walkero
/
cppcheck
1
0
Fork 0
Code Issues Pull Requests Projects Releases 1 Wiki Activity

Fixed #2627 (switch case fall through: redundant strcpy)

This commit is contained in:
Zachary Blair 2011-10-13 01:27:22 -07:00
parent 91d7621994
commit 82366918ff
3 changed files with 103 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
lib/checkother.cpp
View File

@ -482,6 +482,7 @@ void CheckOther::checkRedundantAssignmentInSwitch()
// Check the contents of the switch statement
std::map<unsigned int, const Token*> varsAssigned;
std::map<unsigned int, const Token*> stringsCopied;
int indentLevel = 0;
for (const Token *tok2 = tok->tokAt(5); tok2; tok2 = tok2->next())
{
@ -496,9 +497,17 @@ void CheckOther::checkRedundantAssignmentInSwitch()
for (const Token* tok3 = tok2; tok3 != endOfConditional; tok3 = tok3->next())
{
if (tok3->varId() != 0)
{
varsAssigned.erase(tok3->varId());
stringsCopied.erase(tok3->varId());
}
else if (Token::Match(tok3, functionPattern) || Token::Match(tok3, breakPattern))
{
varsAssigned.clear();
if (tok3->str() != "strcpy" && tok3->str() != "strncpy")
stringsCopied.clear();
}
}
tok2 = endOfConditional;
}
@ -524,6 +533,19 @@ void CheckOther::checkRedundantAssignmentInSwitch()
varsAssigned[tok2->varId()] = tok2;
else
redundantAssignmentInSwitchError(i->second, i->second->str());
stringsCopied.erase(tok2->varId());
}
// String copy. Report an error if it's copied to twice before a break. E.g.:
// case 3: strcpy(str, "a"); // <== redundant
// case 4: strcpy(str, "b");
else if (Token::Match(tok2->previous(), ";|{|}|: strcpy|strncpy ( %var% ,") && tok2->tokAt(2)->varId() != 0)
{
std::map<unsigned int, const Token*>::iterator i = stringsCopied.find(tok2->tokAt(2)->varId());
if (i == stringsCopied.end())
stringsCopied[tok2->tokAt(2)->varId()] = tok2->tokAt(2);
else
redundantStrcpyInSwitchError(i->second, i->second->str());
}
// Not a simple assignment so there may be good reason if this variable is assigned to twice. E.g.:
// case 3: b = 1;
@ -534,8 +556,13 @@ void CheckOther::checkRedundantAssignmentInSwitch()
// Reset our record of assignments if there is a break or function call. E.g.:
// case 3: b = 1; break;
if (Token::Match(tok2, functionPattern) || Token::Match(tok2, breakPattern))
{
varsAssigned.clear();
if (tok2->str() != "strcpy" && tok2->str() != "strncpy")
stringsCopied.clear();
}
}
tok = Token::findmatch(tok->next(), switchPattern);
@ -548,6 +575,14 @@ void CheckOther::redundantAssignmentInSwitchError(const Token *tok, const std::s
"redundantAssignInSwitch", "Redundant assignment of \"" + varname + "\" in switch");
}
void CheckOther::redundantStrcpyInSwitchError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::warning,
"redundantStrcpyInSwitch",
"Switch case fall-through. Redundant strcpy of \"" + varname + "\".\n"
"Switch case fall-through. Redundant strcpy of \"" + varname + "\". The string is overwritten in a later case block.");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void CheckOther::checkSwitchCaseFallThrough()

2
lib/checkother.h
View File

@ -252,6 +252,7 @@ public:
void mathfunctionCallError(const Token *tok, const unsigned int numParam = 1);
void fflushOnInputStreamError(const Token *tok, const std::string &varname);
void redundantAssignmentInSwitchError(const Token *tok, const std::string &varname);
void redundantStrcpyInSwitchError(const Token *tok, const std::string &varname);
void switchCaseFallThrough(const Token *tok);
void selfAssignmentError(const Token *tok, const std::string &varname);
void assignmentInAssertError(const Token *tok, const std::string &varname);
@ -362,6 +363,7 @@ public:
"* condition that is always true/false\n"
"* unusal pointer arithmetic. For example: \"abc\" + 'd'\n"
"* redundant assignment in a switch statement\n"
"* redundant strcpy in a switch statement\n"
"* look for 'sizeof sizeof ..'\n"
"* look for calculations inside sizeof()\n"
"* assignment of a variable to itself\n"

66
test/testother.cpp
View File

@ -1305,6 +1305,72 @@ private:
" }\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("void foo(char *str, int a)\n"
"{\n"
" switch (a)\n"
" {\n"
" case 2:\n"
" strcpy(str, \"a'\");\n"
" case 3:\n"
" strcpy(str, \"b'\");\n"
" }\n"
"}\n");
ASSERT_EQUALS("[test.cpp:6]: (warning) Switch case fall-through. Redundant strcpy of \"str\".\n", errout.str());
check("void foo(char *str, int a)\n"
"{\n"
" switch (a)\n"
" {\n"
" case 2:\n"
" strncpy(str, \"a'\");\n"
" case 3:\n"
" strncpy(str, \"b'\");\n"
" }\n"
"}\n");
ASSERT_EQUALS("[test.cpp:6]: (warning) Switch case fall-through. Redundant strcpy of \"str\".\n", errout.str());
check("void foo(char *str, int a)\n"
"{\n"
" int z = 0;\n"
" switch (a)\n"
" {\n"
" case 2:\n"
" strcpy(str, \"a'\");\n"
" z++;\n"
" case 3:\n"
" strcpy(str, \"b'\");\n"
" z++;\n"
" }\n"
"}\n");
ASSERT_EQUALS("[test.cpp:7]: (warning) Switch case fall-through. Redundant strcpy of \"str\".\n", errout.str());
check("void foo(char *str, int a)\n"
"{\n"
" switch (a)\n"
" {\n"
" case 2:\n"
" strcpy(str, \"a'\");\n"
" break;\n"
" case 3:\n"
" strcpy(str, \"b'\");\n"
" break;\n"
" }\n"
"}\n");
ASSERT_EQUALS("", errout.str());
check("void foo(char *str, int a)\n"
"{\n"
" switch (a)\n"
" {\n"
" case 2:\n"
" strcpy(str, \"a'\");\n"
" printf(str);\n"
" case 3:\n"
" strcpy(str, \"b'\");\n"
" }\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void switchFallThroughCase()