[lldb][lldb-dap] Redirect LLDB's messages to the right output category.

[da-viper]

Based on the DAP specification.
The output categories stdout and stderr should only be used for the debuggee's stdout and stderr.

 /**
     * The output category. If not specified or if the category is not
     * understood by the client, `console` is assumed.
     * Values:
     * 'console': Show the output in the client's default message UI, e.g. a
     * 'debug console'. This category should only be used for informational
     * output from the debugger (as opposed to the debuggee).
     * 'important': A hint for the client to show the output in the client's UI
     * for important and highly visible information, e.g. as a popup
     * notification. This category should only be used for important messages
     * from the debugger (as opposed to the debuggee). Since this category value
     * is a hint, clients might ignore the hint and assume the `console`
     * category.
     * 'stdout': Show the output as normal program output from the debuggee.
     * 'stderr': Show the output as error program output from the debuggee.
     * 'telemetry': Send the output to telemetry instead of showing it to the
     * user.
     * etc.
     */
    category?: 'console' | 'important' | 'stdout' | 'stderr' | 'telemetry' | string;

What I am not sure if error should use the important category ?

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Ebuka Ezike (da-viper)

Changes

Based on the DAP specification.
The output categories stdout and stderr should only be used for the debuggee's stdout and stderr.

 /**
     * The output category. If not specified or if the category is not
     * understood by the client, `console` is assumed.
     * Values:
     * 'console': Show the output in the client's default message UI, e.g. a
     * 'debug console'. This category should only be used for informational
     * output from the debugger (as opposed to the debuggee).
     * 'important': A hint for the client to show the output in the client's UI
     * for important and highly visible information, e.g. as a popup
     * notification. This category should only be used for important messages
     * from the debugger (as opposed to the debuggee). Since this category value
     * is a hint, clients might ignore the hint and assume the `console`
     * category.
     * 'stdout': Show the output as normal program output from the debuggee.
     * 'stderr': Show the output as error program output from the debuggee.
     * 'telemetry': Send the output to telemetry instead of showing it to the
     * user.
     * etc.
     */
    category?: 'console' | 'important' | 'stdout' | 'stderr' | 'telemetry' | string;

What I am not sure if error should use the important category ?

---

Full diff: https://github.com/llvm/llvm-project/pull/137002.diff

1 Files Affected:

• (modified) lldb/tools/lldb-dap/DAP.cpp (+2-2)

diff --git a/lldb/tools/lldb-dap/DAP.cpp b/lldb/tools/lldb-dap/DAP.cpp
index 597fe3a1e323b..831075af1cd63 100644
--- a/lldb/tools/lldb-dap/DAP.cpp
+++ b/lldb/tools/lldb-dap/DAP.cpp
@@ -208,12 +208,12 @@ llvm::Error DAP::ConfigureIO(std::FILE *overrideOut, std::FILE *overrideErr) {
   in = lldb::SBFile(std::fopen(DEV_NULL, "r"), /*transfer_ownership=*/true);
 
   if (auto Error = out.RedirectTo(overrideOut, [this](llvm::StringRef output) {
-        SendOutput(OutputType::Stdout, output);
+        SendOutput(OutputType::Console, output);
       }))
     return Error;
 
   if (auto Error = err.RedirectTo(overrideErr, [this](llvm::StringRef output) {
-        SendOutput(OutputType::Stderr, output);
+        SendOutput(OutputType::Console, output);
       }))
     return Error;
 

[JDevlieghere]

I don't believe this is correct. LLDB has a notion of an output and error stream, which combines the output from the debuggee, and output from the debugger. Since we can't detangle the two, I think the current implementation most closely matches the spec.

[da-viper]

I think that may not apply to LLDB-dap.

Since dap uses the SBAPI it sends the debugee output to the client here.

llvm-project/lldb/tools/lldb-dap/EventHelper.cpp

Lines 205 to 215 in 1b6cbaa

	// Grab any STDOUT and STDERR from the process and send it up to VS Code
	// via an "output" event to the "stdout" and "stderr" categories.
	void SendStdOutStdErr(DAP &dap, lldb::SBProcess &process) {
	char buffer[OutputBufferSize];
	size_t count;
	while ((count = process.GetSTDOUT(buffer, sizeof(buffer))) > 0)
	dap.SendOutput(OutputType::Stdout, llvm::StringRef(buffer, count));
	while ((count = process.GetSTDERR(buffer, sizeof(buffer))) > 0)
	dap.SendOutput(OutputType::Stderr, llvm::StringRef(buffer, count));
	}

[JDevlieghere]

I didn't realize lldb-dap was handing the process output separately. In that case, this LGTM. Apologies for the confusion!