Add documentation for running unit tests under Valgrind

  * NOTES.WIN (any supported Windows)

  * NOTES.DJGPP (DOS platform with DJGPP)

  * NOTES.ANDROID (obviously Android [NDK])

  * NOTES.VALGRIND (testing with Valgrind)

 Notational conventions in this document

 ---------------------------------------

NOTES FOR VALGRIND

==================

Valgrind is a test harness that includes many tools such as memcheck,

which is commonly used to check for memory leaks, etc. The default tool

run by Valgrind is memcheck. There are other tools available, but this

will focus on memcheck.

Valgrind runs programs in a virtual machine, this means OpenSSL unit

tests run under Valgrind will take longer than normal.

Requirements

------------

1. Platform supported by Valgrind

   See: http://valgrind.org/info/platforms.html

2. Valgrind installed on the platform

   See: http://valgrind.org/downloads/current.html

3. OpensSSL compiled

   See: INSTALL

Running Tests

-------------

Test behavior can be modified by adjusting environment variables.

EXE_SHELL

This variable is used to specify the shell used to execute OpenSSL test

programs. The default program (util/shlib_wrap.sh) initializes the

environment to allow programs to find shared libraries. The variable can

be modified to specify a different executable environment.

   EXE_SHELL="`/bin/pwd`/util/shlib_wrap.sh valgrind --error-exitcode=1 --leak-check=full -q"

This will start up Valgrind with the default checker (memcheck).

The --error-exitcode=1 option specifies that Valgrind should exit with an

error code of 1 when memory leaks occur.

The --leak-check=full option specifies extensive memory checking.

The -q option prints only error messages.

Additional Valgrind options may be added to the EXE_SHELL variable.

OPENSSL_ia32cap

This variable controls the processor-specific code on Intel processors.

By default, OpenSSL will attempt to figure out the capabilities of a

processor, and use it to its fullest capability. This variable can be

used to control what capabilities OpenSSL uses.

As of valgrind-3.15.0 on Linux/x86_64, instructions up to AVX2 are

supported. Setting the following disables instructions beyond AVX2:

   OPENSSL_ia32cap=":0"

This variable may need to be set to something different based on the

processor and Valgrind version you are running tests on. More information

may be found in docs/man3/OPENSSL_ia32cap.pod.

Additional variables (i.e. VERBOSE and TESTS) are described in the

INSTALL file in the root of the OpenSSL source tree.

Example command line:

   make test EXE_SHELL="`/bin/pwd`/util/shlib_wrap.sh valgrind --error-exitcode=1 --leak-check=full -q" OPENSSL_ia32cap=":0"

If an error occurs, you can then run the specific test via the TESTS

variable with the VERBOSE option to gather additional information.

   make test VERBOSE=1 TESTS=test_test EXE_SHELL="`/bin/pwd`/util/shlib_wrap.sh valgrind --error-exitcode=1 --leak-check=full -q" OPENSSL_ia32cap=":0"