Merge pull request #72156 from apple/revert-72124-fix-embedded-dead-code-elim

Revert "embedded: allow dead function elimination for de-serialized functions"

Author: xymus

lib/SIL/IR/Linker.cpp

@@ -448,6 +448,11 @@ void SILLinkerVisitor::process() {
       Fn->setSerialized(IsSerialized_t::IsNotSerialized);
     }
 
+    // TODO: This should probably be done as a separate SIL pass ("internalize")
+    if (Fn->getModule().getASTContext().LangOpts.hasFeature(Feature::Embedded)) {
+      Fn->setLinkage(stripExternalFromLinkage(Fn->getLinkage()));
+    }
+
     LLVM_DEBUG(llvm::dbgs() << "Process imports in function: "
                             << Fn->getName() << "\n");
 

lib/SIL/IR/SILFunction.cpp

@@ -940,9 +940,6 @@ bool SILFunction::shouldBePreservedForDebugger() const {
   if (getEffectiveOptimizationMode() != OptimizationMode::NoOptimization)
     return false;
 
-  if (isAvailableExternally())
-    return false;
-
   if (hasSemanticsAttr("no.preserve.debugger"))
     return false;
 

lib/SILOptimizer/Mandatory/IRGenPrepare.cpp

@@ -87,15 +87,6 @@ class IRGenPrepare : public SILFunctionTransform {
   void run() override {
     SILFunction *F = getFunction();
 
-    if (getOptions().EmbeddedSwift) {
-      // In embedded swift all the code is generated in the top-level module.
-      // Even de-serialized functions must be code-gen'd.
-      SILLinkage linkage = F->getLinkage();
-      if (isAvailableExternally(linkage)) {
-        F->setLinkage(stripExternalFromLinkage(linkage));
-      }
-    }
-
     bool shouldInvalidate = cleanFunction(*F);
 
     if (shouldInvalidate)

lib/SILOptimizer/UtilityPasses/Link.cpp

@@ -86,13 +86,6 @@ class SILLinker : public SILModuleTransform {
 
     if (M.linkFunction(Fn, LinkMode))
       invalidateAnalysis(Fn, SILAnalysis::InvalidationKind::Everything);
-
-    // Make sure that dead-function-elimination doesn't remove runtime functions.
-    // TODO: lazily emit runtime functions in IRGen so that we don't have to
-    //       rely on dead-stripping in the linker to remove unused runtime
-    //       functions.
-    if (Fn->isDefinition())
-      Fn->setLinkage(SILLinkage::Public);
   }
 };
 } // end anonymous namespace

test/embedded/floatingpoint.swift

@@ -43,8 +43,12 @@ public func checks(n: Int) {
 
 // CHECK: define {{.*}}i32 @main(i32 %0, ptr %1)
 // CHECK: define {{.*}}i1 @"$s4main4boolSbyF"()
+// CHECK: define {{.*}}i1 @"$sSb22_builtinBooleanLiteralSbBi1__tcfC"(i1 %0)
 // CHECK: define {{.*}}{{i32|i64}} @"$s4main3intSiyF"()
+// CHECK: define {{.*}}{{i32|i64}} @"$sSi22_builtinIntegerLiteralSiBI_tcfC"(ptr %0, {{i32|i64}} %1)
 // CHECK: define {{.*}}ptr @"$s4main3ptr1p1nS2V_SitF"(ptr %0, {{i32|i64}} %1)
+// CHECK: define {{.*}}ptr @"$sSV8advanced2bySVSi_tF"({{i32|i64}} %0, ptr %1)
 // CHECK: define {{.*}}{ {{i32|i64}}, i8 } @"$s4main8optionalSiSgyF"()
 // CHECK: define {{.*}}{ {{i32|i64}}, {{i32|i64}}, i8 } @"$s4main12staticstrings12StaticStringVyF"()
+// CHECK: define {{.*}}{ {{i32|i64}}, {{i32|i64}}, i8 } @"$ss12StaticStringV08_builtinB7Literal17utf8CodeUnitCount7isASCIIABBp_BwBi1_tcfC"(ptr %0, {{i32|i64}} %1, i1 %2)
 // CHECK: define {{.*}}void @"$s4main6checks1nySi_tF"({{i32|i64}} %0)