<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <title>Available Checkers</title> <link type="text/css" rel="stylesheet" href="menu.css"> <link type="text/css" rel="stylesheet" href="content.css"> <script type="text/javascript" src="scripts/menu.js"></script> <script type="text/javascript" src="scripts/expandcollapse.js"></script> <style type="text/css"> tr:first-child { width:20%; } </style> </head> <body onload="initExpandCollapse()"> <div id="page"> <!--#include virtual="menu.html.incl"--> <div id="content"> <h1>Available Checkers</h1> The analyzer performs checks that are categorized into families or "checkers". The default set of checkers covers a variety of checks targeted at finding security and API usage bugs, dead code, and other logic errors. See the <a href = "#default_checkers">Default Checkers</a> list below. In addition to these, the analyzer contains a number of <a href = "alpha_checks.html"> Experimental (Alpha) Checkers</a>. <h3>Writeups with examples of some of the bugs that the analyzer finds</h3> <ul> <li><a href="http://www.mobileorchard.com/bug-finding-with-clang-5-resources-to-get-you-started/">Bug Finding With Clang: 5 Resources To Get You Started</a></li> <li><a href="http://fruitstandsoftware.com/blog/index.php/2008/08/finding-memory-leaks-with-the-llvmclang-static-analyzer/#comment-2">Finding Memory Leaks With The LLVM/Clang Static Analyzer</a></li> <li><a href="http://www.rogueamoeba.com/utm/2008/07/14/the-clang-static-analyzer/">Under the Microscope - The Clang Static Analyzer</a></li> <li><a href="http://www.mikeash.com/?page=pyblog/friday-qa-2009-03-06-using-the-clang-static-analyzer.html">Mike Ash - Using the Clang Static Analyzer</a></li> </ul> <h2 id="default_checkers">Default Checkers</h2> <ul> <li><a href="#core_checkers">Core Checkers</a> model core language features and perform general-purpose checks such as division by zero, null pointer dereference, usage of uninitialized values, etc.</li> <li><a href="#cplusplus_checkers">C++ Checkers</a> perform C++-specific checks</li> <li><a href="#deadcode_checkers">Dead Code Checkers</a> check for unused code</li> <li><a href="#osx_checkers">OS X Checkers</a> perform Objective-C-specific checks and check the use of Apple's SDKs (OS X and iOS)</li> <li><a href="#security_checkers">Security Checkers</a> check for insecure API usage and perform checks based on the CERT Secure Coding Standards</li> <li><a href="#unix_checkers">Unix Checkers</a> check the use of Unix and POSIX APIs</li> </ul> <!------------------------------------ core -----------------------------------> <h3 id="core_checkers">Core Checkers</h3> <table class="checkers"> <colgroup><col class="namedescr"><col class="example"></colgroup> <thead><tr><td>Name, Description</td><td>Example</td></tr></thead> <tbody> <tr><td><div class="namedescr expandable"><span class="name"> core.CallAndMessage</span><span class="lang"> (C, C++, ObjC)</span><div class="descr"> Check for logical errors for function calls and Objective-C message expressions (e.g., uninitialized arguments, null function pointers).</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> // C struct S { int x; }; void f(struct S s); void test() { struct S s; f(s); // warn: passed-by-value arg contain uninitialized data } </pre></div> <div class="example"><pre> // C void test() { void (*foo)(void); foo(); // warn: function pointer is uninitialized } </pre></div> <div class="example"><pre> // C void test() { void (*foo)(void); foo = 0; foo(); // warn: function pointer is null } </pre></div> <div class="example"><pre> // C++ class C { public: void f(); }; void test() { C *pc; pc->f(); // warn: object pointer is uninitialized } </pre></div> <div class="example"><pre> // C++ class C { public: void f(); }; void test() { C *pc = 0; pc->f(); // warn: object pointer is null } </pre></div> <div class="example"><pre> // Objective-C @interface MyClass : NSObject @property (readwrite,assign) id x; - (long double)longDoubleM; @end void test() { MyClass *obj1; long double ld1 = [obj1 longDoubleM]; // warn: receiver is uninitialized } </pre></div> <div class="example"><pre> // Objective-C @interface MyClass : NSObject @property (readwrite,assign) id x; - (long double)longDoubleM; @end void test() { MyClass *obj1; id i = obj1.x; // warn: uninitialized object pointer } </pre></div> <div class="example"><pre> // Objective-C @interface Subscriptable : NSObject - (id)objectAtIndexedSubscript:(unsigned int)index; @end @interface MyClass : Subscriptable @property (readwrite,assign) id x; - (long double)longDoubleM; @end void test() { MyClass *obj1; id i = obj1[0]; // warn: uninitialized object pointer } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.DivideZero</span><span class="lang"> (C, C++, ObjC)</span><div class="descr"> Check for division by zero.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test(int z) { if (z == 0) int x = 1 / z; // warn } </pre></div> <div class="example"><pre> void test() { int x = 1; int y = x % 0; // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.NonNullParamChecker</span><span class="lang"> (C, C++, ObjC)</span><div class="descr"> Check for null pointers passed as arguments to a function whose arguments are marked with the <code>nonnull</code> attribute.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> int f(int *p) __attribute__((nonnull)); void test(int *p) { if (!p) f(p); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.NullDereference</span><span class="lang"> (C, C++, ObjC)</span><div class="descr"> Check for dereferences of null pointers.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> // C void test(int *p) { if (p) return; int x = p[0]; // warn } </pre></div> <div class="example"><pre> // C void test(int *p) { if (!p) *p = 0; // warn } </pre></div> <div class="example"><pre> // C++ class C { public: int x; }; void test() { C *pc = 0; int k = pc->x; // warn } </pre></div> <div class="example"><pre> // Objective-C @interface MyClass { @public int x; } @end void test() { MyClass *obj = 0; obj->x = 1; // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.StackAddressEscape</span><span class="lang"> (C)</span><div class="descr"> Check that addresses of stack memory do not escape the function.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> char const *p; void test() { char const str[] = "string"; p = str; // warn } </pre></div> <div class="example"><pre> void* test() { return __builtin_alloca(12); // warn } </pre></div> <div class="example"><pre> void test() { static int *x; int y; x = &y; // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.UndefinedBinaryOperatorResult</span><span class="lang"> (C)</span><div class="descr"> Check for undefined results of binary operators.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { int x; int y = x + 1; // warn: left operand is garbage } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.VLASize</span><span class="lang"> (C)</span><div class="descr"> Check for declarations of VLA of undefined or zero size.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { int x; int vla1[x]; // warn: garbage as size } </pre></div> <div class="example"><pre> void test() { int x = 0; int vla2[x]; // warn: zero size } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.uninitialized.ArraySubscript</span><span class="lang"> (C)</span><div class="descr"> Check for uninitialized values used as array subscripts.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { int i, a[10]; int x = a[i]; // warn: array subscript is undefined } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.uninitialized.Assign</span><span class="lang"> (C)</span><div class="descr"> Check for assigning uninitialized values.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { int x; x |= 1; // warn: left expression is unitialized } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.uninitialized.Branch</span><span class="lang"> (C)</span><div class="descr"> Check for uninitialized values used as branch conditions.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { int x; if (x) // warn return; } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.uninitialized.CapturedBlockVariable</span><span class="lang"> (C)</span><div class="descr"> Check for blocks that capture uninitialized values.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { int x; ^{ int y = x; }(); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> core.uninitialized.UndefReturn</span><span class="lang"> (C)</span><div class="descr"> Check for uninitialized values being returned to the caller.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> int test() { int x; return x; // warn } </pre></div></div></td></tr> </tbody></table> <!------------------------------------ C++ ------------------------------------> <h3 id="cplusplus_checkers">C++ Checkers</h3> <table class="checkers"> <colgroup><col class="namedescr"><col class="example"></colgroup> <thead><tr><td>Name, Description</td><td>Example</td></tr></thead> <tbody> <tr><td><div class="namedescr expandable"><span class="name"> cplusplus.NewDelete</span><span class="lang"> (C++)</span><div class="descr"> Check for double-free, use-after-free and offset problems involving C++ <code> delete</code>.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void f(int *p); void testUseMiddleArgAfterDelete(int *p) { delete p; f(p); // warn: use after free } </pre></div> <div class="example"><pre> class SomeClass { public: void f(); }; void test() { SomeClass *c = new SomeClass; delete c; c->f(); // warn: use after free } </pre></div> <div class="example"><pre> void test() { int *p = (int *)__builtin_alloca(sizeof(int)); delete p; // warn: deleting memory allocated by alloca } </pre></div> <div class="example"><pre> void test() { int *p = new int; delete p; delete p; // warn: attempt to free released } </pre></div> <div class="example"><pre> void test() { int i; delete &i; // warn: delete address of local } </pre></div> <div class="example"><pre> void test() { int *p = new int[1]; delete[] (++p); // warn: argument to 'delete[]' is offset by 4 bytes // from the start of memory allocated by 'new[]' } </pre></div></div></td></tr> </tbody></table> <!--------------------------------- dead code ---------------------------------> <h3 id="deadcode_checkers">Dead Code Checkers</h3> <table class="checkers"> <colgroup><col class="namedescr"><col class="example"></colgroup> <thead><tr><td>Name, Description</td><td>Example</td></tr></thead> <tbody> <tr><td><div class="namedescr expandable"><span class="name"> deadcode.DeadStores</span><span class="lang"> (C)</span><div class="descr"> Check for values stored to variables that are never read afterwards.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { int x; x = 1; // warn } </pre></div></div></td></tr> </tbody></table> <!---------------------------------- OS X ------------------------------------> <h3 id="osx_checkers">OS X Checkers</h3> <table class="checkers"> <colgroup><col class="namedescr"><col class="example"></colgroup> <thead><tr><td>Name, Description</td><td>Example</td></tr></thead> <tbody> <tr><td><div class="namedescr expandable"><span class="name"> osx.API</span><span class="lang"> (C)</span><div class="descr"> Check for proper uses of various Apple APIs:<div class=functions> dispatch_once</div></div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { dispatch_once_t pred = 0; dispatch_once(&pred, ^(){}); // warn: dispatch_once uses local } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.SecKeychainAPI</span><span class="lang"> (C)</span><div class="descr"> Check for improper uses of the Security framework's Keychain APIs:<div class=functions> SecKeychainItemCopyContent<br> SecKeychainFindGenericPassword<br> SecKeychainFindInternetPassword<br> SecKeychainItemFreeContent<br> SecKeychainItemCopyAttributesAndData<br> SecKeychainItemFreeAttributesAndData</div></div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { unsigned int *ptr = 0; UInt32 length; SecKeychainItemFreeContent(ptr, &length); // warn: trying to free data which has not been allocated } </pre></div> <div class="example"><pre> void test() { unsigned int *ptr = 0; UInt32 *length = 0; void *outData; OSStatus st = SecKeychainItemCopyContent(2, ptr, ptr, length, outData); // warn: data is not released } </pre></div> <div class="example"><pre> void test() { unsigned int *ptr = 0; UInt32 *length = 0; void *outData; OSStatus st = SecKeychainItemCopyContent(2, ptr, ptr, length, &outData); SecKeychainItemFreeContent(ptr, outData); // warn: only call free if a non-NULL buffer was returned } </pre></div> <div class="example"><pre> void test() { unsigned int *ptr = 0; UInt32 *length = 0; void *outData; OSStatus st = SecKeychainItemCopyContent(2, ptr, ptr, length, &outData); st = SecKeychainItemCopyContent(2, ptr, ptr, length, &outData); // warn: release data before another call to the allocator if (st == noErr) SecKeychainItemFreeContent(ptr, outData); } </pre></div> <div class="example"><pre> void test() { SecKeychainItemRef itemRef = 0; SecKeychainAttributeInfo *info = 0; SecItemClass *itemClass = 0; SecKeychainAttributeList *attrList = 0; UInt32 *length = 0; void *outData = 0; OSStatus st = SecKeychainItemCopyAttributesAndData(itemRef, info, itemClass, &attrList, length, &outData); SecKeychainItemFreeContent(attrList, outData); // warn: deallocator doesn't match the allocator } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.cocoa.AtSync</span><span class="lang"> (ObjC)</span><div class="descr"> Check for nil pointers used as mutexes for <code>@synchronized</code>.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test(id x) { if (!x) @synchronized(x) {} // warn: nil value used as mutex } </pre></div> <div class="example"><pre> void test() { id y; @synchronized(y) {} // warn: uninitialized value used as mutex } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.cocoa.ClassRelease</span><span class="lang"> (ObjC)</span><div class="descr"> Check for sending <code>retain</code>, <code>release</code>, or <code> autorelease</code> directly to a class.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> @interface MyClass : NSObject @end void test(void) { [MyClass release]; // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.cocoa.IncompatibleMethodTypes</span><span class="lang"> (ObjC)</span><div class="descr"> Check for an incompatible type signature when overriding an Objective-C method.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> @interface MyClass1 : NSObject - (int)foo; @end @implementation MyClass1 - (int)foo { return 1; } @end @interface MyClass2 : MyClass1 - (float)foo; @end @implementation MyClass2 - (float)foo { return 1.0; } // warn @end </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> alpha.osx.cocoa.MissingSuperCall</span><span class="lang"> (ObjC)</span><div class="descr"> Warn about Objective-C methods that lack a necessary call to super. (Note: The compiler now has a warning for methods annotated with <code>objc_requires_super</code> attribute. The checker exists to check methods in the Cocoa frameworks that haven't yet adopted this attribute.)</div></div></td> <td><div class="example"><pre> @interface Test : UIViewController @end @implementation test - (void)viewDidLoad {} // warn @end </pre></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.cocoa.NSAutoreleasePool</span><span class="lang"> (ObjC)</span><div class="descr"> Warn for suboptimal uses of NSAutoreleasePool in Objective-C GC mode (<code>-fobjc-gc</code> compiler option).</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; [pool release]; // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.cocoa.NSError</span><span class="lang"> (ObjC)</span><div class="descr"> Check usage of <code>NSError**</code> parameters.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> @interface A : NSObject - (void)foo:(NSError **)error; @end @implementation A - (void)foo:(NSError **)error { // warn: method accepting NSError** should have a non-void // return value } @end </pre></div> <div class="example"><pre> @interface A : NSObject - (BOOL)foo:(NSError **)error; @end @implementation A - (BOOL)foo:(NSError **)error { *error = 0; // warn: potential null dereference return 0; } @end </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.cocoa.NilArg</span><span class="lang"> (ObjC)</span><div class="descr"> Check for prohibited nil arguments in specific Objective-C method calls:<div class=functions> - caseInsensitiveCompare:<br> - compare:<br> - compare:options:<br> - compare:options:range:<br> - compare:options:range:locale:<br> - componentsSeparatedByCharactersInSet:<br> - initWithFormat:</div></div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> NSComparisonResult test(NSString *s) { NSString *aString = nil; return [s caseInsensitiveCompare:aString]; // warn: argument to 'NSString' method // 'caseInsensitiveCompare:' cannot be nil } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.cocoa.RetainCount</span><span class="lang"> (ObjC)</span><div class="descr"> Check for leaks and violations of the Cocoa Memory Management rules.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { NSString *s = [[NSString alloc] init]; // warn } </pre></div> <div class="example"><pre> CFStringRef test(char *bytes) { return CFStringCreateWithCStringNoCopy( 0, bytes, NSNEXTSTEPStringEncoding, 0); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.cocoa.SelfInit</span><span class="lang"> (ObjC)</span><div class="descr"> Check that <code>self</code> is properly initialized inside an initializer method.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> @interface MyObj : NSObject { id x; } - (id)init; @end @implementation MyObj - (id)init { [super init]; x = 0; // warn: instance variable used while 'self' is not // initialized return 0; } @end </pre></div> <div class="example"><pre> @interface MyObj : NSObject - (id)init; @end @implementation MyObj - (id)init { [super init]; return self; // warn: returning uninitialized 'self' } @end </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.cocoa.UnusedIvars</span><span class="lang"> (ObjC)</span><div class="descr"> Warn about private ivars that are never used.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> @interface MyObj : NSObject { @private id x; // warn } @end @implementation MyObj @end </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.cocoa.VariadicMethodTypes</span><span class="lang"> (ObjC)</span><div class="descr"> Check for passing non-Objective-C types to variadic collection initialization methods that expect only Objective-C types.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { [NSSet setWithObjects:@"Foo", "Bar", nil]; // warn: argument should be an ObjC pointer type, not 'char *' } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.coreFoundation.CFError</span><span class="lang"> (C)</span><div class="descr"> Check usage of <code>CFErrorRef*</code> parameters.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test(CFErrorRef *error) { // warn: function accepting CFErrorRef* should have a // non-void return } </pre></div> <div class="example"><pre> int foo(CFErrorRef *error) { *error = 0; // warn: potential null dereference return 0; } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.coreFoundation.CFNumber</span><span class="lang"> (C)</span><div class="descr"> Check for improper uses of <code>CFNumberCreate</code>.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> CFNumberRef test(unsigned char x) { return CFNumberCreate(0, kCFNumberSInt16Type, &x); // warn: 8 bit integer is used to initialize a 16 bit integer } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.coreFoundation.CFRetainRelease</span><span class="lang"> (C)</span><div class="descr"> Check for null arguments to <code>CFRetain</code>, <code>CFRelease</code>, <code>CFMakeCollectable</code>.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test(CFTypeRef p) { if (!p) CFRetain(p); // warn } </pre></div> <div class="example"><pre> void test(int x, CFTypeRef p) { if (p) return; CFRelease(p); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.coreFoundation.containers.OutOfBounds</span><span class="lang"> (C)</span><div class="descr"> Checks for index out-of-bounds when using <code>CFArray</code> API.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { CFArrayRef A = CFArrayCreate(0, 0, 0, &kCFTypeArrayCallBacks); CFArrayGetValueAtIndex(A, 0); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> osx.coreFoundation.containers.PointerSizedValues</span><span class="lang"> (C)</span><div class="descr"> Warns if <code>CFArray</code>, <code>CFDictionary</code>, <code>CFSet</code> are created with non-pointer-size values.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { int x[] = { 1 }; CFArrayRef A = CFArrayCreate(0, (const void **)x, 1, &kCFTypeArrayCallBacks); // warn } </pre></div></div></td></tr> </tbody></table> <!------------------------------- security ------------------------------------> <h3 id="security_checkers">Security Checkers</h3> <table class="checkers"> <colgroup><col class="namedescr"><col class="example"></colgroup> <thead><tr><td>Name, Description</td><td>Example</td></tr></thead> <tbody> <tr><td><div class="namedescr expandable"><span class="name"> security.FloatLoopCounter</span><span class="lang"> (C)</span><div class="descr"> Warn on using a floating point value as a loop counter (CERT: FLP30-C, FLP30-CPP).</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { for (float x = 0.1f; x <= 1.0f; x += 0.1f) {} // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> security.insecureAPI.UncheckedReturn</span><span class="lang"> (C)</span><div class="descr"> Warn on uses of functions whose return values must be always checked:<div class=functions> setuid<br> setgid<br> seteuid<br> setegid<br> setreuid<br> setregid</div></div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { setuid(1); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> security.insecureAPI.getpw</span><span class="lang"> (C)</span><div class="descr"> Warn on uses of the <code>getpw</code> function.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { char buff[1024]; getpw(2, buff); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> security.insecureAPI.gets</span><span class="lang"> (C)</span><div class="descr"> Warn on uses of the <code>gets</code> function.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { char buff[1024]; gets(buff); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> security.insecureAPI.mkstemp</span><span class="lang"> (C)</span><div class="descr"> Warn when <code>mktemp</code>, <code>mkstemp</code>, <code>mkstemps</code> or <code>mkdtemp</code> is passed fewer than 6 X's in the format string.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { mkstemp("XX"); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> security.insecureAPI.mktemp</span><span class="lang"> (C)</span><div class="descr"> Warn on uses of the <code>mktemp</code> function.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { char *x = mktemp("/tmp/zxcv"); // warn: insecure, use mkstemp } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> security.insecureAPI.rand</span><span class="lang"> (C)</span><div class="descr"> Warn on uses of inferior random number generating functions (only if <code>arc4random</code> function is available):<div class=functions> drand48<br> erand48<br> jrand48<br> lcong48<br> lrand48<br> mrand48<br> nrand48<br> random<br> rand_r</div></div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { random(); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> security.insecureAPI.strcpy</span><span class="lang"> (C)</span><div class="descr"> Warn on uses of the <code>strcpy</code> and <code>strcat</code> functions.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { char x[4]; char *y = "abcd"; strcpy(x, y); // warn } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> security.insecureAPI.vfork</span><span class="lang"> (C)</span><div class="descr"> Warn on uses of the <code>vfork</code> function.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { vfork(); // warn } </pre></div></div></td></tr> </tbody></table> <!--------------------------------- unix --------------------------------------> <h3 id="unix_checkers">Unix Checkers</h3> <table class="checkers"> <colgroup><col class="namedescr"><col class="example"></colgroup> <thead><tr><td>Name, Description</td><td>Example</td></tr></thead> <tbody> <tr><td><div class="namedescr expandable"><span class="name"> unix.API</span><span class="lang"> (C)</span><div class="descr"> Check calls to various UNIX/POSIX functions:<div class=functions> open<br> pthread_once<br> calloc<br> malloc<br> realloc<br> alloca<br> <td><div class="exampleContainer expandable"> <div class="example"><pre> // Currently the check is performed for apple targets only. void test(const char *path) { int fd = open(path, O_CREAT); // warn: call to 'open' requires a third argument when the // 'O_CREAT' flag is set } </pre></div> <div class="example"><pre> void f(); void test() { pthread_once_t pred = {0x30B1BCBA, {0}}; pthread_once(&pred, f); // warn: call to 'pthread_once' uses the local variable } </pre></div> <div class="example"><pre> void test() { void *p = malloc(0); // warn: allocation size of 0 bytes } </pre></div> <div class="example"><pre> void test() { void *p = calloc(0, 42); // warn: allocation size of 0 bytes } </pre></div> <div class="example"><pre> void test() { void *p = malloc(1); p = realloc(p, 0); // warn: allocation size of 0 bytes } </pre></div> <div class="example"><pre> void test() { void *p = alloca(0); // warn: allocation size of 0 bytes } </pre></div> <div class="example"><pre> void test() { void *p = valloc(0); // warn: allocation size of 0 bytes } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> unix.Malloc</span><span class="lang"> (C)</span><div class="descr"> Check for memory leaks, double free, and use-after-free and offset problems involving <code>malloc</code>.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { int *p = malloc(1); free(p); free(p); // warn: attempt to free released memory } </pre></div> <div class="example"><pre> void test() { int *p = malloc(sizeof(int)); free(p); *p = 1; // warn: use after free } </pre></div> <div class="example"><pre> void test() { int *p = malloc(1); if (p) return; // warn: memory is never released } </pre></div> <div class="example"><pre> void test() { int a[] = { 1 }; free(a); // warn: argument is not allocated by malloc } </pre></div> <div class="example"><pre> void test() { int *p = malloc(sizeof(char)); p = p - 1; free(p); // warn: argument to free() is offset by -4 bytes } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> unix.MallocSizeof</span><span class="lang"> (C)</span><div class="descr"> Check for dubious <code>malloc</code>, <code>calloc</code> or <code>realloc</code> arguments involving <code>sizeof</code>.</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { long *p = malloc(sizeof(short)); // warn: result is converted to 'long *', which is // incompatible with operand type 'short' free(p); } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> unix.MismatchedDeallocator</span><span class="lang"> (C, C++, ObjC)</span><div class="descr"> Check for mismatched deallocators (e.g. passing a pointer allocating with <code>new</code> to <code>free()</code>).</div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> // C, C++ void test() { int *p = (int *)malloc(sizeof(int)); delete p; // warn } </pre></div> <div class="example"><pre> // C, C++ void __attribute((ownership_returns(malloc))) *user_malloc(size_t); void test() { int *p = (int *)user_malloc(sizeof(int)); delete p; // warn } </pre></div> <div class="example"><pre> // C, C++ void test() { int *p = new int; free(p); // warn } </pre></div> <div class="example"><pre> // C, C++ void test() { int *p = new int[1]; realloc(p, sizeof(long)); // warn } </pre></div> <div class="example"><pre> // C, C++ template <typename T> struct SimpleSmartPointer { T *ptr; explicit SimpleSmartPointer(T *p = 0) : ptr(p) {} ~SimpleSmartPointer() { delete ptr; // warn } }; void test() { SimpleSmartPointer<int> a((int *)malloc(4)); } </pre></div> <div class="example"><pre> // C++ void test() { int *p = (int *)operator new(0); delete[] p; // warn } </pre></div> <div class="example"><pre> // Objective-C, C++ void test(NSUInteger dataLength) { int *p = new int; NSData *d = [NSData dataWithBytesNoCopy:p length:sizeof(int) freeWhenDone:1]; // warn +dataWithBytesNoCopy:length:freeWhenDone: cannot take // ownership of memory allocated by 'new' } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> unix.cstring.BadSizeArg</span><span class="lang"> (C)</span><div class="descr"> Check the size argument passed to <code>strncat</code> for common erroneous patterns. Use <code>-Wno-strncat-size</code> compiler option to mute other <code>strncat</code>-related compiler warnings. </div></div></td> <td><div class="exampleContainer expandable"> <div class="example"><pre> void test() { char dest[3]; strncat(dest, "***", sizeof(dest)); // warn: potential buffer overflow } </pre></div></div></td></tr> <tr><td><div class="namedescr expandable"><span class="name"> unix.cstring.NullArg</span><span class="lang"> (C)</span><div class="descr"> Check for null pointers being passed as arguments to C string functions:<div class=functions> strlen<br> strnlen<br> strcpy<br> strncpy<br> strcat<br> strncat<br> strcmp<br> strncmp<br> strcasecmp<br> strncasecmp</div></div></div></td> <td><div class="example"><pre> int test() { return strlen(0); // warn } </pre></div></td></tr> </tbody></table> </div> <!-- page --> </div> <!-- content --> </body> </html>