FileCheck-8(1)



FILECHECK(1)                         LLVM                         FILECHECK(1)

NAME
       FileCheck - Flexible pattern matching file verifier

SYNOPSIS
       FileCheck match-filename [-check-prefix=XXX] [-strict-whitespace]

DESCRIPTION
       FileCheck  reads  two files (one from standard input, and one specified
       on the command line) and uses one to verify the other.   This  behavior
       is  particularly  useful  for the testsuite, which wants to verify that
       the output of some tool (e.g. llc) contains  the  expected  information
       (for  example,  a  movsd from esp or whatever is interesting).  This is
       similar to using grep, but it is optimized for matching  multiple  dif-
       ferent inputs in one file in a specific order.

       The  match-filename  file specifies the file that contains the patterns
       to match.  The file to verify is read from standard  input  unless  the
       --input-file option is used.

OPTIONS
       Options  are  parsed  from  the environment variable FILECHECK_OPTS and
       from the command line.

       -help  Print a summary of command line options.

       --check-prefix prefix
              FileCheck searches the contents of match-filename  for  patterns
              to   match.   By  default,  these  patterns  are  prefixed  with
              "CHECK:".  If you'd like to use a different prefix (e.g. because
              the  same  input file is checking multiple different tool or op-
              tions), the --check-prefix argument allows you to specify one or
              more  prefixes  to match. Multiple prefixes are useful for tests
              which might change for different run options, but most lines re-
              main the same.

       --check-prefixes prefix1,prefix2,...
              An  alias  of --check-prefix that allows multiple prefixes to be
              specified as a comma separated list.

       --input-file filename
              File to check (defaults to stdin).

       --match-full-lines
              By default, FileCheck allows matches of anywhere on a line. This
              option  will  require  all  positive  matches to cover an entire
              line.  Leading  and  trailing  whitespace  is  ignored,   unless
              --strict-whitespace  is  also specified. (Note: negative matches
              from CHECK-NOT are not affected by this option!)

              Passing this option is equivalent to inserting {{^ *}} or  {{^}}
              before, and {{ *$}} or {{$}} after every positive check pattern.

       --strict-whitespace
              By  default, FileCheck canonicalizes input horizontal whitespace
              (spaces and tabs) which causes it to ignore these differences (a
              space  will match a tab).  The --strict-whitespace argument dis-
              ables this behavior. End-of-line sequences are canonicalized  to
              UNIX-style \n in all modes.

       --implicit-check-not check-pattern
              Adds implicit negative checks for the specified patterns between
              positive checks. The option allows writing stricter tests  with-
              out stuffing them with CHECK-NOTs.

              For  example, "--implicit-check-not warning:" can be useful when
              testing diagnostic messages from tools that don't have an option
              similar to clang -verify. With this option FileCheck will verify
              that input does not contain warnings not covered by  any  CHECK:
              patterns.

       --dump-input <mode>
              Dump  input to stderr, adding annotations representing currently
              enabled diagnostics.  Do this either  'always',  on  'fail',  or
              'never'.  Specify 'help' to explain the dump format and quit.

       --dump-input-on-failure
              When  the check fails, dump all of the original input.  This op-
              tion is deprecated in favor of -dump-input=fail.

       --enable-var-scope
              Enables scope for regex variables.

              Variables with names that start with $ are considered global and
              remain set throughout the file.

              All   other  variables  get  undefined  after  each  encountered
              CHECK-LABEL.

       -D<VAR=VALUE>
              Sets a filecheck variable VAR with value VALUE that can be  used
              in CHECK: lines.

       -version
              Show the version number of this program.

       -v     Print directive pattern matches.

       -vv    Print  information  helpful in diagnosing internal FileCheck is-
              sues, such as discarded overlapping CHECK-DAG: matches, implicit
              EOF  pattern  matches,  and CHECK-NOT: patterns that do not have
              matches.  Implies -v.

       --allow-deprecated-dag-overlap
              Enable overlapping among  matches  in  a  group  of  consecutive
              CHECK-DAG:  directives.   This  option is deprecated and is only
              provided for convenience as old tests are migrated  to  the  new
              non-overlapping CHECK-DAG: implementation.

       --color
              Use colors in output (autodetected by default).

EXIT STATUS
       If  FileCheck  verifies that the file matches the expected contents, it
       exits with 0.  Otherwise, if not, or if an error occurs, it  will  exit
       with a non-zero value.

TUTORIAL
       FileCheck  is  typically used from LLVM regression tests, being invoked
       on the RUN line of the test.  A simple example of using FileCheck  from
       a RUN line looks like this:

          ; RUN: llvm-as < %s | llc -march=x86-64 | FileCheck %s

       This  syntax  says  to  pipe the current file ("%s") into llvm-as, pipe
       that into llc, then pipe the output of llc into FileCheck.  This  means
       that  FileCheck  will  be verifying its standard input (the llc output)
       against the filename argument specified (the original .ll  file  speci-
       fied  by  "%s").   To see how this works, let's look at the rest of the
       .ll file (after the RUN line):

          define void @sub1(i32* %p, i32 %v) {
          entry:
          ; CHECK: sub1:
          ; CHECK: subl
                  %0 = tail call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %p, i32 %v)
                  ret void
          }

          define void @inc4(i64* %p) {
          entry:
          ; CHECK: inc4:
          ; CHECK: incq
                  %0 = tail call i64 @llvm.atomic.load.add.i64.p0i64(i64* %p, i64 1)
                  ret void
          }

       Here you can see some "CHECK:" lines specified in  comments.   Now  you
       can  see  how the file is piped into llvm-as, then llc, and the machine
       code output is what we are verifying.   FileCheck  checks  the  machine
       code output to verify that it matches what the "CHECK:" lines specify.

       The syntax of the "CHECK:" lines is very simple: they are fixed strings
       that must occur in order.  FileCheck defaults  to  ignoring  horizontal
       whitespace  differences  (e.g.  a  space is allowed to match a tab) but
       otherwise, the contents of the "CHECK:" line is required to match  some
       thing in the test file exactly.

       One  nice  thing  about  FileCheck (compared to grep) is that it allows
       merging test cases together into logical groups.  For example,  because
       the  test above is checking for the "sub1:" and "inc4:" labels, it will
       not match unless there is a "subl" in between those labels.  If it  ex-
       isted  somewhere  else  in  the file, that would not count: "grep subl"
       matches if "subl" exists anywhere in the file.

   The FileCheck -check-prefix option
       The FileCheck -check-prefix option allows multiple test  configurations
       to  be driven from one .ll file.  This is useful in many circumstances,
       for example, testing different architectural variants with llc.  Here's
       a simple example:

          ; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \
          ; RUN:              | FileCheck %s -check-prefix=X32
          ; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \
          ; RUN:              | FileCheck %s -check-prefix=X64

          define <4 x i32> @pinsrd_1(i32 %s, <4 x i32> %tmp) nounwind {
                  %tmp1 = insertelement <4 x i32>; %tmp, i32 %s, i32 1
                  ret <4 x i32> %tmp1
          ; X32: pinsrd_1:
          ; X32:    pinsrd $1, 4(%esp), %xmm0

          ; X64: pinsrd_1:
          ; X64:    pinsrd $1, %edi, %xmm0
          }

       In  this  case,  we're testing that we get the expected code generation
       with both 32-bit and 64-bit code generation.

   The "CHECK-NEXT:" directive
       Sometimes you want to match lines and would like to verify that matches
       happen  on  exactly  consecutive  lines  with no other lines in between
       them.  In this case, you can use "CHECK:" and "CHECK-NEXT:"  directives
       to  specify  this.   If  you  specified a custom check prefix, just use
       "<PREFIX>-NEXT:".  For example, something like this works as you'd  ex-
       pect:

          define void @t2(<2 x double>* %r, <2 x double>* %A, double %B) {
               %tmp3 = load <2 x double>* %A, align 16
               %tmp7 = insertelement <2 x double> undef, double %B, i32 0
               %tmp9 = shufflevector <2 x double> %tmp3,
                                      <2 x double> %tmp7,
                                      <2 x i32> < i32 0, i32 2 >
               store <2 x double> %tmp9, <2 x double>* %r, align 16
               ret void

          ; CHECK:          t2:
          ; CHECK:             movl    8(%esp), %eax
          ; CHECK-NEXT:        movapd  (%eax), %xmm0
          ; CHECK-NEXT:        movhpd  12(%esp), %xmm0
          ; CHECK-NEXT:        movl    4(%esp), %eax
          ; CHECK-NEXT:        movapd  %xmm0, (%eax)
          ; CHECK-NEXT:        ret
          }

       "CHECK-NEXT:"  directives  reject the input unless there is exactly one
       newline between it and the previous directive.  A "CHECK-NEXT:"  cannot
       be the first directive in a file.

   The "CHECK-SAME:" directive
       Sometimes you want to match lines and would like to verify that matches
       happen on the same line as the previous match.  In this case,  you  can
       use  "CHECK:"  and  "CHECK-SAME:"  directives  to specify this.  If you
       specified a custom check prefix, just use "<PREFIX>-SAME:".

       "CHECK-SAME:" is particularly powerful in conjunction with "CHECK-NOT:"
       (described below).

       For example, the following works like you'd expect:

          !0 = !DILocation(line: 5, scope: !1, inlinedAt: !2)

          ; CHECK:       !DILocation(line: 5,
          ; CHECK-NOT:               column:
          ; CHECK-SAME:              scope: ![[SCOPE:[0-9]+]]

       "CHECK-SAME:" directives reject the input if there are any newlines be-
       tween it and the previous directive.  A  "CHECK-SAME:"  cannot  be  the
       first directive in a file.

   The "CHECK-EMPTY:" directive
       If  you  need  to  check that the next line has nothing on it, not even
       whitespace, you can use the "CHECK-EMPTY:" directive.

          declare void @foo()

          declare void @bar()
          ; CHECK: foo
          ; CHECK-EMPTY:
          ; CHECK-NEXT: bar

       Just like "CHECK-NEXT:" the directive will fail if there is  more  than
       one  newline  before it finds the next blank line, and it cannot be the
       first directive in a file.

   The "CHECK-NOT:" directive
       The "CHECK-NOT:" directive is used to verify that a string doesn't  oc-
       cur  between  two matches (or before the first match, or after the last
       match).  For example, to verify that a load is removed by a transforma-
       tion, a test like this can be used:

          define i8 @coerce_offset0(i32 %V, i32* %P) {
            store i32 %V, i32* %P

            %P2 = bitcast i32* %P to i8*
            %P3 = getelementptr i8* %P2, i32 2

            %A = load i8* %P3
            ret i8 %A
          ; CHECK: @coerce_offset0
          ; CHECK-NOT: load
          ; CHECK: ret i8
          }

   The "CHECK-COUNT:" directive
       If you need to match multiple lines with the same pattern over and over
       again you can repeat a plain CHECK: as many times as  needed.  If  that
       looks    too   boring   you   can   instead   use   a   counted   check
       "CHECK-COUNT-<num>:", where <num> is a positive decimal number. It will
       match  the  pattern  exactly  <num>  times, no more and no less. If you
       specified a custom check prefix, just use  "<PREFIX>-COUNT-<num>:"  for
       the same effect.  Here is a simple example:

          Loop at depth 1
          Loop at depth 1
          Loop at depth 1
          Loop at depth 1
            Loop at depth 2
              Loop at depth 3

          ; CHECK-COUNT-6: Loop at depth {{[0-9]+}}
          ; CHECK-NOT:     Loop at depth {{[0-9]+}}

   The "CHECK-DAG:" directive
       If  it's  necessary to match strings that don't occur in a strictly se-
       quential order, "CHECK-DAG:" could be used to verify them  between  two
       matches (or before the first match, or after the last match). For exam-
       ple, clang emits vtable globals in reverse order. Using CHECK-DAG:,  we
       can keep the checks in the natural order:

          // RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s

          struct Foo { virtual void method(); };
          Foo f;  // emit vtable
          // CHECK-DAG: @_ZTV3Foo =

          struct Bar { virtual void method(); };
          Bar b;
          // CHECK-DAG: @_ZTV3Bar =

       CHECK-NOT:  directives could be mixed with CHECK-DAG: directives to ex-
       clude strings between the surrounding CHECK-DAG: directives. As  a  re-
       sult,  the  surrounding CHECK-DAG: directives cannot be reordered, i.e.
       all occurrences matching CHECK-DAG: before CHECK-NOT: must not fall be-
       hind occurrences matching CHECK-DAG: after CHECK-NOT:. For example,

          ; CHECK-DAG: BEFORE
          ; CHECK-NOT: NOT
          ; CHECK-DAG: AFTER

       This case will reject input strings where BEFORE occurs after AFTER.

       With  captured variables, CHECK-DAG: is able to match valid topological
       orderings of a DAG with edges from the definition of a variable to  its
       use.   It's  useful, e.g., when your test cases need to match different
       output sequences from the instruction scheduler. For example,

          ; CHECK-DAG: add [[REG1:r[0-9]+]], r1, r2
          ; CHECK-DAG: add [[REG2:r[0-9]+]], r3, r4
          ; CHECK:     mul r5, [[REG1]], [[REG2]]

       In this case, any order of that two add instructions will be allowed.

       If you are defining and using variables in the same  CHECK-DAG:  block,
       be aware that the definition rule can match after its use.

       So, for instance, the code below will pass:

          ; CHECK-DAG: vmov.32 [[REG2:d[0-9]+]][0]
          ; CHECK-DAG: vmov.32 [[REG2]][1]
          vmov.32 d0[1]
          vmov.32 d0[0]

       While this other code, will not:

          ; CHECK-DAG: vmov.32 [[REG2:d[0-9]+]][0]
          ; CHECK-DAG: vmov.32 [[REG2]][1]
          vmov.32 d1[1]
          vmov.32 d0[0]

       While this can be very useful, it's also dangerous, because in the case
       of register sequence, you must have a strong order (read before  write,
       copy  before  use,  etc).  If  the  definition your test is looking for
       doesn't match (because of a bug in the compiler), it may match  further
       away from the use, and mask real bugs away.

       In  those  cases, to enforce the order, use a non-DAG directive between
       DAG-blocks.

       A CHECK-DAG: directive skips matches that overlap the  matches  of  any
       preceding CHECK-DAG: directives in the same CHECK-DAG: block.  Not only
       is this non-overlapping behavior consistent with other directives,  but
       it's  also  necessary to handle sets of non-unique strings or patterns.
       For example, the following directives look for  unordered  log  entries
       for two tasks in a parallel program, such as the OpenMP runtime:

          // CHECK-DAG: [[THREAD_ID:[0-9]+]]: task_begin
          // CHECK-DAG: [[THREAD_ID]]: task_end
          //
          // CHECK-DAG: [[THREAD_ID:[0-9]+]]: task_begin
          // CHECK-DAG: [[THREAD_ID]]: task_end

       The  second  pair of directives is guaranteed not to match the same log
       entries as the first pair even though the patterns  are  identical  and
       even  if the text of the log entries is identical because the thread ID
       manages to be reused.

   The "CHECK-LABEL:" directive
       Sometimes in a file containing  multiple  tests  divided  into  logical
       blocks,  one  or  more  CHECK:  directives may inadvertently succeed by
       matching lines in a later block. While an error will usually eventually
       be  generated,  the check flagged as causing the error may not actually
       bear any relationship to the actual source of the problem.

       In  order  to  produce  better  error  messages  in  these  cases,  the
       "CHECK-LABEL:"  directive  can  be used. It is treated identically to a
       normal CHECK directive except that FileCheck makes  an  additional  as-
       sumption that a line matched by the directive cannot also be matched by
       any other check present in match-filename; this is intended to be  used
       for  lines containing labels or other unique identifiers. Conceptually,
       the presence of CHECK-LABEL divides  the  input  stream  into  separate
       blocks,  each  of which is processed independently, preventing a CHECK:
       directive in one block matching a line  in  another  block.   If  --en-
       able-var-scope is in effect, all local variables are cleared at the be-
       ginning of the block.

       For example,

          define %struct.C* @C_ctor_base(%struct.C* %this, i32 %x) {
          entry:
          ; CHECK-LABEL: C_ctor_base:
          ; CHECK: mov [[SAVETHIS:r[0-9]+]], r0
          ; CHECK: bl A_ctor_base
          ; CHECK: mov r0, [[SAVETHIS]]
            %0 = bitcast %struct.C* %this to %struct.A*
            %call = tail call %struct.A* @A_ctor_base(%struct.A* %0)
            %1 = bitcast %struct.C* %this to %struct.B*
            %call2 = tail call %struct.B* @B_ctor_base(%struct.B* %1, i32 %x)
            ret %struct.C* %this
          }

          define %struct.D* @D_ctor_base(%struct.D* %this, i32 %x) {
          entry:
          ; CHECK-LABEL: D_ctor_base:

       The use of CHECK-LABEL: directives in this case ensures that the  three
       CHECK:  directives  only  accept lines corresponding to the body of the
       @C_ctor_base function, even if the patterns match lines found later  in
       the  file.  Furthermore,  if one of these three CHECK: directives fail,
       FileCheck will recover by continuing to the next block, allowing multi-
       ple test failures to be detected in a single invocation.

       There  is  no  requirement that CHECK-LABEL: directives contain strings
       that correspond to actual syntactic labels in a source or  output  lan-
       guage:  they must simply uniquely match a single line in the file being
       verified.

       CHECK-LABEL: directives cannot contain variable definitions or uses.

   FileCheck Pattern Matching Syntax
       All FileCheck directives take a pattern to match.   For  most  uses  of
       FileCheck,  fixed  string  matching  is perfectly sufficient.  For some
       things, a more flexible form of matching is desired.  To support  this,
       FileCheck  allows  you  to  specify  regular  expressions  in  matching
       strings, surrounded by double braces: {{yourregex}}.  FileCheck  imple-
       ments  a  POSIX  regular expression matcher; it supports Extended POSIX
       regular expressions (ERE). Because we want to use fixed string matching
       for  a  majority  of what we do, FileCheck has been designed to support
       mixing and matching fixed string  matching  with  regular  expressions.
       This allows you to write things like this:

          ; CHECK: movhpd      {{[0-9]+}}(%esp), {{%xmm[0-7]}}

       In this case, any offset from the ESP register will be allowed, and any
       xmm register will be allowed.

       Because regular expressions are enclosed with double braces,  they  are
       visually  distinct,  and you don't need to use escape characters within
       the double braces like you would in C.  In the rare case that you  want
       to match double braces explicitly from the input, you can use something
       ugly like {{[{][{]}} as your pattern.

   FileCheck Variables
       It is often useful to match a pattern and then verify  that  it  occurs
       again  later in the file.  For codegen tests, this can be useful to al-
       low any register, but verify that that register  is  used  consistently
       later.   To do this, FileCheck allows named variables to be defined and
       substituted into patterns.  Here is a simple example:

          ; CHECK: test5:
          ; CHECK:    notw     [[REGISTER:%[a-z]+]]
          ; CHECK:    andw     {{.*}}[[REGISTER]]

       The first check line matches a regex %[a-z]+ and captures it  into  the
       variable REGISTER.  The second line verifies that whatever is in REGIS-
       TER occurs later in the file after an "andw".  FileCheck variable  ref-
       erences  are  always  contained  in [[ ]] pairs, and their names can be
       formed with the regex [a-zA-Z_][a-zA-Z0-9_]*.  If a colon  follows  the
       name, then it is a definition of the variable; otherwise, it is a use.

       FileCheck  variables can be defined multiple times, and uses always get
       the latest value.  Variables can also be used later on  the  same  line
       they were defined on. For example:

          ; CHECK: op [[REG:r[0-9]+]], [[REG]]

       Can  be  useful if you want the operands of op to be the same register,
       and don't care exactly which register it is.

       If --enable-var-scope is in effect, variables  with  names  that  start
       with  $  are  considered  to be global. All others variables are local.
       All local variables get undefined at the beginning of each  CHECK-LABEL
       block. Global variables are not affected by CHECK-LABEL.  This makes it
       easier to ensure that individual tests are not  affected  by  variables
       set in preceding tests.

   FileCheck Expressions
       Sometimes  there's a need to verify output which refers line numbers of
       the match file, e.g. when testing compiler  diagnostics.   This  intro-
       duces  a  certain  fragility  of  the match file structure, as "CHECK:"
       lines contain absolute line numbers in the same file, which have to  be
       updated whenever line numbers change due to text addition or deletion.

       To  support  this case, FileCheck allows using [[@LINE]], [[@LINE+<off-
       set>]], [[@LINE-<offset>]] expressions in patterns.  These  expressions
       expand  to a number of the line where a pattern is located (with an op-
       tional integer offset).

       This way match patterns can be put near the relevant test lines and in-
       clude relative line number references, for example:

          // CHECK: test.cpp:[[@LINE+4]]:6: error: expected ';' after top level declarator
          // CHECK-NEXT: {{^int a}}
          // CHECK-NEXT: {{^     \^}}
          // CHECK-NEXT: {{^     ;}}
          int a

   Matching Newline Characters
       To  match newline characters in regular expressions the character class
       [[:space:]] can be used. For example, the following pattern:

          // CHECK: DW_AT_location [DW_FORM_sec_offset] ([[DLOC:0x[0-9a-f]+]]){{[[:space:]].*}}"intd"

       matches output of the form (from llvm-dwarfdump):

          DW_AT_location [DW_FORM_sec_offset]   (0x00000233)
          DW_AT_name [DW_FORM_strp]  ( .debug_str[0x000000c9] = "intd")

       letting us set  the  FileCheck  variable  DLOC  to  the  desired  value
       0x00000233, extracted from the line immediately preceding "intd".

AUTHOR
       Maintained by the LLVM Team (https://llvm.org/).

COPYRIGHT
       2003-2020, LLVM Project

8                                 2020-03-19                      FILECHECK(1)

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