[Sema] Report availability macros in inlinable code

Availability macros can’t be used in inlinable code
as inlinable is copied textually in the generated
swiftinterface files. Further would could lift this
limitation.

Author: xymus

include/swift/AST/AvailabilitySpec.h

@@ -85,6 +85,9 @@ class PlatformVersionConstraintAvailabilitySpec : public AvailabilitySpec {
 
   SourceRange VersionSrcRange;
 
+  // Location of the macro expanded to create this spec.
+  SourceLoc MacroLoc;
+
 public:
   PlatformVersionConstraintAvailabilitySpec(PlatformKind Platform,
                                             SourceLoc PlatformLoc,
@@ -117,6 +120,10 @@ class PlatformVersionConstraintAvailabilitySpec : public AvailabilitySpec {
 
   SourceRange getSourceRange() const;
 
+  // Location of the macro expanded to create this spec.
+  SourceLoc getMacroLoc() const { return MacroLoc; }
+  void setMacroLoc(SourceLoc loc) { MacroLoc = loc; }
+
   void print(raw_ostream &OS, unsigned Indent) const;
 
   static bool classof(const AvailabilitySpec *Spec) {

include/swift/AST/DiagnosticsSema.def

@@ -4922,6 +4922,10 @@ WARNING(public_decl_needs_availability, none,
         "public declarations should have an availability attribute when building "
         "with -require-explicit-availability", ())
 
+ERROR(availability_macro_in_inlinable, none,
+      "availability macro cannot be used in inlinable %0",
+      (DescriptiveDeclKind))
+
 // This doesn't display as an availability diagnostic, but it's
 // implemented there and fires when these subscripts are marked
 // unavailable, so it seems appropriate to put it here.

lib/Parse/ParseDecl.cpp

@@ -1408,8 +1408,18 @@ Parser::parseAvailabilityMacro(SmallVectorImpl<AvailabilitySpec *> &Specs) {
     return makeParserError(); // Failed to match the version, that's an error.
   }
 
-  Specs.append(VersionMatch->getSecond().begin(),
-               VersionMatch->getSecond().end());
+  // Make a copy of the specs to add the macro source location
+  // for the diagnostic about the use of macros in inlinable code.
+  SourceLoc MacroLoc = Tok.getLoc();
+  for (auto *Spec : VersionMatch->getSecond())
+    if (auto *PlatformVersionSpec =
+          dyn_cast<PlatformVersionConstraintAvailabilitySpec>(Spec)) {
+      auto SpecCopy =
+        new (Context) PlatformVersionConstraintAvailabilitySpec(
+                                                       *PlatformVersionSpec);
+      SpecCopy->setMacroLoc(MacroLoc);
+      Specs.push_back(SpecCopy);
+    }
 
   return makeParserSuccess();
 }

lib/Sema/TypeCheckStmt.cpp

@@ -465,6 +465,24 @@ static bool typeCheckConditionForStatement(LabeledConditionalStmt *stmt,
   for (auto &elt : cond) {
     if (elt.getKind() == StmtConditionElement::CK_Availability) {
       hadAnyFalsable = true;
+
+      // Reject inlinable code using availability macros.
+      PoundAvailableInfo *info = elt.getAvailability();
+      if (auto *decl = dc->getAsDecl()) {
+        if (decl->getAttrs().hasAttribute<InlinableAttr>() ||
+            decl->getAttrs().hasAttribute<AlwaysEmitIntoClientAttr>())
+          for (auto queries : info->getQueries())
+            if (auto availSpec =
+                  dyn_cast<PlatformVersionConstraintAvailabilitySpec>(queries))
+              if (availSpec->getMacroLoc().isValid()) {
+                Context.Diags.diagnose(
+                    availSpec->getMacroLoc(),
+                    swift::diag::availability_macro_in_inlinable,
+                    decl->getDescriptiveKind());
+                break;
+              }
+      }
+
       continue;
     }
 

test/Sema/availability_define.swift

@@ -58,3 +58,17 @@ func client() {
 
   if #available(_unknownMacro, *) { } // expected-error {{expected version number}}
 }
+
+@inlinable
+public func forbidMacrosInInlinableCode() {
+  if #available(_iOS9Aligned, *) { } // expected-error {{availability macro cannot be used in inlinable global function}}
+  if #available(_iOS9, _macOS10_11, *) { } // expected-error {{availability macro cannot be used in inlinable global function}}
+  if #available(iOS 9.0, _macOS10_11, tvOS 9.0, *) { } // expected-error {{availability macro cannot be used in inlinable global function}}
+}
+
+@_alwaysEmitIntoClient
+public func forbidMacrosInInlinableCode1() {
+  if #available(_iOS9Aligned, *) { } // expected-error {{availability macro cannot be used in inlinable global function}}
+  if #available(_iOS9, _macOS10_11, *) { } // expected-error {{availability macro cannot be used in inlinable global function}}
+  if #available(iOS 9.0, _macOS10_11, tvOS 9.0, *) { } // expected-error {{availability macro cannot be used in inlinable global function}}
+}