1FileCheck - Flexible pattern matching file verifier 2=================================================== 3 4SYNOPSIS 5-------- 6 7:program:`FileCheck` *match-filename* [*--check-prefix=XXX*] [*--strict-whitespace*] 8 9DESCRIPTION 10----------- 11 12:program:`FileCheck` reads two files (one from standard input, and one 13specified on the command line) and uses one to verify the other. This 14behavior is particularly useful for the testsuite, which wants to verify that 15the output of some tool (e.g. :program:`llc`) contains the expected information 16(for example, a movsd from esp or whatever is interesting). This is similar to 17using :program:`grep`, but it is optimized for matching multiple different 18inputs in one file in a specific order. 19 20The ``match-filename`` file specifies the file that contains the patterns to 21match. The file to verify is read from standard input unless the 22:option:`--input-file` option is used. 23 24OPTIONS 25------- 26 27.. option:: -help 28 29 Print a summary of command line options. 30 31.. option:: --check-prefix prefix 32 33 FileCheck searches the contents of ``match-filename`` for patterns to 34 match. By default, these patterns are prefixed with "``CHECK:``". 35 If you'd like to use a different prefix (e.g. because the same input 36 file is checking multiple different tool or options), the 37 :option:`--check-prefix` argument allows you to specify one or more 38 prefixes to match. Multiple prefixes are useful for tests which might 39 change for different run options, but most lines remain the same. 40 41.. option:: --check-prefixes prefix1,prefix2,... 42 43 An alias of :option:`--check-prefix` that allows multiple prefixes to be 44 specified as a comma separated list. 45 46.. option:: --input-file filename 47 48 File to check (defaults to stdin). 49 50.. option:: --match-full-lines 51 52 By default, FileCheck allows matches of anywhere on a line. This 53 option will require all positive matches to cover an entire 54 line. Leading and trailing whitespace is ignored, unless 55 :option:`--strict-whitespace` is also specified. (Note: negative 56 matches from ``CHECK-NOT`` are not affected by this option!) 57 58 Passing this option is equivalent to inserting ``{{^ *}}`` or 59 ``{{^}}`` before, and ``{{ *$}}`` or ``{{$}}`` after every positive 60 check pattern. 61 62.. option:: --strict-whitespace 63 64 By default, FileCheck canonicalizes input horizontal whitespace (spaces and 65 tabs) which causes it to ignore these differences (a space will match a tab). 66 The :option:`--strict-whitespace` argument disables this behavior. End-of-line 67 sequences are canonicalized to UNIX-style ``\n`` in all modes. 68 69.. option:: --implicit-check-not check-pattern 70 71 Adds implicit negative checks for the specified patterns between positive 72 checks. The option allows writing stricter tests without stuffing them with 73 ``CHECK-NOT``\ s. 74 75 For example, "``--implicit-check-not warning:``" can be useful when testing 76 diagnostic messages from tools that don't have an option similar to ``clang 77 -verify``. With this option FileCheck will verify that input does not contain 78 warnings not covered by any ``CHECK:`` patterns. 79 80.. option:: --enable-var-scope 81 82 Enables scope for regex variables. 83 84 Variables with names that start with ``$`` are considered global and 85 remain set throughout the file. 86 87 All other variables get undefined after each encountered ``CHECK-LABEL``. 88 89.. option:: -version 90 91 Show the version number of this program. 92 93EXIT STATUS 94----------- 95 96If :program:`FileCheck` verifies that the file matches the expected contents, 97it exits with 0. Otherwise, if not, or if an error occurs, it will exit with a 98non-zero value. 99 100TUTORIAL 101-------- 102 103FileCheck is typically used from LLVM regression tests, being invoked on the RUN 104line of the test. A simple example of using FileCheck from a RUN line looks 105like this: 106 107.. code-block:: llvm 108 109 ; RUN: llvm-as < %s | llc -march=x86-64 | FileCheck %s 110 111This syntax says to pipe the current file ("``%s``") into ``llvm-as``, pipe 112that into ``llc``, then pipe the output of ``llc`` into ``FileCheck``. This 113means that FileCheck will be verifying its standard input (the llc output) 114against the filename argument specified (the original ``.ll`` file specified by 115"``%s``"). To see how this works, let's look at the rest of the ``.ll`` file 116(after the RUN line): 117 118.. code-block:: llvm 119 120 define void @sub1(i32* %p, i32 %v) { 121 entry: 122 ; CHECK: sub1: 123 ; CHECK: subl 124 %0 = tail call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %p, i32 %v) 125 ret void 126 } 127 128 define void @inc4(i64* %p) { 129 entry: 130 ; CHECK: inc4: 131 ; CHECK: incq 132 %0 = tail call i64 @llvm.atomic.load.add.i64.p0i64(i64* %p, i64 1) 133 ret void 134 } 135 136Here you can see some "``CHECK:``" lines specified in comments. Now you can 137see how the file is piped into ``llvm-as``, then ``llc``, and the machine code 138output is what we are verifying. FileCheck checks the machine code output to 139verify that it matches what the "``CHECK:``" lines specify. 140 141The syntax of the "``CHECK:``" lines is very simple: they are fixed strings that 142must occur in order. FileCheck defaults to ignoring horizontal whitespace 143differences (e.g. a space is allowed to match a tab) but otherwise, the contents 144of the "``CHECK:``" line is required to match some thing in the test file exactly. 145 146One nice thing about FileCheck (compared to grep) is that it allows merging 147test cases together into logical groups. For example, because the test above 148is checking for the "``sub1:``" and "``inc4:``" labels, it will not match 149unless there is a "``subl``" in between those labels. If it existed somewhere 150else in the file, that would not count: "``grep subl``" matches if "``subl``" 151exists anywhere in the file. 152 153The FileCheck -check-prefix option 154~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 155 156The FileCheck `-check-prefix` option allows multiple test 157configurations to be driven from one `.ll` file. This is useful in many 158circumstances, for example, testing different architectural variants with 159:program:`llc`. Here's a simple example: 160 161.. code-block:: llvm 162 163 ; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \ 164 ; RUN: | FileCheck %s -check-prefix=X32 165 ; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \ 166 ; RUN: | FileCheck %s -check-prefix=X64 167 168 define <4 x i32> @pinsrd_1(i32 %s, <4 x i32> %tmp) nounwind { 169 %tmp1 = insertelement <4 x i32>; %tmp, i32 %s, i32 1 170 ret <4 x i32> %tmp1 171 ; X32: pinsrd_1: 172 ; X32: pinsrd $1, 4(%esp), %xmm0 173 174 ; X64: pinsrd_1: 175 ; X64: pinsrd $1, %edi, %xmm0 176 } 177 178In this case, we're testing that we get the expected code generation with 179both 32-bit and 64-bit code generation. 180 181The "CHECK-NEXT:" directive 182~~~~~~~~~~~~~~~~~~~~~~~~~~~ 183 184Sometimes you want to match lines and would like to verify that matches 185happen on exactly consecutive lines with no other lines in between them. In 186this case, you can use "``CHECK:``" and "``CHECK-NEXT:``" directives to specify 187this. If you specified a custom check prefix, just use "``<PREFIX>-NEXT:``". 188For example, something like this works as you'd expect: 189 190.. code-block:: llvm 191 192 define void @t2(<2 x double>* %r, <2 x double>* %A, double %B) { 193 %tmp3 = load <2 x double>* %A, align 16 194 %tmp7 = insertelement <2 x double> undef, double %B, i32 0 195 %tmp9 = shufflevector <2 x double> %tmp3, 196 <2 x double> %tmp7, 197 <2 x i32> < i32 0, i32 2 > 198 store <2 x double> %tmp9, <2 x double>* %r, align 16 199 ret void 200 201 ; CHECK: t2: 202 ; CHECK: movl 8(%esp), %eax 203 ; CHECK-NEXT: movapd (%eax), %xmm0 204 ; CHECK-NEXT: movhpd 12(%esp), %xmm0 205 ; CHECK-NEXT: movl 4(%esp), %eax 206 ; CHECK-NEXT: movapd %xmm0, (%eax) 207 ; CHECK-NEXT: ret 208 } 209 210"``CHECK-NEXT:``" directives reject the input unless there is exactly one 211newline between it and the previous directive. A "``CHECK-NEXT:``" cannot be 212the first directive in a file. 213 214The "CHECK-SAME:" directive 215~~~~~~~~~~~~~~~~~~~~~~~~~~~ 216 217Sometimes you want to match lines and would like to verify that matches happen 218on the same line as the previous match. In this case, you can use "``CHECK:``" 219and "``CHECK-SAME:``" directives to specify this. If you specified a custom 220check prefix, just use "``<PREFIX>-SAME:``". 221 222"``CHECK-SAME:``" is particularly powerful in conjunction with "``CHECK-NOT:``" 223(described below). 224 225For example, the following works like you'd expect: 226 227.. code-block:: llvm 228 229 !0 = !DILocation(line: 5, scope: !1, inlinedAt: !2) 230 231 ; CHECK: !DILocation(line: 5, 232 ; CHECK-NOT: column: 233 ; CHECK-SAME: scope: ![[SCOPE:[0-9]+]] 234 235"``CHECK-SAME:``" directives reject the input if there are any newlines between 236it and the previous directive. A "``CHECK-SAME:``" cannot be the first 237directive in a file. 238 239The "CHECK-NOT:" directive 240~~~~~~~~~~~~~~~~~~~~~~~~~~ 241 242The "``CHECK-NOT:``" directive is used to verify that a string doesn't occur 243between two matches (or before the first match, or after the last match). For 244example, to verify that a load is removed by a transformation, a test like this 245can be used: 246 247.. code-block:: llvm 248 249 define i8 @coerce_offset0(i32 %V, i32* %P) { 250 store i32 %V, i32* %P 251 252 %P2 = bitcast i32* %P to i8* 253 %P3 = getelementptr i8* %P2, i32 2 254 255 %A = load i8* %P3 256 ret i8 %A 257 ; CHECK: @coerce_offset0 258 ; CHECK-NOT: load 259 ; CHECK: ret i8 260 } 261 262The "CHECK-DAG:" directive 263~~~~~~~~~~~~~~~~~~~~~~~~~~ 264 265If it's necessary to match strings that don't occur in a strictly sequential 266order, "``CHECK-DAG:``" could be used to verify them between two matches (or 267before the first match, or after the last match). For example, clang emits 268vtable globals in reverse order. Using ``CHECK-DAG:``, we can keep the checks 269in the natural order: 270 271.. code-block:: c++ 272 273 // RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s 274 275 struct Foo { virtual void method(); }; 276 Foo f; // emit vtable 277 // CHECK-DAG: @_ZTV3Foo = 278 279 struct Bar { virtual void method(); }; 280 Bar b; 281 // CHECK-DAG: @_ZTV3Bar = 282 283``CHECK-NOT:`` directives could be mixed with ``CHECK-DAG:`` directives to 284exclude strings between the surrounding ``CHECK-DAG:`` directives. As a result, 285the surrounding ``CHECK-DAG:`` directives cannot be reordered, i.e. all 286occurrences matching ``CHECK-DAG:`` before ``CHECK-NOT:`` must not fall behind 287occurrences matching ``CHECK-DAG:`` after ``CHECK-NOT:``. For example, 288 289.. code-block:: llvm 290 291 ; CHECK-DAG: BEFORE 292 ; CHECK-NOT: NOT 293 ; CHECK-DAG: AFTER 294 295This case will reject input strings where ``BEFORE`` occurs after ``AFTER``. 296 297With captured variables, ``CHECK-DAG:`` is able to match valid topological 298orderings of a DAG with edges from the definition of a variable to its use. 299It's useful, e.g., when your test cases need to match different output 300sequences from the instruction scheduler. For example, 301 302.. code-block:: llvm 303 304 ; CHECK-DAG: add [[REG1:r[0-9]+]], r1, r2 305 ; CHECK-DAG: add [[REG2:r[0-9]+]], r3, r4 306 ; CHECK: mul r5, [[REG1]], [[REG2]] 307 308In this case, any order of that two ``add`` instructions will be allowed. 309 310If you are defining `and` using variables in the same ``CHECK-DAG:`` block, 311be aware that the definition rule can match `after` its use. 312 313So, for instance, the code below will pass: 314 315.. code-block:: text 316 317 ; CHECK-DAG: vmov.32 [[REG2:d[0-9]+]][0] 318 ; CHECK-DAG: vmov.32 [[REG2]][1] 319 vmov.32 d0[1] 320 vmov.32 d0[0] 321 322While this other code, will not: 323 324.. code-block:: text 325 326 ; CHECK-DAG: vmov.32 [[REG2:d[0-9]+]][0] 327 ; CHECK-DAG: vmov.32 [[REG2]][1] 328 vmov.32 d1[1] 329 vmov.32 d0[0] 330 331While this can be very useful, it's also dangerous, because in the case of 332register sequence, you must have a strong order (read before write, copy before 333use, etc). If the definition your test is looking for doesn't match (because 334of a bug in the compiler), it may match further away from the use, and mask 335real bugs away. 336 337In those cases, to enforce the order, use a non-DAG directive between DAG-blocks. 338 339The "CHECK-LABEL:" directive 340~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 341 342Sometimes in a file containing multiple tests divided into logical blocks, one 343or more ``CHECK:`` directives may inadvertently succeed by matching lines in a 344later block. While an error will usually eventually be generated, the check 345flagged as causing the error may not actually bear any relationship to the 346actual source of the problem. 347 348In order to produce better error messages in these cases, the "``CHECK-LABEL:``" 349directive can be used. It is treated identically to a normal ``CHECK`` 350directive except that FileCheck makes an additional assumption that a line 351matched by the directive cannot also be matched by any other check present in 352``match-filename``; this is intended to be used for lines containing labels or 353other unique identifiers. Conceptually, the presence of ``CHECK-LABEL`` divides 354the input stream into separate blocks, each of which is processed independently, 355preventing a ``CHECK:`` directive in one block matching a line in another block. 356If ``--enable-var-scope`` is in effect, all local variables are cleared at the 357beginning of the block. 358 359For example, 360 361.. code-block:: llvm 362 363 define %struct.C* @C_ctor_base(%struct.C* %this, i32 %x) { 364 entry: 365 ; CHECK-LABEL: C_ctor_base: 366 ; CHECK: mov [[SAVETHIS:r[0-9]+]], r0 367 ; CHECK: bl A_ctor_base 368 ; CHECK: mov r0, [[SAVETHIS]] 369 %0 = bitcast %struct.C* %this to %struct.A* 370 %call = tail call %struct.A* @A_ctor_base(%struct.A* %0) 371 %1 = bitcast %struct.C* %this to %struct.B* 372 %call2 = tail call %struct.B* @B_ctor_base(%struct.B* %1, i32 %x) 373 ret %struct.C* %this 374 } 375 376 define %struct.D* @D_ctor_base(%struct.D* %this, i32 %x) { 377 entry: 378 ; CHECK-LABEL: D_ctor_base: 379 380The use of ``CHECK-LABEL:`` directives in this case ensures that the three 381``CHECK:`` directives only accept lines corresponding to the body of the 382``@C_ctor_base`` function, even if the patterns match lines found later in 383the file. Furthermore, if one of these three ``CHECK:`` directives fail, 384FileCheck will recover by continuing to the next block, allowing multiple test 385failures to be detected in a single invocation. 386 387There is no requirement that ``CHECK-LABEL:`` directives contain strings that 388correspond to actual syntactic labels in a source or output language: they must 389simply uniquely match a single line in the file being verified. 390 391``CHECK-LABEL:`` directives cannot contain variable definitions or uses. 392 393FileCheck Pattern Matching Syntax 394~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 395 396All FileCheck directives take a pattern to match. 397For most uses of FileCheck, fixed string matching is perfectly sufficient. For 398some things, a more flexible form of matching is desired. To support this, 399FileCheck allows you to specify regular expressions in matching strings, 400surrounded by double braces: ``{{yourregex}}``. FileCheck implements a POSIX 401regular expression matcher; it supports Extended POSIX regular expressions 402(ERE). Because we want to use fixed string matching for a majority of what we 403do, FileCheck has been designed to support mixing and matching fixed string 404matching with regular expressions. This allows you to write things like this: 405 406.. code-block:: llvm 407 408 ; CHECK: movhpd {{[0-9]+}}(%esp), {{%xmm[0-7]}} 409 410In this case, any offset from the ESP register will be allowed, and any xmm 411register will be allowed. 412 413Because regular expressions are enclosed with double braces, they are 414visually distinct, and you don't need to use escape characters within the double 415braces like you would in C. In the rare case that you want to match double 416braces explicitly from the input, you can use something ugly like 417``{{[{][{]}}`` as your pattern. 418 419FileCheck Variables 420~~~~~~~~~~~~~~~~~~~ 421 422It is often useful to match a pattern and then verify that it occurs again 423later in the file. For codegen tests, this can be useful to allow any register, 424but verify that that register is used consistently later. To do this, 425:program:`FileCheck` allows named variables to be defined and substituted into 426patterns. Here is a simple example: 427 428.. code-block:: llvm 429 430 ; CHECK: test5: 431 ; CHECK: notw [[REGISTER:%[a-z]+]] 432 ; CHECK: andw {{.*}}[[REGISTER]] 433 434The first check line matches a regex ``%[a-z]+`` and captures it into the 435variable ``REGISTER``. The second line verifies that whatever is in 436``REGISTER`` occurs later in the file after an "``andw``". :program:`FileCheck` 437variable references are always contained in ``[[ ]]`` pairs, and their names can 438be formed with the regex ``[a-zA-Z_][a-zA-Z0-9_]*``. If a colon follows the name, 439then it is a definition of the variable; otherwise, it is a use. 440 441:program:`FileCheck` variables can be defined multiple times, and uses always 442get the latest value. Variables can also be used later on the same line they 443were defined on. For example: 444 445.. code-block:: llvm 446 447 ; CHECK: op [[REG:r[0-9]+]], [[REG]] 448 449Can be useful if you want the operands of ``op`` to be the same register, 450and don't care exactly which register it is. 451 452If ``--enable-var-scope`` is in effect, variables with names that 453start with ``$`` are considered to be global. All others variables are 454local. All local variables get undefined at the beginning of each 455CHECK-LABEL block. Global variables are not affected by CHECK-LABEL. 456This makes it easier to ensure that individual tests are not affected 457by variables set in preceding tests. 458 459FileCheck Expressions 460~~~~~~~~~~~~~~~~~~~~~ 461 462Sometimes there's a need to verify output which refers line numbers of the 463match file, e.g. when testing compiler diagnostics. This introduces a certain 464fragility of the match file structure, as "``CHECK:``" lines contain absolute 465line numbers in the same file, which have to be updated whenever line numbers 466change due to text addition or deletion. 467 468To support this case, FileCheck allows using ``[[@LINE]]``, 469``[[@LINE+<offset>]]``, ``[[@LINE-<offset>]]`` expressions in patterns. These 470expressions expand to a number of the line where a pattern is located (with an 471optional integer offset). 472 473This way match patterns can be put near the relevant test lines and include 474relative line number references, for example: 475 476.. code-block:: c++ 477 478 // CHECK: test.cpp:[[@LINE+4]]:6: error: expected ';' after top level declarator 479 // CHECK-NEXT: {{^int a}} 480 // CHECK-NEXT: {{^ \^}} 481 // CHECK-NEXT: {{^ ;}} 482 int a 483 484Matching Newline Characters 485~~~~~~~~~~~~~~~~~~~~~~~~~~~ 486 487To match newline characters in regular expressions the character class 488``[[:space:]]`` can be used. For example, the following pattern: 489 490.. code-block:: c++ 491 492 // CHECK: DW_AT_location [DW_FORM_sec_offset] ([[DLOC:0x[0-9a-f]+]]){{[[:space:]].*}}"intd" 493 494matches output of the form (from llvm-dwarfdump): 495 496.. code-block:: text 497 498 DW_AT_location [DW_FORM_sec_offset] (0x00000233) 499 DW_AT_name [DW_FORM_strp] ( .debug_str[0x000000c9] = "intd") 500 501letting us set the :program:`FileCheck` variable ``DLOC`` to the desired value 502``0x00000233``, extracted from the line immediately preceding "``intd``". 503