[libc++] Save benchmark results in a json file (llvm#119761)

ldionne · web-flow · commit 2135babe28b0 · 2024-12-13T14:19:35.000-05:00
When running a benchmark, also save the benchmark results in a JSON
file. That is cheap to do and useful to compare benchmark results
between different runs.
diff --git a/libcxx/utils/libcxx/test/format.py b/libcxx/utils/libcxx/test/format.py
@@ -348,7 +348,7 @@ def execute(self, test, litConfig):
                 "%dbg(COMPILED WITH) %{cxx} %s %{flags} %{compile_flags} %{benchmark_flags} %{link_flags} -o %t.exe",
             ]
             if "enable-benchmarks=run" in test.config.available_features:
-                steps += ["%dbg(EXECUTED AS) %{exec} %t.exe"]
+                steps += ["%dbg(EXECUTED AS) %{exec} %t.exe --benchmark_out=%T/benchmark-result.json --benchmark_out_format=json"]
             return self._executeShTest(test, litConfig, steps)
         else:
             return lit.Test.Result(

Original file line number	Diff line number	Diff line change
`@@ -348,7 +348,7 @@ def execute(self, test, litConfig):`
`348`	`348`	`"%dbg(COMPILED WITH) %{cxx} %s %{flags} %{compile_flags} %{benchmark_flags} %{link_flags} -o %t.exe",`
`349`	`349`	`]`
`350`	`350`	`if "enable-benchmarks=run" in test.config.available_features:`
`351`		`- steps += ["%dbg(EXECUTED AS) %{exec} %t.exe"]`
	`351`	`+ steps += ["%dbg(EXECUTED AS) %{exec} %t.exe --benchmark_out=%T/benchmark-result.json --benchmark_out_format=json"]`
`352`	`352`	`return self._executeShTest(test, litConfig, steps)`
`353`	`353`	`else:`
`354`	`354`	`return lit.Test.Result(`