Add source annotation to SILPrinter under flag -sil-print-sourceinfo (#29444)

* Add source annotation to SILPrinter under flag -sil-print-sourceinfo

rdar://58365252

Author: meg-gupta

include/swift/Basic/SourceManager.h

@@ -243,6 +243,9 @@ class SourceManager {
   llvm::Optional<unsigned> resolveOffsetForEndOfLine(unsigned BufferId,
                                                      unsigned Line) const;
 
+  /// Get the length of the line
+  llvm::Optional<unsigned> getLineLength(unsigned BufferId, unsigned Line) const;
+
   SourceLoc getLocForLineCol(unsigned BufferId, unsigned Line, unsigned Col) const {
     auto Offset = resolveFromLineCol(BufferId, Line, Col);
     return Offset.hasValue() ? getLocForOffset(BufferId, Offset.getValue()) :

lib/Basic/SourceLoc.cpp

@@ -331,10 +331,20 @@ SourceManager::resolveOffsetForEndOfLine(unsigned BufferId,
   return resolveFromLineCol(BufferId, Line, ~0u);
 }
 
+llvm::Optional<unsigned>
+SourceManager::getLineLength(unsigned BufferId, unsigned Line) const {
+  auto BegOffset = resolveFromLineCol(BufferId, Line, 0);
+  auto EndOffset = resolveFromLineCol(BufferId, Line, ~0u);
+  if (BegOffset && EndOffset) {
+     return EndOffset.getValue() - BegOffset.getValue();
+  }
+  return None;
+}
+
 llvm::Optional<unsigned> SourceManager::resolveFromLineCol(unsigned BufferId,
                                                            unsigned Line,
                                                            unsigned Col) const {
-  if (Line == 0 || Col == 0) {
+  if (Line == 0) {
     return None;
   }
   const bool LineEnd = Col == ~0u;
@@ -353,6 +363,9 @@ llvm::Optional<unsigned> SourceManager::resolveFromLineCol(unsigned BufferId,
     return None;
   }
   Ptr = LineStart;
+  if (Col == 0)   {
+      return Ptr - InputBuf->getBufferStart();
+  }
   // The <= here is to allow for non-inclusive range end positions at EOF
   for (; ; ++Ptr) {
     --Col;

lib/SIL/SILPrinter.cpp

@@ -64,6 +64,10 @@ llvm::cl::opt<bool>
 SILPrintDebugInfo("sil-print-debuginfo", llvm::cl::init(false),
                 llvm::cl::desc("Include debug info in SIL output"));
 
+llvm::cl::opt<bool>
+SILPrintSourceInfo("sil-print-sourceinfo", llvm::cl::init(false),
+                   llvm::cl::desc("Include source annotation in SIL output"));
+
 llvm::cl::opt<bool> SILPrintGenericSpecializationInfo(
     "sil-print-generic-specialization-info", llvm::cl::init(false),
     llvm::cl::desc("Include generic specialization"
@@ -618,7 +622,22 @@ class SILPrinter : public SILInstructionVisitor<SILPrinter> {
     }
     *this << '\n';
 
+    const auto &SM = BB->getModule().getASTContext().SourceMgr;
+    Optional<SILLocation> PrevLoc;
     for (const SILInstruction &I : *BB) {
+      if (SILPrintSourceInfo) {
+        auto CurSourceLoc = I.getLoc().getSourceLoc();
+        if (CurSourceLoc.isValid()) {
+          if (!PrevLoc || SM.getLineNumber(CurSourceLoc) > SM.getLineNumber(PrevLoc->getSourceLoc())) {
+              auto Buffer = SM.findBufferContainingLoc(CurSourceLoc);
+              auto Line = SM.getLineNumber(CurSourceLoc);
+              auto LineLength = SM.getLineLength(Buffer, Line);
+              PrintState.OS << "  // " << SM.extractText({SM.getLocForLineCol(Buffer, Line, 0), LineLength.getValueOr(0)}) <<
+              "\tSourceLoc: " << SM.getDisplayNameForLoc(CurSourceLoc) << ":" << Line << "\n";
+              PrevLoc = I.getLoc();
+          }
+        }
+      }
       Ctx.printInstructionCallBack(&I);
       if (SILPrintGenericSpecializationInfo) {
         if (auto AI = ApplySite::isa(const_cast<SILInstruction *>(&I)))