[lldb] Make the system log a NOOP on Windows

[JDevlieghere]

Windows doesn't have a built-in system log. Previously we got away with writing to stdout and stderr because it was used only sporadically. As we're trying to make the system log more useful on the other platforms, the increased use become a concern. Make it a NOOP until someone figures out a reasonable alternative.

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Jonas Devlieghere (JDevlieghere)

Changes

Windows doesn't have a built-in system log. Previously we got away with writing to stdout and stderr because it was used only sporadically. As we're trying to make the system log more useful on the other platforms, the increased use become a concern. Make it a NOOP until someone figures out a reasonable alternative.

---

Full diff: https://github.com/llvm/llvm-project/pull/112052.diff

1 Files Affected:

• (modified) lldb/source/Host/common/Host.cpp (+1-11)

diff --git a/lldb/source/Host/common/Host.cpp b/lldb/source/Host/common/Host.cpp
index f08adea6546ae1..b7d9725d378d0c 100644
--- a/lldb/source/Host/common/Host.cpp
+++ b/lldb/source/Host/common/Host.cpp
@@ -111,17 +111,7 @@ void Host::SystemLog(Severity severity, llvm::StringRef message) {
   syslog(level, "%s", message.data());
 }
 #else
-void Host::SystemLog(Severity severity, llvm::StringRef message) {
-  switch (severity) {
-  case lldb::eSeverityInfo:
-  case lldb::eSeverityWarning:
-    llvm::outs() << message;
-    break;
-  case lldb::eSeverityError:
-    llvm::errs() << message;
-    break;
-  }
-}
+void Host::SystemLog(Severity severity, llvm::StringRef message) {}
 #endif
 #endif
 

[grandinj]

Windows system log : https://learn.microsoft.com/en-us/windows/win32/Events/windows-events

[DavidSpickett]

I wonder if this is going to fix https://lab.llvm.org/buildbot/#/builders/141/builds/3100, so I am testing it right now.

c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\filecheck.exe  C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Settings/Inputs/EchoCommandsQuiet.out <C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Settings\Output\TestEchoCommandsQuiet.test.tmp.file
# executed command: 'c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\filecheck.exe' 'C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Settings/Inputs/EchoCommandsQuiet.out'
# .---command stderr------------
# | C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Settings/Inputs/EchoCommandsQuiet.out:4:13: error: CHECK-NEXT: is not on the line after the previous match
# | CHECK-NEXT: done
# |             ^
# | <stdin>:5:1: note: 'next' match was here
# | done
# | ^
# | <stdin>:1:6: note: previous match ended here
# | start
# |      ^
# | <stdin>:2:1: note: non-matching line after previous match is here
# | lldb version 20.0.0git (https://github.com/llvm/llvm-project.git revision 73e74e496ec32a13a5ae71df71364065f7be3cca)
# | ^
# | 
# | Input file: <stdin>
# | Check file: C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Settings/Inputs/EchoCommandsQuiet.out
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |         1: start 
# |         2: lldb version 20.0.0git (https://github.com/llvm/llvm-project.git revision 73e74e496ec32a13a5ae71df71364065f7be3cca) 
# |         3:  clang revision 73e74e496ec32a13a5ae71df71364065f7be3cca 
# |         4:  llvm revision 73e74e496ec32a13a5ae71df71364065f7be3cca 
# |         5: done 
# | next:4     !~~~  error: match on wrong line
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

[DavidSpickett]

Merging to fix our Windows bot.