[llvm] [llvm][support] Add LLVM_DLOG macro. (PR #143704)

[Mehdi Amini via llvm-commits]

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@@ -0,0 +1,69 @@
+//===- llvm/Support/DebugLog.h - Logging like debug output ------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// This file contains macros for logging like debug output. It builds upon the
+// support in Debug.h but provides a utility function for common debug output
+// style.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_DEBUGLOG_H
+#define LLVM_SUPPORT_DEBUGLOG_H
+
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+#ifndef NDEBUG
+
+// Output with given inputs and trailing newline. E.g.,
+//   LLVM_DLOG() << "Bitset contains: " << Bitset;
+// is equivalent to
+//   LLVM_DEBUG(dbgs() << DEBUG_TYPE << " " << __FILE__ << ":" << __LINE__
+//              << "] " << "Bitset contains: " << Bitset << "\n");
+#define LLVM_DLOG(...)                                                         \
+  DEBUGLOG_WITH_STREAM_AND_TYPE(llvm::dbgs(), DEBUG_TYPE, __VA_ARGS__)
+
+#define DEBUGLOG_WITH_STREAM_AND_TYPE(STREAM, TYPE, ...)                       \
+  for (bool _c = (::llvm::DebugFlag && ::llvm::isCurrentDebugType(TYPE)); _c;  \
+       _c = false)                                                             \
+  ::llvm::impl::LogWithNewline(TYPE, __FILE__, __LINE__, (STREAM))
+
+namespace impl {
+class LogWithNewline {
+public:
+  LogWithNewline(const char *debug_type, const char *file, int line,
+                 raw_ostream &os)
+      : os(os) {
+    if (debug_type)
+      os << debug_type << " ";
+    os << file << ":" << line << "] ";
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joker-eph wrote:

No opening `[` ?

https://github.com/llvm/llvm-project/pull/143704