NAME¶

scan-build — Clang static analyzer

SYNOPSIS¶

DESCRIPTION¶

scan-build is a Perl script that invokes the Clang static analyzer. Options used by scan-build or by the analyzer appear first, followed by the build_command and any build_options normally used to build the target system.

The static analyzer employs a long list of checking algorithms, see CHECKERS. Output can be written in standard .plist and/or HTML format.

The following options are supported:

-analyze-headers

Also analyze functions in #included files.

-enable-checker checker_name, -disable-checker checker_name

Enable/disable checker_name. See CHECKERS.

-h, --help

Display this message.

--help-checkers

List default checkers, see CHECKERS.

--html-title[=title]

Specify the title used on generated HTML pages. A default title is generated if title is not specified.

-k, --keep-going

Add a “keep on going” option to build_command. Currently supports make and xcodebuild. This is a convenience option; one can specify this behavior directly using build options.

-o

Target directory for HTML report files. Subdirectories will be created as needed to represent separate invocations of the analyzer. If this option is not specified, a directory is created in /tmp (TMPDIR on Mac OS X) to store the reports.

-plist

Output the results as a set of .plist files. (By default the output of scan-build is a set of HTML files.)

-plist-html

Output the results as a set of HTML and .plist files

--status-bugs

Set exit status to 1 if it found potential bugs and 0 otherwise. By default the exit status of scan-build is that returned by build_command.

--use-c++[=compiler_path]

Guess the default compiler for your C++ and Objective-C++ code. Use this option to specify an alternate compiler.

--use-cc[=compiler_path]

Guess the default compiler for your C and Objective-C code. Use this option to specify an alternate compiler.

-v

Verbose output from scan-build and the analyzer. A second and third v increases verbosity.

-V, --view

View analysis results in a web browser when the build completes.

-constraints [model]

Specify the contraint engine used by the analyzer. By default the ‘range’ model is used. Specifying ‘basic’ uses a simpler, less powerful constraint model used by checker-0.160 and earlier.

-maxloop N

Specify the number of times a block can be visited before giving up. Default is 4. Increase for more comprehensive coverage at a cost of speed.

-no-failure-reports

Do not create a ‘failures’ subdirectory that includes analyzer crash reports and preprocessed source files.

-stats

Generates visitation statistics for the project being analyzed.

-store [model]

Specify the store model used by the analyzer. By default, the ‘region’ store model is used. ‘region’ specifies a field- sensitive store model. Users can also specify ‘basic’ which is far less precise but can more quickly analyze code. ‘basic’ was the default store model for checker-0.221 and earlier.

EXIT STATUS¶

scan-build returns the value returned by build_command unless --status-bugs or --keep-going is used.

CHECKERS¶

The checkers listed below may be enabled/disabled using the -enable-checker and -disable-checker options. A default group of checkers is run unless explicitly disabled. Exactly which checkers constitute the default group is a function of the operating system in use; they are listed with --help-checkers.

core.AdjustedReturnValue

Check to see if the return value of a function call is different than the caller expects (e.g., from calls through function pointers).

core.AttributeNonNull

Check for null pointers passed as arguments to a function whose arguments are marked with the ‘nonnull’ attribute.

core.CallAndMessage

Check for logical errors for function calls and Objective-C message expressions (e.g., uninitialized arguments, null function pointers).

core.DivideZero

Check for division by zero.

core.NullDereference

Check for dereferences of null pointers.

core.StackAddressEscape

Check that addresses to stack memory do not escape the function.

core.UndefinedBinaryOperatorResult

Check for undefined results of binary operators.

core.VLASize

Check for declarations of VLA of undefined or zero size.

core.builtin.BuiltinFunctions

Evaluate compiler builtin functions, e.g. alloca().

core.builtin.NoReturnFunctions

Evaluate ‘panic’ functions that are known to not return to the caller.

core.uninitialized.ArraySubscript

Check for uninitialized values used as array subscripts.

core.uninitialized.Assign

Check for assigning uninitialized values.

core.uninitialized.Branch

Check for uninitialized values used as branch conditions.

core.uninitialized.CapturedBlockVariable

Check for blocks that capture uninitialized values.

core.uninitialized.UndefReturn

Check for uninitialized values being returned to the caller.

deadcode.DeadStores

Check for values stored to variables that are never read afterwards.

debug.DumpCFG

Display Control-Flow Graphs.

debug.DumpCallGraph

Display Call Graph.

debug.DumpDominators

Print the dominance tree for a given Control-Flow Graph.

debug.DumpLiveVars

Print results of live variable analysis.

debug.Stats

Emit warnings with analyzer statistics.

debug.TaintTest

Mark tainted symbols as such.

debug.ViewCFG

View Control-Flow Graphs using GraphViz.

debug.ViewCallGraph

View Call Graph using GraphViz.

llvm.Conventions

Check code for LLVM codebase conventions.

osx.API

Check for proper uses of various Mac OS X APIs.

osx.AtomicCAS

Evaluate calls to OSAtomic functions.

osx.SecKeychainAPI

Check for proper uses of Secure Keychain APIs.

osx.cocoa.AtSync

Check for null pointers used as mutexes for @synchronized.

osx.cocoa.ClassRelease

Check for sending ‘retain’, ‘release,’ or ‘autorelease’ directly to a Class.

osx.cocoa.IncompatibleMethodTypes

Warn about Objective-C method signatures with type incompatibilities.

osx.cocoa.NSAutoreleasePool

Warn for suboptimal uses of NSAutoreleasePool in Objective-C GC mode.

osx.cocoa.NSError

Check usage of NSError** parameters.

osx.cocoa.NilArg

Check for prohibited nil arguments to Objective-C method calls.

osx.cocoa.RetainCount

Check for leaks and improper reference count management.

osx.cocoa.SelfInit

Check that ‘self’ is properly initialized inside an initializer method.

osx.cocoa.UnusedIvars

Warn about private ivars that are never used.

osx.cocoa.VariadicMethodTypes

Check for passing non-Objective-C types to variadic methods that expect only Objective-C types.

osx.coreFoundation.CFError

Check usage of CFErrorRef* parameters.

osx.coreFoundation.CFNumber

Check for proper uses of CFNumberCreate().

osx.coreFoundation.CFRetainRelease

Check for null arguments to CFRetain(), CFRelease(), and CFMakeCollectable().

osx.coreFoundation.containers.OutOfBounds

Checks for index out-of-bounds when using the CFArray API.

osx.coreFoundation.containers.PointerSizedValues

Warns if CFArray, CFDictionary, or CFSet are created with non-pointer-size values.

security.FloatLoopCounter

Warn on using a floating point value as a loop counter (CERT: FLP30-C, FLP30-CPP).

security.insecureAPI.UncheckedReturn

Warn on uses of functions whose return values must be always checked.

security.insecureAPI.getpw

Warn on uses of getpw().

security.insecureAPI.gets

Warn on uses of gets().

security.insecureAPI.mkstemp

Warn when mkstemp() is passed fewer than 6 X's in the format string.

security.insecureAPI.mktemp

Warn on uses of mktemp().

security.insecureAPI.rand

Warn on uses of rand(), random(), and related functions.

security.insecureAPI.strcpy

Warn on uses of strcpy() and strcat().

security.insecureAPI.vfork

Warn on uses of vfork().

unix.API

Check calls to various UNIX/Posix functions.

unix.Malloc

Check for memory leaks, double free, and use-after-free.

unix.cstring.BadSizeArg

Check the size argument passed into C string functions for common erroneous patterns.

unix.cstring.NullArg

Check for null pointers being passed as arguments to C string functions.

EXAMPLE¶

scan-build -o /tmp/myhtmldir make -j4

The above example causes analysis reports to be deposited into a subdirectory of /tmp/myhtmldir and to run make with the -j4 option. A different subdirectory is created each time scan-build analyzes a project. The analyzer should support most parallel builds, but not distributed builds.

AUTHORS¶

scan-build was written by Ted Kremenek. Documentation contributed by
James K. Lowden ⟨jklowden@schemamania.org⟩.