[llvm-commits] [llvm] r167964 - /llvm/trunk/docs/CommandGuide/FileCheck.rst
Dmitri Gribenko
gribozavr at gmail.com
Wed Nov 14 11:42:32 PST 2012
Author: gribozavr
Date: Wed Nov 14 13:42:32 2012
New Revision: 167964
URL: http://llvm.org/viewvc/llvm-project?rev=167964&view=rev
Log:
FileCheck.rst: change formatting of code-like constructs to use a monospaced
font. These were formatted in bold, but that's not correct.
Modified:
llvm/trunk/docs/CommandGuide/FileCheck.rst
Modified: llvm/trunk/docs/CommandGuide/FileCheck.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/CommandGuide/FileCheck.rst?rev=167964&r1=167963&r2=167964&view=diff
==============================================================================
--- llvm/trunk/docs/CommandGuide/FileCheck.rst (original)
+++ llvm/trunk/docs/CommandGuide/FileCheck.rst Wed Nov 14 13:42:32 2012
@@ -1,18 +1,14 @@
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
@@ -23,77 +19,61 @@
The *match-filename* file specifies the file that contains the patterns to
match. The file to verify is always read from standard input.
-
OPTIONS
-------
-
-
**-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
+ 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 options), the **--check-prefix** argument allows you to specify
a specific prefix to match.
-
-
**--input-file** *filename*
File to check (defaults to stdin).
-
**--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 disables this behavior.
-
+ The **--strict-whitespace** argument disables this behavior.
**-version**
Show the version number of this program.
-
-
-
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:
-
.. code-block:: llvm
; 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 specified by "%s"). To see how this works,
-let's look at the rest of the .ll file (after the RUN line):
-
+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 specified by
+"``%s``"). To see how this works, let's look at the rest of the ``.ll`` file
+(after the RUN line):
.. code-block:: llvm
@@ -114,32 +94,30 @@
}
-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.
+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
+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.
+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 existed somewhere else in the file,
-that would not count: "grep subl" matches if subl exists anywhere in the
-file.
+is checking for the "``sub1:``" and "``inc4:``" labels, it will not match
+unless there is a "``subl``" in between those labels. If it existed 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
+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:
-
.. code-block:: llvm
; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \
@@ -157,21 +135,17 @@
; 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 expect:
-
+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 expect:
.. code-block:: llvm
@@ -193,22 +167,18 @@
; CHECK-NEXT: ret
}
-
-CHECK-NEXT: directives reject the input unless there is exactly one newline
-between it an the previous directive. A CHECK-NEXT cannot be the first
-directive in a file.
-
+"``CHECK-NEXT:``" directives reject the input unless there is exactly one
+newline between it an the previous directive. A "``CHECK-NEXT:``" 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 occur
+The "``CHECK-NOT:``" directive is used to verify that a string doesn't occur
between two matches (or before the first match, or after the last match). For
example, to verify that a load is removed by a transformation, a test like this
can be used:
-
.. code-block:: llvm
define i8 @coerce_offset0(i32 %V, i32* %P) {
@@ -225,26 +195,22 @@
}
-
FileCheck Pattern Matching Syntax
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-The CHECK: and CHECK-NOT: directives both 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}}**. 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:
-
+The "``CHECK:``" and "``CHECK-NOT:``" directives both 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}}``. 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:
.. code-block:: llvm
; 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.
@@ -252,39 +218,37 @@
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.
-
+``{{[{][{]}}`` 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 allow 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:
-
.. code-block:: llvm
; 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 REGISTER
-occurs later in the file after an "andw". FileCheck variable references 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.
+The first check line matches a regex ``%[a-z]+`` and captures it into the
+variable ``REGISTER``. The second line verifies that whatever is in
+``REGISTER`` occurs later in the file after an "``andw``". FileCheck variable
+references 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. Note that variables are all read at the start of a "CHECK" line
-and are all defined at the end. This means that if you have something like
-"**CHECK: [[XYZ:.\\*]]x[[XYZ]]**", the check line will read the previous
-value of the XYZ variable and define a new one after the match is performed. If
-you need to do something like this you can probably take advantage of the fact
-that FileCheck is not actually line-oriented when it matches, this allows you to
-define two separate CHECK lines that match on the same line.
+latest value. Note that variables are all read at the start of a "``CHECK``"
+line and are all defined at the end. This means that if you have something
+like "``CHECK: [[XYZ:.*]]x[[XYZ]]``", the check line will read the previous
+value of the ``XYZ`` variable and define a new one after the match is
+performed. If you need to do something like this you can probably take
+advantage of the fact that FileCheck is not actually line-oriented when it
+matches, this allows you to define two separate "``CHECK``" lines that match on
+the same line.
+
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