Fix FP 8891: Incorrect return scope when using uniform initialization

pfultz2 · danmar · commit be6782d386e3 · 2018-12-14T18:31:10.000+01:00
This fixes the FP in:

```cpp

std::string f(const std::string&amp; data)
{
  if (data.empty())
    return {};

  data[0];
}
```
diff --git a/lib/astutils.cpp b/lib/astutils.cpp
@@ -772,16 +772,19 @@ bool isReturnScope(const Token * const endToken)
             !Token::findsimplematch(prev->link(), "break", prev)) {
             return true;
         }
-        if (Token::simpleMatch(prev->link()->previous(), ") {") &&
-            Token::simpleMatch(prev->link()->linkAt(-1)->previous(), "return (")) {
+        if (Token::Match(prev->link()->astTop(), "return|throw"))
             return true;
-        }
         if (Token::Match(prev->link()->previous(), "[;{}] {"))
             return isReturnScope(prev);
     } else if (Token::simpleMatch(prev, ";")) {
         // noreturn function
         if (Token::simpleMatch(prev->previous(), ") ;") && Token::Match(prev->linkAt(-1)->tokAt(-2), "[;{}] %name% ("))
             return true;
+        if (Token::simpleMatch(prev->previous(), ") ;") && prev->previous()->link() &&
+            Token::Match(prev->previous()->link()->astTop(), "return|throw"))
+            return true;
+        if (Token::Match(prev->previous()->astTop(), "return|throw"))
+            return true;
         // return/goto statement
         prev = prev->previous();
         while (prev && !Token::Match(prev, ";|{|}|return|goto|throw|continue|break"))
diff --git a/test/testastutils.cpp b/test/testastutils.cpp
@@ -85,10 +85,17 @@ class TestAstUtils : public TestFixture {
 
     void isReturnScope() {
         ASSERT_EQUALS(true, isReturnScope("void f() { if (a) { return; } }", -2));
+        ASSERT_EQUALS(true, isReturnScope("int f() { if (a) { return {}; } }", -2));                        // #8891
+        ASSERT_EQUALS(true, isReturnScope("std::string f() { if (a) { return std::string{}; } }", -2));     // #8891
+        ASSERT_EQUALS(true, isReturnScope("std::string f() { if (a) { return std::string{\"\"}; } }", -2)); // #8891
         ASSERT_EQUALS(true, isReturnScope("void f() { if (a) { return (ab){0}; } }", -2)); // #7103
         ASSERT_EQUALS(false, isReturnScope("void f() { if (a) { return (ab){0}; } }", -4)); // #7103
         ASSERT_EQUALS(true, isReturnScope("void f() { if (a) { {throw new string(x);}; } }", -4)); // #7144
         ASSERT_EQUALS(true, isReturnScope("void f() { if (a) { {throw new string(x);}; } }", -2)); // #7144
+        ASSERT_EQUALS(false, isReturnScope("void f() { [=]() { return data; }; }", -1));
+        ASSERT_EQUALS(true, isReturnScope("auto f() { return [=]() { return data; }; }", -1));
+        ASSERT_EQUALS(true, isReturnScope("auto f() { return [=]() { return data; }(); }", -1));
+        ASSERT_EQUALS(false, isReturnScope("auto f() { [=]() { return data; }(); }", -1));
     }
 
     bool isVariableChanged(const char code[], const char startPattern[], const char endPattern[]) {
diff --git a/test/teststl.cpp b/test/teststl.cpp
@@ -263,6 +263,18 @@ class TestStl : public TestFixture {
                     "    c.data();\n"
                     "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        checkNormal("std::string f(std::string x) {\n"
+                    "  if (x.empty()) return {};\n"
+                    "  x[0];\n"
+                    "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        checkNormal("std::string f(std::string x) {\n"
+                    "  if (x.empty()) return std::string{};\n"
+                    "  x[0];\n"
+                    "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void outOfBoundsIndexExpression() {
