[Macros] Pass a static build configuration to macro implementations

include/swift/AST/ASTBridging.h

@@ -58,6 +58,7 @@ class IfConfigClauseRangeInfo;
 class GenericSignature;
 class GenericSignatureImpl;
 struct LabeledStmtInfo;
+class LangOptions;
 class LayoutConstraint;
 class LayoutConstraintInfo;
 struct LifetimeDescriptor;
@@ -82,6 +83,7 @@ enum class RequirementReprKind : unsigned;
 struct BridgedASTType;
 class BridgedCanType;
 class BridgedASTContext;
+class BridgedLangOptions;
 struct BridgedSubstitutionMap;
 struct BridgedGenericSignature;
 struct BridgedConformance;
@@ -192,15 +194,11 @@ BridgedDeclNameLoc_createParsed(BridgedASTContext cContext,
                                 swift::SourceLoc moduleSelectorLoc,
                                 swift::SourceLoc baseNameLoc);
 
+
 //===----------------------------------------------------------------------===//
 // MARK: ASTContext
 //===----------------------------------------------------------------------===//
 
-enum ENUM_EXTENSIBILITY_ATTR(closed) BridgedEndianness : size_t {
-  EndianLittle,
-  EndianBig,
-};
-
 class BridgedASTContext {
   swift::ASTContext * _Nonnull Ctx;
 
@@ -218,16 +216,10 @@ class BridgedASTContext {
   unsigned getMajorLanguageVersion() const;
 
   SWIFT_COMPUTED_PROPERTY
-  unsigned getLangOptsTargetPointerBitWidth() const;
-
-  SWIFT_COMPUTED_PROPERTY
-  bool getLangOptsAttachCommentsToDecls() const;
-
-  SWIFT_COMPUTED_PROPERTY
-  BridgedEndianness getLangOptsTargetEndianness() const;
+  BridgedAvailabilityMacroMap getAvailabilityMacroMap() const;
 
   SWIFT_COMPUTED_PROPERTY
-  BridgedAvailabilityMacroMap getAvailabilityMacroMap() const;
+  BridgedDiagnosticEngine getDiags() const;
 };
 
 #define IDENTIFIER_WITH_NAME(Name, _)                                          \
@@ -259,56 +251,12 @@ SWIFT_NAME("BridgedASTContext.getDollarIdentifier(self:_:)")
 swift::Identifier
 BridgedASTContext_getDollarIdentifier(BridgedASTContext cContext, size_t idx);
 
-SWIFT_NAME("BridgedASTContext.langOptsHasFeature(self:_:)")
-bool BridgedASTContext_langOptsHasFeature(BridgedASTContext cContext,
-                                          BridgedFeature feature);
-
-SWIFT_NAME("BridgedASTContext.langOptsCustomConditionSet(self:_:)")
-bool BridgedASTContext_langOptsCustomConditionSet(BridgedASTContext cContext,
-                                                  BridgedStringRef cName);
-
-SWIFT_NAME("BridgedASTContext.langOptsHasFeatureNamed(self:_:)")
-bool BridgedASTContext_langOptsHasFeatureNamed(BridgedASTContext cContext,
-                                               BridgedStringRef cName);
+SWIFT_NAME("getter:BridgedASTContext.langOpts(self:)")
+BridgedLangOptions BridgedASTContext_langOpts(BridgedASTContext cContext);
 
-SWIFT_NAME("BridgedASTContext.langOptsHasAttributeNamed(self:_:)")
-bool BridgedASTContext_langOptsHasAttributeNamed(BridgedASTContext cContext,
-                                                 BridgedStringRef cName);
-
-SWIFT_NAME("BridgedASTContext.langOptsIsActiveTargetOS(self:_:)")
-bool BridgedASTContext_langOptsIsActiveTargetOS(BridgedASTContext cContext,
-                                                BridgedStringRef cName);
-
-SWIFT_NAME("BridgedASTContext.langOptsIsActiveTargetArchitecture(self:_:)")
-bool BridgedASTContext_langOptsIsActiveTargetArchitecture(BridgedASTContext cContext,
-                                                          BridgedStringRef cName);
-
-SWIFT_NAME("BridgedASTContext.langOptsIsActiveTargetEnvironment(self:_:)")
-bool BridgedASTContext_langOptsIsActiveTargetEnvironment(BridgedASTContext cContext,
-                                                         BridgedStringRef cName);
-
-SWIFT_NAME("BridgedASTContext.langOptsIsActiveTargetRuntime(self:_:)")
-bool BridgedASTContext_langOptsIsActiveTargetRuntime(BridgedASTContext cContext,
-                                                     BridgedStringRef cName);
-
-SWIFT_NAME("BridgedASTContext.langOptsIsActiveTargetPtrAuth(self:_:)")
-bool BridgedASTContext_langOptsIsActiveTargetPtrAuth(BridgedASTContext cContext,
-                                                     BridgedStringRef cName);
-
-SWIFT_NAME("BridgedASTContext.langOptsGetTargetAtomicBitWidths(self:_:)")
-SwiftInt BridgedASTContext_langOptsGetTargetAtomicBitWidths(BridgedASTContext cContext,
-                                                      SwiftInt* _Nullable * _Nonnull cComponents);
-
-SWIFT_NAME("BridgedASTContext.langOptsGetLanguageVersion(self:_:)")
-SwiftInt BridgedASTContext_langOptsGetLanguageVersion(BridgedASTContext cContext,
-                                                      SwiftInt* _Nullable * _Nonnull cComponents);
-
-SWIFT_NAME("BridgedASTContext.langOptsGetCompilerVersion(self:_:)")
-SwiftInt BridgedASTContext_langOptsGetCompilerVersion(BridgedASTContext cContext,
-                                                      SwiftInt* _Nullable * _Nonnull cComponents);
-
-/* Deallocate an array of Swift int values that was allocated in C++. */
-void deallocateIntBuffer(SwiftInt * _Nullable cComponents);
+SWIFT_NAME("BridgedLangOptions.hasAttributeNamed(self:_:)")
+bool BridgedLangOptions_hasAttributeNamed(BridgedLangOptions cLangOpts,
+                                          BridgedStringRef cName);
 
 enum ENUM_EXTENSIBILITY_ATTR(closed) BridgedCanImportVersion : size_t {
   CanImportUnversioned,
@@ -324,6 +272,9 @@ bool BridgedASTContext_canImport(BridgedASTContext cContext,
                                  const SwiftInt *_Nullable versionComponents,
                                  SwiftInt numVersionComponents);
 
+SWIFT_NAME("getter:BridgedASTContext.staticBuildConfigurationPtr(self:)")
+void * _Nonnull BridgedASTContext_staticBuildConfiguration(BridgedASTContext cContext);
+
 //===----------------------------------------------------------------------===//
 // MARK: AST nodes
 //===----------------------------------------------------------------------===//

include/swift/AST/ASTBridgingImpl.h

@@ -66,6 +66,17 @@ swift::DeclNameLoc BridgedDeclNameLoc::unbridged() const {
   return swift::DeclNameLoc(LocationInfo, NumArgumentLabels);
 }
 
+//===----------------------------------------------------------------------===//
+// MARK: BridgedLangOptions
+//===----------------------------------------------------------------------===//
+
+BridgedLangOptions::BridgedLangOptions(const swift::LangOptions &langOpts)
+  : LangOpts(&langOpts) { }
+
+const swift::LangOptions &BridgedLangOptions::unbridged() const {
+  return *LangOpts;
+}
+
 //===----------------------------------------------------------------------===//
 // MARK: BridgedASTContext
 //===----------------------------------------------------------------------===//

include/swift/AST/ASTContextGlobalCache.h

@@ -84,6 +84,10 @@ struct ASTContext::GlobalCache {
     const NormalProtocolConformance *,
     std::vector<ConformanceIsolationError>
   > conformanceIsolationErrors;
+
+  /// The static build configuration. This points to an instance of the Swift
+  /// StaticBuildConfiguration.
+  void *StaticBuildConfiguration = nullptr;
 };
 
 } // end namespace 

include/swift/Basic/BasicBridging.h

@@ -61,6 +61,7 @@ class VersionTuple;
 } // end namespace llvm
 
 namespace swift {
+class LangOptions;
 class SourceLoc;
 class SourceRange;
 class CharSourceRange;
@@ -451,6 +452,84 @@ struct BridgedSwiftClosure {
   BRIDGED_INLINE void operator()(const void *_Nullable);
 };
 
+//===----------------------------------------------------------------------===//
+// MARK: LangOptions
+//===----------------------------------------------------------------------===//
+
+enum ENUM_EXTENSIBILITY_ATTR(closed) BridgedEndianness : size_t {
+  EndianLittle,
+  EndianBig,
+};
+
+class BridgedLangOptions {
+  const swift::LangOptions * _Nonnull LangOpts;
+
+public:
+  SWIFT_UNAVAILABLE("Use init(raw:) instead")
+  BRIDGED_INLINE BridgedLangOptions(const swift::LangOptions &langOpts);
+
+  SWIFT_UNAVAILABLE("Use '.raw' instead")
+  BRIDGED_INLINE const swift::LangOptions &unbridged() const;
+
+  SWIFT_COMPUTED_PROPERTY
+  const void *_Nonnull getRaw() const { return LangOpts; }
+
+  SWIFT_COMPUTED_PROPERTY
+  unsigned getMajorLanguageVersion() const;
+
+  SWIFT_COMPUTED_PROPERTY
+  unsigned getTargetPointerBitWidth() const;
+
+  SWIFT_COMPUTED_PROPERTY
+  BridgedEndianness getTargetEndianness() const;
+
+  SWIFT_COMPUTED_PROPERTY
+  bool getAttachCommentsToDecls() const;
+};
+
+/// Key used when enumerating build configuration entries to the
+/// StaticBuildConfiguration initializer for an ASTContext.
+enum ENUM_EXTENSIBILITY_ATTR(closed) BuildConfigurationKey : size_t {
+  BCKCustomCondition,
+  BCKFeature,
+  BCKAttribute,
+  BCKTargetOSName,
+  BCKTargetArchitecture,
+  BCKTargetEnvironment,
+  BCKTargetRuntime,
+  BCKTargetPointerAuthenticationScheme,
+  BCKTargetObjectFileFormat
+};
+
+SWIFT_NAME("BridgedLangOptions.hasFeature(self:_:)")
+bool BridgedLangOptions_hasFeature(BridgedLangOptions cLangOpts,
+                                   BridgedFeature feature);
+
+SWIFT_NAME("BridgedLangOptions.getTargetAtomicBitWidths(self:_:)")
+SwiftInt BridgedLangOptions_getTargetAtomicBitWidths(BridgedLangOptions cLangOpts,
+                                                     SwiftInt* _Nullable * _Nonnull cComponents);
+
+SWIFT_NAME("BridgedLangOptions.getLanguageVersion(self:_:)")
+SwiftInt BridgedLangOptions_getLanguageVersion(BridgedLangOptions cLangOpts,
+                                               SwiftInt* _Nullable * _Nonnull cComponents);
+
+SWIFT_NAME("BridgedLangOptions.getCompilerVersion(self:_:)")
+SwiftInt BridgedLangOptions_getCompilerVersion(BridgedLangOptions cLangOpts,
+                                               SwiftInt* _Nullable * _Nonnull cComponents);
+
+/* Deallocate an array of Swift int values that was allocated in C++. */
+void deallocateIntBuffer(SwiftInt * _Nullable cComponents);
+
+/// Enumerate all of the key/value pairs for the build configuration by calling
+/// the given callback for each one.
+SWIFT_NAME("BridgedLangOptions.enumerateBuildConfigurationEntries(self:callbackContext:callback:)")
+void BridgedLangOptions_enumerateBuildConfigurationEntries(
+    BridgedLangOptions cLangOpts,
+    void * _Nonnull callbackContext,
+    void (* _Nonnull callback)(
+        BridgedLangOptions cLangOpts, void * _Nonnull callbackContext,
+        BuildConfigurationKey key, BridgedStringRef value));
+
 SWIFT_END_NULLABILITY_ANNOTATIONS
 
 #ifndef PURE_BRIDGING_MODE

include/swift/Bridging/BasicSwift.h

@@ -0,0 +1,32 @@
+//===--- BasicSwift.h -------------------------------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2023 - 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_BRIDGING_BASICSWIFT_H
+#define SWIFT_BRIDGING_BASICSWIFT_H
+
+#include "swift/Basic/BasicBridging.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/// Create a new static build configuration for the given language options.
+void * _Nonnull swift_Basic_createStaticBuildConfiguration(BridgedLangOptions cLangOpts);
+
+/// Free the given static build configuration.
+void swift_Basic_freeStaticBuildConfiguration(void * _Nonnull staticBuildConfiguration);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // SWIFT_BRIDGING_BASICSWIFT_H

include/swift/Bridging/MacroEvaluation.h

@@ -14,6 +14,7 @@
 #define SWIFT_BRIDGING_MACROS_H
 
 #include "swift/Basic/BasicBridging.h"
+#include "swift/AST/ASTBridging.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -40,13 +41,13 @@ void swift_Macros_freeExpansionReplacements(
     ptrdiff_t *_Nullable replacementsPtr, ptrdiff_t numReplacements);
 
 ptrdiff_t swift_Macros_expandFreestandingMacro(
-    void *_Nonnull diagEngine, const void *_Nonnull macro,
+    BridgedASTContext cContext, const void *_Nonnull macro,
     const char *_Nonnull discriminator, uint8_t rawMacroRole,
     void *_Nonnull sourceFile, const void *_Nullable sourceLocation,
     BridgedStringRef *_Nonnull evaluatedSourceOut);
 
 ptrdiff_t swift_Macros_expandAttachedMacro(
-    void *_Nonnull diagEngine, const void *_Nonnull macro,
+    BridgedASTContext cContext, const void *_Nonnull macro,
     const char *_Nonnull discriminator, const char *_Nonnull qualifiedType,
     const char *_Nonnull conformances, uint8_t rawMacroRole,
     void *_Nonnull customAttrSourceFile,

include/swift/Frontend/FrontendOptions.h

@@ -326,6 +326,10 @@ class FrontendOptions {
   /// exit.
   bool PrintTargetInfo = false;
 
+  /// Indicates that the frontend should print the static build configuration
+  /// information as JSON.
+  bool PrintBuildConfig = false;
+
   /// Indicates that the frontend should print the supported features and then
   /// exit.
   bool PrintSupportedFeatures = false;

include/swift/Option/Options.td

@@ -1542,6 +1542,9 @@ def target_legacy_spelling : Joined<["--"], "target=">,
 def print_target_info : Flag<["-"], "print-target-info">,
     Flags<[FrontendOption]>,
     HelpText<"Print target information for the given target <triple>, such as x86_64-apple-macos10.9">, MetaVarName<"<triple>">;
+def print_static_build_config : Flag<["-"], "print-static-build-config">,
+    Flags<[FrontendOption]>,
+    HelpText<"Print static build configuration that can be used to evaluate #ifs in Swift source code">;
 
 def print_supported_features : Flag<["-"], "print-supported-features">,
     Flags<[FrontendOption]>,