Turn on -g by default for dbg builds.

* Adds a flag to Objective-C copts set.
* Adds a method to get Swift compilation flags, these are slightly different from ObjC clang.

RELNOTES:Generate debug symbols (-g) is enabled for all dbg builds of objc_ rules.

--
MOS_MIGRATED_REVID=120845678

2 files changed, 23 insertions, 4 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java b/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
index 73e07e9baa..e1eff2af67 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
@@ -505,14 +505,14 @@ public final class CompilationSupport {
         .add("-emit-object")
         .add("-target").add(swiftTarget(appleConfiguration))
         .add("-sdk").add(AppleToolchain.sdkDir())
-        .add("-enable-objc-interop");
+        .add("-enable-objc-interop")
+        .add(objcConfiguration.getSwiftCoptsForCompilationMode());
 
     if (objcConfiguration.generateDebugSymbols()) {
       commandLine.add("-g");
     }
 
     commandLine
-      .add("-Onone")
       .add("-module-name").add(getModuleName())
       .add("-parse-as-library");
     addSource("-primary-file", commandLine, sourceFile)
@@ -587,7 +587,8 @@ public final class CompilationSupport {
         .add("-frontend")
         .add("-emit-module")
         .add("-sdk").add(AppleToolchain.sdkDir())
-        .add("-target").add(swiftTarget(appleConfiguration));
+        .add("-target").add(swiftTarget(appleConfiguration))
+        .add(objcConfiguration.getSwiftCoptsForCompilationMode());
 
     if (objcConfiguration.generateDebugSymbols()) {
       commandLine.add("-g");
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java
index d42bff1283..8398638ea0 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java
@@ -43,7 +43,7 @@ import javax.annotation.Nullable;
 public class ObjcConfiguration extends BuildConfiguration.Fragment {
   @VisibleForTesting
   static final ImmutableList<String> DBG_COPTS =
-      ImmutableList.of("-O0", "-DDEBUG=1", "-fstack-protector", "-fstack-protector-all");
+      ImmutableList.of("-O0", "-DDEBUG=1", "-fstack-protector", "-fstack-protector-all", "-g");
 
   @VisibleForTesting
   static final ImmutableList<String> GLIBCXX_DBG_COPTS =
@@ -173,6 +173,24 @@ public class ObjcConfiguration extends BuildConfiguration.Fragment {
   }
 
   /**
+   * Returns the default set of swiftc options for the current compilation mode.
+   */
+  @SkylarkCallable(name = "swift_copts_for_current_compilation_mode", structField = true,
+      doc = "Returns a list of default options to use for compiling Swift in the current mode.")
+  public ImmutableList<String> getSwiftCoptsForCompilationMode() {
+    switch (compilationMode) {
+      case DBG:
+        return ImmutableList.of("-Onone", "-DDEBUG=1", "-g");
+      case FASTBUILD:
+        return ImmutableList.of("-Onone", "-DDEBUG=1");
+      case OPT:
+        return ImmutableList.of("-O", "-DNDEBUG=1");
+      default:
+        throw new AssertionError();
+    }
+  }
+
+  /**
    * Returns options passed to (Apple) clang when compiling Objective C. These options should be
    * applied after any default options but before options specified in the attributes of the rule.
    */