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Fixed #1643 (Variable usage (pointer is assigned but never used))

This commit is contained in:
Robert Reif 2010-05-04 17:28:03 +02:00 committed by Daniel Marjamäki
parent eb276346c5
commit 7ce70777a4
2 changed files with 192 additions and 48 deletions
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120
lib/checkother.cpp
View File

@ -453,7 +453,8 @@ public:
_type(type), _type(type),
_read(read), _read(read),
_write(write), _write(write),
_modified(modified) _modified(modified),
_noAlias(false)
{ {
} }
@ -475,6 +476,7 @@ public:
bool _read; bool _read;
bool _write; bool _write;
bool _modified; // read/modify/write bool _modified; // read/modify/write
bool _noAlias; // don't alias
std::set<unsigned int> _aliases; std::set<unsigned int> _aliases;
}; };
@ -506,6 +508,10 @@ public:
void eraseAliases(unsigned int varid); void eraseAliases(unsigned int varid);
void eraseAll(unsigned int varid); void eraseAll(unsigned int varid);
// don't alias this variable because it's aliased to something undefined or unsupported
// or because it's aliased to something in a larger scope
void noAlias(unsigned int varid);
private: private:
VariableMap _varUsage; VariableMap _varUsage;
}; };
@ -517,7 +523,10 @@ void Variables::alias(unsigned int varid1, unsigned int varid2)
{ {
VariableUsage *var = find(varid1); VariableUsage *var = find(varid1);
if (var) if (var)
{
var->_noAlias = false;
var->use(); var->use();
}
return; return;
} }
@ -535,6 +544,7 @@ void Variables::alias(unsigned int varid1, unsigned int varid2)
// remove all aliases from var1 // remove all aliases from var1
var1->_aliases.clear(); var1->_aliases.clear();
var1->_noAlias = false;
VariableUsage *var2 = find(varid2); VariableUsage *var2 = find(varid2);
@ -572,6 +582,14 @@ void Variables::eraseAll(unsigned int varid)
erase(varid); erase(varid);
} }
void Variables::noAlias(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
usage->_noAlias = true;
}
void Variables::addVar(const Token *name, void Variables::addVar(const Token *name,
VariableType type, VariableType type,
bool write_) bool write_)
@ -593,14 +611,17 @@ void Variables::readAliases(unsigned int varid)
if (usage) if (usage)
{ {
std::set<unsigned int>::iterator aliases; if (!usage->_noAlias)
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{ {
VariableUsage *aliased = find(*aliases); std::set<unsigned int>::iterator aliases;
if (aliased) for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
aliased->_read = true; {
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->_read = true;
}
} }
} }
} }
@ -613,19 +634,21 @@ void Variables::readAll(unsigned int varid)
{ {
usage->_read = true; usage->_read = true;
std::set<unsigned int>::iterator aliases; if (!usage->_noAlias)
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{ {
VariableUsage *aliased = find(*aliases); std::set<unsigned int>::iterator aliases;
if (aliased) for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
aliased->_read = true; {
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->_read = true;
}
} }
} }
} }
void Variables::write(unsigned int varid) void Variables::write(unsigned int varid)
{ {
VariableUsage *usage = find(varid); VariableUsage *usage = find(varid);
@ -640,14 +663,17 @@ void Variables::writeAliases(unsigned int varid)
if (usage) if (usage)
{ {
std::set<unsigned int>::iterator aliases; if (!usage->_noAlias)
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{ {
VariableUsage *aliased = find(*aliases); std::set<unsigned int>::iterator aliases;
if (aliased) for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
aliased->_write = true; {
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->_write = true;
}
} }
} }
} }
@ -660,14 +686,17 @@ void Variables::writeAll(unsigned int varid)
{ {
usage->_write = true; usage->_write = true;
std::set<unsigned int>::iterator aliases; if (!usage->_noAlias)
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{ {
VariableUsage *aliased = find(*aliases); std::set<unsigned int>::iterator aliases;
if (aliased) for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
aliased->_write = true; {
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->_write = true;
}
} }
} }
} }
@ -680,14 +709,17 @@ void Variables::use(unsigned int varid)
{ {
usage->use(); usage->use();
std::set<unsigned int>::iterator aliases; if (!usage->_noAlias)
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{ {
VariableUsage *aliased = find(*aliases); std::set<unsigned int>::iterator aliases;
if (aliased) for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
aliased->use(); {
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->use();
}
} }
} }
} }
@ -700,14 +732,17 @@ void Variables::modified(unsigned int varid)
{ {
usage->_modified = true; usage->_modified = true;
std::set<unsigned int>::iterator aliases; if (!usage->_noAlias)
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{ {
VariableUsage *aliased = find(*aliases); std::set<unsigned int>::iterator aliases;
if (aliased) for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
aliased->_modified = true; {
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->_modified = true;
}
} }
} }
} }
@ -840,14 +875,15 @@ static int doAssignment(Variables &variables, const Token *tok, bool pointer)
{ {
variables.alias(varid1, varid2); variables.alias(varid1, varid2);
} }
else
variables.read(varid2);
} }
else // not a local variable else // not a local variable (or an unsupported local variable)
{ {
if (var1->_type == Variables::pointer && !pointer) if (var1->_type == Variables::pointer && !pointer)
{ {
// aliased variables in a larger scope are not supported yet // aliased variables in a larger scope are not supported
if (varid2) var1->_noAlias = true;
variables.erase(varid1);
} }
} }
} }

120
test/testunusedvar.cpp
View File

@ -79,6 +79,7 @@ private:
TEST_CASE(localvaralias1); TEST_CASE(localvaralias1);
TEST_CASE(localvaralias2); // ticket #1637 TEST_CASE(localvaralias2); // ticket #1637
TEST_CASE(localvaralias3); // ticket #1639 TEST_CASE(localvaralias3); // ticket #1639
TEST_CASE(localvaralias4); // ticket #1643
TEST_CASE(localvarasm); TEST_CASE(localvarasm);
// Don't give false positives for variables in structs/unions // Don't give false positives for variables in structs/unions
@ -1125,22 +1126,22 @@ private:
"}\n"); "}\n");
ASSERT_EQUALS(std::string("[test.cpp:3]: (style) Variable 'a' is assigned a value that is never used\n"), errout.str()); ASSERT_EQUALS(std::string("[test.cpp:3]: (style) Variable 'a' is assigned a value that is never used\n"), errout.str());
// a is not a local variable and b is aliased to it (not supported yet) // a is not a local variable and b is aliased to it
functionVariableUsage("int a;\n" functionVariableUsage("int a;\n"
"void foo()\n" "void foo()\n"
"{\n" "{\n"
" int *b = &a;\n" " int *b = &a;\n"
"}\n"); "}\n");
TODO_ASSERT_EQUALS(std::string("[test.cpp:4]: (style) Variable 'b' is assigned a value that is never used\n"), errout.str()); ASSERT_EQUALS(std::string("[test.cpp:4]: (style) Variable 'b' is assigned a value that is never used\n"), errout.str());
// a is not a local variable and b is aliased to it (not supported yet) // a is not a local variable and b is aliased to it
functionVariableUsage("void foo(int a)\n" functionVariableUsage("void foo(int a)\n"
"{\n" "{\n"
" int *b = &a;\n" " int *b = &a;\n"
"}\n"); "}\n");
TODO_ASSERT_EQUALS(std::string("[test.cpp:3]: (style) Variable 'b' is assigned a value that is never used\n"), errout.str()); ASSERT_EQUALS(std::string("[test.cpp:3]: (style) Variable 'b' is assigned a value that is never used\n"), errout.str());
// a is not a local variable and b is aliased to it (not supported yet) // a is not a local variable and b is aliased to it
functionVariableUsage("class A\n" functionVariableUsage("class A\n"
"{\n" "{\n"
" int a;\n" " int a;\n"
@ -1149,7 +1150,7 @@ private:
" int *b = &a;\n" " int *b = &a;\n"
" }\n" " }\n"
"}\n"); "}\n");
TODO_ASSERT_EQUALS(std::string("[test.cpp:6]: (style) Variable 'b' is assigned a value that is never used\n"), errout.str()); ASSERT_EQUALS(std::string("[test.cpp:6]: (style) Variable 'b' is assigned a value that is never used\n"), errout.str());
functionVariableUsage("int a;\n" functionVariableUsage("int a;\n"
"void foo()\n" "void foo()\n"
@ -1241,6 +1242,78 @@ private:
"}\n"); "}\n");
ASSERT_EQUALS(std::string(""), errout.str()); ASSERT_EQUALS(std::string(""), errout.str());
functionVariableUsage("int a[10];\n"
"void foo()\n"
"{\n"
" int *b = a;\n"
" int *c = b;\n"
" *c = 0;\n"
"}\n");
ASSERT_EQUALS(std::string(""), errout.str());
functionVariableUsage("void foo()\n"
"{\n"
" int *b = a;\n"
" int *c = b;\n"
" *c = 0;\n"
"}\n");
ASSERT_EQUALS(std::string(""), errout.str());
functionVariableUsage("void foo()\n"
"{\n"
" int *b = a;\n"
" int *c = b;\n"
" *c = b[0];\n"
"}\n");
ASSERT_EQUALS(std::string(""), errout.str());
functionVariableUsage("void foo()\n"
"{\n"
" int *b = a;\n"
" int *c;\n"
" *c = b[0];\n"
"}\n");
ASSERT_EQUALS(std::string("[test.cpp:4]: (style) Variable 'c' is not assigned a value\n"), errout.str());
functionVariableUsage("int a[10];\n"
"void foo()\n"
"{\n"
" int *b = a;\n"
" int c = b[0];\n"
" c = c;\n"
"}\n");
ASSERT_EQUALS(std::string(""), errout.str());
functionVariableUsage("void foo()\n"
"{\n"
" int *b = a;\n"
" int c = b[0];\n"
" c = c;\n"
"}\n");
ASSERT_EQUALS(std::string(""), errout.str());
functionVariableUsage("int a[10];\n"
"void foo()\n"
"{\n"
" int *b = &a[0];\n"
" a[0] = b[0];\n"
"}\n");
ASSERT_EQUALS(std::string(""), errout.str());
functionVariableUsage("void foo()\n"
"{\n"
" int *b = &a[0];\n"
" a[0] = b[0];\n"
"}\n");
ASSERT_EQUALS(std::string(""), errout.str());
functionVariableUsage("void foo()\n"
"{\n"
" int *b = a;\n"
" a[0] = b[0];\n"
"}\n");
ASSERT_EQUALS(std::string(""), errout.str());
functionVariableUsage("void foo(int a[10])\n" functionVariableUsage("void foo(int a[10])\n"
"{\n" "{\n"
" int *b = a;\n" " int *b = a;\n"
@ -1421,6 +1494,41 @@ private:
ASSERT_EQUALS(std::string(""), errout.str()); ASSERT_EQUALS(std::string(""), errout.str());
} }
void localvaralias4() // ticket 1643
{
functionVariableUsage("struct AB { int a; int b; } ab;\n"
"void foo()\n"
"{\n"
" int * a = &ab.a;\n"
"}\n");
ASSERT_EQUALS(std::string("[test.cpp:4]: (style) Variable 'a' is assigned a value that is never used\n"), errout.str());
functionVariableUsage("struct AB { int a; int b; } ab;\n"
"void foo()\n"
"{\n"
" int * a = &ab.a;\n"
" *a = 0;\n"
"}\n");
ASSERT_EQUALS(std::string(""), errout.str());
functionVariableUsage("struct AB { int a; int b; };\n"
"void foo()\n"
"{\n"
" struct AB ab;\n"
" int * a = &ab.a;\n"
"}\n");
ASSERT_EQUALS(std::string("[test.cpp:5]: (style) Variable 'a' is assigned a value that is never used\n"), errout.str());
functionVariableUsage("struct AB { int a; int b; };\n"
"void foo()\n"
"{\n"
" struct AB ab;\n"
" int * a = &ab.a;\n"
" *a = 0;\n"
"}\n");
ASSERT_EQUALS(std::string(""), errout.str());
}
void localvarasm() void localvarasm()
{ {
functionVariableUsage("void foo(int &b)\n" functionVariableUsage("void foo(int &b)\n"