Simplify empty anonymous namespaces. (#2673)

lib/tokenize.cpp

@@ -5375,10 +5375,11 @@ void Tokenizer::simplifyEmptyNamespaces()
             tok = tok->link();
             continue;
         }
-        if (!Token::Match(tok, "namespace %name% {"))
+        if (!Token::Match(tok, "namespace %name%| {"))
             continue;
-        if (tok->strAt(3) == "}") {
+        bool isAnonymousNS = tok->strAt(1) == "{";
-            tok->deleteNext(3);             // remove '%name% { }'
+        if (tok->strAt(3 - isAnonymousNS) == "}") {
+            tok->deleteNext(3 - isAnonymousNS); // remove '%name%| { }'
             if (!tok->previous()) {
                 // remove 'namespace' or replace it with ';' if isolated
                 tok->deleteThis();
@@ -5386,9 +5387,14 @@ void Tokenizer::simplifyEmptyNamespaces()
             } else {                    // '%any% namespace %any%'
                 tok = tok->previous();  // goto previous token
                 tok->deleteNext();      // remove next token: 'namespace'
+                if (tok->str() == "{") {
+                    // Go back in case we were within a namespace that's empty now
+                    tok = tok->tokAt(-2) ? tok->tokAt(-2) : tok->previous();
+                    goback = true;
+                }
             }
         } else {
-            tok = tok->tokAt(2);
+            tok = tok->tokAt(2 - isAnonymousNS);
         }
     }
 }

test/testsimplifyusing.cpp

@@ -512,9 +512,7 @@ private:
                             "  _LONG A;\n"
                             "}";
 
-        const char exp[] = "namespace NS1 { "
+        const char exp[] = "void f1 ( ) { "
-                           "} "
-                           "void f1 ( ) { "
                            "using namespace NS1 ; "
                            "signed long long A ; "
                            "} "

test/testtokenize.cpp

@@ -443,6 +443,8 @@ private:
 
         TEST_CASE(simplifyCaseRange);
 
+        TEST_CASE(simplifyEmptyNamespaces);
+
         TEST_CASE(compileLimits); // #5592 crash: gcc: testsuit: gcc.c-torture/compile/limits-declparen.c
 
         TEST_CASE(prepareTernaryOpForAST);
@@ -6621,7 +6623,7 @@ private:
         // remove some unhandled macros in the global scope.
         ASSERT_EQUALS("void f ( ) { }", tokenizeAndStringify("void f() NOTHROW { }"));
         ASSERT_EQUALS("struct Foo { } ;", tokenizeAndStringify("struct __declspec(dllexport) Foo {};"));
-        ASSERT_EQUALS("namespace { }", tokenizeAndStringify("ABA() namespace { }"));
+        ASSERT_EQUALS("namespace { int a ; }", tokenizeAndStringify("ABA() namespace { int a ; }"));
 
         // #3750
         ASSERT_THROW(tokenizeAndStringify("; AB(foo*) foo::foo() { }"), InternalError);
@@ -7365,6 +7367,14 @@ private:
         ASSERT_EQUALS("void f ( ) { switch ( x ) { case '[' : case '\\\\' : case ']' : ; } }", tokenizeAndStringify("void f() { switch(x) { case '[' ... ']': } }"));
     }
 
+    void simplifyEmptyNamespaces() {
+        ASSERT_EQUALS("", tokenizeAndStringify("namespace { }"));
+        ASSERT_EQUALS("", tokenizeAndStringify("namespace foo { }"));
+        ASSERT_EQUALS("", tokenizeAndStringify("namespace foo { namespace { } }"));
+        ASSERT_EQUALS("", tokenizeAndStringify("namespace { namespace { } }")); // Ticket #9512
+        ASSERT_EQUALS("", tokenizeAndStringify("namespace foo { namespace bar { } }"));
+    }
+
     void prepareTernaryOpForAST() {
         ASSERT_EQUALS("a ? b : c ;", tokenizeAndStringify("a ? b : c;"));