Documentation for sanitizer special case list format and -f(no-)?sanitize-blacklist flag

llvm-svn: 187871

6 files changed, 135 insertions, 0 deletions

diff --git a/clang/docs/AddressSanitizer.rst b/clang/docs/AddressSanitizer.rst
index 89e86445000..ec97136b097 100644
--- a/clang/docs/AddressSanitizer.rst
+++ b/clang/docs/AddressSanitizer.rst
@@ -126,6 +126,36 @@ globals defined in another translation unit. To enable this check at runtime,
 you should set environment variable
 ``ASAN_OPTIONS=check_initialization_order=1``.
 
+Blacklist
+---------
+
+AddressSanitizer supports ``src`` and ``fun`` entity types in
+:doc:`SanitizerSpecialCaseList`, that can be used to suppress error reports
+in the specified source files or functions. Additionally, AddressSanitizer
+introduces ``global`` and ``type`` entity types that can be used to
+suppress error reports for out-of-bound access to globals with certain
+names and types (you may only specify class or struct types).
+
+You may use an ``init`` category to suppress reports about initialization-order
+problems happening in certain source files or with certain global variables.
+
+.. code-block:: bash
+
+    # Suppress error reports for code in a file or in a function:
+    src:bad_file.cpp
+    # Ignore all functions with names containing MyFooBar:
+    fun:*MyFooBar*
+    # Disable out-of-bound checks for global:
+    global:bad_array
+    # Disable out-of-bound checks for global instances of a given class ...
+    type:class.Namespace::BadClassName
+    # ... or a given struct. Use wildcard to deal with anonymous namespace.
+    type:struct.Namespace2::*::BadStructName
+    # Disable initialization-order checks for globals:
+    global:bad_init_global=init
+    type:*BadInitClassSubstring*=init
+    src:bad/init/files/*=init
+
 Supported Platforms
 ===================
 
diff --git a/clang/docs/MemorySanitizer.rst b/clang/docs/MemorySanitizer.rst
index 439acc47fa2..6039addad64 100644
--- a/clang/docs/MemorySanitizer.rst
+++ b/clang/docs/MemorySanitizer.rst
@@ -93,6 +93,15 @@ supported by other compilers, so we suggest to use it together with
 ``__has_feature(memory_sanitizer)``. Note: currently, this attribute will be
 lost if the function is inlined.
 
+Blacklist
+---------
+
+MemorySanitizer supports ``src`` and ``fun`` entity types in
+:doc:`SanitizerSpecialCaseList`, that can be used to relax MemorySanitizer
+checks for certain source files and functions. All "Use of uninitialized value"
+warnings will be suppressed and all values loaded from memory will be
+considered fully initialized.
+
 Origin Tracking
 ===============
 
diff --git a/clang/docs/SanitizerSpecialCaseList.rst b/clang/docs/SanitizerSpecialCaseList.rst
new file mode 100644
index 00000000000..8f4727c2fbc
--- /dev/null
+++ b/clang/docs/SanitizerSpecialCaseList.rst
@@ -0,0 +1,79 @@
+===========================
+Sanitizer special case list
+===========================
+
+.. contents::
+   :local:
+
+Introduction
+============
+
+This document describes the way to disable or alter the behavior of
+sanitizer tools for certain source-level entities by providing a special
+file at compile-time.
+
+Goal and usage
+==============
+
+User of sanitizer tools, such as :doc:`AddressSanitizer`, :doc:`ThreadSanitizer`
+or :doc:`MemorySanitizer` may want to disable or alter some checks for
+certain source-level entities to:
+
+* speedup hot function, which is known to be correct;
+* ignore a function that does some low-level magic (e.g. walks through the
+  thread stack, bypassing the frame boundaries);
+* ignore a known problem.
+
+To achieve this, user may create a file listing the entities he wants to
+ignore, and pass it to clang at compile-time using
+``-fsanitize-blacklist`` flag. See :doc:`UsersManual` for details.
+
+Example
+=======
+
+.. code-block:: bash
+
+  $ cat foo.c
+  #include <stdlib.h>
+  void bad_foo() {
+    int *a = (int*)malloc(40);
+    a[10] = 1;
+  }
+  int main() { bad_foo(); }
+  $ cat blacklist.txt
+  # Ignore reports from bad_foo function.
+  fun:bad_foo
+  $ clang -fsanitize=address foo.c ; ./a.out
+  # AddressSanitizer prints an error report.
+  $ clang -fsanitize=address -fsanitize-blacklist=blacklist.txt foo.c ; ./a.out
+  # No error report here.
+
+Format
+======
+
+Each line contains an entity type, followed by a colon and a regular
+expression, specifying the names of the entities, optionally followed by
+an equals sign and a tool-specific category. Empty lines and lines starting
+with "#" are ignored. The meanining of ``*`` in regular expression for entity
+names is different - it is treated as in shell wildcarding. Two generic
+entity types are ``src`` and ``fun``, which allow user to add, respectively,
+source files and functions to special case list. Some sanitizer tools may
+introduce custom entity types - refer to tool-specific docs.
+
+.. code-block:: bash
+
+    # Lines starting with # are ignored.
+    # Turn off checks for the source file (use absolute path or path relative
+    # to the current working directory):
+    src:/path/to/source/file.c
+    # Turn off checks for a particular functions (use mangled names):
+    fun:MyFooBar
+    fun:_Z8MyFooBarv
+    # Extended regular expressions are supported:
+    fun:bad_(foo|bar)
+    src:bad_source[1-9].c
+    # Shell like usage of * is supported (* is treated as .*):
+    src:bad/sources/*
+    fun:*BadFunction*
+    # Specific sanitizer tools may introduce categories.
+    src:/special/path/*=special_sources
diff --git a/clang/docs/ThreadSanitizer.rst b/clang/docs/ThreadSanitizer.rst
index 5e5ee48f7f4..cfe52526bcd 100644
--- a/clang/docs/ThreadSanitizer.rst
+++ b/clang/docs/ThreadSanitizer.rst
@@ -97,6 +97,13 @@ supported by other compilers, so we suggest to use it together with
 ``__has_feature(thread_sanitizer)``. Note: currently, this attribute will be
 lost if the function is inlined.
 
+Blacklist
+---------
+
+ThreadSanitizer supports ``src`` and ``fun`` entity types in
+:doc:`SanitizerSpecialCaseList`, that can be used to suppress data race reports in
+the specified source files or functions.
+
 Limitations
 -----------
 
diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst
index daa90b64e40..80956f89212 100644
--- a/clang/docs/UsersManual.rst
+++ b/clang/docs/UsersManual.rst
@@ -940,6 +940,15 @@ are listed below.
       it is of the wrong dynamic type, or that its lifetime has not
       begun or has ended. Incompatible with ``-fno-rtti``.
 
+   You can turn off or modify checks for certain source files, functions
+   or even variables by providing a special file:
+
+   -  ``-fsanitize-blacklist=/path/to/blacklist/file``: disable or modify
+      sanitizer checks for objects listed in the file. See
+      :doc:`SanitizerSpecialCaseList` for file format description.
+   -  ``-fno-sanitize-blacklist``: don't use blacklist file, if it was
+      specified earlier in the command line.
+
    Experimental features of AddressSanitizer (not ready for widespread
    use, require explicit ``-fsanitize=address``):
 
diff --git a/clang/docs/index.rst b/clang/docs/index.rst
index 5cdfb6bb5b1..293a61ad85f 100644
--- a/clang/docs/index.rst
+++ b/clang/docs/index.rst
@@ -21,6 +21,7 @@ Using Clang as a Compiler
    AddressSanitizer
    ThreadSanitizer
    MemorySanitizer
+   SanitizerSpecialCaseList
    Modules
    FAQ