[clang-tools-extra] r318906 - [clang-tidy] Misplaced Operator in Strlen in Alloc

[Adam Balogh via cfe-commits]

Author: baloghadamsoftware
Date: Thu Nov 23 04:26:28 2017
New Revision: 318906

URL: http://llvm.org/viewvc/llvm-project?rev=318906&view=rev
Log:
[clang-tidy] Misplaced Operator in Strlen in Alloc

A possible error is to write `malloc(strlen(s+1))` instead of
`malloc(strlen(s)+1)`. Unfortunately the former is also valid syntactically,
but allocates less memory by two bytes (if s` is at least one character long,
undefined behavior otherwise) which may result in overflow cases. This check
detects such cases and also suggests the fix for them.


Modified:
    clang-tools-extra/trunk/clang-tidy/bugprone/BugproneTidyModule.cpp
    clang-tools-extra/trunk/clang-tidy/bugprone/CMakeLists.txt
    clang-tools-extra/trunk/docs/ReleaseNotes.rst
    clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst

Modified: clang-tools-extra/trunk/clang-tidy/bugprone/BugproneTidyModule.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/bugprone/BugproneTidyModule.cpp?rev=318906&r1=318905&r2=318906&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/bugprone/BugproneTidyModule.cpp (original)
+++ clang-tools-extra/trunk/clang-tidy/bugprone/BugproneTidyModule.cpp Thu Nov 23 04:26:28 2017
@@ -12,6 +12,7 @@
 #include "../ClangTidyModuleRegistry.h"
 #include "CopyConstructorInitCheck.h"
 #include "IntegerDivisionCheck.h"
+#include "MisplacedOperatorInStrlenInAllocCheck.h"
 #include "SuspiciousMemsetUsageCheck.h"
 #include "UndefinedMemoryManipulationCheck.h"
 
@@ -26,6 +27,8 @@ public:
         "bugprone-copy-constructor-init");
     CheckFactories.registerCheck<IntegerDivisionCheck>(
         "bugprone-integer-division");
+    CheckFactories.registerCheck<MisplacedOperatorInStrlenInAllocCheck>(
+        "bugprone-misplaced-operator-in-strlen-in-alloc");
     CheckFactories.registerCheck<SuspiciousMemsetUsageCheck>(
         "bugprone-suspicious-memset-usage");
     CheckFactories.registerCheck<UndefinedMemoryManipulationCheck>(

Modified: clang-tools-extra/trunk/clang-tidy/bugprone/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/bugprone/CMakeLists.txt?rev=318906&r1=318905&r2=318906&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/bugprone/CMakeLists.txt (original)
+++ clang-tools-extra/trunk/clang-tidy/bugprone/CMakeLists.txt Thu Nov 23 04:26:28 2017
@@ -4,6 +4,7 @@ add_clang_library(clangTidyBugproneModul
   BugproneTidyModule.cpp
   CopyConstructorInitCheck.cpp
   IntegerDivisionCheck.cpp
+  MisplacedOperatorInStrlenInAllocCheck.cpp
   SuspiciousMemsetUsageCheck.cpp
   UndefinedMemoryManipulationCheck.cpp
 

Modified: clang-tools-extra/trunk/docs/ReleaseNotes.rst
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/ReleaseNotes.rst?rev=318906&r1=318905&r2=318906&view=diff
==============================================================================
--- clang-tools-extra/trunk/docs/ReleaseNotes.rst (original)
+++ clang-tools-extra/trunk/docs/ReleaseNotes.rst Thu Nov 23 04:26:28 2017
@@ -85,6 +85,15 @@ Improvements to clang-tidy
   not intended to be subclassed. Includes a list of classes from Foundation
   and UIKit which are documented as not supporting subclassing.
 
+- New `bugprone-misplaced-operator-in-strlen-in-alloc
+  <http://clang.llvm.org/extra/clang-tidy/checks/bugprone-misplaced-operator-in-strlen-in-alloc.html>`_ check
+
+  Finds cases where ``1`` is added to the string in the argument to
+  ``strlen()``, ``strnlen()``, ``strnlen_s()``, ``wcslen()``, ``wcsnlen()``, and
+  ``wcsnlen_s()`` instead of the result and the value is used as an argument to
+  a memory allocation function (``malloc()``, ``calloc()``, ``realloc()``,
+  ``alloca()``).
+
 - Renamed checks to use correct term "implicit conversion" instead of "implicit
   cast" and modified messages and option names accordingly:
 

Modified: clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst?rev=318906&r1=318905&r2=318906&view=diff
==============================================================================
--- clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst (original)
+++ clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst Thu Nov 23 04:26:28 2017
@@ -19,6 +19,7 @@ Clang-Tidy Checks
    boost-use-to-string
    bugprone-copy-constructor-init
    bugprone-integer-division
+   bugprone-misplaced-operator-in-strlen-in-alloc
    bugprone-suspicious-memset-usage
    bugprone-undefined-memory-manipulation
    cert-dcl03-c (redirects to misc-static-assert) <cert-dcl03-c>