Add a clang-tidy check that flags string-to-number conversion functions that have insufficient error checking, suggesting a better alternative.

This check corresponds to: https://www.securecoding.cert.org/confluence/display/c/ERR34-C.+Detect+errors+when+converting+a+string+to+a+number

llvm-svn: 268100

2 files changed, 29 insertions, 0 deletions

diff --git a/clang-tools-extra/docs/clang-tidy/checks/cert-err34-c.rst b/clang-tools-extra/docs/clang-tidy/checks/cert-err34-c.rst
new file mode 100644
index 00000000000..11a8ceca0a1
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/cert-err34-c.rst
@@ -0,0 +1,28 @@
+.. title:: clang-tidy - cert-err34-c
+
+cert-err34-c
+============
+
+This check flags calls to string-to-number conversion functions that do not
+verify the validity of the conversion, such as ``atoi()`` or ``scanf()``. It
+does not flag calls to ``strtol()``, or other, related conversion functions that
+do perform better error checking.
+
+.. code:: c
+
+  #include <stdlib.h>
+  
+  void func(const char *buff) {
+    int si;
+    
+    if (buff) {
+      si = atoi(buff); /* 'atoi' used to convert a string to an integer, but function will
+                           not report conversion errors; consider using 'strtol' instead. */
+    } else {
+      /* Handle error */
+    }
+  }
+
+This check corresponds to the CERT C Coding Standard rule
+`ERR34-C. Detect errors when converting a string to a number
+<https://www.securecoding.cert.org/confluence/display/c/ERR34-C.+Detect+errors+when+converting+a+string+to+a+number>`_.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index 267eb314017..cff26126050 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -11,6 +11,7 @@ Clang-Tidy Checks
    cert-dcl54-cpp (redirects to misc-new-delete-overloads) <cert-dcl54-cpp>
    cert-dcl59-cpp (redirects to google-build-namespaces) <cert-dcl59-cpp>
    cert-env33-c
+   cert-err34-c
    cert-err52-cpp
    cert-err58-cpp
    cert-err60-cpp