[clang] bf55b9f - [analyzer][docs] Ellaborate the docs of cplusplus.StringChecker

[Balazs Benics via cfe-commits]

Author: Balazs Benics
Date: 2021-11-19T11:59:46+01:00
New Revision: bf55b9f0d0e938def5d24629325b271cbfc3b04a

URL: https://github.com/llvm/llvm-project/commit/bf55b9f0d0e938def5d24629325b271cbfc3b04a
DIFF: https://github.com/llvm/llvm-project/commit/bf55b9f0d0e938def5d24629325b271cbfc3b04a.diff

LOG: [analyzer][docs] Ellaborate the docs of cplusplus.StringChecker

Let's describe accurately what the users can expect from the checker in
a direct way.
Also, add an example warning message.

Reviewed By: martong, Szelethus

Differential Revision: https://reviews.llvm.org/D113401

Added: 
    

Modified: 
    clang/docs/analyzer/checkers.rst

Removed: 
    


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diff  --git a/clang/docs/analyzer/checkers.rst b/clang/docs/analyzer/checkers.rst
index 80cf3bc7c313..df62fb0643f8 100644
--- a/clang/docs/analyzer/checkers.rst
+++ b/clang/docs/analyzer/checkers.rst
@@ -319,13 +319,22 @@ cplusplus.StringChecker (C++)
 """""""""""""""""""""""""""""
 Checks std::string operations.
 
+Checks if the cstring pointer from which the ``std::string`` object is
+constructed is ``NULL`` or not.
+If the checker cannot reason about the nullness of the pointer it will assume
+that it was non-null to satisfy the precondition of the constructor.
+
+This checker is capable of checking the `SEI CERT C++ coding rule STR51-CPP.
+Do not attempt to create a std::string from a null pointer
+<https://wiki.sei.cmu.edu/confluence/x/E3s-BQ>`__.
+
 .. code-block:: cpp
 
  #include <string>
 
  void f(const char *p) {
    if (!p) {
-     std::string msg(p); // warn: p is NULL
+     std::string msg(p); // warn: The parameter must not be null
    }
  }