1 files changed, 50 insertions, 0 deletions
diff --git a/clang/lib/ExtractAPI/AvailabilityInfo.cpp b/clang/lib/ExtractAPI/AvailabilityInfo.cpp
new file mode 100644
index 000000000000..ada64cfb92e6
--- /dev/null
+++ b/clang/lib/ExtractAPI/AvailabilityInfo.cpp
@@ -0,0 +1,50 @@
+#include "clang/ExtractAPI/AvailabilityInfo.h"
+#include "clang/AST/Attr.h"
+#include "llvm/ADT/STLExtras.h"
+
+using namespace clang;
+using namespace extractapi;
+
+AvailabilitySet::AvailabilitySet(const Decl *Decl) {
+  // Collect availability attributes from all redeclrations.
+  for (const auto *RD : Decl->redecls()) {
+    if (const auto *A = RD->getAttr<UnavailableAttr>()) {
+      if (!A->isImplicit()) {
+        this->Availabilities.clear();
+        UnconditionallyUnavailable = true;
+      }
+    }
+
+    if (const auto *A = RD->getAttr<DeprecatedAttr>()) {
+      if (!A->isImplicit()) {
+        this->Availabilities.clear();
+        UnconditionallyDeprecated = true;
+      }
+    }
+
+    for (const auto *Attr : RD->specific_attrs<AvailabilityAttr>()) {
+      StringRef Domain = Attr->getPlatform()->getName();
+      auto *Availability =
+          llvm::find_if(Availabilities, [Domain](const AvailabilityInfo &Info) {
+            return Domain.equals(Info.Domain);
+          });
+      if (Availability != Availabilities.end()) {
+        // Get the highest introduced version for all redeclarations.
+        if (Availability->Introduced < Attr->getIntroduced())
+          Availability->Introduced = Attr->getIntroduced();
+
+        // Get the lowest deprecated version for all redeclarations.
+        if (Availability->Deprecated > Attr->getDeprecated())
+          Availability->Deprecated = Attr->getDeprecated();
+
+        // Get the lowest obsoleted version for all redeclarations.
+        if (Availability->Obsoleted > Attr->getObsoleted())
+          Availability->Obsoleted = Attr->getObsoleted();
+      } else {
+        Availabilities.emplace_back(Domain, Attr->getIntroduced(),
+                                    Attr->getDeprecated(),
+                                    Attr->getObsoleted());
+      }
+    }
+  }
+}