Merge pull request #16693 from jketema/func-fix

C++: Correctly identify orphaned variables as static

Author: jketema

cpp/ql/lib/semmle/code/cpp/Variable.qll

@@ -410,6 +410,10 @@ class LocalVariable extends LocalScopeVariable, @localvariable {
     or
     orphaned_variables(underlyingElement(this), unresolveElement(result))
   }
+
+  override predicate isStatic() {
+    super.isStatic() or orphaned_variables(underlyingElement(this), _)
+  }
 }
 
 /**

cpp/ql/test/library-tests/ir/ir/aliased_ir.expected

@@ -13430,6 +13430,32 @@ ir.cpp:
 # 1898|     v1898_6(void)            = AliasedUse                           : m1898_3
 # 1898|     v1898_7(void)            = ExitFunction                         : 
 
+# 1899| const char[17] __PRETTY_FUNCTION__
+# 1899|   Block 0
+# 1899|     v1899_1(void)            = EnterFunction                        : 
+# 1899|     m1899_2(unknown)         = AliasedDefinition                    : 
+# 1899|     r1899_3(glval<char[17]>) = VariableAddress[__PRETTY_FUNCTION__] : 
+# 1899|     r1899_4(glval<char[17]>) = StringConstant[__PRETTY_FUNCTION__]  : 
+# 1899|     r1899_5(char[17])        = Load[?]                              : &:r1899_4, ~m?
+# 1899|     m1899_6(char[17])        = Store[__PRETTY_FUNCTION__]           : &:r1899_3, r1899_5
+# 1899|     m1899_7(unknown)         = Chi                                  : total:m1899_2, partial:m1899_6
+# 1899|     v1899_8(void)            = ReturnVoid                           : 
+# 1899|     v1899_9(void)            = AliasedUse                           : ~m1899_7
+# 1899|     v1899_10(void)           = ExitFunction                         : 
+
+# 1900| const char[10] __func__
+# 1900|   Block 0
+# 1900|     v1900_1(void)            = EnterFunction             : 
+# 1900|     m1900_2(unknown)         = AliasedDefinition         : 
+# 1900|     r1900_3(glval<char[10]>) = VariableAddress[__func__] : 
+# 1900|     r1900_4(glval<char[10]>) = StringConstant[__func__]  : 
+# 1900|     r1900_5(char[10])        = Load[?]                   : &:r1900_4, ~m?
+# 1900|     m1900_6(char[10])        = Store[__func__]           : &:r1900_3, r1900_5
+# 1900|     m1900_7(unknown)         = Chi                       : total:m1900_2, partial:m1900_6
+# 1900|     v1900_8(void)            = ReturnVoid                : 
+# 1900|     v1900_9(void)            = AliasedUse                : ~m1900_7
+# 1900|     v1900_10(void)           = ExitFunction              : 
+
 # 1911| void* missing_declaration_entries::Bar1<int>::missing_type_decl_entry(missing_declaration_entries::Bar1<int>::pointer)
 # 1911|   Block 0
 # 1911|     v1911_1(void)             = EnterFunction                : 

cpp/ql/test/library-tests/ir/ir/raw_ir.expected

@@ -12384,6 +12384,30 @@ ir.cpp:
 # 1898|     v1898_5(void)            = AliasedUse                           : ~m?
 # 1898|     v1898_6(void)            = ExitFunction                         : 
 
+# 1899| const char[17] __PRETTY_FUNCTION__
+# 1899|   Block 0
+# 1899|     v1899_1(void)            = EnterFunction                        : 
+# 1899|     mu1899_2(unknown)        = AliasedDefinition                    : 
+# 1899|     r1899_3(glval<char[17]>) = VariableAddress[__PRETTY_FUNCTION__] : 
+# 1899|     r1899_4(glval<char[17]>) = StringConstant[__PRETTY_FUNCTION__]  : 
+# 1899|     r1899_5(char[17])        = Load[?]                              : &:r1899_4, ~m?
+# 1899|     mu1899_6(char[17])       = Store[__PRETTY_FUNCTION__]           : &:r1899_3, r1899_5
+# 1899|     v1899_7(void)            = ReturnVoid                           : 
+# 1899|     v1899_8(void)            = AliasedUse                           : ~m?
+# 1899|     v1899_9(void)            = ExitFunction                         : 
+
+# 1900| const char[10] __func__
+# 1900|   Block 0
+# 1900|     v1900_1(void)            = EnterFunction             : 
+# 1900|     mu1900_2(unknown)        = AliasedDefinition         : 
+# 1900|     r1900_3(glval<char[10]>) = VariableAddress[__func__] : 
+# 1900|     r1900_4(glval<char[10]>) = StringConstant[__func__]  : 
+# 1900|     r1900_5(char[10])        = Load[?]                   : &:r1900_4, ~m?
+# 1900|     mu1900_6(char[10])       = Store[__func__]           : &:r1900_3, r1900_5
+# 1900|     v1900_7(void)            = ReturnVoid                : 
+# 1900|     v1900_8(void)            = AliasedUse                : ~m?
+# 1900|     v1900_9(void)            = ExitFunction              : 
+
 # 1911| void* missing_declaration_entries::Bar1<int>::missing_type_decl_entry(missing_declaration_entries::Bar1<int>::pointer)
 # 1911|   Block 0
 # 1911|     v1911_1(void)              = EnterFunction                : 

cpp/ql/test/library-tests/variables/variables/variable.expected

@@ -39,3 +39,4 @@
 | variables.cpp:51:9:51:12 | town | file://:0:0:0:0 | char * | Field |  |  |
 | variables.cpp:52:16:52:22 | country | file://:0:0:0:0 | char * | MemberVariable, StaticStorageDurationVariable |  | static |
 | variables.cpp:56:14:56:29 | externInFunction | file://:0:0:0:0 | int | GlobalLikeVariable, GlobalVariable, StaticStorageDurationVariable |  |  |
+| variables.cpp:60:10:60:17 | __func__ | file://:0:0:0:0 | const char[9] | GlobalLikeVariable, StaticInitializedStaticLocalVariable |  | static |

cpp/ql/test/library-tests/variables/variables/variables.cpp

@@ -55,3 +55,7 @@ struct address {
 void hasExtern() {
   extern int externInFunction;
 }
+
+const char* isStatic() {
+  return __func__;
+}