Language-design credit goes to a lot of people, but I particularly want
to single out Blaine Garst and Patrick Beard for their contributions.

Compiler implementation credit goes to Argyrios, Doug, Fariborz, and myself,
in no particular order.

llvm-svn: 133103

- (bounded copies) Be more conservative about how much is being copied.
- (str(n)cat) If we can't compute the exact final length of an append operation, we can still lower-bound it.
- (stpcpy) Fix the conjured return value at the end to actually be returned.

This requires these supporting changes:
- C string metadata symbols are still live even when buried in a SymExpr.
- "Hypothetical" C string lengths, to represent a value that /will/ be passed to setCStringLength() if all goes well. (The idea is to allow for temporary constrainable symbols that may end up becoming permanent.)
- The 'checkAdditionOverflow' helper makes sure that the two strings being appended in a strcat don't overflow size_t. This should never *actually* happen; the real effect is to keep the final string length from "wrapping around" in the constraint manager.

This doesn't actually test the "bounded" operations (strncpy and strncat) because they can leave strings unterminated. Next on the list!

llvm-svn: 133046

[analyzer] If a C string length is UnknownVal, clear any existing length binding. No tests yet because the only thing that sets string length is strcpy(), and that needs some work anyway.

llvm-svn: 133044

[analyzer] CStringChecker checks functions in the C standard library, not C++. Its external name is now unix.experimental.CString.

llvm-svn: 132958

llvm-svn: 132956

[analyzer] Fix modeling of strnlen to be more conservative. Move tests we can't properly model (yet?) to string-fail.c.

llvm-svn: 132955

llvm-svn: 132618

[analyzer] Don't crash when copying an unknown number of bytes with memcpy(). Also handle all memcpy-family return values in evalCopyCommon(), rather than having some outside and some inside.

llvm-svn: 132617

llvm-svn: 132614

llvm-svn: 132608

llvm-svn: 132607

llvm-svn: 132605

 - New isDefined() function checks for deletedness
 - isThisDeclarationADefinition checks for deletedness
 - New doesThisDeclarationHaveABody() does what
   isThisDeclarationADefinition() used to do
 - The IsDeleted bit is not propagated across redeclarations
 - isDeleted() now checks the canoncial declaration
 - New isDeletedAsWritten() does what it says on the tin.
 - isUserProvided() now correct (thanks Richard!)

This fixes the bug that we weren't catching

void foo() = delete;
void foo() {}

as being a redefinition.

llvm-svn: 131013

Removing strncpy() checking in CString checker for now. Some significant changes need to be made to properly support modeling of it since it potentially leaves strings non-null terminated.

llvm-svn: 130758

Augment retain/release checker to not warn about tracked objects passed as arguments to C++ constructors.  This is a stop-gap measure for Objective-C++ code that uses smart pointers to manage reference counts.

llvm-svn: 130711

Implements strncasecmp() checker and simplifies some of the logic around creating substrings if necessary and calling the appropriate StringRef::compare/compare_lower().

llvm-svn: 130708

llvm-svn: 130598

Use StringRef::substr() and unbounded StringRef::compare() instead of bounded version of StringRef::compare() because bounded version of StringRef::compare() is going to be removed.

llvm-svn: 130425

Eliminates an assert in the strncpy/strncat checker caused by not validating a cast was successful. If the value of an argument was unknown, the cast would result in a NULL pointer which was later being dereferenced.

This fixes Bugzilla #9806.

llvm-svn: 130422

llvm-svn: 130398

More accurately model realloc() when the size argument is 0. realloc() with a size of 0 is equivalent to free(). The memory region should be marked as free and not used again.

Unit tests f2_realloc_0(), f6_realloc(), and f7_realloc() contributed by Marshall Clow <mclow.lists@gmail.com>. Thanks! 

llvm-svn: 130303

Allow 'Environment::getSVal()' to allow an optional way for checkers to do a direct lookup to values bound to expressions, without
resulting to lazy logic.  This is critical for the OSAtomicChecker that does a simulated load on any arbitrary expression.

llvm-svn: 130292

Implements the strncmp() checker just like the strcmp() checker, but with bounds. Requires LLVM svn r129582.

llvm-svn: 130161

llvm-svn: 130068

llvm-svn: 129741

llvm-svn: 129567

Luis Felipe Strano Moraes!

llvm-svn: 129559

llvm-svn: 129395

Fix another IdempotentOperationsChecker corner case when determining if an active block on the worklist
impacts the results of the check.

llvm-svn: 129394

ArrayBoundCheckerV2: don't arbitrarily warn about indexing before the 0-index of a symbolic region.  In many cases that isn't really the base offset.

llvm-svn: 129366

This patch adds modeling of strcmp() to the CString checker. Validates inputs are not NULL and are real C strings, then does the comparison and binds the proper return value. Unit tests included. 

llvm-svn: 129364

Validates inputs are not NULL, checks for overlapping strings, concatenates the strings checking for buffer overflow, sets the length of the destination string to the sum of the s1 length and the s2 length, binds the return value to the s1 value.

llvm-svn: 129215

Add security syntax checker for strcat() which causes the Static Analyzer to generate a warning any time the strcat() function is used with a note suggesting to use a function which provides bounded buffers. CWE-119.

Also, brings the security syntax checker more inline with coding standards.

llvm-svn: 128916

Refactoring the security checker a little bit so that each CallExpr check doesn't get called for each CallExpr. Instead it does a switch and only runs the check for the proper identifier. Slight speed improvement (probably significant on very large ASTs), and should make it easier and more clear to add more checks for other CallExpr's later.

llvm-svn: 128785

llvm-svn: 128762

Teach IdempotentOperationsChecker about paths aborted because ExprEngine didn't know how to handle a specific Expr type.

llvm-svn: 128761

static analyzer: Rename 'BlocksAborted' to 'BlocksExhausted' to reflect that a given CFGBlock was analyzed too many times.

llvm-svn: 128760

Add security syntax checker for strcpy() which causes the Static Analyzer to generate a warning any time the strcpy() function is used with a note suggesting to use a function which provides bounded buffers. 

llvm-svn: 128679

Models mempcpy() so that if length is NULL the destination pointer is returned. Otherwise, the source and destination are confirmed not to be NULL and not overlapping. Finally the copy is validated to not cause a buffer overrun and the return value is bound to the address of the byte after the last byte copied.

llvm-svn: 128677

llvm-svn: 128670