improve loplugin:blockblock

look for nested blocks where the inner block also contains a break
statement.

Change-Id: I1e5b6ca4c42b995c9479a68b34a1e2f1eb015f57
Reviewed-on: https://gerrit.libreoffice.org/74946
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

compilerplugins/clang/blockblock.cxx

@@ -43,6 +43,7 @@ public:
     }
 
     bool VisitCompoundStmt(CompoundStmt const * );
+    bool VisitCaseStmt(CaseStmt const * );
 };
 
 bool BlockBlock::VisitCompoundStmt(CompoundStmt const * compound)
@@ -74,6 +75,30 @@ bool BlockBlock::VisitCompoundStmt(CompoundStmt const * compound)
     return true;
 }
 
+bool BlockBlock::VisitCaseStmt(CaseStmt const * caseStmt)
+{
+    if (ignoreLocation(caseStmt))
+        return true;
+    auto compoundStmt = dyn_cast<CompoundStmt>(caseStmt->getSubStmt());
+    if (!compoundStmt)
+        return true;
+    if (compoundStmt->size() != 2)
+        return true;
+    auto it = compoundStmt->body_begin();
+    auto inner1 = *it;
+    if (!isa<CompoundStmt>(inner1))
+        return true;
+    ++it;
+    if (!isa<BreakStmt>(*it))
+        return true;
+    report(
+        DiagnosticsEngine::Warning,
+        "block directly inside block",
+         compat::getBeginLoc(compoundStmt))
+        << compoundStmt->getSourceRange();
+    return true;
+}
+
 loplugin::Plugin::Registration< BlockBlock > blockblock("blockblock", true);
 
 }

compilerplugins/clang/test/blockblock.cxx

@@ -21,6 +21,22 @@ int f(bool b1, bool b2) {
     return 1;
 }
 
+void foo(int x)
+{
+    switch (x)
+    {
+        case 1: break;
+        case 2: {} break;
+        case 3:
+        { // expected-error {{block directly inside block [loplugin:blockblock]}}
+            {
+            }
+            break;
+        }
+    }
+}
+
+
 int main() { // expected-error {{block directly inside block [loplugin:blockblock]}}
     { // expected-note {{inner block here [loplugin:blockblock]}}
         int x = 1;