[embedded] In -no-allocations, avoid linking allocating/deallocating runtime functions

include/swift/Runtime/RuntimeFunctions.def

@@ -2635,7 +2635,7 @@ FUNCTION(GenericAssignWithCopy,
          RETURNS(Int8PtrTy),
          ARGS(Int8PtrTy, Int8PtrTy, TypeMetadataPtrTy),
          ATTRS(NoUnwind),
-         EFFECT(Refcounting, Deallocating),
+         EFFECT(RefCounting, Deallocating),
          UNKNOWN_MEMEFFECTS)
 
 // void *swift_generic_assignWithTake(opaque* dest, opaque* src, const Metadata* type);
@@ -2645,7 +2645,7 @@ FUNCTION(GenericAssignWithTake,
          RETURNS(Int8PtrTy),
          ARGS(Int8PtrTy, Int8PtrTy, TypeMetadataPtrTy),
          ATTRS(NoUnwind),
-         EFFECT(Refcounting, Deallocating),
+         EFFECT(RefCounting, Deallocating),
          UNKNOWN_MEMEFFECTS)
 
 // void *swift_generic_initWithCopy(opaque* dest, opaque* src, const Metadata* type);
@@ -2655,7 +2655,7 @@ FUNCTION(GenericInitWithCopy,
          RETURNS(Int8PtrTy),
          ARGS(Int8PtrTy, Int8PtrTy, TypeMetadataPtrTy),
          ATTRS(NoUnwind),
-         EFFECT(Refcounting),
+         EFFECT(RefCounting),
          UNKNOWN_MEMEFFECTS)
 
 // void *swift_generic_initWithTake(opaque* dest, opaque* src, const Metadata* type);
@@ -2665,7 +2665,7 @@ FUNCTION(GenericInitWithTake,
          RETURNS(Int8PtrTy),
          ARGS(Int8PtrTy, Int8PtrTy, TypeMetadataPtrTy),
          ATTRS(NoUnwind),
-         EFFECT(Refcounting),
+         EFFECT(RefCounting),
          UNKNOWN_MEMEFFECTS)
 
 // void *swift_generic_initializeBufferWithCopyOfBuffer(ValueBuffer* dest, ValueBuffer* src, const Metadata* type);
@@ -2677,7 +2677,7 @@ FUNCTION(GenericInitializeBufferWithCopyOfBuffer,
               getFixedBufferTy()->getPointerTo(),
               TypeMetadataPtrTy),
          ATTRS(NoUnwind),
-         EFFECT(Refcounting),
+         EFFECT(RefCounting),
          UNKNOWN_MEMEFFECTS)
 
 // unsigned swift_singletonEnum_getEnumTag(swift::OpaqueValue *address,

include/swift/SIL/RuntimeEffect.h

@@ -79,6 +79,20 @@ inline bool operator&(RuntimeEffect lhs, RuntimeEffect rhs) {
 
 } // end swift namespace
 
+namespace RuntimeConstants {
+  const auto NoEffect = swift::RuntimeEffect::NoEffect;
+  const auto Locking = swift::RuntimeEffect::Locking;
+  const auto Allocating = swift::RuntimeEffect::Allocating;
+  const auto Deallocating = swift::RuntimeEffect::Deallocating;
+  const auto RefCounting = swift::RuntimeEffect::RefCounting;
+  const auto ObjectiveC = swift::RuntimeEffect::ObjectiveC;
+  const auto Concurrency = swift::RuntimeEffect::Concurrency;
+  const auto AutoDiff = swift::RuntimeEffect::AutoDiff;
+  const auto MetaData = swift::RuntimeEffect::MetaData;
+  const auto Casting = swift::RuntimeEffect::Casting;
+  const auto ExclusivityChecking = swift::RuntimeEffect::ExclusivityChecking;
+}
+
 // Enable the following macro to perform validation check on the runtime effects
 // of instructions in IRGen.
 // #define CHECK_RUNTIME_EFFECT_ANALYSIS

lib/IRGen/IRGenModule.cpp

@@ -787,20 +787,6 @@ namespace RuntimeConstants {
   const auto FirstParamReturned = llvm::Attribute::Returned;
   const auto WillReturn = llvm::Attribute::WillReturn;
 
-#ifdef CHECK_RUNTIME_EFFECT_ANALYSIS
-  const auto NoEffect = RuntimeEffect::NoEffect;
-  const auto Locking = RuntimeEffect::Locking;
-  const auto Allocating = RuntimeEffect::Allocating;
-  const auto Deallocating = RuntimeEffect::Deallocating;
-  const auto RefCounting = RuntimeEffect::RefCounting;
-  const auto ObjectiveC = RuntimeEffect::ObjectiveC;
-  const auto Concurrency = RuntimeEffect::Concurrency;
-  const auto AutoDiff = RuntimeEffect::AutoDiff;
-  const auto MetaData = RuntimeEffect::MetaData;
-  const auto Casting = RuntimeEffect::Casting;
-  const auto ExclusivityChecking = RuntimeEffect::ExclusivityChecking;
-#endif
-
   RuntimeAvailability AlwaysAvailable(ASTContext &Context) {
     return RuntimeAvailability::AlwaysAvailable;
   }

lib/SILOptimizer/UtilityPasses/Link.cpp

@@ -48,25 +48,35 @@ class SILLinker : public SILModuleTransform {
   }
 
   void linkEmbeddedRuntimeFromStdlib() {
+    using namespace RuntimeConstants;
 #define FUNCTION(ID, NAME, CC, AVAILABILITY, RETURNS, ARGS, ATTRS, EFFECT,     \
                  MEMORY_EFFECTS)                                               \
-  linkEmbeddedRuntimeFunctionByName(#NAME);
+  linkEmbeddedRuntimeFunctionByName(#NAME, EFFECT);
 
 #define RETURNS(...)
 #define ARGS(...)
 #define NO_ARGS
 #define ATTRS(...)
 #define NO_ATTRS
-#define EFFECT(...)
+#define EFFECT(...) { __VA_ARGS__ }
 #define MEMORY_EFFECTS(...)
 #define UNKNOWN_MEMEFFECTS
 
 #include "swift/Runtime/RuntimeFunctions.def"
   }
 
-  void linkEmbeddedRuntimeFunctionByName(StringRef name) {
+  void linkEmbeddedRuntimeFunctionByName(StringRef name,
+                                         ArrayRef<RuntimeEffect> effects) {
     SILModule &M = *getModule();
 
+    bool allocating = false;
+    for (RuntimeEffect rt : effects)
+      if (rt == RuntimeEffect::Allocating || rt == RuntimeEffect::Deallocating)
+        allocating = true;
+
+    // Don't link allocating runtime functions in -no-allocations mode.
+    if (M.getOptions().NoAllocations && allocating) return;
+
     // Bail if runtime function is already loaded.
     if (M.lookUpFunction(name)) return;
 

test/embedded/dependencies-no-allocations.swift

@@ -0,0 +1,44 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -enable-experimental-feature Embedded -no-allocations %s -c -o %t/a.o
+
+// RUN: grep DEP\: %s | sed 's#// DEP\: ##' | sort > %t/allowed-dependencies.txt
+
+// Linux/ELF doesn't use the "_" prefix in symbol mangling.
+// RUN: if [ %target-os == "linux-gnu" ]; then sed -E -i -e 's/^_(.*)$/\1/' %t/allowed-dependencies.txt; fi
+
+// RUN: %llvm-nm --undefined-only --format=just-symbols %t/a.o | sort | tee %t/actual-dependencies.txt
+
+// Fail if there is any entry in actual-dependencies.txt that's not in allowed-dependencies.txt
+// RUN: test -z "`comm -13 %t/allowed-dependencies.txt %t/actual-dependencies.txt`"
+
+// DEP: ___stack_chk_fail
+// DEP: ___stack_chk_guard
+// DEP: _memset
+// DEP: _putchar
+
+// RUN: %target-clang -x c -c %S/Inputs/print.c -o %t/print.o
+// RUN: %target-clang %t/a.o %t/print.o -o %t/a.out
+// RUN: %target-run %t/a.out | %FileCheck %s
+
+// REQUIRES: swift_in_compiler
+// REQUIRES: executable_test
+// REQUIRES: optimized_stdlib
+// REQUIRES: OS=macosx || OS=linux-gnu
+
+@_silgen_name("putchar")
+func putchar(_: UInt8)
+
+public func print(_ s: StaticString, terminator: StaticString = "\n") {
+  var p = s.utf8Start
+  while p.pointee != 0 {
+    putchar(p.pointee)
+    p += 1
+  }
+  p = terminator.utf8Start
+  while p.pointee != 0 {
+    putchar(p.pointee)
+    p += 1
+  }
+}
+
+print("Hello Embedded Swift!") // CHECK: Hello Embedded Swift!