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| <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/BitCast.ll' test by itself you can run:</p> | |
| <div class="doc_code"> | |
| <pre> | |
| % llvm-lit ~/llvm/test/Integer/BitCast.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 < %s | llvm-dis > %t1 | |
| ; RUN: llvm-dis < %s.bc-13 > %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>&1</tt>. That will cause Tcl to write to a | |
| file named <tt>&1</tt>. Usually this is done to get stderr to go through | |
| a pipe. You can do that in tcl with <tt>|&</tt> so replace this idiom: | |
| <tt>... 2>&1 | grep</tt> with <tt>... |& 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 < %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 < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \ | |
| ; RUN: | <b>FileCheck %s -check-prefix=X32</b> | |
| ; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \ | |
| ; RUN: | <b>FileCheck %s -check-prefix=X64</b> | |
| 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 | |
| ; <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 "<PREFIX>-NEXT:". For | |
| example, something like this works as you'd expect:</p> | |
| <div class="doc_code"> | |
| <pre> | |
| 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 | |
| ; <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> | |
| <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> | |
| </div> | |
| <!-- _______________________________________________________________________ --> | |
| <h4> | |
| <a name="FileCheck-Variables">FileCheck Variables</a> | |
| </h4> | |
| <div> | |
| <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> | |
| </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>$srcdir</b></dt> | |
| <dd>The source directory from where the "<tt>make check</tt>" was run.</dd> | |
| <dt><b>objdir</b></dt> | |
| <dd>The object directory that corresponds to the <tt>$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 regular expressions (separated by | |
| a comma). The regular expressions allow you to XFAIL the test conditionally by | |
| host platform. The regular expressions following the : are matched against the | |
| target triplet for the host machine. 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> | |
| <!-- *********************************************************************** --> | |
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