[embedded] Mark all functions as 'nounwind' in embedded Swift, add dependency tests

Author: kubamracek

lib/IRGen/IRGenModule.cpp

@@ -1444,6 +1444,10 @@ void IRGenModule::constructInitialFnAttributes(
     Attrs.addAttribute(llvm::Attribute::StackProtectReq);
     Attrs.addAttribute("stack-protector-buffer-size", llvm::utostr(8));
   }
+
+  if (Context.LangOpts.hasFeature(Feature::Embedded)) {
+    Attrs.addAttribute(llvm::Attribute::NoUnwind);
+  }
 }
 
 llvm::AttributeList IRGenModule::constructInitialAttributes() {

lib/IRGen/IRGenSIL.cpp

@@ -1846,6 +1846,10 @@ IRGenSILFunction::IRGenSILFunction(IRGenModule &IGM, SILFunction *f)
     CurFn->addFnAttr(llvm::Attribute::NoInline);
   }
 
+  if (IGM.Context.LangOpts.hasFeature(Feature::Embedded)) {
+    CurFn->addFnAttr(llvm::Attribute::NoUnwind);
+  }
+
   auto optMode = f->getOptimizationMode();
   if (optMode != OptimizationMode::NotSet &&
       optMode != f->getModule().getOptions().OptMode) {

test/embedded/dependencies.swift

@@ -0,0 +1,44 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -enable-experimental-feature Embedded %s -c -o %t/a.o
+
+// backslash is not doing anything, just to make the grep not match its own line
+// RUN: grep DEP-%target-os %s | sed 's#// DEP-%target-os: ##' | sort > %t/expected-dependencies.txt
+// RUN: %llvm-nm --undefined-only --format=just-symbols %t/a.out | sort > %t/actual-dependencies.txt
+// RUN: diff -u %t/expected-dependencies.txt %t/actual-dependencies.txt
+
+// DEP-macosx: ___stack_chk_fail
+// DEP-macosx: ___stack_chk_guard
+// DEP-macosx: _free
+// DEP-macosx: _posix_memalign
+// DEP-macosx: _printf
+// DEP-macosx: _putchar
+// DEP-macosx: dyld_stub_binder
+
+// DEP-linux-gnu: __stack_chk_fail
+// DEP-linux-gnu: __stack_chk_guard
+// DEP-linux-gnu: free
+// DEP-linux-gnu: posix_memalign
+// DEP-linux-gnu: putchar
+
+// 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!