[utils] update_llc_test_checks --downstream-target-handler-path option #135879
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✅ With the latest revision this PR passed the Python code formatter. |
This patch adds a new option to update_llce_test_checks that points to a downstream python module implementing handler functions for a downstream compiler.
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@llvm/pr-subscribers-testing-tools Author: vporpo (vporpo) ChangesThis patch adds a new option to Full diff: https://github.com/llvm/llvm-project/pull/135879.diff 5 Files Affected:
diff --git a/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/downstream_target.ll b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/downstream_target.ll
new file mode 100644
index 0000000000000..1003194769a61
--- /dev/null
+++ b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/downstream_target.ll
@@ -0,0 +1,4 @@
+; RUN: llc < %s -mtriple=i686-- | FileCheck %s
+define void @foo() {
+ ret void
+}
diff --git a/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/downstream_target.ll.expected b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/downstream_target.ll.expected
new file mode 100644
index 0000000000000..263c787c910a1
--- /dev/null
+++ b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/downstream_target.ll.expected
@@ -0,0 +1,8 @@
+; RUN: llc < %s -mtriple=i686-- | FileCheck %s
+define void @foo() {
+; CHECK-LABEL: foo:
+; CHECK: Test
+; CHECK-NEXT: Downstream
+; CHECK-NEXT: Target
+ ret void
+}
diff --git a/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/downstream_target.py b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/downstream_target.py
new file mode 100644
index 0000000000000..6df7421b92ab6
--- /dev/null
+++ b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/Inputs/downstream_target.py
@@ -0,0 +1,65 @@
+# This is an example of a downstream module, which in this case is for i686.
+# The goal is to test the updater's downstream-target-module-path option.
+#
+# This target module implements a simple scrubber that returns a fixed string,
+# a regex that matches the fixed strings generated by the scrubber.
+#
+# This module needs to define:
+# 2. The `downstream_scrub(asm, arg)` scrubber function
+# 3. The `downstream_asm_fn_re` regex for matching func, body, etc.
+
+import re
+import sys
+import os
+from pathlib import Path
+
+common_dir = Path(__file__).parent / "../../../../../utils/"
+sys.path.append(common_dir)
+from UpdateTestChecks import common
+
+
+# The asm scrubber returns the scrubbed asm.
+# In this test we return a fixed string.
+def scrub(asm, args):
+ return "Test\n" "Downstream\n" "Target\n"
+
+
+# The regular expression for matching func, body, etc.
+regex = re.compile(
+ r'^_?(?P<func>[^:]+):[ \t]*#+[ \t]*(@"?(?P=func)"?| -- Begin function (?P=func))\n(?:\s*\.?Lfunc_begin[^:\n]*:\n)?'
+ r"(?:\.L(?P=func)\$local:\n)?" # drop .L<func>$local:
+ r"(?:\s*\.type\s+\.L(?P=func)\$local,@function\n)?" # drop .type .L<func>$local
+ r"(?:[ \t]*(?:\.cfi_startproc|\.cfi_personality|\.cfi_lsda|\.seh_proc|\.seh_handler)\b[^\n]*\n)*" # drop optional cfi
+ r"(?P<body>^##?[ \t]+[^:]+:.*?)\s*"
+ r"^\s*(?:[^:\n]+?:\s*\n\s*\.size|\.cfi_endproc|\.globl|\.comm|\.(?:sub)?section|#+ -- End function)",
+ flags=(re.M | re.S),
+)
+
+
+def get_run_handler(triple):
+ return (scrub, regex)
+
+
+def add_checks(
+ output_lines,
+ comment_marker,
+ prefix_list,
+ func_dict,
+ func_name,
+ ginfo: common.GeneralizerInfo,
+ global_vars_seen_dict,
+ is_filtered,
+):
+ # Label format is based on ASM string.
+ check_label_format = "{} %s-LABEL: %s%s%s%s".format(comment_marker)
+ return common.add_checks(
+ output_lines,
+ comment_marker,
+ prefix_list,
+ func_dict,
+ func_name,
+ check_label_format,
+ ginfo,
+ global_vars_seen_dict,
+ is_filtered=is_filtered,
+ )
diff --git a/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/downstream_target.test b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/downstream_target.test
new file mode 100644
index 0000000000000..dc7f9b8da95fa
--- /dev/null
+++ b/llvm/test/tools/UpdateTestChecks/update_llc_test_checks/downstream_target.test
@@ -0,0 +1,7 @@
+# REQUIRES: x86-registered-target
+## Tests that the downstream module support works
+
+# RUN: cp -f %S/Inputs/downstream_target.ll %t.ll && %update_llc_test_checks %t.ll --downstream-target-handler-path=%S/Inputs/downstream_target.py
+# RUN: grep -v '^; NOTE:' %t.ll > %t.ll.expected
+# RUN: diff -b -u %S/Inputs/downstream_target.ll.expected %t.ll.expected
+
diff --git a/llvm/utils/update_llc_test_checks.py b/llvm/utils/update_llc_test_checks.py
index 3e9380d95e3f6..05d370d794d15 100755
--- a/llvm/utils/update_llc_test_checks.py
+++ b/llvm/utils/update_llc_test_checks.py
@@ -11,6 +11,8 @@
import argparse
import os # Used to advertise this file's name ("autogenerated_note").
+import sys
+import importlib.util
from UpdateTestChecks import common
@@ -21,6 +23,19 @@
]
+# Helper that imports module from `module_path` and returns it.
+def import_module(module_path):
+ if not os.path.exists(module_path):
+ common.error("Path does not exist", module_path)
+ sys.exit(1)
+ module_name_with_ext = os.path.basename(module_path)
+ module_name = os.path.splitext(module_name_with_ext)[0]
+ spec = importlib.util.spec_from_file_location(module_name, module_path)
+ module = importlib.util.module_from_spec(spec)
+ sys.modules[module_name] = module
+ spec.loader.exec_module(module)
+ return module
+
def main():
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument(
@@ -67,6 +82,12 @@ def main():
help="Set a default -march for when neither triple nor arch are found in a RUN line",
)
parser.add_argument("tests", nargs="+")
+ parser.add_argument(
+ "--downstream-target-handler-path",
+ default=None,
+ dest="downstream_target_handler_path",
+ help="The path of a python module that implements the scrubber and the regex generator and adds it to the targets handlers map for a downstream target",
+ )
initial_args = common.parse_commandline_args(parser)
script_name = os.path.basename(__file__)
@@ -107,10 +128,17 @@ def main():
march_in_cmd = m.groups()[0]
m = common.DEBUG_ONLY_ARG_RE.search(llc_cmd)
- if m and m.groups()[0] == "isel":
- from UpdateTestChecks import isel as output_type
+ if initial_args.downstream_target_handler_path:
+ common.warn(
+ "Downstream handlers provided by '%s'"
+ % initial_args.downstream_target_handler_path
+ )
+ output_type = import_module(initial_args.downstream_target_handler_path)
else:
- from UpdateTestChecks import asm as output_type
+ if m and m.groups()[0] == "isel":
+ from UpdateTestChecks import isel as output_type
+ else:
+ from UpdateTestChecks import asm as output_type
common.verify_filecheck_prefixes(filecheck_cmd)
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(I am travelling with limited computer access until May 4th, and my response time may be delayed..) The target-specific component is highly stable. Downstream targets typically require only a few lines of script, which rarely need updates, even after a year or two. I don't see sufficient justification for the proposed loaded module patch. |
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Thank you for your reply @MaskRay . These scripts are indeed stable, so they won't probably cause any merge conflicts. But there is a downstream cost for each one of these patches as they have to go through a process for getting them added in or getting them updated, which could be saved if we added this simple feature. |
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If the patches don't change I don't see how this adds a lot of maintainance on your side? I have worked on a fork with huge diff relative to upstream llvm including changes to this script and I think we only needed to resolve one (trivial) conflict over many years. |
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I think LLVM knows that downstream out-of-tree targets exist, and we should be willing to take reasonable, low-cost steps to make them easier to maintain. The entire TargetMachine backend interface is virtual, so we did 80% of the work to make LLVM support out-of-tree plugins as loadable modules, but then we stopped at some point and started adding Triple ISA checks throughout the compiler, compromising the abstraction. I think we ought to lean in the direction of minimizing target awareness and increasing abstraction over all targets, and that's the intuition I'd use the judge this. If it handles out of tree targets uniformly with our in-tree set, then it's a reasonable cost for us to bear. |
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Thanks for your feedback @arichardson . The main argument is along the lines of what @rnk mentioned above. The patch provides a way to decouple downstream from upstream and make the |
This patch adds a new option to
update_llc_test_checks.pythat points to a downstream python module implementing handler functions for a downstream compiler.RFC: https://discourse.llvm.org/t/rfc-update-llc-test-checks-support-downstream-targets-with-a-new-option-pointing-to-downstream-handlers/85883