Commit Graph

2701 Commits

Author SHA1 Message Date
Richard Trieu c771d5d79f Move the logic for testing for namespace std into one location. This check can
be performed by using Decl::isInStdNamespace or DeclContext::isStdNamespace

llvm-svn: 209708
2014-05-28 02:16:01 +00:00
Manuel Klimek 5fbdc93d97 Make dead return statement detection more robust against changes in the CFG.
This change is a precondition to the proposed change to handle temporary
dtors correctly.

The idea is to explicitly search for the next return that doesn't have other
paths into it (that is, if the current block is dead, the block containing the
return must be dead, too). Thus, introducing non-control-flow block
transitions will not break the logic.

llvm-svn: 209531
2014-05-23 17:09:56 +00:00
Jordan Rose 7afd71e4ff Add a check for tautological bitwise comparisons to -Wtautological-compare.
This catches issues like:

if ((x & 8) == 4) { ... }
if ((x | 4) != 3) { ... }

Patch by Anders Rönnholm!

llvm-svn: 209221
2014-05-20 17:31:11 +00:00
Craig Topper 2554294321 [C++11] Use 'nullptr'. Analysis edition.
llvm-svn: 209191
2014-05-20 04:30:07 +00:00
DeLesley Hutchins f4b5e7c60f Thread Safety Analysis: add new node types to thread safety TIL.
This fills in a few missing gaps in functionality.

llvm-svn: 208830
2014-05-15 00:50:36 +00:00
Aaron Ballman 9ee54d119c Converting some for loops to use range-based for loops. No functional changes intended.
llvm-svn: 208810
2014-05-14 20:42:13 +00:00
Aaron Ballman 59a72b93a2 Amending r208783 based on a suggestion by David Blaikie.
llvm-svn: 208800
2014-05-14 18:32:59 +00:00
Aaron Ballman 42f9a8a7f9 Replacing some manual iterations with standard algorithms. No functional changes intended.
llvm-svn: 208783
2014-05-14 15:01:43 +00:00
Aaron Ballman 2f3fc6badd Formatting and style changes; no functional changes intended.
llvm-svn: 208774
2014-05-14 13:03:55 +00:00
Aaron Ballman 0c6a14ca82 Amending r208439 to remove buildLExpr; this code isn't strictly required yet, and fixes a dead code warning.
llvm-svn: 208440
2014-05-09 18:44:48 +00:00
Aaron Ballman 7c192b452f Add the ability to use logical expressions for capability attributes. This is to allow requirements to be expressed not just in terms of lists, but in terms of logical expressions. Eg)
void foo(void) __attribute__((requires_capability((FlightControl || Worker) && !Logger)));

This is WIP code.

llvm-svn: 208439
2014-05-09 18:26:23 +00:00
Benjamin Kramer a7bcab75d2 ThreadSafetyAnalysis: Don't crash when trying to analyze objc methods.
The thread safety analysis isn't very useful in ObjC (you can't annotate
ObjC classes or methods) but we can still analyze the actual code and
show violations in usage of C/C++ functions.

Fixes PR19541, which does not use thread safety attributes but crashes
with -Weverything.

llvm-svn: 208436
2014-05-09 17:08:01 +00:00
Manuel Klimek b33bded176 Explicitly keep track of temporaries during the consumed analysis.
This makes the consumed analysis less dependent on the CFG layout and fixes
a bug where we wouldn't warn on an unconsumed value.

llvm-svn: 208300
2014-05-08 11:50:00 +00:00
Manuel Klimek 75f34c1386 Fix handling of condition variables in the face of temp dtors.
The assignment needs to be before the destruction of the temporary.
This patch calls out to addStmt, which invokes VisitDeclStmt, which has
all the correct logic for handling temporaries.

llvm-svn: 207985
2014-05-05 18:21:06 +00:00
Nico Weber b0f9e4ace7 Remove unused typedef found by gcc's -Wunused-local-typedefs.
llvm-svn: 207870
2014-05-02 21:22:21 +00:00
Hans Wennborg 802df13e4d Fix bad comment from r207573.
llvm-svn: 207854
2014-05-02 18:12:30 +00:00
Aaron Ballman a82eaa70f1 Updated the attribute tablegen emitter for variadic arguments to emit a range accessor in addition to the iterators. Updated code using iterators to use range-based for loops.
llvm-svn: 207837
2014-05-02 13:35:42 +00:00
Aaron Ballman 73b3651e9d Renaming the CallableState variadic attribute argument to be CallableStates. No functional changes intended.
llvm-svn: 207836
2014-05-02 13:17:57 +00:00
Hans Wennborg df51ee6c50 scanf analysis: handle scanlists that start with ^] (PR19559)
llvm-svn: 207573
2014-04-29 19:42:27 +00:00
Aaron Ballman 35897d97a3 Renaming range-based for loop variables so they don't appear iterator-like.
llvm-svn: 207422
2014-04-28 14:56:59 +00:00
Aaron Ballman fe46e62e99 [C++11] Converting to range-based for loops. No functional changes intended.
llvm-svn: 207416
2014-04-28 13:01:32 +00:00
Aaron Ballman 8e8026d5b3 Replacing a naked pointer with a unique_ptr. No functional changes intended.
llvm-svn: 206986
2014-04-23 14:26:59 +00:00
Aaron Ballman bf58a6a892 Updated to be a bit more const friendly. Also switched the linkage to be static since this function is file-local. No functional changes intended.
llvm-svn: 206982
2014-04-23 13:58:21 +00:00
DeLesley Hutchins f1a311653a Thread safety analysis: add array operations to SExpr.
llvm-svn: 206907
2014-04-22 17:31:23 +00:00
DeLesley Hutchins 7834001496 Thread safety analysis: fix warning.
llvm-svn: 206899
2014-04-22 14:51:04 +00:00
Chandler Carruth 1034666777 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, clang edition.

If you want more details about this, you can see some of the commits to
Debug.h in LLVM recently. This is just the clang section of a cleanup
I've done for all uses of DEBUG_TYPE in LLVM.

llvm-svn: 206849
2014-04-22 03:17:02 +00:00
DeLesley Hutchins f8b412adbb Thread safety analysis: misc updates to SExpr handling. Fix to minimal SSA,
function parameters, and compound assignment.

llvm-svn: 206827
2014-04-21 23:18:18 +00:00
DeLesley Hutchins a9db0019a2 Thread Safety Analysis: Convert to minimal SSA.
llvm-svn: 206681
2014-04-19 03:54:41 +00:00
DeLesley Hutchins ae497deddf Thread Safety Analysis: Update SSA pass to handle loops.
llvm-svn: 206676
2014-04-19 00:35:54 +00:00
Aaron Ballman 0491afaf5f Updating to use more range-based for loops, nullptr and auto. No functional changes.
llvm-svn: 206590
2014-04-18 13:13:15 +00:00
Aaron Ballman e80bfcd048 Making some public members into private members. This also introduces a bit more const-correctness, and now uses some range-based for loops. No functional changes intended.
llvm-svn: 206503
2014-04-17 21:44:08 +00:00
Aaron Ballman ed5aced64e Since the object is new'ed in the enterCFG function, now deleting in the exitCFG function instead of the destructor to ensure proper pairing. This allows reuse of the builder without creating a memory leak.
llvm-svn: 206471
2014-04-17 15:23:50 +00:00
Ted Kremenek 6f375e5604 -Wunreachable-code: refine recognition of unreachable "sigil" to cope with implicit casts in C++.
Fixes <rdar://problem/16631033>.

llvm-svn: 206360
2014-04-16 07:26:09 +00:00
DeLesley Hutchins aab9aff058 Thread Safety Analysis: rewrite SSA pass to use the new SExpr and CFG
traversal system.  The new pass is still undergoing testing; no change in
functionality.

llvm-svn: 206338
2014-04-15 23:23:19 +00:00
Richard Trieu e729d9b598 Fix typo from r206232
llvm-svn: 206234
2014-04-15 01:06:38 +00:00
Richard Trieu e9fa266cba Fix a bad interaction between -Wtautological-overlap-compare and delayed
diagnostics which caused delayed diagnostics on dead paths to be emitted.

llvm-svn: 206232
2014-04-15 00:57:50 +00:00
DeLesley Hutchins 7e615c2f65 Thread Safety Analysis: reorganized SExpr header files. No change in
functionality.

llvm-svn: 205936
2014-04-09 22:39:43 +00:00
Aaron Ballman 28347a72c9 Thread Safety Analysis: now with less includes. No functional changes.
llvm-svn: 205929
2014-04-09 21:12:04 +00:00
Aaron Ballman 3f993c1320 Thread Safety Analysis: some minor cleanups to the latest thread safety changes. No functional changes intended.
* Adds an iterator_range interface to CallExpr to get the arguments
* Modifies SExpr such that it must be allocated in the Arena, and cannot be deleted
* Minor const-correctness and nullptr updates
* Adds some operator!= implementations to complement operator==
* Removes unused functionality

llvm-svn: 205915
2014-04-09 17:45:44 +00:00
DeLesley Hutchins f7813c56b4 Thread Safety Analysis. Misc fixes to SExpr code, responding to code review
by Aaron Ballman.

llvm-svn: 205809
2014-04-08 22:21:22 +00:00
DeLesley Hutchins 11bb308739 Thread Safety Analysis: various fixes to new SExpr code.
Implemented ownership policy, updated to use nullptr, const-cleanup.

llvm-svn: 205745
2014-04-07 22:56:24 +00:00
DeLesley Hutchins b2213910de Thread Safety Analysis: update to internal SExpr handling.
This patch is the first part of a significant refactoring that seeks to restore
sanity to way thread safety analysis deals with capability expressions.  The
current patch merely provides an outline of the structure of the new system.
It's not yet connected to the actual analysis, so there's no change in
functionality.

llvm-svn: 205728
2014-04-07 18:09:54 +00:00
Richard Trieu f935b562b9 Add a new subgroup to -Wtautological-compare, -Wtautological-overlap-compare,
which warns on compound conditionals that always evaluate to the same value.
For instance, (x > 5 && x < 3) will always be false since no value for x can
satisfy both conditions.

This patch also changes the CFG to use these tautological values for better
branch analysis.  The test for -Wunreachable-code shows how this change catches
additional dead code.

Patch by Anders Rönnholm.

llvm-svn: 205665
2014-04-05 05:17:01 +00:00
Aaron Ballman e044904301 Updating the capability attribute diagnostics to be more capability-neutral. Instead of using terminology such as "lock", "unlock" and "locked", the new terminology is "acquire", "release" and "held". Additionally, the capability attribute's name argument is now reported as part of the diagnostic, instead of hard coding as "mutex."
llvm-svn: 205359
2014-04-01 21:43:23 +00:00
Jordan Rose 398fb00e1e [analyzer] Fix a CFG printing bug.
Also, add several destructor-related tests. Most of them don't work yet, but it's
good to have them recorded.

Patch by Alex McCarthy!

llvm-svn: 205326
2014-04-01 16:39:33 +00:00
Ted Kremenek ab57a1555a [-Wunreachable-code] Expand paren-suppression heuristic to C++/ObjC bools.
llvm-svn: 205074
2014-03-29 04:49:20 +00:00
Ted Kremenek ec3bbf4933 Improve -Wunreachable-code to provide a means to indicate code is intentionally marked dead via if((0)).
Taking a hint from -Wparentheses, use an extra '()' as a sigil that
a dead condition is intentionally dead.  For example:

  if ((0)) { dead }

When this sigil is found, do not emit a dead code warning.  When the
analysis sees:

  if (0)

it suggests inserting '()' as a Fix-It.

llvm-svn: 205069
2014-03-29 00:35:20 +00:00
Nuno Lopes fb744589bc remove a bunch of unused private methods
found with a smarter version of -Wunused-member-function that I'm playwing with.
Appologies in advance if I removed someone's WIP code.

 ARCMigrate/TransProperties.cpp                  |    8 -----
 AST/MicrosoftMangle.cpp                         |    1 
 Analysis/AnalysisDeclContext.cpp                |    5 ---
 Analysis/LiveVariables.cpp                      |   14 ----------
 Index/USRGeneration.cpp                         |   10 -------
 Sema/Sema.cpp                                   |   33 +++++++++++++++++++++---
 Sema/SemaChecking.cpp                           |    3 --
 Sema/SemaDecl.cpp                               |   20 ++------------
 StaticAnalyzer/Checkers/GenericTaintChecker.cpp |    1 
 9 files changed, 34 insertions(+), 61 deletions(-)

llvm-svn: 204561
2014-03-23 17:12:37 +00:00
Aaron Ballman df115d9bf3 The release_capability, release_shared_capability and release_generic_capability functions are now functionally distinct for capability analysis. The unlock_function attribute maps directly to release_generic_capability.
llvm-svn: 204469
2014-03-21 14:48:48 +00:00
Ted Kremenek 1421037ece [-Wunreachable-code] add a specialized diagnostic for unreachable increment expressions of loops.
llvm-svn: 204430
2014-03-21 06:02:36 +00:00
DeLesley Hutchins d7fa5bd431 Consumed Analysis: IgnoreParens bugfix.
llvm-svn: 204395
2014-03-20 20:39:20 +00:00
Ted Kremenek d4576318b4 [-Wunreachable-code] Tweak isTrivialDoWhile() to handle implicit casts.
llvm-svn: 204376
2014-03-20 18:47:53 +00:00
Aaron Ballman 18d85aed39 Replacing the exclusive_lock_function, shared_lock_function and unlock_function attributes with the acquire_capability and release_capability attributes. The old spellings will continue to work, but the underlying semantic attributes have been replaced.
Downgraded the capability diagnostics from error to warning to match the desired behavior, and updated the existing test cases.

llvm-svn: 204350
2014-03-20 16:02:49 +00:00
Ted Kremenek f5ae0bc671 [-Wunreachable-code] Look through member accesses for 'static const bool' configuration values.
llvm-svn: 204315
2014-03-20 06:44:35 +00:00
Ted Kremenek 2766ad27e8 [-Wunreachable-code] constexpr functions can be used as configuration values.
llvm-svn: 204308
2014-03-20 06:07:35 +00:00
Ted Kremenek f3c93bb61b [-Wunreachable-code] Simplify and broad -Wunreachable-code-return, including nontrivial returns.
The exception is return statements that include control-flow,
which are clearly doing something "interesting".

99% of the cases I examined for -Wunreachable-code that fired
on return statements were not interesting enough to warrant
being in -Wunreachable-code by default.  Thus the move to
include them in -Wunreachable-code-return.

This simplifies a bunch of logic, including removing the ad hoc
logic to look for std::string literals.

llvm-svn: 204307
2014-03-20 06:07:30 +00:00
Jordan Rose 177b0a3600 scanf format checking: include the buffer length in the fix-it for %s.
Patch by Zach Davis!

llvm-svn: 204300
2014-03-20 03:32:39 +00:00
Aaron Ballman c7e4e219b5 [C++11] Replacing CompoundStmt iterators body_begin() and body_end() with iterator_range body(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 204040
2014-03-17 14:19:37 +00:00
Benjamin Kramer 8cef8867ee Remove dead functions from unreachable code analysis.
llvm-svn: 204004
2014-03-15 10:20:49 +00:00
Ted Kremenek 9dfe400dc2 -Wunreachable-code: treat 'const bool' locals as control values.
llvm-svn: 204001
2014-03-15 06:47:45 +00:00
Ted Kremenek ad8753c00e Further refine -Wunreachable-code groups so that -Wno-unreachable-code-break doesn't turn off all unreachable code warnings.
Also relax unreachable 'break' and 'return' to not check for being
preceded by a call to 'noreturn'.  That turns out to not be so
interesting in practice.

llvm-svn: 204000
2014-03-15 05:47:06 +00:00
Ted Kremenek 1a8641c1e7 Start breaking -Wunreachable-code up into different diagnostic groups.
Recent work on -Wunreachable-code has focused on suppressing uninteresting
unreachable code that center around "configuration values", but
there are still some set of cases that are sometimes interesting
or uninteresting depending on the codebase.  For example, a dead
"break" statement may not be interesting for a particular codebase,
potentially because it is auto-generated or simply because code
is written defensively.

To address these workflow differences, -Wunreachable-code is now
broken into several diagnostic groups:

-Wunreachable-code: intended to be a reasonable "default" for
most users.

and then other groups that turn on more aggressive checking:

-Wunreachable-code-break: warn about dead break statements

-Wunreachable-code-trivial-return: warn about dead return statements
that return "trivial" values (e.g., return 0).  Other return
statements that return non-trivial values are still reported
under -Wunreachable-code (this is an area subject to more refinement).

-Wunreachable-code-aggressive: supergroup that enables all these
groups.

The goal is to eventually make -Wunreachable-code good enough to
either be in -Wall or on-by-default, thus finessing these warnings
into different groups helps achieve maximum signal for more users.

TODO: the tests need to be updated to reflect this extra control
via diagnostic flags.

llvm-svn: 203994
2014-03-15 01:26:32 +00:00
Aaron Ballman 9371dd2287 [C++11] Replacing BlockDecl iterators capture_begin() and capture_end() with iterator_range captures(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203958
2014-03-14 18:34:04 +00:00
Aaron Ballman 535bbcccb1 [C++11] Replacing DeclStmt iterators decl_begin() and decl_end() with iterator_range decls(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203947
2014-03-14 17:01:24 +00:00
Aaron Ballman d85eff49a3 [C++11] Replacing ObjCCategoryDecl iterators propimpl_begin() and propimpl_end() with iterator_range property_impls(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203930
2014-03-14 15:02:45 +00:00
Craig Topper b45acb8a16 [C++11] Add 'override' keyword to virtual methods that override their base class.
llvm-svn: 203893
2014-03-14 06:02:07 +00:00
Aaron Ballman 0ad78303de [C++11] Replacing CXXRecordDecl iterators init_begin() and init_end() with iterator_range inits(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203819
2014-03-13 17:34:31 +00:00
Aaron Ballman 445a939db8 [C++11] Replacing CXXRecordDecl iterators vbases_begin() and vbases_end() with iterator_range vbases(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203808
2014-03-13 16:15:17 +00:00
Aaron Ballman 574705ed7f [C++11] Replacing CXXRecordDecl iterators bases_begin() and bases_end() with iterator_range bases(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203803
2014-03-13 15:41:46 +00:00
DeLesley Hutchins d1c9b37db9 Thread safety analysis: move smart pointer checks from -Wthread-safety-beta
to -Wthread-safety.

llvm-svn: 203510
2014-03-10 23:03:49 +00:00
Aaron Ballman be22bcb180 [C++11] Replacing DeclBase iterators specific_attr_begin() and specific_attr_end() with iterator_range specific_attrs(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203474
2014-03-10 17:08:28 +00:00
Ahmed Charles dfca6f97bc [C++11] Replace OwningPtr include with <memory>.
llvm-svn: 203389
2014-03-09 11:36:40 +00:00
Ted Kremenek 2dd810a331 [-Wunreachable-code] Handle Objective-C bool literals in 'isConfigurationValue'.
This includes special casing 'YES' and 'NO', which are constants
defined as macros.

llvm-svn: 203380
2014-03-09 08:13:49 +00:00
Ted Kremenek c980afc578 [-Wunreachable-code] Tweak heuristic for configuration values to include arithmetic operations involving sizeof(), but not raw integers.
This case was motivated by a false positive with the
llvm::AlignOf<> specialization in LLVM.

llvm-svn: 203363
2014-03-08 23:20:11 +00:00
Aaron Ballman e8a8baef44 [C++11] Replacing RecordDecl iterators field_begin() and field_end() with iterator_range fields(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203355
2014-03-08 20:12:42 +00:00
Ted Kremenek efea63450b [-Wunreachabe-code] Don't warn about unreachable destructors for temporaries.
This can possibly be refined later, but right now the experience
is so incomprehensible for a user to understand what is going on
this isn't a useful warning.

llvm-svn: 203336
2014-03-08 02:22:32 +00:00
Ted Kremenek fcc1417fad Fix CFG bug where the 'isTemporaryDtorsBranch' bit was silently lost for terminators.
llvm-svn: 203335
2014-03-08 02:22:29 +00:00
Ted Kremenek ff909f907c [CFG] Record would-be successor for noreturn destructor.
llvm-svn: 203334
2014-03-08 02:22:25 +00:00
Ted Kremenek 04bfbeea04 [-Wunreachable-code] Handle 'return' with no argument dominated by 'noreturn' function.
llvm-svn: 203333
2014-03-08 02:22:23 +00:00
Benjamin Kramer 4cadf292a5 [C++11] Revert uses of lambdas with array_pod_sort.
Looks like GCC implements the lambda->function pointer conversion differently.

llvm-svn: 203293
2014-03-07 21:51:58 +00:00
Benjamin Kramer 15ae783e14 [C++11] Convert sort predicates into lambdas.
No functionality change.

llvm-svn: 203289
2014-03-07 21:35:40 +00:00
Ted Kremenek 94d1617a1f [-Wunreachable-code] Treat constant globals as configuration values in unreachable code heuristics.
This one could possibly be refined even further; e.g. looking
at the initializer and see if it is truly a configuration value.

llvm-svn: 203283
2014-03-07 20:51:13 +00:00
Ahmed Charles b89843299a Replace OwningPtr with std::unique_ptr.
This compiles cleanly with lldb/lld/clang-tools-extra/llvm.

llvm-svn: 203279
2014-03-07 20:03:18 +00:00
Aaron Ballman 629afaefe0 [C++11] Replacing DeclBase iterators decls_begin() and decls_end() with iterator_range decls(). The same is true for the noload versions of these APIs. Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203278
2014-03-07 19:56:05 +00:00
Ahmed Charles 9a16beb8bc Change OwningPtr::take() to OwningPtr::release().
This is a precursor to moving to std::unique_ptr.

llvm-svn: 203275
2014-03-07 19:33:25 +00:00
Aaron Ballman f6bf62e2d0 [C++11] Replacing FunctionDecl iterators param_begin() and param_end() with iterator_range params(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203248
2014-03-07 15:12:56 +00:00
Ted Kremenek 7d47cace55 Fix recent regressions in -Wreturn-type caused by heuristics to -Wunreachable-code.
I had forgotten that the same reachability code is used by both -Wreturn-type
and -Wunreachable-code, so the heuristics applied to the latter were indirectly
impacting the former.

To address this, the reachability code is more refactored so that whiled
the logic at its core is shared, the intention of the clients are better
captured and segregated in helper APIs.

Fixes PR19074, and also some false positives reported offline to me
by Nick Lewycky.

llvm-svn: 203209
2014-03-07 07:14:36 +00:00
Ted Kremenek 782f003c62 [-Wunreachable-code] Correctly expand artificial reachability to pruned '&&' and '||' branches involving configuration values.
llvm-svn: 203194
2014-03-07 02:25:53 +00:00
Ted Kremenek c10830b308 [-Wunreachable-code] Teach reachable code analysis heuristics about more literal types.
llvm-svn: 203193
2014-03-07 02:25:50 +00:00
Aaron Ballman 69bb592ad1 Based on usage, the NamedDecl is always set when constructing a CallingContext, but none of the other optional parameters are. Removing the optional parameters, and making the NamedDecl required.
No functional changes intended.

llvm-svn: 203149
2014-03-06 19:37:24 +00:00
Aaron Ballman 19842c437a Refactored to use a simple helper function that wraps the logic of creating an SExprNode and returning the position in which it was inserted.
No functional change intended.

llvm-svn: 203148
2014-03-06 19:25:11 +00:00
Aaron Ballman cea2609b59 Very minor simplification and typo correction; no functional changes intended.
llvm-svn: 203144
2014-03-06 19:10:16 +00:00
Ted Kremenek 6999d02587 [-Wunreachable-code] Refine treating all branches of 'switch' as reachable, which includes those with all cases covered but with no 'default:'.
llvm-svn: 203094
2014-03-06 08:09:00 +00:00
Ted Kremenek ec2dc73e86 [-Wunreachable-code] don't warn about dead 'return <string literal>' dominated by a 'noreturn' call, where literal becomes an std::string.
I have mixed feelings about this one.  It's used all over the codebase,
and is analogous to the current heuristic for ordinary C string literals.

This requires some ad hoc pattern matching of the AST.  While the
test case mirrors what we see std::string in libc++, it's not really
testing the libc++ headers.

llvm-svn: 203091
2014-03-06 06:50:46 +00:00
Ted Kremenek 7549f0f9bf [-Wunreachable-code] Handle idiomatic do...while() with an uninteresting condition.
Sometimes do..while() is used to create a scope that can be left early.
In such cases, the unreachable 'while()' test is not usually interesting
unless it actually does something that is observable.

llvm-svn: 203051
2014-03-06 01:09:45 +00:00
Ted Kremenek 1de2e14f2f [-Wunreachable-code] Handle idiomatic do...while() with an uninteresting condition.
Sometimes do..while() is used to create a scope that can be left early.
In such cases, the unreachable 'while()' test is not usually interesting
unless it actually does something that is observable.

llvm-svn: 203036
2014-03-06 00:17:44 +00:00
Ted Kremenek 0a69cabd35 [-Wunreachable-code] generalize pruning out warning on trivial returns.
Previously we only pruned dead returns preceded by a call to a
'noreturn' function.  After looking at the results of the LLVM codebase,
there are many others that should be pruned as well.

llvm-svn: 203029
2014-03-05 23:46:07 +00:00
Ted Kremenek 01a39b601f [-Wunreachable-code] include some enum constants in "configuration value" heuristic
llvm-svn: 203026
2014-03-05 23:38:41 +00:00
Ted Kremenek 3cdbc39a6e [-Wunreachable-code] generalize configuration value checking to all comparison operators.
llvm-svn: 203016
2014-03-05 22:32:39 +00:00
Ted Kremenek 6d9bb56cd3 [-Wunreachable-code] Don't warn about dead code guarded by a "configuration value".
Some unreachable code is only "sometimes unreachable" because it
is guarded by a configuration value that is determined at compile
time and is always constant.  Sometimes those represent real bugs,
but often they do not.  This patch causes the reachability analysis
to cover such branches even if they are technically unreachable
in the CFG itself.  There are some conservative heuristics at
play here to determine a "configuration value"; these are intended
to be refined over time.

llvm-svn: 202912
2014-03-05 00:01:17 +00:00