1 FileCheck - Flexible pattern matching file verifier 2 =================================================== 3 4 SYNOPSIS 5 -------- 6 7 :program:`FileCheck` *match-filename* [*--check-prefix=XXX*] [*--strict-whitespace*] 8 9 DESCRIPTION 10 ----------- 11 12 :program:`FileCheck` reads two files (one from standard input, and one 13 specified on the command line) and uses one to verify the other. This 14 behavior is particularly useful for the testsuite, which wants to verify that 15 the 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 17 using :program:`grep`, but it is optimized for matching multiple different 18 inputs in one file in a specific order. 19 20 The ``match-filename`` file specifies the file that contains the patterns to 21 match. The file to verify is always read from standard input. 22 23 OPTIONS 24 ------- 25 26 .. option:: -help 27 28 Print a summary of command line options. 29 30 .. option:: --check-prefix prefix 31 32 FileCheck searches the contents of ``match-filename`` for patterns to match. 33 By default, these patterns are prefixed with "``CHECK:``". If you'd like to 34 use a different prefix (e.g. because the same input file is checking multiple 35 different tool or options), the :option:`--check-prefix` argument allows you 36 to specify a specific prefix to match. 37 38 .. option:: --input-file filename 39 40 File to check (defaults to stdin). 41 42 .. option:: --strict-whitespace 43 44 By default, FileCheck canonicalizes input horizontal whitespace (spaces and 45 tabs) which causes it to ignore these differences (a space will match a tab). 46 The :option:`--strict-whitespace` argument disables this behavior. End-of-line 47 sequences are canonicalized to UNIX-style '\n' in all modes. 48 49 .. option:: -version 50 51 Show the version number of this program. 52 53 EXIT STATUS 54 ----------- 55 56 If :program:`FileCheck` verifies that the file matches the expected contents, 57 it exits with 0. Otherwise, if not, or if an error occurs, it will exit with a 58 non-zero value. 59 60 TUTORIAL 61 -------- 62 63 FileCheck is typically used from LLVM regression tests, being invoked on the RUN 64 line of the test. A simple example of using FileCheck from a RUN line looks 65 like this: 66 67 .. code-block:: llvm 68 69 ; RUN: llvm-as < %s | llc -march=x86-64 | FileCheck %s 70 71 This syntax says to pipe the current file ("``%s``") into ``llvm-as``, pipe 72 that into ``llc``, then pipe the output of ``llc`` into ``FileCheck``. This 73 means that FileCheck will be verifying its standard input (the llc output) 74 against the filename argument specified (the original ``.ll`` file specified by 75 "``%s``"). To see how this works, let's look at the rest of the ``.ll`` file 76 (after the RUN line): 77 78 .. code-block:: llvm 79 80 define void @sub1(i32* %p, i32 %v) { 81 entry: 82 ; CHECK: sub1: 83 ; CHECK: subl 84 %0 = tail call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %p, i32 %v) 85 ret void 86 } 87 88 define void @inc4(i64* %p) { 89 entry: 90 ; CHECK: inc4: 91 ; CHECK: incq 92 %0 = tail call i64 @llvm.atomic.load.add.i64.p0i64(i64* %p, i64 1) 93 ret void 94 } 95 96 Here you can see some "``CHECK:``" lines specified in comments. Now you can 97 see how the file is piped into ``llvm-as``, then ``llc``, and the machine code 98 output is what we are verifying. FileCheck checks the machine code output to 99 verify that it matches what the "``CHECK:``" lines specify. 100 101 The syntax of the "``CHECK:``" lines is very simple: they are fixed strings that 102 must occur in order. FileCheck defaults to ignoring horizontal whitespace 103 differences (e.g. a space is allowed to match a tab) but otherwise, the contents 104 of the "``CHECK:``" line is required to match some thing in the test file exactly. 105 106 One nice thing about FileCheck (compared to grep) is that it allows merging 107 test cases together into logical groups. For example, because the test above 108 is checking for the "``sub1:``" and "``inc4:``" labels, it will not match 109 unless there is a "``subl``" in between those labels. If it existed somewhere 110 else in the file, that would not count: "``grep subl``" matches if "``subl``" 111 exists anywhere in the file. 112 113 The FileCheck -check-prefix option 114 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 115 116 The FileCheck :option:`-check-prefix` option allows multiple test 117 configurations to be driven from one `.ll` file. This is useful in many 118 circumstances, for example, testing different architectural variants with 119 :program:`llc`. Here's a simple example: 120 121 .. code-block:: llvm 122 123 ; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \ 124 ; RUN: | FileCheck %s -check-prefix=X32 125 ; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \ 126 ; RUN: | FileCheck %s -check-prefix=X64 127 128 define <4 x i32> @pinsrd_1(i32 %s, <4 x i32> %tmp) nounwind { 129 %tmp1 = insertelement <4 x i32>; %tmp, i32 %s, i32 1 130 ret <4 x i32> %tmp1 131 ; X32: pinsrd_1: 132 ; X32: pinsrd $1, 4(%esp), %xmm0 133 134 ; X64: pinsrd_1: 135 ; X64: pinsrd $1, %edi, %xmm0 136 } 137 138 In this case, we're testing that we get the expected code generation with 139 both 32-bit and 64-bit code generation. 140 141 The "CHECK-NEXT:" directive 142 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ 143 144 Sometimes you want to match lines and would like to verify that matches 145 happen on exactly consecutive lines with no other lines in between them. In 146 this case, you can use "``CHECK:``" and "``CHECK-NEXT:``" directives to specify 147 this. If you specified a custom check prefix, just use "``<PREFIX>-NEXT:``". 148 For example, something like this works as you'd expect: 149 150 .. code-block:: llvm 151 152 define void @t2(<2 x double>* %r, <2 x double>* %A, double %B) { 153 %tmp3 = load <2 x double>* %A, align 16 154 %tmp7 = insertelement <2 x double> undef, double %B, i32 0 155 %tmp9 = shufflevector <2 x double> %tmp3, 156 <2 x double> %tmp7, 157 <2 x i32> < i32 0, i32 2 > 158 store <2 x double> %tmp9, <2 x double>* %r, align 16 159 ret void 160 161 ; CHECK: t2: 162 ; CHECK: movl 8(%esp), %eax 163 ; CHECK-NEXT: movapd (%eax), %xmm0 164 ; CHECK-NEXT: movhpd 12(%esp), %xmm0 165 ; CHECK-NEXT: movl 4(%esp), %eax 166 ; CHECK-NEXT: movapd %xmm0, (%eax) 167 ; CHECK-NEXT: ret 168 } 169 170 "``CHECK-NEXT:``" directives reject the input unless there is exactly one 171 newline between it and the previous directive. A "``CHECK-NEXT:``" cannot be 172 the first directive in a file. 173 174 The "CHECK-NOT:" directive 175 ~~~~~~~~~~~~~~~~~~~~~~~~~~ 176 177 The "``CHECK-NOT:``" directive is used to verify that a string doesn't occur 178 between two matches (or before the first match, or after the last match). For 179 example, to verify that a load is removed by a transformation, a test like this 180 can be used: 181 182 .. code-block:: llvm 183 184 define i8 @coerce_offset0(i32 %V, i32* %P) { 185 store i32 %V, i32* %P 186 187 %P2 = bitcast i32* %P to i8* 188 %P3 = getelementptr i8* %P2, i32 2 189 190 %A = load i8* %P3 191 ret i8 %A 192 ; CHECK: @coerce_offset0 193 ; CHECK-NOT: load 194 ; CHECK: ret i8 195 } 196 197 FileCheck Pattern Matching Syntax 198 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 199 200 The "``CHECK:``" and "``CHECK-NOT:``" directives both take a pattern to match. 201 For most uses of FileCheck, fixed string matching is perfectly sufficient. For 202 some things, a more flexible form of matching is desired. To support this, 203 FileCheck allows you to specify regular expressions in matching strings, 204 surrounded by double braces: ``{{yourregex}}``. Because we want to use fixed 205 string matching for a majority of what we do, FileCheck has been designed to 206 support mixing and matching fixed string matching with regular expressions. 207 This allows you to write things like this: 208 209 .. code-block:: llvm 210 211 ; CHECK: movhpd {{[0-9]+}}(%esp), {{%xmm[0-7]}} 212 213 In this case, any offset from the ESP register will be allowed, and any xmm 214 register will be allowed. 215 216 Because regular expressions are enclosed with double braces, they are 217 visually distinct, and you don't need to use escape characters within the double 218 braces like you would in C. In the rare case that you want to match double 219 braces explicitly from the input, you can use something ugly like 220 ``{{[{][{]}}`` as your pattern. 221 222 FileCheck Variables 223 ~~~~~~~~~~~~~~~~~~~ 224 225 It is often useful to match a pattern and then verify that it occurs again 226 later in the file. For codegen tests, this can be useful to allow any register, 227 but verify that that register is used consistently later. To do this, 228 :program:`FileCheck` allows named variables to be defined and substituted into 229 patterns. Here is a simple example: 230 231 .. code-block:: llvm 232 233 ; CHECK: test5: 234 ; CHECK: notw [[REGISTER:%[a-z]+]] 235 ; CHECK: andw {{.*}}[[REGISTER]] 236 237 The first check line matches a regex ``%[a-z]+`` and captures it into the 238 variable ``REGISTER``. The second line verifies that whatever is in 239 ``REGISTER`` occurs later in the file after an "``andw``". :program:`FileCheck` 240 variable references are always contained in ``[[ ]]`` pairs, and their names can 241 be formed with the regex ``[a-zA-Z][a-zA-Z0-9]*``. If a colon follows the name, 242 then it is a definition of the variable; otherwise, it is a use. 243 244 :program:`FileCheck` variables can be defined multiple times, and uses always 245 get the latest value. Variables can also be used later on the same line they 246 were defined on. For example: 247 248 .. code-block:: llvm 249 250 ; CHECK: op [[REG:r[0-9]+]], [[REG]] 251 252 Can be useful if you want the operands of ``op`` to be the same register, 253 and don't care exactly which register it is. 254 255 FileCheck Expressions 256 ~~~~~~~~~~~~~~~~~~~~~ 257 258 Sometimes there's a need to verify output which refers line numbers of the 259 match file, e.g. when testing compiler diagnostics. This introduces a certain 260 fragility of the match file structure, as "``CHECK:``" lines contain absolute 261 line numbers in the same file, which have to be updated whenever line numbers 262 change due to text addition or deletion. 263 264 To support this case, FileCheck allows using ``[[@LINE]]``, 265 ``[[@LINE+<offset>]]``, ``[[@LINE-<offset>]]`` expressions in patterns. These 266 expressions expand to a number of the line where a pattern is located (with an 267 optional integer offset). 268 269 This way match patterns can be put near the relevant test lines and include 270 relative line number references, for example: 271 272 .. code-block:: c++ 273 274 // CHECK: test.cpp:[[@LINE+4]]:6: error: expected ';' after top level declarator 275 // CHECK-NEXT: {{^int a}} 276 // CHECK-NEXT: {{^ \^}} 277 // CHECK-NEXT: {{^ ;}} 278 int a 279 280
