1 FileCheck - Flexible pattern matching file verifier 2 =================================================== 3 4 5 SYNOPSIS 6 -------- 7 8 9 **FileCheck** *match-filename* [*--check-prefix=XXX*] [*--strict-whitespace*] 10 11 12 DESCRIPTION 13 ----------- 14 15 16 **FileCheck** reads two files (one from standard input, and one specified on the 17 command line) and uses one to verify the other. This behavior is particularly 18 useful for the testsuite, which wants to verify that the output of some tool 19 (e.g. llc) contains the expected information (for example, a movsd from esp or 20 whatever is interesting). This is similar to using grep, but it is optimized 21 for matching multiple different inputs in one file in a specific order. 22 23 The *match-filename* file specifies the file that contains the patterns to 24 match. The file to verify is always read from standard input. 25 26 27 OPTIONS 28 ------- 29 30 31 32 **-help** 33 34 Print a summary of command line options. 35 36 37 38 **--check-prefix** *prefix* 39 40 FileCheck searches the contents of *match-filename* for patterns to match. By 41 default, these patterns are prefixed with "CHECK:". If you'd like to use a 42 different prefix (e.g. because the same input file is checking multiple 43 different tool or options), the **--check-prefix** argument allows you to specify 44 a specific prefix to match. 45 46 47 48 **--strict-whitespace** 49 50 By default, FileCheck canonicalizes input horizontal whitespace (spaces and 51 tabs) which causes it to ignore these differences (a space will match a tab). 52 The --strict-whitespace argument disables this behavior. 53 54 55 56 **-version** 57 58 Show the version number of this program. 59 60 61 62 63 EXIT STATUS 64 ----------- 65 66 67 If **FileCheck** verifies that the file matches the expected contents, it exits 68 with 0. Otherwise, if not, or if an error occurs, it will exit with a non-zero 69 value. 70 71 72 TUTORIAL 73 -------- 74 75 76 FileCheck is typically used from LLVM regression tests, being invoked on the RUN 77 line of the test. A simple example of using FileCheck from a RUN line looks 78 like this: 79 80 81 .. code-block:: llvm 82 83 ; RUN: llvm-as < %s | llc -march=x86-64 | FileCheck %s 84 85 86 This syntax says to pipe the current file ("%s") into llvm-as, pipe that into 87 llc, then pipe the output of llc into FileCheck. This means that FileCheck will 88 be verifying its standard input (the llc output) against the filename argument 89 specified (the original .ll file specified by "%s"). To see how this works, 90 let's look at the rest of the .ll file (after the RUN line): 91 92 93 .. code-block:: llvm 94 95 define void @sub1(i32* %p, i32 %v) { 96 entry: 97 ; CHECK: sub1: 98 ; CHECK: subl 99 %0 = tail call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %p, i32 %v) 100 ret void 101 } 102 103 define void @inc4(i64* %p) { 104 entry: 105 ; CHECK: inc4: 106 ; CHECK: incq 107 %0 = tail call i64 @llvm.atomic.load.add.i64.p0i64(i64* %p, i64 1) 108 ret void 109 } 110 111 112 Here you can see some "CHECK:" lines specified in comments. Now you can see 113 how the file is piped into llvm-as, then llc, and the machine code output is 114 what we are verifying. FileCheck checks the machine code output to verify that 115 it matches what the "CHECK:" lines specify. 116 117 The syntax of the CHECK: lines is very simple: they are fixed strings that 118 must occur in order. FileCheck defaults to ignoring horizontal whitespace 119 differences (e.g. a space is allowed to match a tab) but otherwise, the contents 120 of the CHECK: line is required to match some thing in the test file exactly. 121 122 One nice thing about FileCheck (compared to grep) is that it allows merging 123 test cases together into logical groups. For example, because the test above 124 is checking for the "sub1:" and "inc4:" labels, it will not match unless there 125 is a "subl" in between those labels. If it existed somewhere else in the file, 126 that would not count: "grep subl" matches if subl exists anywhere in the 127 file. 128 129 The FileCheck -check-prefix option 130 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 131 132 133 The FileCheck -check-prefix option allows multiple test configurations to be 134 driven from one .ll file. This is useful in many circumstances, for example, 135 testing different architectural variants with llc. Here's a simple example: 136 137 138 .. code-block:: llvm 139 140 ; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \ 141 ; RUN: | FileCheck %s -check-prefix=X32 142 ; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \ 143 ; RUN: | FileCheck %s -check-prefix=X64 144 145 define <4 x i32> @pinsrd_1(i32 %s, <4 x i32> %tmp) nounwind { 146 %tmp1 = insertelement <4 x i32>; %tmp, i32 %s, i32 1 147 ret <4 x i32> %tmp1 148 ; X32: pinsrd_1: 149 ; X32: pinsrd $1, 4(%esp), %xmm0 150 151 ; X64: pinsrd_1: 152 ; X64: pinsrd $1, %edi, %xmm0 153 } 154 155 156 In this case, we're testing that we get the expected code generation with 157 both 32-bit and 64-bit code generation. 158 159 160 The "CHECK-NEXT:" directive 161 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ 162 163 164 Sometimes you want to match lines and would like to verify that matches 165 happen on exactly consecutive lines with no other lines in between them. In 166 this case, you can use CHECK: and CHECK-NEXT: directives to specify this. If 167 you specified a custom check prefix, just use "<PREFIX>-NEXT:". For 168 example, something like this works as you'd expect: 169 170 171 .. code-block:: llvm 172 173 define void @t2(<2 x double>* %r, <2 x double>* %A, double %B) { 174 %tmp3 = load <2 x double>* %A, align 16 175 %tmp7 = insertelement <2 x double> undef, double %B, i32 0 176 %tmp9 = shufflevector <2 x double> %tmp3, 177 <2 x double> %tmp7, 178 <2 x i32> < i32 0, i32 2 > 179 store <2 x double> %tmp9, <2 x double>* %r, align 16 180 ret void 181 182 ; CHECK: t2: 183 ; CHECK: movl 8(%esp), %eax 184 ; CHECK-NEXT: movapd (%eax), %xmm0 185 ; CHECK-NEXT: movhpd 12(%esp), %xmm0 186 ; CHECK-NEXT: movl 4(%esp), %eax 187 ; CHECK-NEXT: movapd %xmm0, (%eax) 188 ; CHECK-NEXT: ret 189 } 190 191 192 CHECK-NEXT: directives reject the input unless there is exactly one newline 193 between it an the previous directive. A CHECK-NEXT cannot be the first 194 directive in a file. 195 196 197 The "CHECK-NOT:" directive 198 ~~~~~~~~~~~~~~~~~~~~~~~~~~ 199 200 201 The CHECK-NOT: directive is used to verify that a string doesn't occur 202 between two matches (or before the first match, or after the last match). For 203 example, to verify that a load is removed by a transformation, a test like this 204 can be used: 205 206 207 .. code-block:: llvm 208 209 define i8 @coerce_offset0(i32 %V, i32* %P) { 210 store i32 %V, i32* %P 211 212 %P2 = bitcast i32* %P to i8* 213 %P3 = getelementptr i8* %P2, i32 2 214 215 %A = load i8* %P3 216 ret i8 %A 217 ; CHECK: @coerce_offset0 218 ; CHECK-NOT: load 219 ; CHECK: ret i8 220 } 221 222 223 224 FileCheck Pattern Matching Syntax 225 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 226 227 228 The CHECK: and CHECK-NOT: directives both take a pattern to match. For most 229 uses of FileCheck, fixed string matching is perfectly sufficient. For some 230 things, a more flexible form of matching is desired. To support this, FileCheck 231 allows you to specify regular expressions in matching strings, surrounded by 232 double braces: **{{yourregex}}**. Because we want to use fixed string 233 matching for a majority of what we do, FileCheck has been designed to support 234 mixing and matching fixed string matching with regular expressions. This allows 235 you to write things like this: 236 237 238 .. code-block:: llvm 239 240 ; CHECK: movhpd {{[0-9]+}}(%esp), {{%xmm[0-7]}} 241 242 243 In this case, any offset from the ESP register will be allowed, and any xmm 244 register will be allowed. 245 246 Because regular expressions are enclosed with double braces, they are 247 visually distinct, and you don't need to use escape characters within the double 248 braces like you would in C. In the rare case that you want to match double 249 braces explicitly from the input, you can use something ugly like 250 **{{[{][{]}}** as your pattern. 251 252 253 FileCheck Variables 254 ~~~~~~~~~~~~~~~~~~~ 255 256 257 It is often useful to match a pattern and then verify that it occurs again 258 later in the file. For codegen tests, this can be useful to allow any register, 259 but verify that that register is used consistently later. To do this, FileCheck 260 allows named variables to be defined and substituted into patterns. Here is a 261 simple example: 262 263 264 .. code-block:: llvm 265 266 ; CHECK: test5: 267 ; CHECK: notw [[REGISTER:%[a-z]+]] 268 ; CHECK: andw {{.*}}[[REGISTER]] 269 270 271 The first check line matches a regex (**%[a-z]+**) and captures it into 272 the variable "REGISTER". The second line verifies that whatever is in REGISTER 273 occurs later in the file after an "andw". FileCheck variable references are 274 always contained in **[[ ]]** pairs, are named, and their names can be 275 name, then it is a definition of the variable, if not, it is a use. 276 277 FileCheck variables can be defined multiple times, and uses always get the 278 latest value. Note that variables are all read at the start of a "CHECK" line 279 and are all defined at the end. This means that if you have something like 280 "**CHECK: [[XYZ:.\\*]]x[[XYZ]]**", the check line will read the previous 281 value of the XYZ variable and define a new one after the match is performed. If 282 you need to do something like this you can probably take advantage of the fact 283 that FileCheck is not actually line-oriented when it matches, this allows you to 284 define two separate CHECK lines that match on the same line. 285
