Add a more succinct logging syntax
This adds the LLDB_LOG macro, which enables one to write more succinct log
statements.
if (log)
log->Printf("log something: %d", var);
becomes
LLDB_LOG(log, "log something: {0}, var);
The macro still internally does the "if(log)" dance, so the arguments are only
evaluated if logging is enabled, meaning it has the same overhead as the
previous syntax.
Additionally, the log statements will be automatically prefixed with the file
and function generating the log (if the corresponding new argument to the "log
enable" command is enabled), so one does not need to manually specify this in
the log statement.
It also uses the new llvm formatv syntax, which means we don't have to worry
about PRIx64 macros and similar, and we can log complex object (llvm::StringRef,
lldb_private::Error, ...) more easily.
Differential Revision: https://reviews.llvm.org/D27459
llvm-svn: 292360
diff --git a/lldb/source/Core/Log.cpp b/lldb/source/Core/Log.cpp
index 28fb711..1329ea0 100644
--- a/lldb/source/Core/Log.cpp
+++ b/lldb/source/Core/Log.cpp
@@ -20,6 +20,7 @@
// Other libraries and framework includes
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/Chrono.h"
+#include "llvm/Support/Path.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/raw_ostream.h"
@@ -69,58 +70,18 @@
// a valid file handle, we also log to the file.
//----------------------------------------------------------------------
void Log::VAPrintf(const char *format, va_list args) {
- // Make a copy of our stream shared pointer in case someone disables our
- // log while we are logging and releases the stream
- StreamSP stream_sp(m_stream_sp);
- if (stream_sp) {
- static uint32_t g_sequence_id = 0;
- StreamString header;
+ std::string message_string;
+ llvm::raw_string_ostream message(message_string);
+ WriteHeader(message, "", "");
- // Add a sequence ID if requested
- if (m_options.Test(LLDB_LOG_OPTION_PREPEND_SEQUENCE))
- header.Printf("%u ", ++g_sequence_id);
+ char *text;
+ vasprintf(&text, format, args);
+ message << text;
+ free(text);
- // Timestamp if requested
- if (m_options.Test(LLDB_LOG_OPTION_PREPEND_TIMESTAMP)) {
- auto now = std::chrono::duration<double>(
- std::chrono::system_clock::now().time_since_epoch());
- header.Printf("%.9f ", now.count());
- }
+ message << "\n";
- // Add the process and thread if requested
- if (m_options.Test(LLDB_LOG_OPTION_PREPEND_PROC_AND_THREAD))
- header.Printf("[%4.4x/%4.4" PRIx64 "]: ", getpid(),
- Host::GetCurrentThreadID());
-
- // Add the thread name if requested
- if (m_options.Test(LLDB_LOG_OPTION_PREPEND_THREAD_NAME)) {
- llvm::SmallString<32> thread_name;
- ThisThread::GetName(thread_name);
- if (!thread_name.empty())
- header.Printf("%s ", thread_name.c_str());
- }
-
- header.PrintfVarArg(format, args);
- header.PutCString("\n");
-
- if (m_options.Test(LLDB_LOG_OPTION_BACKTRACE)) {
- std::string back_trace;
- llvm::raw_string_ostream stream(back_trace);
- llvm::sys::PrintStackTrace(stream);
- stream.flush();
- header.PutCString(back_trace);
- }
-
- if (m_options.Test(LLDB_LOG_OPTION_THREADSAFE)) {
- static std::recursive_mutex g_LogThreadedMutex;
- std::lock_guard<std::recursive_mutex> guard(g_LogThreadedMutex);
- stream_sp->PutCString(header.GetString());
- stream_sp->Flush();
- } else {
- stream_sp->PutCString(header.GetString());
- stream_sp->Flush();
- }
- }
+ WriteMessage(message.str());
}
//----------------------------------------------------------------------
@@ -353,6 +314,71 @@
return false;
}
+void Log::WriteHeader(llvm::raw_ostream &OS, llvm::StringRef file,
+ llvm::StringRef function) {
+ static uint32_t g_sequence_id = 0;
+ // Add a sequence ID if requested
+ if (m_options.Test(LLDB_LOG_OPTION_PREPEND_SEQUENCE))
+ OS << ++g_sequence_id << " ";
+
+ // Timestamp if requested
+ if (m_options.Test(LLDB_LOG_OPTION_PREPEND_TIMESTAMP)) {
+ auto now = std::chrono::duration<double>(
+ std::chrono::system_clock::now().time_since_epoch());
+ OS << llvm::formatv("{0:f9} ", now.count());
+ }
+
+ // Add the process and thread if requested
+ if (m_options.Test(LLDB_LOG_OPTION_PREPEND_PROC_AND_THREAD))
+ OS << llvm::formatv("[{0,0+4}/{1,0+4}] ", getpid(),
+ Host::GetCurrentThreadID());
+
+ // Add the thread name if requested
+ if (m_options.Test(LLDB_LOG_OPTION_PREPEND_THREAD_NAME)) {
+ llvm::SmallString<32> thread_name;
+ ThisThread::GetName(thread_name);
+ if (!thread_name.empty())
+ OS << thread_name;
+ }
+
+ if (m_options.Test(LLDB_LOG_OPTION_BACKTRACE))
+ llvm::sys::PrintStackTrace(OS);
+
+ if (m_options.Test(LLDB_LOG_OPTION_PREPEND_FILE_FUNCTION) &&
+ (!file.empty() || !function.empty())) {
+ file = llvm::sys::path::filename(file).take_front(40);
+ function = function.take_front(40);
+ OS << llvm::formatv("{0,-60:60} ", (file + ":" + function).str());
+ }
+}
+
+void Log::WriteMessage(const std::string &message) {
+ // Make a copy of our stream shared pointer in case someone disables our
+ // log while we are logging and releases the stream
+ StreamSP stream_sp(m_stream_sp);
+ if (!stream_sp)
+ return;
+
+ if (m_options.Test(LLDB_LOG_OPTION_THREADSAFE)) {
+ static std::recursive_mutex g_LogThreadedMutex;
+ std::lock_guard<std::recursive_mutex> guard(g_LogThreadedMutex);
+ stream_sp->PutCString(message.c_str());
+ stream_sp->Flush();
+ } else {
+ stream_sp->PutCString(message.c_str());
+ stream_sp->Flush();
+ }
+}
+
+void Log::Format(llvm::StringRef file, llvm::StringRef function,
+ const llvm::formatv_object_base &payload) {
+ std::string message_string;
+ llvm::raw_string_ostream message(message_string);
+ WriteHeader(message, file, function);
+ message << payload << "\n";
+ WriteMessage(message.str());
+}
+
LogChannelSP LogChannel::FindPlugin(const char *plugin_name) {
LogChannelSP log_channel_sp;
LogChannelMap &channel_map = GetChannelMap();