompoundStmt::body_iterator BI = CS->body_begin(), BE = CS->body_end()
         ; BI != BE; ++BI) {
-      Stmt *SI = *BI;
-      if (LabelStmt *LS = dyn_cast<LabelStmt>(SI))
-        SI = LS->getSubStmt();
+      Stmt *SI = (*BI)->stripLabelLikeStatements();
       if (DeclStmt *DS = dyn_cast<DeclStmt>(SI))
         Scope = addLocalScopeForDeclStmt(DS, Scope);
     }
@@ -734,9 +732,7 @@ void CFGBuilder::addLocalScopeForStmt(Stmt *S) {
 
   // For any other statement scope will be implicit and as such will be
   // interesting only for DeclStmt.
-  if (LabelStmt *LS = dyn_cast<LabelStmt>(S))
-    S = LS->getSubStmt();
-  if (DeclStmt *DS = dyn_cast<DeclStmt>(S))
+  if (DeclStmt *DS = dyn_cast<DeclStmt>(S->stripLabelLikeStatements()))
     addLocalScopeForDeclStmt(DS);
 }
 

diff --git a/test/SemaCXX/return-noreturn.cpp b/test/SemaCXX/return-noreturn.cpp
index 53ed0d724527231a80e5339d1d2749517987abbd..1a10c2aa1687cbb81649c6b10ff804b5303a8a91 100644 (file)
--- a/test/SemaCXX/return-noreturn.cpp
+++ b/test/SemaCXX/return-noreturn.cpp
@@ -8,23 +8,37 @@ struct pr6884_abort_struct {
   ~pr6884_abort_struct() __attribute__((noreturn)) { pr6884_abort(); }
 };
 
-int pr6884_f(int x) {
-  switch (x) { default: pr6884_abort(); }
-}
-
-int pr6884_g(int x) {
-  switch (x) { default: pr6884_abort_struct(); }
-}
-
-int pr6884_g_positive(int x) {
-  switch (x) { default: ; }
-} // expected-warning {{control reaches end of non-void function}}
+// Ensure that destructors from objects are properly modeled in the CFG despite
+// the presence of switches, case statements, labels, and blocks. These tests
+// try to cover bugs reported in both PR6884 and PR10063.
+namespace abort_struct_complex_cfgs {
+  int basic(int x) {
+    switch (x) { default: pr6884_abort(); }
+  }
+  int f1(int x) {
+    switch (x) default: pr6884_abort_struct();
+  }
+  int f2(int x) {
+    switch (x) { default: pr6884_abort_struct(); }
+  }
+  int f2_positive(int x) {
+    switch (x) { default: ; }
+  } // expected-warning {{control reaches end of non-void function}}
+  int f3(int x) {
+    switch (x) { default: { pr6884_abort_struct(); } }
+  }
+  int f4(int x) {
+    switch (x) default: L1: L2: case 4: pr6884_abort_struct();
+  }
+  int f5(int x) {
+    switch (x) default: L1: { L2: case 4: pr6884_abort_struct(); }
+  }
+  int f6(int x) {
+    switch (x) default: L1: L2: case 4: { pr6884_abort_struct(); }
+  }
 
-int pr6884_h(int x) {
-  switch (x) {
-    default: {
-      pr6884_abort_struct a;
-    }
+  int h(int x) {
+    switch (x) { default: { pr6884_abort_struct a; } }
   }
 }