Common infrastructure for reading a profile remapping file and building

a mangling remapper from it.

Differential Revision: https://reviews.llvm.org/D51246

llvm-svn: 342161

2 files changed, 82 insertions, 0 deletions

diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
index 9451f2f9db1..88129b09d2d 100644
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -122,6 +122,7 @@ add_llvm_library(LLVMSupport
   StringPool.cpp
   StringSaver.cpp
   StringRef.cpp
+  SymbolRemappingReader.cpp
   SystemUtils.cpp
   TarWriter.cpp
   TargetParser.cpp
diff --git a/llvm/lib/Support/SymbolRemappingReader.cpp b/llvm/lib/Support/SymbolRemappingReader.cpp
new file mode 100644
index 00000000000..264c890ce8f
--- /dev/null
+++ b/llvm/lib/Support/SymbolRemappingReader.cpp
@@ -0,0 +1,81 @@
+//===- SymbolRemappingReader.cpp - Read symbol remapping file -------------===//
+//
+//                      The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains definitions needed for reading and applying symbol
+// remapping files.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/SymbolRemappingReader.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/LineIterator.h"
+
+using namespace llvm;
+
+char SymbolRemappingParseError::ID;
+
+/// Load a set of name remappings from a text file.
+///
+/// See the documentation at the top of the file for an explanation of
+/// the expected format.
+Error SymbolRemappingReader::read(MemoryBuffer &B) {
+  line_iterator LineIt(B, /*SkipBlanks=*/true, '#');
+
+  auto ReportError = [&](Twine Msg) {
+    return llvm::make_error<SymbolRemappingParseError>(
+        B.getBufferIdentifier(), LineIt.line_number(), Msg);
+  };
+
+  for (; !LineIt.is_at_eof(); ++LineIt) {
+    StringRef Line = *LineIt;
+    Line = Line.ltrim(' ');
+    // line_iterator only detects comments starting in column 1.
+    if (Line.startswith("#") || Line.empty())
+      continue;
+
+    SmallVector<StringRef, 4> Parts;
+    Line.split(Parts, ' ', /*MaxSplits*/-1, /*KeepEmpty*/false);
+
+    if (Parts.size() != 3)
+      return ReportError("Expected 'kind mangled_name mangled_name', "
+                         "found '" + Line + "'");
+
+    using FK = ItaniumManglingCanonicalizer::FragmentKind;
+    Optional<FK> FragmentKind = StringSwitch<Optional<FK>>(Parts[0])
+                                    .Case("name", FK::Name)
+                                    .Case("type", FK::Type)
+                                    .Case("encoding", FK::Encoding)
+                                    .Default(None);
+    if (!FragmentKind)
+      return ReportError("Invalid kind, expected 'name', 'type', or 'encoding',"
+                         " found '" + Parts[0] + "'");
+
+    using EE = ItaniumManglingCanonicalizer::EquivalenceError;
+    switch (Canonicalizer.addEquivalence(*FragmentKind, Parts[1], Parts[2])) {
+    case EE::Success:
+      break;
+
+    case EE::ManglingAlreadyUsed:
+      return ReportError("Manglings '" + Parts[1] + "' and '" + Parts[2] + "' "
+                         "have both been used in prior remappings. Move this "
+                         "remapping earlier in the file.");
+
+    case EE::InvalidFirstMangling:
+      return ReportError("Could not demangle '" + Parts[1] + "' "
+                         "as a <" + Parts[0] + ">; invalid mangling?");
+
+    case EE::InvalidSecondMangling:
+      return ReportError("Could not demangle '" + Parts[2] + "' "
+                         "as a <" + Parts[0] + ">; invalid mangling?");
+    }
+  }
+
+  return Error::success();
+}