impl and tests

Author: aadanen

lib/checkuninitvar.cpp

@@ -834,7 +834,7 @@ bool CheckUninitVarImpl::checkScopeForVariable(const Token *tok, const Variable&
                         }
                     }
                 }
-                if (Token::simpleMatch(parent->astParent(), "=") && astIsLHS(parent)) {
+                if (parent->astParent() && parent->astParent()->isAssignmentOp() && astIsLHS(parent)) {
                     const Token *eq = parent->astParent();
                     if (const Token *errorToken = checkExpr(eq->astOperand2(), var, *alloc, number_of_if==0)) {
                         if (!suppressErrors)
@@ -1295,7 +1295,17 @@ const Token* CheckUninitVarImpl::isVariableUsage(const Token *vartok, const Libr
             }
             if (alloc != NO_ALLOC && astIsRhs(valueExpr))
                 return nullptr;
+        } else if (tok->astParent() && tok->astParent()->isAssignmentOp()) {
+            // all variables in a compound assignment get read, so NO_ALLOC is
+            // never acceptable
+            if (alloc != NO_ALLOC) {
+                // if its not a pointer or array, or not dereferenced it is safe
+                if (!(pointer || alloc == ARRAY) || !derefValue) {
+                    return nullptr;
+                }
+            }
         }
+
     }
 
     // Initialize reference variable

test/testuninitvar.cpp

@@ -2202,6 +2202,25 @@ class TestUninitVar : public TestFixture {
                        "    return i;\n"
                        "}\n");
         ASSERT_EQUALS("", errout_str());
+
+
+        checkUninitVar("void f() {\n"
+                       "    char *buf = (char *)malloc(1);\n"
+                       "    if (!buf)\n"
+                       "        return NULL;\n"
+                       "    buf += 1;\n"
+                       "    free(buf - 1);\n"
+                       "}\n");
+        ASSERT_EQUALS("", errout_str());
+
+        checkUninitVar("void f() {\n"
+                       "    char *buf = (char *)malloc(1);\n"
+                       "    if (!buf)\n"
+                       "        return NULL;\n"
+                       "    buf += buf[0];\n"
+                       "    free(buf);\n"
+                       "}\n");
+        ASSERT_EQUALS("[test.cpp:5:15]: (error) Memory is allocated but not initialized: buf[0] [uninitdata]\n", errout_str());
     }
 
     // class / struct..