Merge pull request #75688 from DougGregor/swiftifconfig-replace-cpp

Use the SwiftIfConfig library for evaluating #if conditions

Author: DougGregor

include/swift/AST/ParseRequests.h

@@ -175,6 +175,23 @@ class IDEInspectionSecondPassRequest
   readDependencySource(const evaluator::DependencyRecorder &) const;
 };
 
+class EvaluateIfConditionRequest
+    : public SimpleRequest<EvaluateIfConditionRequest,
+          std::pair<bool, bool>(SourceFile *, SourceRange conditionRange,
+                                bool shouldEvaluate),
+                           RequestFlags::Uncached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  std::pair<bool, bool> evaluate(
+      Evaluator &evaluator, SourceFile *SF, SourceRange conditionRange,
+      bool shouldEvaluate) const;
+};
+
 /// The zone number for the parser.
 #define SWIFT_TYPEID_ZONE Parse
 #define SWIFT_TYPEID_HEADER "swift/AST/ParseTypeIDZone.def"

include/swift/AST/ParseTypeIDZone.def

@@ -31,3 +31,6 @@ SWIFT_REQUEST(Parse, ParseTopLevelDeclsRequest,
 SWIFT_REQUEST(Parse, ExportedSourceFileRequest,
               void *(const SourceFile *), Cached,
               NoLocationInfo)
+SWIFT_REQUEST(Parse, EvaluateIfConditionRequest,
+              (std::pair<bool, bool>)(SourceFile *, SourceRange, bool), Uncached,
+              NoLocationInfo)

include/swift/Basic/SourceLoc.h

@@ -163,6 +163,15 @@ class SourceRange {
   }
 
   SWIFT_DEBUG_DUMPER(dump(const SourceManager &SM));
+
+  friend size_t hash_value(SourceRange range) {
+    return llvm::hash_combine(range.Start, range.End);
+  }
+
+  friend void simple_display(raw_ostream &OS, const SourceRange &loc) {
+    // Nothing meaningful to print.
+  }
+
 };
 
 /// A half-open character-based source range.

lib/ASTGen/Sources/ASTGen/CompilerBuildConfiguration.swift

@@ -12,7 +12,7 @@
 
 import ASTBridging
 import SwiftDiagnostics
-import SwiftIfConfig
+@_spi(Compiler) import SwiftIfConfig
 import SwiftParser
 import SwiftSyntax
 
@@ -109,6 +109,13 @@ struct CompilerBuildConfiguration: BuildConfiguration {
 
   func isActiveTargetRuntime(name: String) throws -> Bool {
     var name = name
+
+    // Complain if the provided runtime isn't one of the known values.
+    switch name {
+    case "_Native", "_ObjC", "_multithreaded": break
+    default: throw IfConfigError.unexpectedRuntimeCondition
+    }
+
     return name.withBridgedString { nameRef in
       ctx.langOptsIsActiveTargetRuntime(nameRef)
     }
@@ -161,6 +168,18 @@ struct CompilerBuildConfiguration: BuildConfiguration {
   }
 }
 
+enum IfConfigError: Error, CustomStringConvertible {
+  case unexpectedRuntimeCondition
+
+  var description: String {
+    switch self {
+      case .unexpectedRuntimeCondition:
+        return "unexpected argument for the '_runtime' condition; expected '_Native' or '_ObjC'"
+    }
+  }
+}
+
+
 /// Extract the #if clause range information for the given source file.
 @_cdecl("swift_ASTGen_configuredRegions")
 public func configuredRegions(
@@ -301,3 +320,53 @@ public func freeConfiguredRegions(
 ) {
   UnsafeMutableBufferPointer(start: regions, count: numRegions).deallocate()
 }
+
+/// Evaluate the #if condition at ifClauseLocationPtr.
+@_cdecl("swift_ASTGen_evaluatePoundIfCondition")
+public func evaluatePoundIfCondition(
+  astContext: BridgedASTContext,
+  diagEnginePtr: UnsafeMutableRawPointer,
+  sourceFileBuffer: BridgedStringRef,
+  ifConditionText: BridgedStringRef,
+  shouldEvaluate: Bool
+) -> Int {
+  // Retrieve the #if condition that we're evaluating here.
+  // FIXME: Use 'ExportedSourceFile' when C++ parser is replaced.
+  let textBuffer = UnsafeBufferPointer<UInt8>(start: ifConditionText.data, count: ifConditionText.count)
+  var parser = Parser(textBuffer)
+  let conditionExpr = ExprSyntax.parse(from: &parser)
+
+  let isActive: Bool
+  let syntaxErrorsAllowed: Bool
+  let diagnostics: [Diagnostic]
+  if shouldEvaluate {
+    // Evaluate the condition against the compiler's build configuration.
+    let configuration = CompilerBuildConfiguration(
+      ctx: astContext,
+      sourceBuffer: textBuffer
+    )
+
+    let state: IfConfigRegionState
+    (state, syntaxErrorsAllowed, diagnostics) = IfConfigRegionState.evaluating(conditionExpr, in: configuration)
+    isActive = (state == .active)
+  } else {
+    // Don't evaluate the condition, because we know it's inactive. Determine
+    // whether syntax errors are permitted within this region according to the
+    // condition.
+    isActive = false
+    (syntaxErrorsAllowed, diagnostics) = IfConfigClauseSyntax.syntaxErrorsAllowed(conditionExpr)
+  }
+
+  // Render the diagnostics.
+  for diagnostic in diagnostics {
+    emitDiagnostic(
+      diagnosticEngine: BridgedDiagnosticEngine(raw: diagEnginePtr),
+      sourceFileBuffer: UnsafeBufferPointer(start: sourceFileBuffer.data, count: sourceFileBuffer.count),
+      sourceFileBufferOffset: ifConditionText.data! - sourceFileBuffer.data!,
+      diagnostic: diagnostic,
+      diagnosticSeverity: diagnostic.diagMessage.severity
+    )
+  }
+
+  return (isActive ? 0x1 : 0) | (syntaxErrorsAllowed ? 0x2 : 0)
+}

lib/Parse/ParseIfConfig.cpp

@@ -16,6 +16,7 @@
 
 #include "swift/Parse/Parser.h"
 
+#include "swift/AST/ASTBridging.h"
 #include "swift/AST/ASTVisitor.h"
 #include "swift/AST/DiagnosticSuppression.h"
 #include "swift/Basic/Assertions.h"
@@ -766,6 +767,26 @@ static Expr *findAnyLikelySimulatorEnvironmentTest(Expr *Condition) {
 
 } // end anonymous namespace
 
+/// Call into the Swift implementation of #if condition evaluation.
+///
+/// \returns std::nullopt if the Swift implementation is not available, or
+/// a pair (isActive, allowSyntaxErrors) describing whether the evaluated
+/// condition indicates that the region is active and whether, if inactive,
+/// the code in that region is allowed to have syntax errors.
+static std::optional<std::pair<bool, bool>> evaluateWithSwiftIfConfig(
+    Parser &parser,
+    SourceRange conditionRange,
+    bool shouldEvaluate
+) {
+#if SWIFT_BUILD_SWIFT_SYNTAX
+  return evaluateOrDefault(
+      parser.Context.evaluator,
+      EvaluateIfConditionRequest{&parser.SF, conditionRange, shouldEvaluate},
+      std::pair(false, false));
+#else
+  return std::nullopt;
+#endif
+}
 
 /// Parse and populate a #if ... #endif directive.
 /// Delegate callback function to parse elements in the blocks.
@@ -842,7 +863,15 @@ Result Parser::parseIfConfigRaw(
       if (result.isNull())
         return makeParserError();
       Condition = result.get();
-      if (validateIfConfigCondition(Condition, Context, Diags)) {
+      if (std::optional<std::pair<bool, bool>> evalResult =
+              evaluateWithSwiftIfConfig(*this,
+                                        Condition->getSourceRange(),
+                                        shouldEvaluate)) {
+        if (!foundActive) {
+          isActive = evalResult->first;
+          isVersionCondition = evalResult->second;
+        }
+      } else if (validateIfConfigCondition(Condition, Context, Diags)) {
         // Error in the condition;
         isActive = false;
         isVersionCondition = false;

lib/Sema/TypeChecker.cpp

@@ -23,6 +23,7 @@
 #include "TypeCheckType.h"
 #include "CodeSynthesis.h"
 #include "MiscDiagnostics.h"
+#include "swift/AST/ASTBridging.h"
 #include "swift/AST/ASTWalker.h"
 #include "swift/AST/ASTVisitor.h"
 #include "swift/AST/Attr.h"
@@ -765,3 +766,31 @@ bool TypeChecker::diagnoseInvalidFunctionType(
 
   return hadAnyError;
 }
+
+extern "C" intptr_t swift_ASTGen_evaluatePoundIfCondition(
+                        BridgedASTContext astContext,
+                        void *_Nonnull diagEngine,
+                        BridgedStringRef sourceFileBuffer,
+                        BridgedStringRef conditionText,
+                        bool);
+
+std::pair<bool, bool> EvaluateIfConditionRequest::evaluate(
+    Evaluator &evaluator, SourceFile *sourceFile, SourceRange conditionRange,
+    bool shouldEvaluate
+) const {
+  // FIXME: When we migrate to SwiftParser, use the parsed syntax tree.
+  ASTContext &ctx = sourceFile->getASTContext();
+  auto &sourceMgr = ctx.SourceMgr;
+  StringRef sourceFileText =
+      sourceMgr.getEntireTextForBuffer(*sourceFile->getBufferID());
+  StringRef conditionText =
+      sourceMgr.extractText(Lexer::getCharSourceRangeFromSourceRange(
+          sourceMgr, conditionRange));
+  intptr_t evalResult = swift_ASTGen_evaluatePoundIfCondition(
+      ctx, &ctx.Diags, sourceFileText, conditionText, shouldEvaluate
+  );
+
+  bool isActive = (evalResult & 0x01) != 0;
+  bool allowSyntaxErrors = (evalResult & 0x02) != 0;
+  return std::pair(isActive, allowSyntaxErrors);
+}

test/Parse/ConditionalCompilation/basicParseErrors.swift

@@ -8,7 +8,7 @@ var x = 0
 var y = 0
 #endif
 
-#if foo(BAR) // expected-error {{unexpected platform condition (expected 'os', 'arch', or 'swift')}}
+#if foo(BAR) // expected-error {{invalid conditional compilation expression}}
 var z = 0
 #endif
 
@@ -27,7 +27,7 @@ func h() {}
 #else /* aaa */
 #endif /* bbb */
 
-#if foo.bar() // expected-error {{unexpected platform condition (expected 'os', 'arch', or 'swift')}}
+#if foo.bar() // expected-error {{invalid conditional compilation expression}}
       .baz()
 
 #endif
@@ -67,30 +67,23 @@ struct S {
 #else
 #endif
 
-#if os(ios) // expected-warning {{unknown operating system for build configuration 'os'}} expected-note{{did you mean 'iOS'?}} {{8-11=iOS}}
+#if os(ios)
 #endif
 
-#if os(uOS) // expected-warning {{unknown operating system for build configuration 'os'}} expected-note{{did you mean 'iOS'?}} {{8-11=iOS}}
+#if os(uOS)
 #endif
 
-#if os(xxxxxxd) // expected-warning {{unknown operating system for build configuration 'os'}}
-// expected-note@-1{{did you mean 'Linux'?}} {{8-15=Linux}}
-// expected-note@-2{{did you mean 'FreeBSD'?}} {{8-15=FreeBSD}}
-// expected-note@-3{{did you mean 'Android'?}} {{8-15=Android}}
-// expected-note@-4{{did you mean 'OSX'?}} {{8-15=OSX}}
-// expected-note@-5{{did you mean 'OpenBSD'?}} {{8-15=OpenBSD}}
-// expected-note@-6{{did you mean 'xrOS'?}} {{8-15=xrOS}}
+#if os(xxxxxxd)
 #endif
 
-#if os(bisionos) // expected-warning {{unknown operating system for build configuration 'os'}}
-// expected-note@-1{{did you mean 'visionOS'?}} {{8-16=visionOS}}
+#if os(bisionos)
 
 #endif
 
-#if arch(arn) // expected-warning {{unknown architecture for build configuration 'arch'}} expected-note{{did you mean 'arm'?}} {{10-13=arm}}
+#if arch(arn)
 #endif
 
-#if _endian(mid) // expected-warning {{unknown endianness for build configuration '_endian'}} expected-note{{did you mean 'big'?}} {{13-16=big}}
+#if _endian(mid) // expected-warning {{unknown endianness for build configuration '_endian'}}
 #endif
 
 LABEL: #if true // expected-error {{expected statement}}
@@ -104,7 +97,7 @@ func fn_j() {}
 #endif
 fn_j() // OK
 
-#if foo || bar || nonExistent() // expected-error {{expected argument to platform condition}}
+#if foo || bar || nonExistent() // expected-error {{invalid conditional compilation expression}}
 #endif
 
 #if FOO = false
@@ -123,47 +116,33 @@ undefinedFunc() // expected-error {{cannot find 'undefinedFunc' in scope}}
 #endif
 
 /// Invalid platform condition arguments don't invalidate the whole condition.
+// expected-warning@+1{{unknown endianness}}
 #if !arch(arn) && !os(ystem) && !_endian(ness)
-// expected-warning@-1 {{unknown architecture for build configuration 'arch'}}
-// expected-note@-2 {{did you mean 'arm'?}} {{11-14=arm}}
-// expected-warning@-3 {{unknown operating system for build configuration 'os'}}
-// expected-note@-4 {{did you mean 'OSX'?}} {{23-28=OSX}}
-// expected-note@-5 {{did you mean 'PS4'?}} {{23-28=PS4}}
-// expected-note@-6 {{did you mean 'none'?}} {{23-28=none}}
-// expected-warning@-7 {{unknown endianness for build configuration '_endian'}}
-// expected-note@-8 {{did you mean 'big'?}} {{42-46=big}}
 func fn_k() {}
 #endif
 fn_k()
 
 #if os(cillator) || arch(i3rm)
-// expected-warning@-1 {{unknown operating system for build configuration 'os'}}
-// expected-note@-2 {{did you mean 'macOS'?}} {{8-16=macOS}}
-// expected-note@-3 {{did you mean 'iOS'?}} {{8-16=iOS}}
-// expected-warning@-4 {{unknown architecture for build configuration 'arch'}}
-// expected-note@-5 {{did you mean 'arm'?}} {{26-30=arm}}
-// expected-note@-6 {{did you mean 'i386'?}} {{26-30=i386}}
-// expected-note@-7 {{did you mean 'visionOS'?}} {{8-16=visionOS}}
 func undefinedFunc() // ignored.
 #endif
 undefinedFunc() // expected-error {{cannot find 'undefinedFunc' in scope}}
 
-#if os(simulator) // expected-warning {{unknown operating system for build configuration 'os'}} expected-note {{did you mean 'targetEnvironment'}} {{5-7=targetEnvironment}}
+#if os(simulator)
 #endif
 
-#if arch(iOS) // expected-warning {{unknown architecture for build configuration 'arch'}} expected-note {{did you mean 'os'}} {{5-9=os}}
+#if arch(iOS)
 #endif
 
-#if _endian(arm64) // expected-warning {{unknown endianness for build configuration '_endian'}} expected-note {{did you mean 'arch'}} {{5-12=arch}}
+#if _endian(arm64) // expected-warning {{unknown endianness for build configuration '_endian'}}
 #endif
 
-#if targetEnvironment(_ObjC) // expected-warning {{unknown target environment for build configuration 'targetEnvironment'}} expected-note {{did you mean 'macabi'}} {{23-28=macabi}}
+#if targetEnvironment(_ObjC)
 #endif
 
-#if os(iOS) || os(simulator) // expected-warning {{unknown operating system for build configuration 'os'}} expected-note {{did you mean 'targetEnvironment'}} {{16-18=targetEnvironment}}
+#if os(iOS) || os(simulator)
 #endif
 
-#if arch(ios) // expected-warning {{unknown architecture for build configuration 'arch'}} expected-note {{did you mean 'os'}} {{5-9=os}} expected-note {{did you mean 'iOS'}} {{10-13=iOS}}
+#if arch(ios)
 #endif
 
 #if FOO
@@ -179,5 +158,5 @@ if true {}
 
 // rdar://83017601 Make sure we don't crash
 #if canImport()
-// expected-error@-1 {{expected argument to platform condition}}
+// expected-error@-1 {{'canImport' requires a module name}}
 #endif

test/Parse/ConditionalCompilation/can_import_in_inactive.swift

@@ -21,7 +21,7 @@
 #endif
 
 #if canImport(SomeModule)
-// CHECK: :[[@LINE-1]]:15: error: could not find module 'SomeModule' for target '{{.*}}'; found: i386
+// CHECK: :[[@LINE-1]]:{{.*}}: error: could not find module 'SomeModule' for target '{{.*}}'; found: i386
 #endif
 
 import SomeModule

test/Parse/ConditionalCompilation/can_import_submodule.swift

@@ -48,17 +48,17 @@ import A.B.C
 #endif
 
 
-#if canImport(A(_:).B) // expected-error@:15 {{unexpected platform condition argument: expected module name}}
+#if canImport(A(_:).B) // expected-error@:15 {{expected module name}}
 #endif
 
-#if canImport(A.B(c: "arg")) // expected-error@:15 {{unexpected platform condition argument: expected module name}}
+#if canImport(A.B(c: "arg")) // expected-error@:15 {{expected module name}}
 #endif
 
-#if canImport(A(b: 1, c: 2).B.C) // expected-error@:15 {{unexpected platform condition argument: expected module name}}
+#if canImport(A(b: 1, c: 2).B.C) // expected-error@:15 {{expected module name}}
 #endif
 
-#if canImport(A.B("arg")(3).C) // expected-error@:15 {{unexpected platform condition argument: expected module name}}
+#if canImport(A.B("arg")(3).C) // expected-error@:15 {{expected module name}}
 #endif
 
-#if canImport(A.B.C()) // expected-error@:15 {{unexpected platform condition argument: expected module name}}
+#if canImport(A.B.C()) // expected-error@:15 {{expected module name}}
 #endif