Merge pull request swiftlang#71934 from adrian-prantl/123117522

Emit original-source-range comment in inline macro expansion files.

Author: adrian-prantl

lib/IRGen/IRGenDebugInfo.cpp

@@ -286,8 +286,31 @@ class IRGenDebugInfoImpl : public IRGenDebugInfo {
         // We only care about macros, so skip everything else.
         if (generatedInfo->kind != GeneratedSourceInfo::ReplacedFunctionBody &&
             generatedInfo->kind != GeneratedSourceInfo::PrettyPrinted)
-          if (auto *MemBuf = SM.getLLVMSourceMgr().getMemoryBuffer(BufferID))
+          if (auto *MemBuf = SM.getLLVMSourceMgr().getMemoryBuffer(BufferID)) {
             Source = MemBuf->getBuffer();
+            // This is copying the buffer twice, but Xcode depends on this
+            // comment in the file.
+            auto origRange = generatedInfo->originalSourceRange;
+            if (origRange.isValid()) {
+              std::string s;
+              {
+                llvm::raw_string_ostream buffer(s);
+                buffer << MemBuf->getBuffer() << "\n";
+                auto originalFilename =
+                    SM.getDisplayNameForLoc(origRange.getStart(), true);
+                unsigned startLine, startColumn, endLine, endColumn;
+                std::tie(startLine, startColumn) =
+                    SM.getPresumedLineAndColumnForLoc(origRange.getStart());
+                std::tie(endLine, endColumn) =
+                    SM.getPresumedLineAndColumnForLoc(origRange.getEnd());
+                buffer << "// original-source-range: "
+                       << DebugPrefixMap.remapPath(originalFilename) << ":"
+                       << startLine << ":" << startColumn << "-" << endLine
+                       << ":" << endColumn << "\n";
+              }
+              Source = BumpAllocatedString(s);
+            }
+          }
       }
     }
     Cached.File = getOrCreateFile(

test/Macros/macro_expand.swift

@@ -165,7 +165,7 @@ func testFileID(a: Int, b: Int) {
   print(
     // CHECK-IR-DAG: ![[L1:[0-9]+]] = distinct !DILocation(line: [[@LINE+3]], column: 5
     // CHECK-IR-DAG: ![[L2:[0-9]+]] = distinct !DILocation({{.*}}inlinedAt: ![[L1]])
-    // CHECK-IR-DAG: !DIFile(filename: "{{.*}}@__swiftmacro_9MacroUser10testFileID1a1bySi_SitF06customdE0fMf_.swift", {{.*}}source: "{{.*}}MacroUser/macro_expand.swift{{.*}}")
+    // CHECK-IR-DAG: !DIFile(filename: "{{.*}}@__swiftmacro_9MacroUser10testFileID1a1bySi_SitF06customdE0fMf_.swift", {{.*}}source: "{{.*}}MacroUser/macro_expand.swift{{.*}}// original-source-range: {{.*}}")
     #addBlocker(
       #stringify(a - b)
       )