1FileCheck - Flexible pattern matching file verifier 2=================================================== 3 4SYNOPSIS 5-------- 6 7**FileCheck** *match-filename* [*--check-prefix=XXX*] [*--strict-whitespace*] 8 9DESCRIPTION 10----------- 11 12**FileCheck** reads two files (one from standard input, and one specified on the 13command line) and uses one to verify the other. This behavior is particularly 14useful for the testsuite, which wants to verify that the output of some tool 15(e.g. llc) contains the expected information (for example, a movsd from esp or 16whatever is interesting). This is similar to using grep, but it is optimized 17for matching multiple different inputs in one file in a specific order. 18 19The *match-filename* file specifies the file that contains the patterns to 20match. The file to verify is always read from standard input. 21 22OPTIONS 23------- 24 25**-help** 26 27 Print a summary of command line options. 28 29**--check-prefix** *prefix* 30 31 FileCheck searches the contents of *match-filename* for patterns to match. By 32 default, these patterns are prefixed with "``CHECK:``". If you'd like to use a 33 different prefix (e.g. because the same input file is checking multiple 34 different tool or options), the **--check-prefix** argument allows you to specify 35 a specific prefix to match. 36 37**--input-file** *filename* 38 39 File to check (defaults to stdin). 40 41**--strict-whitespace** 42 43 By default, FileCheck canonicalizes input horizontal whitespace (spaces and 44 tabs) which causes it to ignore these differences (a space will match a tab). 45 The **--strict-whitespace** argument disables this behavior. 46 47 48**-version** 49 50 Show the version number of this program. 51 52EXIT STATUS 53----------- 54 55If **FileCheck** verifies that the file matches the expected contents, it exits 56with 0. Otherwise, if not, or if an error occurs, it will exit with a non-zero 57value. 58 59TUTORIAL 60-------- 61 62FileCheck is typically used from LLVM regression tests, being invoked on the RUN 63line of the test. A simple example of using FileCheck from a RUN line looks 64like this: 65 66.. code-block:: llvm 67 68 ; RUN: llvm-as < %s | llc -march=x86-64 | FileCheck %s 69 70 71This syntax says to pipe the current file ("``%s``") into ``llvm-as``, pipe 72that into ``llc``, then pipe the output of ``llc`` into ``FileCheck``. This 73means that FileCheck will be verifying its standard input (the llc output) 74against 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 97Here you can see some "``CHECK:``" lines specified in comments. Now you can 98see how the file is piped into ``llvm-as``, then ``llc``, and the machine code 99output is what we are verifying. FileCheck checks the machine code output to 100verify that it matches what the "``CHECK:``" lines specify. 101 102The syntax of the "``CHECK:``" lines is very simple: they are fixed strings that 103must occur in order. FileCheck defaults to ignoring horizontal whitespace 104differences (e.g. a space is allowed to match a tab) but otherwise, the contents 105of the "``CHECK:``" line is required to match some thing in the test file exactly. 106 107One nice thing about FileCheck (compared to grep) is that it allows merging 108test cases together into logical groups. For example, because the test above 109is checking for the "``sub1:``" and "``inc4:``" labels, it will not match 110unless there is a "``subl``" in between those labels. If it existed somewhere 111else in the file, that would not count: "``grep subl``" matches if "``subl``" 112exists anywhere in the file. 113 114The FileCheck -check-prefix option 115~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 116 117The FileCheck ``-check-prefix`` option allows multiple test configurations to be 118driven from one .ll file. This is useful in many circumstances, for example, 119testing different architectural variants with 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 138In this case, we're testing that we get the expected code generation with 139both 32-bit and 64-bit code generation. 140 141The "CHECK-NEXT:" directive 142~~~~~~~~~~~~~~~~~~~~~~~~~~~ 143 144Sometimes you want to match lines and would like to verify that matches 145happen on exactly consecutive lines with no other lines in between them. In 146this case, you can use "``CHECK:``" and "``CHECK-NEXT:``" directives to specify 147this. If you specified a custom check prefix, just use "``<PREFIX>-NEXT:``". 148For 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 171newline between it and the previous directive. A "``CHECK-NEXT:``" cannot be 172the first directive in a file. 173 174The "CHECK-NOT:" directive 175~~~~~~~~~~~~~~~~~~~~~~~~~~ 176 177The "``CHECK-NOT:``" directive is used to verify that a string doesn't occur 178between two matches (or before the first match, or after the last match). For 179example, to verify that a load is removed by a transformation, a test like this 180can 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 198FileCheck Pattern Matching Syntax 199~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 200 201The "``CHECK:``" and "``CHECK-NOT:``" directives both take a pattern to match. 202For most uses of FileCheck, fixed string matching is perfectly sufficient. For 203some things, a more flexible form of matching is desired. To support this, 204FileCheck allows you to specify regular expressions in matching strings, 205surrounded by double braces: ``{{yourregex}}``. Because we want to use fixed 206string matching for a majority of what we do, FileCheck has been designed to 207support mixing and matching fixed string matching with regular expressions. 208This allows you to write things like this: 209 210.. code-block:: llvm 211 212 ; CHECK: movhpd {{[0-9]+}}(%esp), {{%xmm[0-7]}} 213 214In this case, any offset from the ESP register will be allowed, and any xmm 215register will be allowed. 216 217Because regular expressions are enclosed with double braces, they are 218visually distinct, and you don't need to use escape characters within the double 219braces like you would in C. In the rare case that you want to match double 220braces explicitly from the input, you can use something ugly like 221``{{[{][{]}}`` as your pattern. 222 223FileCheck Variables 224~~~~~~~~~~~~~~~~~~~ 225 226It is often useful to match a pattern and then verify that it occurs again 227later in the file. For codegen tests, this can be useful to allow any register, 228but verify that that register is used consistently later. To do this, FileCheck 229allows named variables to be defined and substituted into patterns. Here is a 230simple example: 231 232.. code-block:: llvm 233 234 ; CHECK: test5: 235 ; CHECK: notw [[REGISTER:%[a-z]+]] 236 ; CHECK: andw {{.*}}[[REGISTER]] 237 238The first check line matches a regex ``%[a-z]+`` and captures it into the 239variable ``REGISTER``. The second line verifies that whatever is in 240``REGISTER`` occurs later in the file after an "``andw``". FileCheck variable 241references are always contained in ``[[ ]]`` pairs, and their names can be 242formed with the regex ``[a-zA-Z][a-zA-Z0-9]*``. If a colon follows the name, 243then it is a definition of the variable; otherwise, it is a use. 244 245FileCheck variables can be defined multiple times, and uses always get the 246latest value. Note that variables are all read at the start of a "``CHECK``" 247line and are all defined at the end. This means that if you have something 248like "``CHECK: [[XYZ:.*]]x[[XYZ]]``", the check line will read the previous 249value of the ``XYZ`` variable and define a new one after the match is 250performed. If you need to do something like this you can probably take 251advantage of the fact that FileCheck is not actually line-oriented when it 252matches, this allows you to define two separate "``CHECK``" lines that match on 253the same line. 254 255 256FileCheck Expressions 257~~~~~~~~~~~~~~~~~~~~~ 258 259 260Sometimes there's a need to verify output which refers line numbers of the match 261file, e.g. when testing compiler diagnostics. This introduces a certain 262fragility of the match file structure, as CHECK: lines contain absolute line 263numbers in the same file, which have to be updated whenever line numbers change 264due to text addition or deletion. 265 266To support this case, FileCheck allows using ``[[@LINE]]``, 267``[[@LINE+<offset>]]``, ``[[@LINE-<offset>]]`` expressions in patterns. These 268expressions expand to a number of the line where a pattern is located (with an 269optional integer offset). 270 271This way match patterns can be put near the relevant test lines and include 272relative line number references, for example: 273 274.. code-block:: c++ 275 276 // CHECK: test.cpp:[[@LINE+4]]:6: error: expected ';' after top level declarator 277 // CHECK-NEXT: {{^int a}} 278 // CHECK-NEXT: {{^ \^}} 279 // CHECK-NEXT: {{^ ;}} 280 int a 281 282