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Fixed #1812 (false negative: functionVariableUsage doesn't support static variables)

This commit is contained in:
Robert Reif 2010-06-24 17:00:32 +02:00 committed by Daniel Marjamäki
parent 6fd4ba6e4f
commit 2a1edff77f
2 changed files with 229 additions and 163 deletions
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347
lib/checkother.cpp
View File

@ -891,6 +891,29 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
return next; return next;
} }
static bool nextIsStandardType(const Token *tok)
{
tok = tok->next();
if (tok->str() == "static")
tok = tok->next();
return tok->isStandardType();
}
static bool nextIsStandardTypeOrVoid(const Token *tok)
{
tok = tok->next();
if (tok->str() == "static")
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
return tok->isStandardType() || tok->str() == "void";
}
void CheckOther::functionVariableUsage() void CheckOther::functionVariableUsage()
{ {
if (!_settings->_checkCodingStyle) if (!_settings->_checkCodingStyle)
@ -940,72 +963,133 @@ void CheckOther::functionVariableUsage()
} }
// standard type declaration with possible initialization // standard type declaration with possible initialization
// int i; int j = 0; // int i; int j = 0; static int k;
if (Token::Match(tok, "[;{}] %type% %var% ;|=") && if (Token::Match(tok, "[;{}] static| %type% %var% ;|=") &&
tok->next()->isStandardType()) nextIsStandardType(tok))
{ {
variables.addVar(tok->tokAt(2), Variables::standard, tok = tok->next();
tok->tokAt(3)->str() == "=");
tok = tok->tokAt(2); if (tok->str() == "static")
tok = tok->next();
variables.addVar(tok->next(), Variables::standard,
tok->tokAt(2)->str() == "=" ||
tok->previous()->str() == "static");
tok = tok->next();
} }
// standard type declaration and initialization using constructor // standard type declaration and initialization using constructor
// int i(0); // int i(0); static int j(0);
else if (Token::Match(tok, "[;{}] %type% %var% ( %any% ) ;") && else if (Token::Match(tok, "[;{}] static| %type% %var% ( %any% ) ;") &&
tok->next()->isStandardType()) nextIsStandardType(tok))
{ {
variables.addVar(tok->tokAt(2), Variables::standard, true); tok = tok->next();
if (tok->str() == "static")
tok = tok->next();
variables.addVar(tok->next(), Variables::standard, true);
// check if a local variable is used to initialize this variable // check if a local variable is used to initialize this variable
if (tok->tokAt(4)->varId() > 0) if (tok->tokAt(3)->varId() > 0)
variables.readAll(tok->tokAt(4)->varId()); variables.readAll(tok->tokAt(3)->varId());
tok = tok->tokAt(5); tok = tok->tokAt(4);
} }
// standard type declaration of array of with possible initialization // standard type declaration of array of with possible initialization
// int i[10]; int j[2] = { 0, 1 }; // int i[10]; int j[2] = { 0, 1 }; static int k[2] = { 2, 3 };
else if (Token::Match(tok, "[;{}] %type% %var% [ %any% ] ;|=") && else if (Token::Match(tok, "[;{}] static| %type% %var% [ %any% ] ;|=") &&
tok->next()->isStandardType()) nextIsStandardType(tok))
{ {
variables.addVar(tok->tokAt(2), Variables::array, tok = tok->next();
tok->tokAt(6)->str() == "=");
if (tok->str() == "static")
tok = tok->next();
variables.addVar(tok->tokAt(1), Variables::array,
tok->tokAt(5)->str() == "=" || tok->str() == "static");
// check for reading array size from local variable // check for reading array size from local variable
if (tok->tokAt(4)->varId() != 0) if (tok->tokAt(3)->varId() != 0)
variables.read(tok->tokAt(4)->varId()); variables.read(tok->tokAt(3)->varId());
// look at initializers // look at initializers
if (Token::Match(tok->tokAt(6), "= {")) if (Token::Match(tok->tokAt(5), "= {"))
{ {
tok = tok->tokAt(8); tok = tok->tokAt(7);
while (tok && tok->str() != "}") while (tok->str() != "}")
{ {
if (Token::Match(tok, "%var%")) if (Token::Match(tok, "%var%"))
variables.read(tok->varId()); variables.read(tok->varId());
tok = tok->next(); tok = tok->next();
} }
tok = tok->next();
} }
else else
tok = tok->tokAt(5); tok = tok->tokAt(4);
} }
// pointer or reference declaration with possible initialization // pointer or reference declaration with possible initialization
// int * i; int * j = 0; // int * i; int * j = 0; static int * k = 0;
else if (Token::Match(tok, "[;{}] %type% *|& %var% ;|=")) else if (Token::Match(tok, "[;{}] static| const| %type% *|& %var% ;|="))
{ {
if (tok->next()->str() != "return") bool isStatic = false;
tok = tok->next();
if (tok->str() == "static")
{
tok = tok->next();
isStatic = true;
}
if (tok->str() == "const")
tok = tok->next();
if (tok->str() != "return")
{ {
Variables::VariableType type; Variables::VariableType type;
if (tok->tokAt(2)->str() == "*") if (tok->next()->str() == "*")
type = Variables::pointer; type = Variables::pointer;
else else
type = Variables::reference; type = Variables::reference;
bool written = tok->tokAt(3)->str() == "=";
variables.addVar(tok->tokAt(2), type, written || isStatic);
int offset = 0;
// check for assignment
if (written)
offset = doAssignment(variables, tok->tokAt(2), false);
tok = tok->tokAt(2 + offset);
}
}
// pointer to pointer declaration with possible initialization
// int ** i; int ** j = 0; static int ** k = 0;
else if (Token::Match(tok, "[;{}] static| const| %type% * * %var% ;|="))
{
bool isStatic = false;
tok = tok->next();
if (tok->str() == "static")
{
tok = tok->next();
isStatic = true;
}
if (tok->str() == "const")
tok = tok->next();
if (tok->str() != "return")
{
bool written = tok->tokAt(4)->str() == "="; bool written = tok->tokAt(4)->str() == "=";
variables.addVar(tok->tokAt(3), type, written); variables.addVar(tok->tokAt(3), Variables::pointerPointer, written || isStatic);
int offset = 0; int offset = 0;
@ -1017,57 +1101,21 @@ void CheckOther::functionVariableUsage()
} }
} }
// const pointer or reference declaration with possible initialization
// const int * i; const int * j = 0;
else if (Token::Match(tok, "[;{}] const %type% *|& %var% ;|="))
{
Variables::VariableType type;
if (tok->tokAt(3)->str() == "*")
type = Variables::pointer;
else
type = Variables::reference;
bool written = tok->tokAt(5)->str() == "=";
variables.addVar(tok->tokAt(4), type, written);
int offset = 0;
// check for assignment
if (written)
offset = doAssignment(variables, tok->tokAt(4), false);
tok = tok->tokAt(4 + offset);
}
// pointer to pointer declaration with possible initialization
// int ** i; int ** j = 0;
else if (Token::Match(tok, "[;{}] %type% * * %var% ;|="))
{
if (tok->next()->str() != "return")
{
bool written = tok->tokAt(5)->str() == "=";
variables.addVar(tok->tokAt(4), Variables::pointerPointer, written);
int offset = 0;
// check for assignment
if (written)
offset = doAssignment(variables, tok->tokAt(4), false);
tok = tok->tokAt(4 + offset);
}
}
// pointer or reference of struct or union declaration with possible initialization // pointer or reference of struct or union declaration with possible initialization
// struct s * i; struct s * j = 0; // struct s * i; struct s * j = 0; static struct s * k = 0;
else if (Token::Match(tok, "[;{}] const| struct|union %type% *|& %var% ;|=")) else if (Token::Match(tok, "[;{}] static| const| struct|union %type% *|& %var% ;|="))
{ {
Variables::VariableType type; Variables::VariableType type;
bool isStatic = false;
tok = tok->next(); tok = tok->next();
if (tok->str() == "static")
{
tok = tok->next();
isStatic = true;
}
if (tok->str() == "const") if (tok->str() == "const")
tok = tok->next(); tok = tok->next();
@ -1078,7 +1126,7 @@ void CheckOther::functionVariableUsage()
const bool written = tok->strAt(4) == "="; const bool written = tok->strAt(4) == "=";
variables.addVar(tok->tokAt(3), type, written); variables.addVar(tok->tokAt(3), type, written || isStatic);
int offset = 0; int offset = 0;
@ -1090,13 +1138,21 @@ void CheckOther::functionVariableUsage()
} }
// pointer or reference declaration with initialization using constructor // pointer or reference declaration with initialization using constructor
// int * i(j); int * k(i); // int * i(j); int * k(i); static int * l(i);
else if (Token::Match(tok, "[;{}] %type% &|* %var% ( %any% ) ;") && else if (Token::Match(tok, "[;{}] static| const| %type% &|* %var% ( %any% ) ;") &&
(tok->next()->isStandardType() || tok->next()->str() == "void")) nextIsStandardTypeOrVoid(tok))
{ {
Variables::VariableType type; Variables::VariableType type;
if (tok->tokAt(2)->str() == "*") tok = tok->next();
if (tok->str() == "static")
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
if (tok->next()->str() == "*")
type = Variables::pointer; type = Variables::pointer;
else else
type = Variables::reference; type = Variables::reference;
@ -1104,10 +1160,10 @@ void CheckOther::functionVariableUsage()
unsigned int varid = 0; unsigned int varid = 0;
// check for aliased variable // check for aliased variable
if (Token::Match(tok->tokAt(5), "%var%")) if (Token::Match(tok->tokAt(4), "%var%"))
varid = tok->tokAt(5)->varId(); varid = tok->tokAt(4)->varId();
variables.addVar(tok->tokAt(3), type, true); variables.addVar(tok->tokAt(2), type, true);
// check if a local variable is used to initialize this variable // check if a local variable is used to initialize this variable
if (varid > 0) if (varid > 0)
@ -1116,7 +1172,7 @@ void CheckOther::functionVariableUsage()
if (type == Variables::pointer) if (type == Variables::pointer)
{ {
variables.use(tok->tokAt(5)->varId()); variables.use(tok->tokAt(4)->varId());
if (var && (var->_type == Variables::array || if (var && (var->_type == Variables::array ||
var->_type == Variables::pointer)) var->_type == Variables::pointer))
@ -1124,106 +1180,71 @@ void CheckOther::functionVariableUsage()
} }
else else
{ {
variables.readAll(tok->tokAt(5)->varId()); variables.readAll(tok->tokAt(4)->varId());
if (var) if (var)
var->_aliases.insert(tok->varId()); var->_aliases.insert(tok->varId());
} }
} }
tok = tok->tokAt(6); tok = tok->tokAt(5);
}
// const pointer or reference declaration with initialization using constructor
// const int * i(j); const int * k(i);
else if (Token::Match(tok, "[;{}] const %type% &|* %var% ( %any% ) ;") &&
(tok->tokAt(2)->isStandardType() || tok->tokAt(2)->str() == "void"))
{
Variables::VariableType type;
if (tok->tokAt(3)->str() == "*")
type = Variables::pointer;
else
type = Variables::reference;
unsigned int varid = 0;
// check for aliased variable
if (Token::Match(tok->tokAt(6), "%var%"))
varid = tok->tokAt(6)->varId();
variables.addVar(tok->tokAt(4), type, true);
// check if a local variable is used to initialize this variable
if (varid > 0)
{
Variables::VariableUsage *var = variables.find(varid);
if (type == Variables::pointer)
{
variables.use(tok->tokAt(6)->varId());
if (var && (var->_type == Variables::array ||
var->_type == Variables::pointer))
var->_aliases.insert(tok->varId());
}
else
{
variables.readAll(tok->tokAt(6)->varId());
if (var)
var->_aliases.insert(tok->varId());
}
}
tok = tok->tokAt(7);
} }
// array of pointer or reference declaration with possible initialization // array of pointer or reference declaration with possible initialization
// int * p[10]; int * q[10] = { 0 }; // int * p[10]; int * q[10] = { 0 }; static int * * r[10] = { 0 };
else if (Token::Match(tok, "[;{}] %type% *|& %var% [ %any% ] ;|=")) else if (Token::Match(tok, "[;{}] static| const| %type% *|& %var% [ %any% ] ;|="))
{ {
if (tok->next()->str() != "return") bool isStatic = false;
tok = tok->next();
if (tok->str() == "static")
{ {
variables.addVar(tok->tokAt(3), tok = tok->next();
tok->tokAt(2)->str() == "*" ? Variables::pointerArray : Variables::referenceArray, isStatic = true;
tok->tokAt(7)->str() == "="); }
if (tok->str() == "const")
tok = tok->next();
if (tok->str() != "return")
{
variables.addVar(tok->tokAt(2),
tok->next()->str() == "*" ? Variables::pointerArray : Variables::referenceArray,
tok->tokAt(6)->str() == "=" || isStatic);
// check for reading array size from local variable // check for reading array size from local variable
if (tok->tokAt(5)->varId() != 0) if (tok->tokAt(4)->varId() != 0)
variables.read(tok->tokAt(5)->varId()); variables.read(tok->tokAt(4)->varId());
tok = tok->tokAt(6); tok = tok->tokAt(5);
} }
} }
// const array of pointer or reference declaration with possible initialization
// const int * p[10]; const int * q[10] = { 0 };
else if (Token::Match(tok, "[;{}] const %type% *|& %var% [ %any% ] ;|="))
{
variables.addVar(tok->tokAt(4),
tok->tokAt(3)->str() == "*" ? Variables::pointerArray : Variables::referenceArray,
tok->tokAt(8)->str() == "=");
// check for reading array size from local variable
if (tok->tokAt(6)->varId() != 0)
variables.read(tok->tokAt(6)->varId());
tok = tok->tokAt(7);
}
// array of pointer or reference of struct or union declaration with possible initialization // array of pointer or reference of struct or union declaration with possible initialization
// struct S * p[10]; struct T * q[10] = { 0 }; // struct S * p[10]; struct T * q[10] = { 0 }; static struct S * r[10] = { 0 };
else if (Token::Match(tok, "[;{}] const| struct|union %type% *|& %var% [ %any% ] ;|=")) else if (Token::Match(tok, "[;{}] static| const| struct|union %type% *|& %var% [ %any% ] ;|="))
{ {
if (tok->next()->str() == "const") bool isStatic = false;
tok = tok->next();
if (tok->str() == "static")
{
tok = tok->next();
isStatic = true;
}
if (tok->str() == "const")
tok = tok->next(); tok = tok->next();
variables.addVar(tok->tokAt(4), variables.addVar(tok->tokAt(3),
tok->tokAt(3)->str() == "*" ? Variables::pointerArray : Variables::referenceArray, tok->tokAt(2)->str() == "*" ? Variables::pointerArray : Variables::referenceArray,
tok->tokAt(8)->str() == "="); tok->tokAt(7)->str() == "=" || isStatic);
// check for reading array size from local variable // check for reading array size from local variable
if (tok->tokAt(6)->varId() != 0) if (tok->tokAt(5)->varId() != 0)
variables.read(tok->tokAt(6)->varId()); variables.read(tok->tokAt(5)->varId());
tok = tok->tokAt(7); tok = tok->tokAt(6);
} }
else if (Token::Match(tok, "delete|return|throw %var%")) else if (Token::Match(tok, "delete|return|throw %var%"))

45
test/testunusedvar.cpp
View File

@ -75,6 +75,7 @@ private:
TEST_CASE(localvaralias6); // ticket #1729 TEST_CASE(localvaralias6); // ticket #1729
TEST_CASE(localvaralias7); // ticket #1732 TEST_CASE(localvaralias7); // ticket #1732
TEST_CASE(localvarasm); TEST_CASE(localvarasm);
TEST_CASE(localvarstatic);
// Don't give false positives for variables in structs/unions // Don't give false positives for variables in structs/unions
TEST_CASE(localvarStruct1); TEST_CASE(localvarStruct1);
@ -1970,6 +1971,50 @@ private:
"}"); "}");
ASSERT_EQUALS("", errout.str()); ASSERT_EQUALS("", errout.str());
} }
void localvarstatic()
{
functionVariableUsage("void foo()\n"
"{\n"
" static int i;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (style) Variable 'i' is assigned a value that is never used\n", errout.str());
functionVariableUsage("void foo()\n"
"{\n"
" static int i = 0;\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (style) Variable 'i' is assigned a value that is never used\n", errout.str());
functionVariableUsage("void foo()\n"
"{\n"
" static int i(0);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (style) Variable 'i' is assigned a value that is never used\n", errout.str());
functionVariableUsage("void foo()\n"
"{\n"
" static int i(a);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (style) Variable 'i' is assigned a value that is never used\n", errout.str());
functionVariableUsage("void foo()\n"
"{\n"
" static int j = 0;\n"
" static int i(j);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (style) Variable 'i' is assigned a value that is never used\n", errout.str());
functionVariableUsage("int * foo(int x)\n"
"{\n"
" static int a[] = { 3, 4, 5, 6 };\n"
" static int b[] = { 4, 5, 6, 7 };\n"
" static int c[] = { 5, 6, 7, 8 };\n"
" b[1] = 1;\n"
" return x ? a : c;\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (style) Variable 'b' is assigned a value that is never used\n", errout.str());
}
}; };
REGISTER_TEST(TestUnusedVar) REGISTER_TEST(TestUnusedVar)