[llvm] [FileCheck] Allow -check-prefix to take multiple prefixes (PR #178187)
Jay Foad via llvm-commits
llvm-commits at lists.llvm.org
Tue Jan 27 04:17:00 PST 2026
https://github.com/jayfoad created https://github.com/llvm/llvm-project/pull/178187
There was no real benefit to disallowing this, and it sometimes caused
unnecessary churn in the RUN lines of tests which were updated from
single-to-multiple or multiple-to-single prefixes.
This effectively makes -check-prefixes the primary option and
-check-prefix just an alias of it. The documentation is upated
accordingly.
>From e498cfd669b25e48f776d14f12cb0e2719980aa6 Mon Sep 17 00:00:00 2001
From: Jay Foad <jay.foad at amd.com>
Date: Tue, 27 Jan 2026 11:47:55 +0000
Subject: [PATCH] [FileCheck] Allow -check-prefix to take multiple prefixes
There was no real benefit to disallowing this, and it sometimes caused
unnecessary churn in the RUN lines of tests which were updated from
single-to-multiple or multiple-to-single prefixes.
This effectively makes -check-prefixes the primary option and
-check-prefix just an alias of it. The documentation is upated
accordingly.
---
llvm/docs/CommandGuide/FileCheck.rst | 21 +++++++++----------
.../check-multiple-prefixes-mixed.txt | 4 ++++
llvm/utils/FileCheck/FileCheck.cpp | 15 +++++++------
3 files changed, 21 insertions(+), 19 deletions(-)
diff --git a/llvm/docs/CommandGuide/FileCheck.rst b/llvm/docs/CommandGuide/FileCheck.rst
index af4930409da1a..69b9300c81918 100644
--- a/llvm/docs/CommandGuide/FileCheck.rst
+++ b/llvm/docs/CommandGuide/FileCheck.rst
@@ -6,7 +6,7 @@ FileCheck - Flexible pattern matching file verifier
SYNOPSIS
--------
-:program:`FileCheck` *match-filename* [*--check-prefix=XXX*] [*--strict-whitespace*]
+:program:`FileCheck` *match-filename* [*--check-prefixes=XXX*] [*--strict-whitespace*]
DESCRIPTION
-----------
@@ -33,23 +33,22 @@ and from the command line.
Print a summary of command line options.
-.. option:: --check-prefix prefix
+.. option:: --check-prefixes prefix1,prefix2,...
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 options), the
- :option:`--check-prefix` argument allows you to specify (without the trailing
+ :option:`--check-prefixes` argument allows you to specify (without the trailing
"``:``") one or more prefixes to match. Multiple prefixes are useful for tests
which might change for different run options, but most lines remain the same.
FileCheck does not permit duplicate prefixes, even if one is a check prefix
and one is a comment prefix (see :option:`--comment-prefixes` below).
-.. option:: --check-prefixes prefix1,prefix2,...
+.. option:: --check-prefix prefix1,prefix2,...
- An alias of :option:`--check-prefix` that allows multiple prefixes to be
- specified as a comma separated list.
+ An alias of :option:`--check-prefixes`.
.. option:: --comment-prefixes prefix1,prefix2,...
@@ -67,7 +66,7 @@ and from the command line.
.. option:: --allow-unused-prefixes
This option controls the behavior when using more than one prefix as specified
- by :option:`--check-prefix` or :option:`--check-prefixes`, and some of these
+ by :option:`--check-prefixes`, and some of these
prefixes are missing in the test file. If true, this is allowed, if false,
FileCheck will report an error, listing the missing prefixes. The default value
is false.
@@ -257,10 +256,10 @@ 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-prefixes option
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The FileCheck `-check-prefix` option allows multiple test
+The FileCheck `-check-prefixes` 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
:program:`llc`. Here's a simple example:
@@ -268,9 +267,9 @@ circumstances, for example, testing different architectural variants with
.. code-block:: llvm
; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin9 -mattr=sse41 \
- ; RUN: | FileCheck %s -check-prefix=X32
+ ; RUN: | FileCheck %s -check-prefixes=X32
; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin9 -mattr=sse41 \
- ; RUN: | FileCheck %s -check-prefix=X64
+ ; RUN: | FileCheck %s -check-prefixes=X64
define <4 x i32> @pinsrd_1(i32 %s, <4 x i32> %tmp) nounwind {
%tmp1 = insertelement <4 x i32>; %tmp, i32 %s, i32 1
diff --git a/llvm/test/FileCheck/check-multiple-prefixes-mixed.txt b/llvm/test/FileCheck/check-multiple-prefixes-mixed.txt
index 1e6bcbf3e72a1..011d26365c167 100644
--- a/llvm/test/FileCheck/check-multiple-prefixes-mixed.txt
+++ b/llvm/test/FileCheck/check-multiple-prefixes-mixed.txt
@@ -2,10 +2,14 @@
// RUN: FileCheck -check-prefix=A -check-prefix=BOTH -input-file %s %s
// RUN: FileCheck -check-prefixes=B,BOTH -input-file %s %s
// RUN: FileCheck -check-prefixes=A,BOTH -input-file %s %s
+// RUN: FileCheck -check-prefix=B,BOTH -input-file %s %s
+// RUN: FileCheck -check-prefix=A,BOTH -input-file %s %s
+// RUN: FileCheck -check-prefix=A,B -check-prefix=BOTH,C -input-file %s %s
; A: {{a}}aaaaa
; B: {{b}}bbbb
; BOTH: {{q}}qqqqq
+; C: {{c}}cccc
aaaaaa
bbbbb
qqqqqq
diff --git a/llvm/utils/FileCheck/FileCheck.cpp b/llvm/utils/FileCheck/FileCheck.cpp
index a5473f951492e..8c109ccab4dc6 100644
--- a/llvm/utils/FileCheck/FileCheck.cpp
+++ b/llvm/utils/FileCheck/FileCheck.cpp
@@ -38,14 +38,13 @@ static cl::opt<std::string>
InputFilename("input-file", cl::desc("File to check (defaults to stdin)"),
cl::init("-"), cl::value_desc("filename"));
-static cl::list<std::string> CheckPrefixes(
- "check-prefix",
- cl::desc("Prefix to use from check file (defaults to 'CHECK')"));
-static cl::alias CheckPrefixesAlias(
- "check-prefixes", cl::aliasopt(CheckPrefixes), cl::CommaSeparated,
- cl::NotHidden,
- cl::desc(
- "Alias for -check-prefix permitting multiple comma separated values"));
+static cl::list<std::string>
+ CheckPrefixes("check-prefixes", cl::CommaSeparated,
+ cl::desc("Comma separated list of prefixes to use from check "
+ "file\n(defaults to 'CHECK')"));
+static cl::alias CheckPrefixesAlias("check-prefix", cl::aliasopt(CheckPrefixes),
+ cl::CommaSeparated, cl::NotHidden,
+ cl::desc("Alias for -check-prefixes"));
static cl::list<std::string> CommentPrefixes(
"comment-prefixes", cl::CommaSeparated, cl::Hidden,
More information about the llvm-commits
mailing list