Implement extractInlinableText with swift-syntax

Replace the existing C++ implementation of extractInlinableText with
a new implementation based on swift-syntax. It uses SwiftIfConfig to
remove inactive regions (with a special mode), and a new compiler-only
entrypoint in the library to remove comments and `#sourceLocation`.

Author: DougGregor

lib/AST/ASTPrinter.cpp

@@ -4516,7 +4516,7 @@ void PrintAST::visitMacroDecl(MacroDecl *decl) {
       ASTContext &ctx = decl->getASTContext();
       SmallString<64> scratch;
       Printer << " = "
-              << extractInlinableText(ctx.SourceMgr, decl->definition, scratch);
+              << extractInlinableText(ctx, decl->definition, scratch);
     } else {
       auto def = decl->getDefinition();
       switch (def.kind) {

lib/AST/Decl.cpp

@@ -2225,9 +2225,9 @@ StringRef PatternBindingEntry::getInitStringRepresentation(
   if (InitContextAndFlags.getInt().contains(PatternFlags::IsText) &&
       !InitStringRepresentation.empty())
     return InitStringRepresentation;
-  auto &sourceMgr = getAnchoringVarDecl()->getASTContext().SourceMgr;
+  auto &ctx = getAnchoringVarDecl()->getASTContext();
   auto init = getOriginalInit();
-  return extractInlinableText(sourceMgr, init, scratch);
+  return extractInlinableText(ctx, init, scratch);
 }
 
 SourceRange PatternBindingDecl::getSourceRange() const {
@@ -9022,7 +9022,7 @@ ParamDecl::getDefaultValueStringRepresentation(
 
     assert(hasDefaultExpr()
            && "Normal default argument with no default expression?!");
-    return extractInlinableText(getASTContext().SourceMgr,
+    return extractInlinableText(getASTContext(),
                                 getStructuralDefaultExpr(), scratch);
   }
   case DefaultArgumentKind::StoredProperty: {
@@ -9066,8 +9066,7 @@ ParamDecl::getDefaultValueStringRepresentation(
           return ".init()";
         }
 
-        auto &sourceMgr = getASTContext().SourceMgr;
-        return extractInlinableText(sourceMgr, wrappedValue, scratch);
+        return extractInlinableText(getASTContext(), wrappedValue, scratch);
       }
     }
 
@@ -9087,9 +9086,7 @@ ParamDecl::getDefaultValueStringRepresentation(
       return "<<empty>>";
     }
 
-    return extractInlinableText(getASTContext().SourceMgr,
-                                init,
-                                scratch);
+    return extractInlinableText(getASTContext(), init, scratch);
   }
   case DefaultArgumentKind::Inherited: return "super";
 #define MAGIC_IDENTIFIER(NAME, STRING, SYNTAX_KIND) \
@@ -10275,7 +10272,7 @@ StringRef AbstractFunctionDecl::getInlinableBodyText(
     return BodyStringRepresentation;
 
   auto body = getBody();
-  return extractInlinableText(getASTContext().SourceMgr, body, scratch);
+  return extractInlinableText(getASTContext(), body, scratch);
 }
 
 /// A uniqued list of derivative function configurations.

lib/AST/InlinableText.cpp

@@ -10,13 +10,15 @@
 //
 //===----------------------------------------------------------------------===//
 #include "InlinableText.h"
+#include "swift/AST/ASTBridging.h"
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/ASTNode.h"
 #include "swift/AST/ASTVisitor.h"
 #include "swift/AST/ASTWalker.h"
 #include "swift/AST/Decl.h"
 #include "swift/AST/Expr.h"
 #include "swift/Basic/Assertions.h"
+#include "swift/Bridging/ASTGen.h"
 #include "swift/Parse/Lexer.h"
 
 #include "llvm/ADT/SmallVector.h"
@@ -291,8 +293,28 @@ static void appendRange(
   }
 }
 
-StringRef swift::extractInlinableText(SourceManager &sourceMgr, ASTNode node,
+extern "C"
+BridgedStringRef swift_ASTGen_extractInlinableText(
+    BridgedASTContext ctx, BridgedStringRef sourceText);
+
+StringRef swift::extractInlinableText(ASTContext &ctx, ASTNode node,
                                       SmallVectorImpl<char> &scratch) {
+  SourceManager &sourceMgr = ctx.SourceMgr;
+
+#if SWIFT_BUILD_SWIFT_SYNTAX
+  CharSourceRange sourceTextRange =
+      Lexer::getCharSourceRangeFromSourceRange(
+        sourceMgr, node.getSourceRange());
+  StringRef sourceText = sourceMgr.extractText(sourceTextRange);
+  auto resultText = swift_ASTGen_extractInlinableText(ctx, sourceText);
+
+  scratch.clear();
+  scratch.insert(scratch.begin(),
+                 resultText.unbridged().begin(),
+                 resultText.unbridged().end());
+  swift_ASTGen_freeBridgedString(resultText);
+  return { scratch.data(), scratch.size() };
+#else
   // Extract inactive ranges from the text of the node.
   ExtractInactiveRanges extractor(sourceMgr);
   node.walk(extractor);
@@ -316,4 +338,5 @@ StringRef swift::extractInlinableText(SourceManager &sourceMgr, ASTNode node,
   }
 
   return { scratch.data(), scratch.size() };
+#endif
 }

lib/AST/InlinableText.h

@@ -19,11 +19,11 @@
 #include "llvm/ADT/SmallVector.h"
 
 namespace swift {
-class SourceManager;
+class ASTContext;
 
 /// Extracts the text of this ASTNode from the source buffer, ignoring
 /// all #if declarations and clauses except the elements that are active.
-StringRef extractInlinableText(SourceManager &sourceMgr, ASTNode node,
+StringRef extractInlinableText(ASTContext &ctx, ASTNode node,
                                SmallVectorImpl<char> &scratch);
 
 } // end namespace swift

lib/ASTGen/Sources/ASTGen/CompilerBuildConfiguration.swift

@@ -370,3 +370,27 @@ public func evaluatePoundIfCondition(
 
   return (isActive ? 0x1 : 0) | (syntaxErrorsAllowed ? 0x2 : 0)
 }
+
+@_cdecl("swift_ASTGen_extractInlinableText")
+public func extractInlinableText(
+  astContext: BridgedASTContext,
+  sourceText: BridgedStringRef
+) -> BridgedStringRef {
+  let textBuffer = UnsafeBufferPointer<UInt8>(start: sourceText.data, count: sourceText.count)
+  var parser = Parser(textBuffer)
+  let syntax = SourceFileSyntax.parse(from: &parser)
+
+  let configuration = CompilerBuildConfiguration(
+    ctx: astContext,
+    sourceBuffer: textBuffer
+  )
+
+  // Remove any inactive #if regions.
+  let syntaxWithoutInactive = syntax.removingInactive(
+    in: configuration,
+    retainFeatureCheckIfConfigs: true
+  ).result
+
+  // Remove comments and return the result.
+  return allocateBridgedString(syntaxWithoutInactive.descriptionWithoutCommentsAndSourceLocations)
+}

lib/Sema/TypeCheckMacros.cpp

@@ -797,8 +797,7 @@ static std::string expandMacroDefinition(
     if (isExpressionReplacement) {
       auto argExpr = args->getArgExprs()[replacement.parameterIndex];
       SmallString<32> argTextBuffer;
-      auto argText =
-          extractInlinableText(ctx.SourceMgr, argExpr, argTextBuffer);
+      auto argText = extractInlinableText(ctx, argExpr, argTextBuffer);
       expandedResult.append(argText);
     } else {
       auto typeArgType = subs.getReplacementTypes()[replacement.parameterIndex];

test/ModuleInterface/if-configs.swift

@@ -178,4 +178,4 @@ public func hasIfCompilerCheck(_ x: () -> Bool = {
   return false
 #endif
   }) {
-}
+}