[llvm] [ctx_profile] Profile reader and writer (PR #91859)

[Snehasish Kumar via llvm-commits]

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@@ -0,0 +1,164 @@
+//===- PGOCtxProfReader.cpp - Contextual Instrumentation profile reader ---===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Read a contextual profile into a datastructure suitable for maintenance
+// throughout IPO
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ProfileData/PGOCtxProfReader.h"
+#include "llvm/Bitstream/BitCodeEnums.h"
+#include "llvm/Bitstream/BitstreamReader.h"
+#include "llvm/ProfileData/PGOCtxProfWriter.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/Error.h"
+
+using namespace llvm;
+
+#define EXPECT_OR_RET(LHS, RHS)                                                \
+  auto LHS = RHS;                                                              \
+  if (!LHS)                                                                    \
+    return LHS.takeError();
+
+#define RET_ON_ERR(EXPR)                                                       \
+  if (auto Err = (EXPR))                                                       \
+    return Err;
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snehasish wrote:

This pattern is being used within LLVM with different names in at least a couple of other places that I could find easily.

1. https://github.com/llvm/llvm-project/blob/c3028a230557405b0f10bdd7d450f7f92747bbe3/llvm/tools/llvm-rc/ResourceScriptParser.cpp#L20-L30
2. https://github.com/llvm/llvm-project/blob/c3028a230557405b0f10bdd7d450f7f92747bbe3/llvm/unittests/tools/llvm-profdata/OutputSizeLimitTest.cpp#L56-L70

I'm sure there are more that I missed. I think we should formalize this as a macro in Support/Error.h so that others can reuse. Should be in a separate patch though. What do you think?

https://github.com/llvm/llvm-project/pull/91859