maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

docs: Sphinxify TestingGuide 

llvm-svn: 167979
This commit is contained in:
Sean Silva 2012-11-14 21:09:30 +00:00
parent 92987fb311
commit a89edf6a61
7 changed files with 723 additions and 930 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
llvm/docs/DeveloperPolicy.rst
View File

@ -180,8 +180,8 @@ Developers are required to create test cases for any bugs fixed and any new
features added. Some tips for getting your testcase approved:
* All feature and regression test cases are added to the ``llvm/test``
directory. The appropriate sub-directory should be selected (see the `Testing
Guide <TestingGuide.html>`_ for details).
directory. The appropriate sub-directory should be selected (see the
:doc:`Testing Guide <TestingGuide>` for details).
* Test cases should be written in `LLVM assembly language <LangRef.html>`_
unless the feature or regression being tested requires another language

4
llvm/docs/GettingStarted.rst
View File

@ -1073,8 +1073,8 @@ module that must be checked out (usually to ``projects/test-suite``). This
module contains a comprehensive correctness, performance, and benchmarking test
suite for LLVM. It is a separate Subversion module because not every LLVM user
is interested in downloading or building such a comprehensive test suite. For
further details on this test suite, please see the `Testing
Guide <TestingGuide.html>`_ document.
further details on this test suite, please see the :doc:`Testing Guide
<TestingGuide>` document.
.. _tools:

2
llvm/docs/MakefileGuide.rst
View File

@ -339,7 +339,7 @@ the invocation of ``make check-local`` in the ``test`` directory. The intended
usage for this is to assist in running specific suites of tests. If
``TESTSUITE`` is not set, the implementation of ``check-local`` should run all
normal tests. It is up to the project to define what different values for
``TESTSUTE`` will do. See the `Testing Guide <TestingGuide.html>`_ for further
``TESTSUTE`` will do. See the :doc:`Testing Guide <TestingGuide>` for further
details.
``check-local``

6
llvm/docs/Projects.rst
View File

@ -156,9 +156,9 @@ Underneath your top level directory, you should have the following directories:
* LLVM provides a ``tcl`` procedure that is used by ``Dejagnu`` to run tests.
It can be found in ``llvm/lib/llvm-dg.exp``. This test procedure uses ``RUN``
lines in the actual test case to determine how to run the test. See the
`TestingGuide <TestingGuide.html>`_ for more details. You can easily write
Makefile support similar to the Makefiles in ``llvm/test`` to use ``Dejagnu``
to run your project's tests.
:doc:`TestingGuide` for more details. You can easily write Makefile
support similar to the Makefiles in ``llvm/test`` to use ``Dejagnu`` to
run your project's tests.
* LLVM contains an optional package called ``llvm-test``, which provides
benchmarks and programs that are known to compile with the Clang front

921
llvm/docs/TestingGuide.html
View File

@ -1,921 +0,0 @@
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>LLVM Testing Infrastructure Guide</title>
<link rel="stylesheet" href="_static/llvm.css" type="text/css">
</head>
<body>
<h1>
LLVM Testing Infrastructure Guide
</h1>
<ol>
<li><a href="#overview">Overview</a></li>
<li><a href="#requirements">Requirements</a></li>
<li><a href="#org">LLVM testing infrastructure organization</a>
<ul>
<li><a href="#regressiontests">Regression tests</a></li>
<li><a href="#testsuite"><tt>test-suite</tt></a></li>
<li><a href="#debuginfotests">Debugging Information tests</a></li>
</ul>
</li>
<li><a href="#quick">Quick start</a>
<ul>
<li><a href="#quickregressiontests">Regression tests</a></li>
<li><a href="#quickdebuginfotests">Debugging Information tests</a></li>
</ul>
</li>
<li><a href="#rtstructure">Regression test structure</a>
<ul>
<li><a href="#rtcustom">Writing new regression tests</a></li>
<li><a href="#FileCheck">The FileCheck utility</a></li>
<li><a href="#rtvars">Variables and substitutions</a></li>
<li><a href="#rtfeatures">Other features</a></li>
</ul>
</li>
<li><a href="#testsuiteoverview"><tt>test-suite</tt> Overview</a>
<ul>
<li><a href="#testsuitequickstart"><tt>test-suite</tt> Quickstart</a></li>
<li><a href="#testsuitemakefiles"><tt>test-suite</tt> Makefiles</a></li>
</ul>
</li>
</ol>
<div class="doc_author">
<p>Written by John T. Criswell, Daniel Dunbar, Reid Spencer, and Tanya Lattner</p>
</div>
<!--=========================================================================-->
<h2><a name="overview">Overview</a></h2>
<!--=========================================================================-->
<div>
<p>This document is the reference manual for the LLVM testing infrastructure. It
documents the structure of the LLVM testing infrastructure, the tools needed to
use it, and how to add and run tests.</p>
</div>
<!--=========================================================================-->
<h2><a name="requirements">Requirements</a></h2>
<!--=========================================================================-->
<div>
<p>In order to use the LLVM testing infrastructure, you will need all of the
software required to build LLVM, as well
as <a href="http://python.org">Python</a> 2.4 or later.</p>
</div>
<!--=========================================================================-->
<h2><a name="org">LLVM testing infrastructure organization</a></h2>
<!--=========================================================================-->
<div>
<p>The LLVM testing infrastructure contains two major categories of tests:
regression tests and whole programs. The regression tests are contained inside
the LLVM repository itself under <tt>llvm/test</tt> and are expected to always
pass -- they should be run before every commit.</p>
<p>The whole programs tests are referred to as the "LLVM test suite" (or
"test-suite") and are in the <tt>test-suite</tt> module in subversion. For
historical reasons, these tests are also referred to as the "nightly tests" in
places, which is less ambiguous than "test-suite" and remains in use although we
run them much more often than nightly.</p>
<!-- _______________________________________________________________________ -->
<h3><a name="regressiontests">Regression tests</a></h3>
<!-- _______________________________________________________________________ -->
<div>
<p>The regression tests are small pieces of code that test a specific feature of
LLVM or trigger a specific bug in LLVM. They are usually written in LLVM
assembly language, but can be written in other languages if the test targets a
particular language front end (and the appropriate <tt>--with-llvmgcc</tt>
options were used at <tt>configure</tt> time of the <tt>llvm</tt> module). These
tests are driven by the 'lit' testing tool, which is part of LLVM.</p>
<p>These code fragments are not complete programs. The code generated
from them is never executed to determine correct behavior.</p>
<p>These code fragment tests are located in the <tt>llvm/test</tt>
directory.</p>
<p>Typically when a bug is found in LLVM, a regression test containing
just enough code to reproduce the problem should be written and placed
somewhere underneath this directory. In most cases, this will be a small
piece of LLVM assembly language code, often distilled from an actual
application or benchmark.</p>
</div>
<!-- _______________________________________________________________________ -->
<h3><a name="testsuite"><tt>test-suite</tt></a></h3>
<!-- _______________________________________________________________________ -->
<div>
<p>The test suite contains whole programs, which are pieces of code which can be
compiled and linked into a stand-alone program that can be executed. These
programs are generally written in high level languages such as C or C++.</p>
<p>These programs are compiled using a user specified compiler and set of flags,
and then executed to capture the program output and timing information. The
output of these programs is compared to a reference output to ensure that the
program is being compiled correctly.</p>
<p>In addition to compiling and executing programs, whole program tests serve as
a way of benchmarking LLVM performance, both in terms of the efficiency of the
programs generated as well as the speed with which LLVM compiles, optimizes, and
generates code.</p>
<p>The test-suite is located in the <tt>test-suite</tt> Subversion module.</p>
</div>
<!-- _______________________________________________________________________ -->
<h3><a name="debuginfotests">Debugging Information tests</a></h3>
<!-- _______________________________________________________________________ -->
<div>
<p>The test suite contains tests to check quality of debugging information.
The test are written in C based languages or in LLVM assembly language. </p>
<p>These tests are compiled and run under a debugger. The debugger output
is checked to validate of debugging information. See README.txt in the
test suite for more information . This test suite is located in the
<tt>debuginfo-tests</tt> Subversion module. </p>
</div>
</div>
<!--=========================================================================-->
<h2><a name="quick">Quick start</a></h2>
<!--=========================================================================-->
<div>
<p>The tests are located in two separate Subversion modules. The regressions
tests are in the main "llvm" module under the directory
<tt>llvm/test</tt> (so you get these tests for free with the main llvm
tree). Use "make check-all" to run the regression tests after building
LLVM.</p>
<p>The more comprehensive test suite that includes whole programs in C and C++
is in the <tt>test-suite</tt>
module. See <a href="#testsuitequickstart"><tt>test-suite</tt> Quickstart</a>
for more information on running these tests.</p>
<!-- _______________________________________________________________________ -->
<h3><a name="quickregressiontests">Regression tests</a></h3>
<div>
<!-- _______________________________________________________________________ -->
<p>To run all of the LLVM regression tests, use master Makefile in
the <tt>llvm/test</tt> directory:</p>
<div class="doc_code">
<pre>
% gmake -C llvm/test
</pre>
</div>
<p>or</p>
<div class="doc_code">
<pre>
% gmake check
</pre>
</div>
<p>If you have <a href="http://clang.llvm.org/">Clang</a> checked out and built,
you can run the LLVM and Clang tests simultaneously using:</p>
<p>or</p>
<div class="doc_code">
<pre>
% gmake check-all
</pre>
</div>
<p>To run the tests with Valgrind (Memcheck by default), just append
<tt>VG=1</tt> to the commands above, e.g.:</p>
<div class="doc_code">
<pre>
% gmake check VG=1
</pre>
</div>
<p>To run individual tests or subsets of tests, you can use the 'llvm-lit'
script which is built as part of LLVM. For example, to run the
'Integer/BitPacked.ll' test by itself you can run:</p>
<div class="doc_code">
<pre>
% llvm-lit ~/llvm/test/Integer/BitPacked.ll
</pre>
</div>
<p>or to run all of the ARM CodeGen tests:</p>
<div class="doc_code">
<pre>
% llvm-lit ~/llvm/test/CodeGen/ARM
</pre>
</div>
<p>For more information on using the 'lit' tool, see 'llvm-lit --help' or the
'lit' man page.</p>
</div>
<!-- _______________________________________________________________________ -->
<h3><a name="quickdebuginfotests">Debugging Information tests</a></h3>
<div>
<!-- _______________________________________________________________________ -->
<div>
<p> To run debugging information tests simply checkout the tests inside
clang/test directory. </p>
<div class="doc_code">
<pre>
%cd clang/test
% svn co http://llvm.org/svn/llvm-project/debuginfo-tests/trunk debuginfo-tests
</pre>
</div>
<p> These tests are already set up to run as part of clang regression tests.</p>
</div>
</div>
</div>
<!--=========================================================================-->
<h2><a name="rtstructure">Regression test structure</a></h2>
<!--=========================================================================-->
<div>
<p>The LLVM regression tests are driven by 'lit' and are located in
the <tt>llvm/test</tt> directory.
<p>This directory contains a large array of small tests
that exercise various features of LLVM and to ensure that regressions do not
occur. The directory is broken into several sub-directories, each focused on
a particular area of LLVM. A few of the important ones are:</p>
<ul>
<li><tt>Analysis</tt>: checks Analysis passes.</li>
<li><tt>Archive</tt>: checks the Archive library.</li>
<li><tt>Assembler</tt>: checks Assembly reader/writer functionality.</li>
<li><tt>Bitcode</tt>: checks Bitcode reader/writer functionality.</li>
<li><tt>CodeGen</tt>: checks code generation and each target.</li>
<li><tt>Features</tt>: checks various features of the LLVM language.</li>
<li><tt>Linker</tt>: tests bitcode linking.</li>
<li><tt>Transforms</tt>: tests each of the scalar, IPO, and utility
transforms to ensure they make the right transformations.</li>
<li><tt>Verifier</tt>: tests the IR verifier.</li>
</ul>
<!-- _______________________________________________________________________ -->
<h3><a name="rtcustom">Writing new regression tests</a></h3>
<!-- _______________________________________________________________________ -->
<div>
<p>The regression test structure is very simple, but does require some
information to be set. This information is gathered via <tt>configure</tt> and
is written to a file, <tt>lit.site.cfg</tt>
in <tt>llvm/test</tt>. The <tt>llvm/test</tt> Makefile does this work for
you.</p>
<p>In order for the regression tests to work, each directory of tests must
have a <tt>lit.local.cfg</tt> file. Lit looks for this file to determine how
to run the tests. This file is just Python code and thus is very flexible,
but we've standardized it for the LLVM regression tests. If you're adding a
directory of tests, just copy <tt>lit.local.cfg</tt> from another directory to
get running. The standard <tt>lit.local.cfg</tt> simply specifies which files
to look in for tests. Any directory that contains only directories does not
need the <tt>lit.local.cfg</tt> file. Read the
<a href="http://llvm.org/cmds/lit.html">Lit documentation</a> for more
information. </p>
<p>The <tt>llvm-runtests</tt> function looks at each file that is passed to
it and gathers any lines together that match "RUN:". These are the "RUN" lines
that specify how the test is to be run. So, each test script must contain
RUN lines if it is to do anything. If there are no RUN lines, the
<tt>llvm-runtests</tt> function will issue an error and the test will
fail.</p>
<p>RUN lines are specified in the comments of the test program using the
keyword <tt>RUN</tt> followed by a colon, and lastly the command (pipeline)
to execute. Together, these lines form the "script" that
<tt>llvm-runtests</tt> executes to run the test case. The syntax of the
RUN lines is similar to a shell's syntax for pipelines including I/O
redirection and variable substitution. However, even though these lines
may <i>look</i> like a shell script, they are not. RUN lines are interpreted
directly by the Tcl <tt>exec</tt> command. They are never executed by a
shell. Consequently the syntax differs from normal shell script syntax in a
few ways. You can specify as many RUN lines as needed.</p>
<p>lit performs substitution on each RUN line to replace LLVM tool
names with the full paths to the executable built for each tool (in
$(LLVM_OBJ_ROOT)/$(BuildMode)/bin). This ensures that lit does not
invoke any stray LLVM tools in the user's path during testing.</p>
<p>Each RUN line is executed on its own, distinct from other lines unless
its last character is <tt>\</tt>. This continuation character causes the RUN
line to be concatenated with the next one. In this way you can build up long
pipelines of commands without making huge line lengths. The lines ending in
<tt>\</tt> are concatenated until a RUN line that doesn't end in <tt>\</tt> is
found. This concatenated set of RUN lines then constitutes one execution.
Tcl will substitute variables and arrange for the pipeline to be executed. If
any process in the pipeline fails, the entire line (and test case) fails too.
</p>
<p> Below is an example of legal RUN lines in a <tt>.ll</tt> file:</p>
<div class="doc_code">
<pre>
; RUN: llvm-as &lt; %s | llvm-dis &gt; %t1
; RUN: llvm-dis &lt; %s.bc-13 &gt; %t2
; RUN: diff %t1 %t2
</pre>
</div>
<p>As with a Unix shell, the RUN: lines permit pipelines and I/O redirection
to be used. However, the usage is slightly different than for Bash. To check
what's legal, see the documentation for the
<a href="http://www.tcl.tk/man/tcl8.5/TclCmd/exec.htm#M2">Tcl exec</a>
command and the
<a href="http://www.tcl.tk/man/tcl8.5/tutorial/Tcl26.html">tutorial</a>.
The major differences are:</p>
<ul>
<li>You can't do <tt>2&gt;&amp;1</tt>. That will cause Tcl to write to a
file named <tt>&amp;1</tt>. Usually this is done to get stderr to go through
a pipe. You can do that in tcl with <tt>|&amp;</tt> so replace this idiom:
<tt>... 2&gt;&amp;1 | grep</tt> with <tt>... |&amp; grep</tt></li>
<li>You can only redirect to a file, not to another descriptor and not from
a here document.</li>
<li>tcl supports redirecting to open files with the @ syntax but you
shouldn't use that here.</li>
</ul>
<p>There are some quoting rules that you must pay attention to when writing
your RUN lines. In general nothing needs to be quoted. Tcl won't strip off any
quote characters so they will get passed to the invoked program. For
example:</p>
<div class="doc_code">
<pre>
... | grep 'find this string'
</pre>
</div>
<p>This will fail because the ' characters are passed to grep. This would
instruction grep to look for <tt>'find</tt> in the files <tt>this</tt> and
<tt>string'</tt>. To avoid this use curly braces to tell Tcl that it should
treat everything enclosed as one value. So our example would become:</p>
<div class="doc_code">
<pre>
... | grep {find this string}
</pre>
</div>
<p>Additionally, the characters <tt>[</tt> and <tt>]</tt> are treated
specially by Tcl. They tell Tcl to interpret the content as a command to
execute. Since these characters are often used in regular expressions this can
have disastrous results and cause the entire test run in a directory to fail.
For example, a common idiom is to look for some basicblock number:</p>
<div class="doc_code">
<pre>
... | grep bb[2-8]
</pre>
</div>
<p>This, however, will cause Tcl to fail because its going to try to execute
a program named "2-8". Instead, what you want is this:</p>
<div class="doc_code">
<pre>
... | grep {bb\[2-8\]}
</pre>
</div>
<p>Finally, if you need to pass the <tt>\</tt> character down to a program,
then it must be doubled. This is another Tcl special character. So, suppose
you had:
<div class="doc_code">
<pre>
... | grep 'i32\*'
</pre>
</div>
<p>This will fail to match what you want (a pointer to i32). First, the
<tt>'</tt> do not get stripped off. Second, the <tt>\</tt> gets stripped off
by Tcl so what grep sees is: <tt>'i32*'</tt>. That's not likely to match
anything. To resolve this you must use <tt>\\</tt> and the <tt>{}</tt>, like
this:</p>
<div class="doc_code">
<pre>
... | grep {i32\\*}
</pre>
</div>
<p>If your system includes GNU <tt>grep</tt>, make sure
that <tt>GREP_OPTIONS</tt> is not set in your environment. Otherwise,
you may get invalid results (both false positives and false
negatives).</p>
</div>
<!-- _______________________________________________________________________ -->
<h3><a name="FileCheck">The FileCheck utility</a></h3>
<!-- _______________________________________________________________________ -->
<div>
<p>A powerful feature of the RUN: lines is that it allows any arbitrary commands
to be executed as part of the test harness. While standard (portable) unix
tools like 'grep' work fine on run lines, as you see above, there are a lot
of caveats due to interaction with Tcl syntax, and we want to make sure the
run lines are portable to a wide range of systems. Another major problem is
that grep is not very good at checking to verify that the output of a tools
contains a series of different output in a specific order. The FileCheck
tool was designed to help with these problems.</p>
<p>FileCheck (whose basic command line arguments are described in <a
href="http://llvm.org/cmds/FileCheck.html">the FileCheck man page</a> is
designed to read a file to check from standard input, and the set of things
to verify from a file specified as a command line argument. A simple example
of using FileCheck from a RUN line looks like this:</p>
<div class="doc_code">
<pre>
; RUN: llvm-as &lt; %s | llc -march=x86-64 | <b>FileCheck %s</b>
</pre>
</div>
<p>This syntax says to pipe the current file ("%s") into llvm-as, pipe that into
llc, then pipe the output of llc into FileCheck. This means that FileCheck will
be verifying its standard input (the llc output) against the filename argument
specified (the original .ll file specified by "%s"). To see how this works,
let's look at the rest of the .ll file (after the RUN line):</p>
<div class="doc_code">
<pre>
define void @sub1(i32* %p, i32 %v) {
entry:
; <b>CHECK: sub1:</b>
; <b>CHECK: subl</b>
%0 = tail call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %p, i32 %v)
ret void
}
define void @inc4(i64* %p) {
entry:
; <b>CHECK: inc4:</b>
; <b>CHECK: incq</b>
%0 = tail call i64 @llvm.atomic.load.add.i64.p0i64(i64* %p, i64 1)
ret void
}
</pre>
</div>
<p>Here you can see some "CHECK:" lines specified in comments. Now you can see
how the file is piped into llvm-as, then llc, and the machine code output is
what we are verifying. FileCheck checks the machine code output to verify that
it matches what the "CHECK:" lines specify.</p>
<p>The syntax of the CHECK: lines is very simple: they are fixed strings that
must occur in order. FileCheck defaults to ignoring horizontal whitespace
differences (e.g. a space is allowed to match a tab) but otherwise, the contents
of the CHECK: line is required to match some thing in the test file exactly.</p>
<p>One nice thing about FileCheck (compared to grep) is that it allows merging
test cases together into logical groups. For example, because the test above
is checking for the "sub1:" and "inc4:" labels, it will not match unless there
is a "subl" in between those labels. If it existed somewhere else in the file,
that would not count: "grep subl" matches if subl exists anywhere in the
file.</p>
<!-- _______________________________________________________________________ -->
<h4>
<a name="FileCheck-check-prefix">The FileCheck -check-prefix option</a>
</h4>
<div>
<p>The FileCheck -check-prefix option allows multiple test configurations to be
driven from one .ll file. This is useful in many circumstances, for example,
testing different architectural variants with llc. Here's a simple example:</p>
<div class="doc_code">
<pre>
; RUN: llvm-as &lt; %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \
; RUN: | <b>FileCheck %s -check-prefix=X32</b>
; RUN: llvm-as &lt; %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \
; RUN: | <b>FileCheck %s -check-prefix=X64</b>
define &lt;4 x i32&gt; @pinsrd_1(i32 %s, &lt;4 x i32&gt; %tmp) nounwind {
%tmp1 = insertelement &lt;4 x i32&gt; %tmp, i32 %s, i32 1
ret &lt;4 x i32&gt; %tmp1
; <b>X32:</b> pinsrd_1:
; <b>X32:</b> pinsrd $1, 4(%esp), %xmm0
; <b>X64:</b> pinsrd_1:
; <b>X64:</b> pinsrd $1, %edi, %xmm0
}
</pre>
</div>
<p>In this case, we're testing that we get the expected code generation with
both 32-bit and 64-bit code generation.</p>
</div>
<!-- _______________________________________________________________________ -->
<h4>
<a name="FileCheck-CHECK-NEXT">The "CHECK-NEXT:" directive</a>
</h4>
<div>
<p>Sometimes you want to match lines and would like to verify that matches
happen on exactly consecutive lines with no other lines in between them. In
this case, you can use CHECK: and CHECK-NEXT: directives to specify this. If
you specified a custom check prefix, just use "&lt;PREFIX&gt;-NEXT:". For
example, something like this works as you'd expect:</p>
<div class="doc_code">
<pre>
define void @t2(&lt;2 x double&gt;* %r, &lt;2 x double&gt;* %A, double %B) {
%tmp3 = load &lt;2 x double&gt;* %A, align 16
%tmp7 = insertelement &lt;2 x double&gt; undef, double %B, i32 0
%tmp9 = shufflevector &lt;2 x double&gt; %tmp3,
&lt;2 x double&gt; %tmp7,
&lt;2 x i32&gt; &lt; i32 0, i32 2 &gt;
store &lt;2 x double&gt; %tmp9, &lt;2 x double&gt;* %r, align 16
ret void
; <b>CHECK:</b> t2:
; <b>CHECK:</b> movl 8(%esp), %eax
; <b>CHECK-NEXT:</b> movapd (%eax), %xmm0
; <b>CHECK-NEXT:</b> movhpd 12(%esp), %xmm0
; <b>CHECK-NEXT:</b> movl 4(%esp), %eax
; <b>CHECK-NEXT:</b> movapd %xmm0, (%eax)
; <b>CHECK-NEXT:</b> ret
}
</pre>
</div>
<p>CHECK-NEXT: directives reject the input unless there is exactly one newline
between it an the previous directive. A CHECK-NEXT cannot be the first
directive in a file.</p>
</div>
<!-- _______________________________________________________________________ -->
<h4>
<a name="FileCheck-CHECK-NOT">The "CHECK-NOT:" directive</a>
</h4>
<div>
<p>The CHECK-NOT: directive is used to verify that a string doesn't occur
between two matches (or the first match and the beginning of the file). For
example, to verify that a load is removed by a transformation, a test like this
can be used:</p>
<div class="doc_code">
<pre>
define i8 @coerce_offset0(i32 %V, i32* %P) {
store i32 %V, i32* %P
%P2 = bitcast i32* %P to i8*
%P3 = getelementptr i8* %P2, i32 2
%A = load i8* %P3
ret i8 %A
; <b>CHECK:</b> @coerce_offset0
; <b>CHECK-NOT:</b> load
; <b>CHECK:</b> ret i8
}
</pre>
</div>
</div>
<!-- _______________________________________________________________________ -->
<h4>
<a name="FileCheck-Matching">FileCheck Pattern Matching Syntax</a>
</h4>
<div>
<!-- {% raw %} -->
<p>The CHECK: and CHECK-NOT: directives both take a pattern to match. For most
uses of FileCheck, fixed string matching is perfectly sufficient. For some
things, a more flexible form of matching is desired. To support this, FileCheck
allows you to specify regular expressions in matching strings, surrounded by
double braces: <b>{{yourregex}}</b>. Because we want to use fixed string
matching for a majority of what we do, FileCheck has been designed to support
mixing and matching fixed string matching with regular expressions. This allows
you to write things like this:</p>
<div class="doc_code">
<pre>
; CHECK: movhpd <b>{{[0-9]+}}</b>(%esp), <b>{{%xmm[0-7]}}</b>
</pre>
</div>
<p>In this case, any offset from the ESP register will be allowed, and any xmm
register will be allowed.</p>
<p>Because regular expressions are enclosed with double braces, they are
visually distinct, and you don't need to use escape characters within the double
braces like you would in C. In the rare case that you want to match double
braces explicitly from the input, you can use something ugly like
<b>{{[{][{]}}</b> as your pattern.</p>
<!-- {% endraw %} -->
</div>
<!-- _______________________________________________________________________ -->
<h4>
<a name="FileCheck-Variables">FileCheck Variables</a>
</h4>
<div>
<!-- {% raw %} -->
<p>It is often useful to match a pattern and then verify that it occurs again
later in the file. For codegen tests, this can be useful to allow any register,
but verify that that register is used consistently later. To do this, FileCheck
allows named variables to be defined and substituted into patterns. Here is a
simple example:</p>
<div class="doc_code">
<pre>
; CHECK: test5:
; CHECK: notw <b>[[REGISTER:%[a-z]+]]</b>
; CHECK: andw {{.*}}<b>[[REGISTER]]</b>
</pre>
</div>
<p>The first check line matches a regex (<tt>%[a-z]+</tt>) and captures it into
the variables "REGISTER". The second line verifies that whatever is in REGISTER
occurs later in the file after an "andw". FileCheck variable references are
always contained in <tt>[[ ]]</tt> pairs, are named, and their names can be
formed with the regex "<tt>[a-zA-Z][a-zA-Z0-9]*</tt>". If a colon follows the
name, then it is a definition of the variable, if not, it is a use.</p>
<p>FileCheck variables can be defined multiple times, and uses always get the
latest value. Note that variables are all read at the start of a "CHECK" line
and are all defined at the end. This means that if you have something like
"<tt>CHECK: [[XYZ:.*]]x[[XYZ]]</tt>" that the check line will read the previous
value of the XYZ variable and define a new one after the match is performed. If
you need to do something like this you can probably take advantage of the fact
that FileCheck is not actually line-oriented when it matches, this allows you to
define two separate CHECK lines that match on the same line.
</p>
<!-- {% endraw %} -->
</div>
</div>
<!-- _______________________________________________________________________ -->
<h3><a name="rtvars">Variables and substitutions</a></h3>
<!-- _______________________________________________________________________ -->
<div>
<p>With a RUN line there are a number of substitutions that are permitted. In
general, any Tcl variable that is available in the <tt>substitute</tt>
function (in <tt>test/lib/llvm.exp</tt>) can be substituted into a RUN line.
To make a substitution just write the variable's name preceded by a $.
Additionally, for compatibility reasons with previous versions of the test
library, certain names can be accessed with an alternate syntax: a % prefix.
These alternates are deprecated and may go away in a future version.
</p>
<p>Here are the available variable names. The alternate syntax is listed in
parentheses.</p>
<dl style="margin-left: 25px">
<dt><b>$test</b> (%s)</dt>
<dd>The full path to the test case's source. This is suitable for passing
on the command line as the input to an llvm tool.</dd>
<dt><b>%(line), %(line+<i>number</i>), %(line-<i>number</i>)</b></dt>
<dd>The number of the line where this variable is used, with an optional
integer offset. This can be used in tests with multiple RUN: lines, which
reference test file's line numbers.</dd>
<dt><b>$srcdir</b></dt>
<dd>The source directory from where the "<tt>make check</tt>" was run.</dd>
<dt><b>objdir</b></dt>
<dd>The object directory that corresponds to the <tt>$srcdir</tt>.</dd>
<dt><b>subdir</b></dt>
<dd>A partial path from the <tt>test</tt> directory that contains the
sub-directory that contains the test source being executed.</dd>
<dt><b>srcroot</b></dt>
<dd>The root directory of the LLVM src tree.</dd>
<dt><b>objroot</b></dt>
<dd>The root directory of the LLVM object tree. This could be the same
as the srcroot.</dd>
<dt><b>path</b><dt>
<dd>The path to the directory that contains the test case source. This is
for locating any supporting files that are not generated by the test, but
used by the test.</dd>
<dt><b>tmp</b></dt>
<dd>The path to a temporary file name that could be used for this test case.
The file name won't conflict with other test cases. You can append to it if
you need multiple temporaries. This is useful as the destination of some
redirected output.</dd>
<dt><b>target_triplet</b> (%target_triplet)</dt>
<dd>The target triplet that corresponds to the current host machine (the one
running the test cases). This should probably be called "host".<dd>
<dt><b>link</b> (%link)</dt>
<dd>This full link command used to link LLVM executables. This has all the
configured -I, -L and -l options.</dd>
<dt><b>shlibext</b> (%shlibext)</dt>
<dd>The suffix for the host platforms share library (dll) files. This
includes the period as the first character.</dd>
</dl>
<p>To add more variables, two things need to be changed. First, add a line in
the <tt>test/Makefile</tt> that creates the <tt>site.exp</tt> file. This will
"set" the variable as a global in the site.exp file. Second, in the
<tt>test/lib/llvm.exp</tt> file, in the substitute proc, add the variable name
to the list of "global" declarations at the beginning of the proc. That's it,
the variable can then be used in test scripts.</p>
</div>
<!-- _______________________________________________________________________ -->
<h3><a name="rtfeatures">Other Features</a></h3>
<!-- _______________________________________________________________________ -->
<div>
<p>To make RUN line writing easier, there are several shell scripts located
in the <tt>llvm/test/Scripts</tt> directory. This directory is in the PATH
when running tests, so you can just call these scripts using their name. For
example:</p>
<dl>
<dt><b>ignore</b></dt>
<dd>This script runs its arguments and then always returns 0. This is useful
in cases where the test needs to cause a tool to generate an error (e.g. to
check the error output). However, any program in a pipeline that returns a
non-zero result will cause the test to fail. This script overcomes that
issue and nicely documents that the test case is purposefully ignoring the
result code of the tool</dd>
<dt><b>not</b></dt>
<dd>This script runs its arguments and then inverts the result code from
it. Zero result codes become 1. Non-zero result codes become 0. This is
useful to invert the result of a grep. For example "not grep X" means
succeed only if you don't find X in the input.</dd>
</dl>
<p>Sometimes it is necessary to mark a test case as "expected fail" or XFAIL.
You can easily mark a test as XFAIL just by including <tt>XFAIL: </tt> on a
line near the top of the file. This signals that the test case should succeed
if the test fails. Such test cases are counted separately by the testing
tool. To specify an expected fail, use the XFAIL keyword in the comments of
the test program followed by a colon and one or more failure patterns. Each
failure pattern can be either '*' (to specify fail everywhere), or a part of a
target triple (indicating the test should fail on that platform), or the name
of a configurable feature (for example, "loadable_module"). If there is a
match, the test is expected to fail. If not, the test is expected to
succeed. To XFAIL everywhere just specify <tt>XFAIL: *</tt>. Here is an
example of an <tt>XFAIL</tt> line:</p>
<div class="doc_code">
<pre>
; XFAIL: darwin,sun
</pre>
</div>
<p>To make the output more useful, the <tt>llvm_runtest</tt> function wil
scan the lines of the test case for ones that contain a pattern that matches
PR[0-9]+. This is the syntax for specifying a PR (Problem Report) number that
is related to the test case. The number after "PR" specifies the LLVM bugzilla
number. When a PR number is specified, it will be used in the pass/fail
reporting. This is useful to quickly get some context when a test fails.</p>
<p>Finally, any line that contains "END." will cause the special
interpretation of lines to terminate. This is generally done right after the
last RUN: line. This has two side effects: (a) it prevents special
interpretation of lines that are part of the test program, not the
instructions to the test case, and (b) it speeds things up for really big test
cases by avoiding interpretation of the remainder of the file.</p>
</div>
</div>
<!--=========================================================================-->
<h2><a name="testsuiteoverview"><tt>test-suite</tt> Overview</a></h2>
<!--=========================================================================-->
<div>
<p>The <tt>test-suite</tt> module contains a number of programs that can be
compiled and executed. The <tt>test-suite</tt> includes reference outputs for
all of the programs, so that the output of the executed program can be checked
for correctness.</p>
<p><tt>test-suite</tt> tests are divided into three types of tests: MultiSource,
SingleSource, and External.</p>
<ul>
<li><tt>test-suite/SingleSource</tt>
<p>The SingleSource directory contains test programs that are only a single
source file in size. These are usually small benchmark programs or small
programs that calculate a particular value. Several such programs are grouped
together in each directory.</p></li>
<li><tt>test-suite/MultiSource</tt>
<p>The MultiSource directory contains subdirectories which contain entire
programs with multiple source files. Large benchmarks and whole applications
go here.</p></li>
<li><tt>test-suite/External</tt>
<p>The External directory contains Makefiles for building code that is external
to (i.e., not distributed with) LLVM. The most prominent members of this
directory are the SPEC 95 and SPEC 2000 benchmark suites. The <tt>External</tt>
directory does not contain these actual tests, but only the Makefiles that know
how to properly compile these programs from somewhere else. When
using <tt>LNT</tt>, use the <tt>--test-externals</tt> option to include these
tests in the results.</p></li>
</ul>
</div>
<!--=========================================================================-->
<h2><a name="testsuitequickstart"><tt>test-suite</tt> Quickstart</a></h2>
<!--=========================================================================-->
<div>
<p>The modern way of running the <tt>test-suite</tt> is focused on testing and
benchmarking complete compilers using
the <a href="http://llvm.org/docs/lnt">LNT</a> testing infrastructure.</p>
<p>For more information on using LNT to execute the <tt>test-suite</tt>, please
see the <a href="http://llvm.org/docs/lnt/quickstart.html">LNT Quickstart</a>
documentation.</p>
</div>
<!--=========================================================================-->
<h2><a name="testsuitemakefiles"><tt>test-suite</tt> Makefiles</a></h2>
<!--=========================================================================-->
<div>
<p>Historically, the <tt>test-suite</tt> was executed using a complicated setup
of Makefiles. The LNT based approach above is recommended for most users, but
there are some testing scenarios which are not supported by the LNT approach. In
addition, LNT currently uses the Makefile setup under the covers and so
developers who are interested in how LNT works under the hood may want to
understand the Makefile based setup.</p>
<p>For more information on the <tt>test-suite</tt> Makefile setup, please see
the <a href="TestSuiteMakefileGuide.html">Test Suite Makefile Guide.</a></p>
</div>
<!-- *********************************************************************** -->
<hr>
<address>
<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
<a href="http://validator.w3.org/check/referer"><img
src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
John T. Criswell, Daniel Dunbar, Reid Spencer, and Tanya Lattner<br>
<a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Last modified: $Date$
</address>
</body>
</html>

713
llvm/docs/TestingGuide.rst Normal file
View File

@ -0,0 +1,713 @@
=================================
LLVM Testing Infrastructure Guide
=================================
Written by John T. Criswell, Daniel Dunbar, Reid Spencer, and Tanya
Lattner
.. contents::
:local:
Overview
========
This document is the reference manual for the LLVM testing
infrastructure. It documents the structure of the LLVM testing
infrastructure, the tools needed to use it, and how to add and run
tests.
Requirements
============
In order to use the LLVM testing infrastructure, you will need all of
the software required to build LLVM, as well as
`Python <http://python.org>`_ 2.4 or later.
LLVM testing infrastructure organization
========================================
The LLVM testing infrastructure contains two major categories of tests:
regression tests and whole programs. The regression tests are contained
inside the LLVM repository itself under ``llvm/test`` and are expected
to always pass -- they should be run before every commit.
The whole programs tests are referred to as the "LLVM test suite" (or
"test-suite") and are in the ``test-suite`` module in subversion. For
historical reasons, these tests are also referred to as the "nightly
tests" in places, which is less ambiguous than "test-suite" and remains
in use although we run them much more often than nightly.
Regression tests
----------------
The regression tests are small pieces of code that test a specific
feature of LLVM or trigger a specific bug in LLVM. They are usually
written in LLVM assembly language, but can be written in other languages
if the test targets a particular language front end (and the appropriate
``--with-llvmgcc`` options were used at ``configure`` time of the
``llvm`` module). These tests are driven by the 'lit' testing tool,
which is part of LLVM.
These code fragments are not complete programs. The code generated from
them is never executed to determine correct behavior.
These code fragment tests are located in the ``llvm/test`` directory.
Typically when a bug is found in LLVM, a regression test containing just
enough code to reproduce the problem should be written and placed
somewhere underneath this directory. In most cases, this will be a small
piece of LLVM assembly language code, often distilled from an actual
application or benchmark.
``test-suite``
--------------
The test suite contains whole programs, which are pieces of code which
can be compiled and linked into a stand-alone program that can be
executed. These programs are generally written in high level languages
such as C or C++.
These programs are compiled using a user specified compiler and set of
flags, and then executed to capture the program output and timing
information. The output of these programs is compared to a reference
output to ensure that the program is being compiled correctly.
In addition to compiling and executing programs, whole program tests
serve as a way of benchmarking LLVM performance, both in terms of the
efficiency of the programs generated as well as the speed with which
LLVM compiles, optimizes, and generates code.
The test-suite is located in the ``test-suite`` Subversion module.
Debugging Information tests
---------------------------
The test suite contains tests to check quality of debugging information.
The test are written in C based languages or in LLVM assembly language.
These tests are compiled and run under a debugger. The debugger output
is checked to validate of debugging information. See README.txt in the
test suite for more information . This test suite is located in the
``debuginfo-tests`` Subversion module.
Quick start
===========
The tests are located in two separate Subversion modules. The
regressions tests are in the main "llvm" module under the directory
``llvm/test`` (so you get these tests for free with the main llvm tree).
Use "make check-all" to run the regression tests after building LLVM.
The more comprehensive test suite that includes whole programs in C and
C++ is in the ``test-suite`` module. See ```test-suite``
Quickstart <#testsuitequickstart>`_ for more information on running
these tests.
Regression tests
----------------
To run all of the LLVM regression tests, use master Makefile in the
``llvm/test`` directory:
.. code-block:: bash
% gmake -C llvm/test
or
.. code-block:: bash
% gmake check
If you have `Clang <http://clang.llvm.org/>`_ checked out and built, you
can run the LLVM and Clang tests simultaneously using:
or
.. code-block:: bash
% gmake check-all
To run the tests with Valgrind (Memcheck by default), just append
``VG=1`` to the commands above, e.g.:
.. code-block:: bash
% gmake check VG=1
To run individual tests or subsets of tests, you can use the 'llvm-lit'
script which is built as part of LLVM. For example, to run the
'Integer/BitPacked.ll' test by itself you can run:
.. code-block:: bash
% llvm-lit ~/llvm/test/Integer/BitPacked.ll
or to run all of the ARM CodeGen tests:
.. code-block:: bash
% llvm-lit ~/llvm/test/CodeGen/ARM
For more information on using the 'lit' tool, see 'llvm-lit --help' or
the 'lit' man page.
Debugging Information tests
---------------------------
To run debugging information tests simply checkout the tests inside
clang/test directory.
.. code-block:: bash
% cd clang/test
% svn co http://llvm.org/svn/llvm-project/debuginfo-tests/trunk debuginfo-tests
These tests are already set up to run as part of clang regression tests.
Regression test structure
=========================
The LLVM regression tests are driven by 'lit' and are located in the
``llvm/test`` directory.
This directory contains a large array of small tests that exercise
various features of LLVM and to ensure that regressions do not occur.
The directory is broken into several sub-directories, each focused on a
particular area of LLVM. A few of the important ones are:
- ``Analysis``: checks Analysis passes.
- ``Archive``: checks the Archive library.
- ``Assembler``: checks Assembly reader/writer functionality.
- ``Bitcode``: checks Bitcode reader/writer functionality.
- ``CodeGen``: checks code generation and each target.
- ``Features``: checks various features of the LLVM language.
- ``Linker``: tests bitcode linking.
- ``Transforms``: tests each of the scalar, IPO, and utility transforms
to ensure they make the right transformations.
- ``Verifier``: tests the IR verifier.
Writing new regression tests
----------------------------
The regression test structure is very simple, but does require some
information to be set. This information is gathered via ``configure``
and is written to a file, ``lit.site.cfg`` in ``llvm/test``. The
``llvm/test`` Makefile does this work for you.
In order for the regression tests to work, each directory of tests must
have a ``lit.local.cfg`` file. Lit looks for this file to determine how
to run the tests. This file is just Python code and thus is very
flexible, but we've standardized it for the LLVM regression tests. If
you're adding a directory of tests, just copy ``lit.local.cfg`` from
another directory to get running. The standard ``lit.local.cfg`` simply
specifies which files to look in for tests. Any directory that contains
only directories does not need the ``lit.local.cfg`` file. Read the `Lit
documentation <http://llvm.org/cmds/lit.html>`_ for more information.
The ``llvm-runtests`` function looks at each file that is passed to it
and gathers any lines together that match "RUN:". These are the "RUN"
lines that specify how the test is to be run. So, each test script must
contain RUN lines if it is to do anything. If there are no RUN lines,
the ``llvm-runtests`` function will issue an error and the test will
fail.
RUN lines are specified in the comments of the test program using the
keyword ``RUN`` followed by a colon, and lastly the command (pipeline)
to execute. Together, these lines form the "script" that
``llvm-runtests`` executes to run the test case. The syntax of the RUN
lines is similar to a shell's syntax for pipelines including I/O
redirection and variable substitution. However, even though these lines
may *look* like a shell script, they are not. RUN lines are interpreted
directly by the Tcl ``exec`` command. They are never executed by a
shell. Consequently the syntax differs from normal shell script syntax
in a few ways. You can specify as many RUN lines as needed.
lit performs substitution on each RUN line to replace LLVM tool names
with the full paths to the executable built for each tool (in
$(LLVM\_OBJ\_ROOT)/$(BuildMode)/bin). This ensures that lit does not
invoke any stray LLVM tools in the user's path during testing.
Each RUN line is executed on its own, distinct from other lines unless
its last character is ``\``. This continuation character causes the RUN
line to be concatenated with the next one. In this way you can build up
long pipelines of commands without making huge line lengths. The lines
ending in ``\`` are concatenated until a RUN line that doesn't end in
``\`` is found. This concatenated set of RUN lines then constitutes one
execution. Tcl will substitute variables and arrange for the pipeline to
be executed. If any process in the pipeline fails, the entire line (and
test case) fails too.
Below is an example of legal RUN lines in a ``.ll`` file:
.. code-block:: llvm
; RUN: llvm-as < %s | llvm-dis > %t1
; RUN: llvm-dis < %s.bc-13 > %t2
; RUN: diff %t1 %t2
As with a Unix shell, the RUN: lines permit pipelines and I/O
redirection to be used. However, the usage is slightly different than
for Bash. To check what's legal, see the documentation for the `Tcl
exec <http://www.tcl.tk/man/tcl8.5/TclCmd/exec.htm#M2>`_ command and the
`tutorial <http://www.tcl.tk/man/tcl8.5/tutorial/Tcl26.html>`_. The
major differences are:
- You can't do ``2>&1``. That will cause Tcl to write to a file named
``&1``. Usually this is done to get stderr to go through a pipe. You
can do that in tcl with ``|&`` so replace this idiom:
``... 2>&1 | grep`` with ``... |& grep``
- You can only redirect to a file, not to another descriptor and not
from a here document.
- tcl supports redirecting to open files with the @ syntax but you
shouldn't use that here.
There are some quoting rules that you must pay attention to when writing
your RUN lines. In general nothing needs to be quoted. Tcl won't strip
off any quote characters so they will get passed to the invoked program.
For example:
.. code-block:: bash
... | grep 'find this string'
This will fail because the ' characters are passed to grep. This would
instruction grep to look for ``'find`` in the files ``this`` and
``string'``. To avoid this use curly braces to tell Tcl that it should
treat everything enclosed as one value. So our example would become:
.. code-block:: bash
... | grep {find this string}
Additionally, the characters ``[`` and ``]`` are treated specially by
Tcl. They tell Tcl to interpret the content as a command to execute.
Since these characters are often used in regular expressions this can
have disastrous results and cause the entire test run in a directory to
fail. For example, a common idiom is to look for some basicblock number:
.. code-block:: bash
... | grep bb[2-8]
This, however, will cause Tcl to fail because its going to try to
execute a program named "2-8". Instead, what you want is this:
.. code-block:: bash
... | grep {bb\[2-8\]}
Finally, if you need to pass the ``\`` character down to a program, then
it must be doubled. This is another Tcl special character. So, suppose
you had:
.. code-block:: bash
... | grep 'i32\*'
This will fail to match what you want (a pointer to i32). First, the
``'`` do not get stripped off. Second, the ``\`` gets stripped off by
Tcl so what grep sees is: ``'i32*'``. That's not likely to match
anything. To resolve this you must use ``\\`` and the ``{}``, like this:
.. code-block:: bash
... | grep {i32\\*}
If your system includes GNU ``grep``, make sure that ``GREP_OPTIONS`` is
not set in your environment. Otherwise, you may get invalid results
(both false positives and false negatives).
The FileCheck utility
---------------------
A powerful feature of the RUN: lines is that it allows any arbitrary
commands to be executed as part of the test harness. While standard
(portable) unix tools like 'grep' work fine on run lines, as you see
above, there are a lot of caveats due to interaction with Tcl syntax,
and we want to make sure the run lines are portable to a wide range of
systems. Another major problem is that grep is not very good at checking
to verify that the output of a tools contains a series of different
output in a specific order. The FileCheck tool was designed to help with
these problems.
FileCheck (whose basic command line arguments are described in `the
FileCheck man page <http://llvm.org/cmds/FileCheck.html>`_ is designed
to read a file to check from standard input, and the set of things to
verify from a file specified as a command line argument. A simple
example of using FileCheck from a RUN line looks like this:
.. code-block:: llvm
; RUN: llvm-as < %s | llc -march=x86-64 | FileCheck %s
This syntax says to pipe the current file ("%s") into llvm-as, pipe that
into llc, then pipe the output of llc into FileCheck. This means that
FileCheck will be verifying its standard input (the llc output) against
the filename argument specified (the original .ll file specified by
"%s"). To see how this works, let's look at the rest of the .ll file
(after the RUN line):
.. code-block:: llvm
define void @sub1(i32* %p, i32 %v) {
entry:
; CHECK: sub1:
; CHECK: subl
%0 = tail call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %p, i32 %v)
ret void
}
define void @inc4(i64* %p) {
entry:
; CHECK: inc4:
; CHECK: incq
%0 = tail call i64 @llvm.atomic.load.add.i64.p0i64(i64* %p, i64 1)
ret void
}
Here you can see some "CHECK:" lines specified in comments. Now you can
see how the file is piped into llvm-as, then llc, and the machine code
output is what we are verifying. FileCheck checks the machine code
output to verify that it matches what the "CHECK:" lines specify.
The syntax of the CHECK: lines is very simple: they are fixed strings
that must occur in order. FileCheck defaults to ignoring horizontal
whitespace differences (e.g. a space is allowed to match a tab) but
otherwise, the contents of the CHECK: line is required to match some
thing in the test file exactly.
One nice thing about FileCheck (compared to grep) is that it allows
merging test cases together into logical groups. For example, because
the test above is checking for the "sub1:" and "inc4:" labels, it will
not match unless there is a "subl" in between those labels. If it
existed somewhere else in the file, that would not count: "grep subl"
matches if subl exists anywhere in the file.
The FileCheck -check-prefix option
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The FileCheck -check-prefix option allows multiple test configurations
to be driven from one .ll file. This is useful in many circumstances,
for example, testing different architectural variants with llc. Here's a
simple example:
.. code-block:: llvm
; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \
; RUN: | FileCheck %s -check-prefix=X32
; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \
; RUN: | FileCheck %s -check-prefix=X64
define <4 x i32> @pinsrd_1(i32 %s, <4 x i32> %tmp) nounwind {
%tmp1 = insertelement <4 x i32> %tmp, i32 %s, i32 1
ret <4 x i32> %tmp1
; X32: pinsrd_1:
; X32: pinsrd $1, 4(%esp), %xmm0
; X64: pinsrd_1:
; X64: pinsrd $1, %edi, %xmm0
}
In this case, we're testing that we get the expected code generation
with both 32-bit and 64-bit code generation.
The "CHECK-NEXT:" directive
^^^^^^^^^^^^^^^^^^^^^^^^^^^
Sometimes you want to match lines and would like to verify that matches
happen on exactly consecutive lines with no other lines in between them.
In this case, you can use CHECK: and CHECK-NEXT: directives to specify
this. If you specified a custom check prefix, just use "<PREFIX>-NEXT:".
For example, something like this works as you'd expect:
.. code-block:: llvm
define void @t2(<2 x double>* %r, <2 x double>* %A, double %B) {
%tmp3 = load <2 x double>* %A, align 16
%tmp7 = insertelement <2 x double> undef, double %B, i32 0
%tmp9 = shufflevector <2 x double> %tmp3,
<2 x double> %tmp7,
<2 x i32> < i32 0, i32 2 >
store <2 x double> %tmp9, <2 x double>* %r, align 16
ret void
; CHECK: t2:
; CHECK: movl 8(%esp), %eax
; CHECK-NEXT: movapd (%eax), %xmm0
; CHECK-NEXT: movhpd 12(%esp), %xmm0
; CHECK-NEXT: movl 4(%esp), %eax
; CHECK-NEXT: movapd %xmm0, (%eax)
; CHECK-NEXT: ret
}
CHECK-NEXT: directives reject the input unless there is exactly one
newline between it an the previous directive. A CHECK-NEXT cannot be the
first directive in a file.
The "CHECK-NOT:" directive
^^^^^^^^^^^^^^^^^^^^^^^^^^
The CHECK-NOT: directive is used to verify that a string doesn't occur
between two matches (or the first match and the beginning of the file).
For example, to verify that a load is removed by a transformation, a
test like this can be used:
.. code-block:: llvm
define i8 @coerce_offset0(i32 %V, i32* %P) {
store i32 %V, i32* %P
%P2 = bitcast i32* %P to i8*
%P3 = getelementptr i8* %P2, i32 2
%A = load i8* %P3
ret i8 %A
; CHECK: @coerce_offset0
; CHECK-NOT: load
; CHECK: ret i8
}
FileCheck Pattern Matching Syntax
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The CHECK: and CHECK-NOT: directives both take a pattern to match. For
most uses of FileCheck, fixed string matching is perfectly sufficient.
For some things, a more flexible form of matching is desired. To support
this, FileCheck allows you to specify regular expressions in matching
strings, surrounded by double braces: **{{yourregex}}**. Because we want
to use fixed string matching for a majority of what we do, FileCheck has
been designed to support mixing and matching fixed string matching with
regular expressions. This allows you to write things like this:
.. code-block:: llvm
; CHECK: movhpd {{[0-9]+}}(%esp), {{%xmm[0-7]}}
In this case, any offset from the ESP register will be allowed, and any
xmm register will be allowed.
Because regular expressions are enclosed with double braces, they are
visually distinct, and you don't need to use escape characters within
the double braces like you would in C. In the rare case that you want to
match double braces explicitly from the input, you can use something
ugly like **{{[{][{]}}** as your pattern.
FileCheck Variables
^^^^^^^^^^^^^^^^^^^
It is often useful to match a pattern and then verify that it occurs
again later in the file. For codegen tests, this can be useful to allow
any register, but verify that that register is used consistently later.
To do this, FileCheck allows named variables to be defined and
substituted into patterns. Here is a simple example:
.. code-block:: llvm
; CHECK: test5:
; CHECK: notw [[REGISTER:%[a-z]+]]
; CHECK: andw {{.*}}[[REGISTER]]
The first check line matches a regex (``%[a-z]+``) and captures it into
the variables "REGISTER". The second line verifies that whatever is in
REGISTER occurs later in the file after an "andw". FileCheck variable
references are always contained in ``[[ ]]`` pairs, are named, and their
names can be formed with the regex "``[a-zA-Z][a-zA-Z0-9]*``". If a
colon follows the name, then it is a definition of the variable, if not,
it is a use.
FileCheck variables can be defined multiple times, and uses always get
the latest value. Note that variables are all read at the start of a
"CHECK" line and are all defined at the end. This means that if you have
something like "``CHECK: [[XYZ:.*]]x[[XYZ]]``" that the check line will
read the previous value of the XYZ variable and define a new one after
the match is performed. If you need to do something like this you can
probably take advantage of the fact that FileCheck is not actually
line-oriented when it matches, this allows you to define two separate
CHECK lines that match on the same line.
Variables and substitutions
---------------------------
With a RUN line there are a number of substitutions that are permitted.
In general, any Tcl variable that is available in the ``substitute``
function (in ``test/lib/llvm.exp``) can be substituted into a RUN line.
To make a substitution just write the variable's name preceded by a $.
Additionally, for compatibility reasons with previous versions of the
test library, certain names can be accessed with an alternate syntax: a
% prefix. These alternates are deprecated and may go away in a future
version.
Here are the available variable names. The alternate syntax is listed in
parentheses.
``$test`` (``%s``)
The full path to the test case's source. This is suitable for passing on
the command line as the input to an llvm tool.
``%(line)``, ``%(line+<number>)``, ``%(line-<number>)``
The number of the line where this variable is used, with an optional
integer offset. This can be used in tests with multiple RUN: lines,
which reference test file's line numbers.
``$srcdir``
The source directory from where the "``make check``" was run.
``objdir``
The object directory that corresponds to the ``$srcdir``.
``subdir``
A partial path from the ``test`` directory that contains the
sub-directory that contains the test source being executed.
``srcroot``
The root directory of the LLVM src tree.
``objroot``
The root directory of the LLVM object tree. This could be the same as
the srcroot.
``path``
The path to the directory that contains the test case source. This is
for locating any supporting files that are not generated by the test,
but used by the test.
``tmp``
The path to a temporary file name that could be used for this test case.
The file name won't conflict with other test cases. You can append to it
if you need multiple temporaries. This is useful as the destination of
some redirected output.
``target_triplet`` (``%target_triplet``)
The target triplet that corresponds to the current host machine (the one
running the test cases). This should probably be called "host".
``link`` (``%link``)
This full link command used to link LLVM executables. This has all the
configured -I, -L and -l options.
``shlibext`` (``%shlibext``)
The suffix for the host platforms share library (dll) files. This
includes the period as the first character.
To add more variables, two things need to be changed. First, add a line
in the ``test/Makefile`` that creates the ``site.exp`` file. This will
"set" the variable as a global in the site.exp file. Second, in the
``test/lib/llvm.exp`` file, in the substitute proc, add the variable
name to the list of "global" declarations at the beginning of the proc.
That's it, the variable can then be used in test scripts.
Other Features
--------------
To make RUN line writing easier, there are several shell scripts located
in the ``llvm/test/Scripts`` directory. This directory is in the PATH
when running tests, so you can just call these scripts using their name.
For example:
``ignore``
This script runs its arguments and then always returns 0. This is useful
in cases where the test needs to cause a tool to generate an error (e.g.
to check the error output). However, any program in a pipeline that
returns a non-zero result will cause the test to fail. This script
overcomes that issue and nicely documents that the test case is
purposefully ignoring the result code of the tool
``not``
This script runs its arguments and then inverts the result code from it.
Zero result codes become 1. Non-zero result codes become 0. This is
useful to invert the result of a grep. For example "not grep X" means
succeed only if you don't find X in the input.
Sometimes it is necessary to mark a test case as "expected fail" or
XFAIL. You can easily mark a test as XFAIL just by including ``XFAIL:``
on a line near the top of the file. This signals that the test case
should succeed if the test fails. Such test cases are counted separately
by the testing tool. To specify an expected fail, use the XFAIL keyword
in the comments of the test program followed by a colon and one or more
failure patterns. Each failure pattern can be either ``*`` (to specify
fail everywhere), or a part of a target triple (indicating the test
should fail on that platform), or the name of a configurable feature
(for example, ``loadable_module``). If there is a match, the test is
expected to fail. If not, the test is expected to succeed. To XFAIL
everywhere just specify ``XFAIL: *``. Here is an example of an ``XFAIL``
line:
.. code-block:: llvm
; XFAIL: darwin,sun
To make the output more useful, the ``llvm_runtest`` function wil scan
the lines of the test case for ones that contain a pattern that matches
``PR[0-9]+``. This is the syntax for specifying a PR (Problem Report) number
that is related to the test case. The number after "PR" specifies the
LLVM bugzilla number. When a PR number is specified, it will be used in
the pass/fail reporting. This is useful to quickly get some context when
a test fails.
Finally, any line that contains "END." will cause the special
interpretation of lines to terminate. This is generally done right after
the last RUN: line. This has two side effects:
(a) it prevents special interpretation of lines that are part of the test
program, not the instructions to the test case, and
(b) it speeds things up for really big test cases by avoiding
interpretation of the remainder of the file.
``test-suite`` Overview
=======================
The ``test-suite`` module contains a number of programs that can be
compiled and executed. The ``test-suite`` includes reference outputs for
all of the programs, so that the output of the executed program can be
checked for correctness.
``test-suite`` tests are divided into three types of tests: MultiSource,
SingleSource, and External.
- ``test-suite/SingleSource``
The SingleSource directory contains test programs that are only a
single source file in size. These are usually small benchmark
programs or small programs that calculate a particular value. Several
such programs are grouped together in each directory.
- ``test-suite/MultiSource``
The MultiSource directory contains subdirectories which contain
entire programs with multiple source files. Large benchmarks and
whole applications go here.
- ``test-suite/External``
The External directory contains Makefiles for building code that is
external to (i.e., not distributed with) LLVM. The most prominent
members of this directory are the SPEC 95 and SPEC 2000 benchmark
suites. The ``External`` directory does not contain these actual
tests, but only the Makefiles that know how to properly compile these
programs from somewhere else. When using ``LNT``, use the
``--test-externals`` option to include these tests in the results.
``test-suite`` Quickstart
-------------------------
The modern way of running the ``test-suite`` is focused on testing and
benchmarking complete compilers using the
`LNT <http://llvm.org/docs/lnt>`_ testing infrastructure.
For more information on using LNT to execute the ``test-suite``, please
see the `LNT Quickstart <http://llvm.org/docs/lnt/quickstart.html>`_
documentation.
``test-suite`` Makefiles
------------------------
Historically, the ``test-suite`` was executed using a complicated setup
of Makefiles. The LNT based approach above is recommended for most
users, but there are some testing scenarios which are not supported by
the LNT approach. In addition, LNT currently uses the Makefile setup
under the covers and so developers who are interested in how LNT works
under the hood may want to understand the Makefile based setup.
For more information on the ``test-suite`` Makefile setup, please see
the `Test Suite Makefile Guide. <TestSuiteMakefileGuide.html>`_

3
llvm/docs/userguides.rst
View File

@ -20,6 +20,7 @@ User Guides
HowToSubmitABug
SphinxQuickstartTemplate
Phabricator
TestingGuide
* :ref:`getting_started`
@ -77,7 +78,7 @@ User Guides
A template + tutorial for writing new Sphinx documentation. It is meant
to be read in source form.
* `LLVM Testing Infrastructure Guide <TestingGuide.html>`_
* :doc:`LLVM Testing Infrastructure Guide <TestingGuide>`
A reference manual for using the LLVM testing infrastructure.