[clang-tools-extra] c3ad4b7 - [include-cleaner] Follow `IWYU pragma: export` links transitively.

[Viktoriia Bakalova via cfe-commits]

Author: Viktoriia Bakalova
Date: 2023-08-09T12:10:13Z
New Revision: c3ad4b7636022db387e33ab03247a93aa63d7488

URL: https://github.com/llvm/llvm-project/commit/c3ad4b7636022db387e33ab03247a93aa63d7488
DIFF: https://github.com/llvm/llvm-project/commit/c3ad4b7636022db387e33ab03247a93aa63d7488.diff

LOG: [include-cleaner] Follow `IWYU pragma: export` links transitively.

Differential Revision: https://reviews.llvm.org/D157395

Added: 
    

Modified: 
    clang-tools-extra/include-cleaner/lib/FindHeaders.cpp
    clang-tools-extra/include-cleaner/lib/Record.cpp
    clang-tools-extra/include-cleaner/unittests/FindHeadersTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/include-cleaner/lib/FindHeaders.cpp b/clang-tools-extra/include-cleaner/lib/FindHeaders.cpp
index a1d9d3b5fb2154..f9438a2c8c49e4 100644
--- a/clang-tools-extra/include-cleaner/lib/FindHeaders.cpp
+++ b/clang-tools-extra/include-cleaner/lib/FindHeaders.cpp
@@ -25,6 +25,8 @@
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <optional>
+#include <queue>
+#include <set>
 #include <utility>
 
 namespace clang::include_cleaner {
@@ -188,13 +190,13 @@ llvm::SmallVector<Hinted<Header>> findHeaders(const SymbolLocation &Loc,
     if (!PI)
       return {{FE, Hints::PublicHeader | Hints::OriginHeader}};
     bool IsOrigin = true;
+    std::queue<const FileEntry *> Exporters;
     while (FE) {
       Results.emplace_back(FE,
                            isPublicHeader(FE, *PI) |
                                (IsOrigin ? Hints::OriginHeader : Hints::None));
-      // FIXME: compute transitive exporter headers.
       for (const auto *Export : PI->getExporters(FE, SM.getFileManager()))
-        Results.emplace_back(Export, isPublicHeader(Export, *PI));
+        Exporters.push(Export);
 
       if (auto Verbatim = PI->getPublic(FE); !Verbatim.empty()) {
         Results.emplace_back(Verbatim,
@@ -209,6 +211,20 @@ llvm::SmallVector<Hinted<Header>> findHeaders(const SymbolLocation &Loc,
       FE = SM.getFileEntryForID(FID);
       IsOrigin = false;
     }
+    // Now traverse provider trees rooted at exporters.
+    // Note that we only traverse export edges, and ignore private -> public
+    // mappings, as those pragmas apply to exporter, and not the main provider
+    // being exported in this header.
+    std::set<const FileEntry *> SeenExports;
+    while (!Exporters.empty()) {
+      auto *Export = Exporters.front();
+      Exporters.pop();
+      if (!SeenExports.insert(Export).second) // In case of cyclic exports
+        continue;
+      Results.emplace_back(Export, isPublicHeader(Export, *PI));
+      for (const auto *Export : PI->getExporters(Export, SM.getFileManager()))
+        Exporters.push(Export);
+    }
     return Results;
   }
   case SymbolLocation::Standard: {

diff  --git a/clang-tools-extra/include-cleaner/lib/Record.cpp b/clang-tools-extra/include-cleaner/lib/Record.cpp
index 62eaa16dbf3373..d7237325f701bb 100644
--- a/clang-tools-extra/include-cleaner/lib/Record.cpp
+++ b/clang-tools-extra/include-cleaner/lib/Record.cpp
@@ -12,6 +12,7 @@
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclGroup.h"
 #include "clang/Basic/FileEntry.h"
+#include "clang/Basic/FileManager.h"
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
@@ -24,16 +25,21 @@
 #include "clang/Tooling/Inclusions/HeaderAnalysis.h"
 #include "clang/Tooling/Inclusions/StandardLibrary.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/iterator_range.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/Error.h"
+#include "llvm/Support/FileSystem/UniqueID.h"
 #include "llvm/Support/StringSaver.h"
 #include <algorithm>
 #include <assert.h>
 #include <memory>
 #include <optional>
+#include <set>
 #include <utility>
 #include <vector>
 

diff  --git a/clang-tools-extra/include-cleaner/unittests/FindHeadersTest.cpp b/clang-tools-extra/include-cleaner/unittests/FindHeadersTest.cpp
index cbe1f67d9bf7e5..be97eb13a704ee 100644
--- a/clang-tools-extra/include-cleaner/unittests/FindHeadersTest.cpp
+++ b/clang-tools-extra/include-cleaner/unittests/FindHeadersTest.cpp
@@ -481,6 +481,55 @@ TEST_F(HeadersForSymbolTest, PublicOverPrivateWithoutUmbrella) {
               ElementsAre(physicalHeader("bar.h"), physicalHeader("foo.h")));
 }
 
+TEST_F(HeadersForSymbolTest, IWYUTransitiveExport) {
+  Inputs.Code = R"cpp(
+    #include "export1.h"
+  )cpp";
+  Inputs.ExtraFiles["export1.h"] = guard(R"cpp(
+    #include "export2.h" // IWYU pragma: export
+  )cpp");
+  Inputs.ExtraFiles["export2.h"] = guard(R"cpp(
+    #include "foo.h" // IWYU pragma: export
+  )cpp");
+  Inputs.ExtraFiles["foo.h"] = guard(R"cpp(
+    struct foo {};
+  )cpp");
+  buildAST();
+  EXPECT_THAT(headersForFoo(),
+              ElementsAre(physicalHeader("foo.h"), physicalHeader("export1.h"),
+                          physicalHeader("export2.h")));
+}
+
+TEST_F(HeadersForSymbolTest, IWYUTransitiveExportWithPrivate) {
+  Inputs.Code = R"cpp(
+    #include "export1.h"
+    void bar() { foo();}
+  )cpp";
+  Inputs.ExtraFiles["export1.h"] = guard(R"cpp(
+    // IWYU pragma: private, include "public1.h"
+    #include "export2.h" // IWYU pragma: export
+    void foo();
+  )cpp");
+  Inputs.ExtraFiles["export2.h"] = guard(R"cpp(
+    // IWYU pragma: private, include "public2.h"
+    #include "export3.h" // IWYU pragma: export
+  )cpp");
+  Inputs.ExtraFiles["export3.h"] = guard(R"cpp(
+    // IWYU pragma: private, include "public3.h"
+    #include "foo.h" // IWYU pragma: export
+  )cpp");
+  Inputs.ExtraFiles["foo.h"] = guard(R"cpp(
+    void foo();
+  )cpp");
+  buildAST();
+  EXPECT_THAT(headersForFoo(),
+              ElementsAre(physicalHeader("foo.h"),
+                                           Header(StringRef("\"public1.h\"")),
+                                           physicalHeader("export1.h"),
+                                           physicalHeader("export2.h"),
+                                           physicalHeader("export3.h")));
+}
+
 TEST_F(HeadersForSymbolTest, AmbiguousStdSymbols) {
   struct {
     llvm::StringRef Code;