1 2 =pod 3 4 =head1 NAME 5 6 FileCheck - Flexible pattern matching file verifier 7 8 =head1 SYNOPSIS 9 10 B<FileCheck> I<match-filename> [I<--check-prefix=XXX>] [I<--strict-whitespace>] 11 12 =head1 DESCRIPTION 13 14 B<FileCheck> reads two files (one from standard input, and one specified on the 15 command line) and uses one to verify the other. This behavior is particularly 16 useful for the testsuite, which wants to verify that the output of some tool 17 (e.g. llc) contains the expected information (for example, a movsd from esp or 18 whatever is interesting). This is similar to using grep, but it is optimized 19 for matching multiple different inputs in one file in a specific order. 20 21 The I<match-filename> file specifies the file that contains the patterns to 22 match. The file to verify is always read from standard input. 23 24 =head1 OPTIONS 25 26 =over 27 28 =item B<-help> 29 30 Print a summary of command line options. 31 32 =item B<--check-prefix> I<prefix> 33 34 FileCheck searches the contents of I<match-filename> for patterns to match. By 35 default, these patterns are prefixed with "CHECK:". If you'd like to use a 36 different prefix (e.g. because the same input file is checking multiple 37 different tool or options), the B<--check-prefix> argument allows you to specify 38 a specific prefix to match. 39 40 =item B<--strict-whitespace> 41 42 By default, FileCheck canonicalizes input horizontal whitespace (spaces and 43 tabs) which causes it to ignore these differences (a space will match a tab). 44 The --strict-whitespace argument disables this behavior. 45 46 =item B<-version> 47 48 Show the version number of this program. 49 50 =back 51 52 =head1 EXIT STATUS 53 54 If B<FileCheck> verifies that the file matches the expected contents, it exits 55 with 0. Otherwise, if not, or if an error occurs, it will exit with a non-zero 56 value. 57 58 =head1 TUTORIAL 59 60 FileCheck is typically used from LLVM regression tests, being invoked on the RUN 61 line of the test. A simple example of using FileCheck from a RUN line looks 62 like this: 63 64 ; RUN: llvm-as < %s | llc -march=x86-64 | FileCheck %s 65 66 This syntax says to pipe the current file ("%s") into llvm-as, pipe that into 67 llc, then pipe the output of llc into FileCheck. This means that FileCheck will 68 be verifying its standard input (the llc output) against the filename argument 69 specified (the original .ll file specified by "%s"). To see how this works, 70 lets look at the rest of the .ll file (after the RUN line): 71 72 define void @sub1(i32* %p, i32 %v) { 73 entry: 74 ; <b>CHECK: sub1:</b> 75 ; <b>CHECK: subl</b> 76 %0 = tail call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %p, i32 %v) 77 ret void 78 } 79 80 define void @inc4(i64* %p) { 81 entry: 82 ; <b>CHECK: inc4:</b> 83 ; <b>CHECK: incq</b> 84 %0 = tail call i64 @llvm.atomic.load.add.i64.p0i64(i64* %p, i64 1) 85 ret void 86 } 87 88 Here you can see some "CHECK:" lines specified in comments. Now you can see 89 how the file is piped into llvm-as, then llc, and the machine code output is 90 what we are verifying. FileCheck checks the machine code output to verify that 91 it matches what the "CHECK:" lines specify. 92 93 The syntax of the CHECK: lines is very simple: they are fixed strings that 94 must occur in order. FileCheck defaults to ignoring horizontal whitespace 95 differences (e.g. a space is allowed to match a tab) but otherwise, the contents 96 of the CHECK: line is required to match some thing in the test file exactly. 97 98 One nice thing about FileCheck (compared to grep) is that it allows merging 99 test cases together into logical groups. For example, because the test above 100 is checking for the "sub1:" and "inc4:" labels, it will not match unless there 101 is a "subl" in between those labels. If it existed somewhere else in the file, 102 that would not count: "grep subl" matches if subl exists anywhere in the 103 file. 104 105 106 107 =head2 The FileCheck -check-prefix option 108 109 The FileCheck -check-prefix option allows multiple test configurations to be 110 driven from one .ll file. This is useful in many circumstances, for example, 111 testing different architectural variants with llc. Here's a simple example: 112 113 ; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \ 114 ; RUN: | <b>FileCheck %s -check-prefix=X32</b> 115 ; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \ 116 ; RUN: | <b>FileCheck %s -check-prefix=X64</b> 117 118 define <4 x i32> @pinsrd_1(i32 %s, <4 x i32> %tmp) nounwind { 119 %tmp1 = insertelement <4 x i32>; %tmp, i32 %s, i32 1 120 ret <4 x i32> %tmp1 121 ; <b>X32:</b> pinsrd_1: 122 ; <b>X32:</b> pinsrd $1, 4(%esp), %xmm0 123 124 ; <b>X64:</b> pinsrd_1: 125 ; <b>X64:</b> pinsrd $1, %edi, %xmm0 126 } 127 128 In this case, we're testing that we get the expected code generation with 129 both 32-bit and 64-bit code generation. 130 131 132 133 =head2 The "CHECK-NEXT:" directive 134 135 Sometimes you want to match lines and would like to verify that matches 136 happen on exactly consecutive lines with no other lines in between them. In 137 this case, you can use CHECK: and CHECK-NEXT: directives to specify this. If 138 you specified a custom check prefix, just use "<PREFIX>-NEXT:". For 139 example, something like this works as you'd expect: 140 141 define void @t2(<2 x double>* %r, <2 x double>* %A, double %B) { 142 %tmp3 = load <2 x double>* %A, align 16 143 %tmp7 = insertelement <2 x double> undef, double %B, i32 0 144 %tmp9 = shufflevector <2 x double> %tmp3, 145 <2 x double> %tmp7, 146 <2 x i32> < i32 0, i32 2 > 147 store <2 x double> %tmp9, <2 x double>* %r, align 16 148 ret void 149 150 ; <b>CHECK:</b> t2: 151 ; <b>CHECK:</b> movl 8(%esp), %eax 152 ; <b>CHECK-NEXT:</b> movapd (%eax), %xmm0 153 ; <b>CHECK-NEXT:</b> movhpd 12(%esp), %xmm0 154 ; <b>CHECK-NEXT:</b> movl 4(%esp), %eax 155 ; <b>CHECK-NEXT:</b> movapd %xmm0, (%eax) 156 ; <b>CHECK-NEXT:</b> ret 157 } 158 159 CHECK-NEXT: directives reject the input unless there is exactly one newline 160 between it an the previous directive. A CHECK-NEXT cannot be the first 161 directive in a file. 162 163 164 165 =head2 The "CHECK-NOT:" directive 166 167 The CHECK-NOT: directive is used to verify that a string doesn't occur 168 between two matches (or before the first match, or after the last match). For 169 example, to verify that a load is removed by a transformation, a test like this 170 can be used: 171 172 define i8 @coerce_offset0(i32 %V, i32* %P) { 173 store i32 %V, i32* %P 174 175 %P2 = bitcast i32* %P to i8* 176 %P3 = getelementptr i8* %P2, i32 2 177 178 %A = load i8* %P3 179 ret i8 %A 180 ; <b>CHECK:</b> @coerce_offset0 181 ; <b>CHECK-NOT:</b> load 182 ; <b>CHECK:</b> ret i8 183 } 184 185 186 187 =head2 FileCheck Pattern Matching Syntax 188 189 The CHECK: and CHECK-NOT: directives both take a pattern to match. For most 190 uses of FileCheck, fixed string matching is perfectly sufficient. For some 191 things, a more flexible form of matching is desired. To support this, FileCheck 192 allows you to specify regular expressions in matching strings, surrounded by 193 double braces: B<{{yourregex}}>. Because we want to use fixed string 194 matching for a majority of what we do, FileCheck has been designed to support 195 mixing and matching fixed string matching with regular expressions. This allows 196 you to write things like this: 197 198 ; CHECK: movhpd <b>{{[0-9]+}}</b>(%esp), <b>{{%xmm[0-7]}}</b> 199 200 In this case, any offset from the ESP register will be allowed, and any xmm 201 register will be allowed. 202 203 Because regular expressions are enclosed with double braces, they are 204 visually distinct, and you don't need to use escape characters within the double 205 braces like you would in C. In the rare case that you want to match double 206 braces explicitly from the input, you can use something ugly like 207 B<{{[{][{]}}> as your pattern. 208 209 210 211 =head2 FileCheck Variables 212 213 It is often useful to match a pattern and then verify that it occurs again 214 later in the file. For codegen tests, this can be useful to allow any register, 215 but verify that that register is used consistently later. To do this, FileCheck 216 allows named variables to be defined and substituted into patterns. Here is a 217 simple example: 218 219 ; CHECK: test5: 220 ; CHECK: notw <b>[[REGISTER:%[a-z]+]]</b> 221 ; CHECK: andw {{.*}}<b>[[REGISTER]]</b> 222 223 The first check line matches a regex (<tt>%[a-z]+</tt>) and captures it into 224 the variables "REGISTER". The second line verifies that whatever is in REGISTER 225 occurs later in the file after an "andw". FileCheck variable references are 226 always contained in <tt>[[ ]]</tt> pairs, are named, and their names can be 227 formed with the regex "<tt>[a-zA-Z_][a-zA-Z0-9_]*</tt>". If a colon follows the 228 name, then it is a definition of the variable, if not, it is a use. 229 230 FileCheck variables can be defined multiple times, and uses always get the 231 latest value. Note that variables are all read at the start of a "CHECK" line 232 and are all defined at the end. This means that if you have something like 233 "<tt>CHECK: [[XYZ:.*]]x[[XYZ]]<tt>" that the check line will read the previous 234 value of the XYZ variable and define a new one after the match is performed. If 235 you need to do something like this you can probably take advantage of the fact 236 that FileCheck is not actually line-oriented when it matches, this allows you to 237 define two separate CHECK lines that match on the same line. 238 239 240 241 =head1 AUTHORS 242 243 Maintained by The LLVM Team (L<http://llvm.org/>). 244 245 =cut 246
