[ClangImporter] Query Preprocessor::macros instead of getPreprocessingRecord for header printing

This better matches what the clang importer does
normally, avoids a Clang issue where
`getPreprocessedEntitiesInRange` returns incorrect
results, and avoids the need to enable the
preprocessor record. This then lets us re-enable
`print_clang_headers.swift`.

rdar://102151774

Author: hamishknight

lib/ClangImporter/ClangImporter.cpp

@@ -3029,33 +3029,26 @@ bool ClangImporter::lookupDeclsFromHeader(StringRef Filename,
     }
 
     // Macros.
-    if (auto *ppRec = ClangPP.getPreprocessingRecord()) {
-      clang::SourceLocation B = ClangSM.getLocForStartOfFile(FID);
-      clang::SourceLocation E = ClangSM.getLocForEndOfFile(FID);
-      clang::SourceRange R(B, E);
-      const auto &Entities = ppRec->getPreprocessedEntitiesInRange(R);
-      for (auto I = Entities.begin(), E = Entities.end(); I != E; ++I) {
-        if (!ppRec->isEntityInFileID(I, FID))
-          continue;
-        clang::PreprocessedEntity *PPE = *I;
-        if (!PPE)
-          continue;
-        if (auto *MDR = dyn_cast<clang::MacroDefinitionRecord>(PPE)) {
-          auto *II = const_cast<clang::IdentifierInfo*>(MDR->getName());
-          auto MD = ClangPP.getMacroDefinition(II);
-          if (auto macroNode = getClangNodeForMacroDefinition(MD)) {
-            if (filter(macroNode)) {
-              auto MI = macroNode.getAsMacro();
-              Identifier Name = Impl.getNameImporter().importMacroName(II, MI);
-              if (Decl *imported = Impl.importMacro(Name, macroNode))
-                receiver(imported);
-            }
-          }
-        }
-      }
+    for (const auto &Iter : ClangPP.macros()) {
+      auto *II = Iter.first;
+      auto MD = ClangPP.getMacroDefinition(II);
+      MD.forAllDefinitions([&](clang::MacroInfo *Info) {
+        if (Info->isBuiltinMacro())
+          return;
+
+        auto Loc = Info->getDefinitionLoc();
+        if (Loc.isInvalid() || ClangSM.getFileID(Loc) != FID)
+          return;
 
-      // FIXME: Module imports inside that header.
+        ClangNode MacroNode = Info;
+        if (filter(MacroNode)) {
+          auto Name = Impl.getNameImporter().importMacroName(II, Info);
+          if (auto *Imported = Impl.importMacro(Name, MacroNode))
+            receiver(Imported);
+        }
+      });
     }
+    // FIXME: Module imports inside that header.
     return false;
   }
 

test/IDE/Inputs/print_clang_header/header-to-print.h

@@ -7,6 +7,9 @@
 #undef MACRO_GOT_UNDEFINED
 #define MY_MACRO 1
 
+#define MACRO_DUP 2
+#define MACRO_DUP 3
+
 void doSomethingInHead(int arg);
 
 @interface BaseInHead

test/IDE/Inputs/print_clang_header/header-to-print.h.command-line-include.printed.txt

@@ -4,6 +4,8 @@ import Dispatch
 
 var MY_MACRO: Int32 { get }
 
+var MACRO_DUP: Int32 { get }
+
 func doSomethingInHead(_ arg: Int32)
 
 class BaseInHead {

test/IDE/Inputs/print_clang_header/header-to-print.h.module.printed.txt

@@ -1,6 +1,8 @@
 
 var MY_MACRO: Int32 { get }
 
+var MACRO_DUP: Int32 { get }
+
 func doSomethingInHead(_ arg: Int32)
 
 class BaseInHead {

test/IDE/Inputs/print_clang_header/header-to-print.h.printed.txt

@@ -4,6 +4,8 @@ import Dispatch
 
 var MY_MACRO: Int32 { get }
 
+var MACRO_DUP: Int32 { get }
+
 func doSomethingInHead(_ arg: Int32)
 
 class BaseInHead {

test/IDE/print_clang_header.swift

@@ -1,8 +1,6 @@
 // FIXME: rdar://problem/19648117 Needs splitting objc parts out
 // REQUIRES: objc_interop
 
-// REQUIRES: rdar102151774
-
 // RUN: echo '#include "header-to-print.h"' > %t.m
 // RUN: %target-swift-ide-test(mock-sdk: %clang-importer-sdk) -source-filename %s -print-header -header-to-print %S/Inputs/print_clang_header/header-to-print.h -print-regular-comments -enable-objc-interop -disable-objc-attr-requires-foundation-module --cc-args %target-cc-options -isysroot %clang-importer-sdk-path -fsyntax-only %t.m -I %S/Inputs/print_clang_header > %t.txt
 // RUN: diff -u %S/Inputs/print_clang_header/header-to-print.h.printed.txt %t.txt
@@ -19,9 +17,6 @@
 // RUN: %target-swift-ide-test(mock-sdk: %clang-importer-sdk) -source-filename %s -print-header -header-to-print %S/Inputs/print_clang_header/header-to-print.h -print-regular-comments -enable-objc-interop -disable-objc-attr-requires-foundation-module --cc-args %target-cc-options -isysroot %clang-importer-sdk-path -fsyntax-only %t.framework.m -F %t -ivfsoverlay %t.yaml -Xclang -fmodule-name=Foo > %t.framework.txt
 // RUN: diff -u %S/Inputs/print_clang_header/header-to-print.h.printed.txt %t.framework.txt
 
-// Test header interface printing from a clang module, with the preprocessing record enabled before the CC args.
-// RUN: %target-swift-ide-test(mock-sdk: %clang-importer-sdk) -source-filename %s -print-header -header-to-print %S/Inputs/print_clang_header/header-to-print.h -print-regular-comments -Xcc -Xclang -Xcc -detailed-preprocessing-record -enable-objc-interop -disable-objc-attr-requires-foundation-module --cc-args %target-cc-options -isysroot %clang-importer-sdk-path -fsyntax-only %t.framework.m -F %t -ivfsoverlay %t.yaml > %t.module.txt
+// Test header interface printing from a clang module.
+// RUN: %target-swift-ide-test(mock-sdk: %clang-importer-sdk) -source-filename %s -print-header -header-to-print %S/Inputs/print_clang_header/header-to-print.h -print-regular-comments -enable-objc-interop -disable-objc-attr-requires-foundation-module --cc-args %target-cc-options -isysroot %clang-importer-sdk-path -fsyntax-only %t.framework.m -F %t -ivfsoverlay %t.yaml > %t.module.txt
 // RUN: diff -u %S/Inputs/print_clang_header/header-to-print.h.module.printed.txt %t.module.txt
-// Test header interface printing from a clang module, with the preprocessing record enabled by the CC args.
-// RUN: %target-swift-ide-test(mock-sdk: %clang-importer-sdk) -source-filename %s -print-header -header-to-print %S/Inputs/print_clang_header/header-to-print.h -print-regular-comments -enable-objc-interop -disable-objc-attr-requires-foundation-module --cc-args %target-cc-options -isysroot %clang-importer-sdk-path -fsyntax-only %t.framework.m -F %t -ivfsoverlay %t.yaml -Xclang -detailed-preprocessing-record > %t.module2.txt
-// RUN: diff -u %S/Inputs/print_clang_header/header-to-print.h.module.printed.txt %t.module2.txt