[gn build] port a3172df59c32 (check-lldb)

[zequanwu]

Summary

https://reviews.llvm.org/rGa3172df59c32aac48c113eb7d6a1324aaa95c474 breaks
check-lldb gn build.

[thakis]

Thanks!

write_file runs at gn time. Is it possible to instead make an action that writes this as a build step, and then make check-lldb depend on that?

It's a bit more involved: You have to create a python script that writes the output (since action()s always run python scripts). llvm/utils/gn/secondary/clang/tools/libclang/BUILD.gn has an example of an action(), I can help you if you get stuck. (llvm/utils/gn/gn.py help action has some notes too.)

On one hand, write_file is pretty fast. On the other hand, we currently don't need to do any work like this at GN time in LLVM's gn build, and it'd be nice if it stayed that way. (People who don't build check-lldb don't need this file, so it's wasted work.)

And just FYI, iirc check-lldb in the GN build only runs a subset of the tests that run in the CMake build. (Maybe only the lit-based ones? Maybe those are called "API" tests?)

Thanks again for working on unbreaking check-lldb in the GN build :)

[zequanwu]

Use an action to write file.

[thakis]

Thanks!

llvm/utils/gn/secondary/lldb/test/BUILD.gn

139

If you llvm/utils/gn/gn.py format llvm/utils/gn/secondary/lldb/test/BUILD.gn, it'll probably put this on a single line. (But whatever gn's formatter output is correct.)

143

Pass root_build_dir as second arg, then GN will write a relative path in the generated ninja file. As-is works too, but then it writes an absolute path. It's nice if the generated ninja files are machine-independent. (i.e. replace this line with rebase_path(outputs[0], root_build_dir),)

151–152

Please keep alphabetized, put new dep here. (gn format should fix this for you.)

llvm/utils/gn/build/write_file.py

+#!/usr/bin/env python3
+
+"""Write content into file."""
+
+import argparse
+import sys
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('filepath')
+    parser.add_argument('content')
+
+    args = parser.parse_args()
+
+    with open(args.filepath, 'w') as f:
+        f.write(args.content)
+
+
+if __name__ == '__main__':
+    sys.exit(main())

llvm/utils/gn/secondary/lldb/test/BUILD.gn

 
 write_lit_cfg("lit_unit_site_cfg") {
   # Fully-qualified instead of relative for LIT_SITE_CFG_IN_HEADER.
   input = "//lldb/test/Unit/lit.site.cfg.py.in"
   output = lldb_lit_unit_site_cfg_file
   extra_values = [ "LLVM_BUILD_MODE=." ]
 }
 
+action("lit-lldb-init-quiet") {
+  script = "//llvm/utils/gn/build/write_file.py"
+  outputs = [ "$root_out_dir/obj/lldb/test/Shell/lit-lldb-init-quiet" ]
+  args = [
+    rebase_path(outputs[0], root_build_dir),
+    "command source -C --silent-run true lit-lldb-init",
+  ]
+}
+
 # This target should contain all dependencies of check-lldb.
 # //:default depends on it, so that ninja's default target builds all
 # prerequisites for check-lldb but doesn't run check-lldb itself.
 group("test") {
   deps = [
     ":lit-lldb-init",
+    ":lit-lldb-init-quiet",
     ":lit_api_site_cfg",
     ":lit_shell_site_cfg",
     ":lit_site_cfg",
     ":lit_unit_site_cfg",
     "//clang/tools/driver:symlinks",
     "//lld/tools/lld:symlinks",
     "//lldb/tools/driver:lldb",