Add bp2build conversion to reference to fdo_profile targets

The fdo_profile targets are handcrafted in ag/20469925. Bp2build creates fdo_profile attribute on cc_library_shared and references to the fdo_profile target if the profile exists. This works under assumption that all afdo profiles have an associated Bazel fdo_profile target declared in the same folder/package.

As noted in b/253540178, this won't work when we check in the BUILD files (which is likely 6+ months away) because some profiles might only exist internally but not in AOSP. We will implement a long-term solution once we figure out all the requirements we need to support afdo both in Soong and Bazel.

Bug: 253540178
Test: go tests
Change-Id: Iebd5dd7a76583b4b2bf0d9ee56d58f247d313a54
Merged-In: Iebd5dd7a76583b4b2bf0d9ee56d58f247d313a54
diff --git a/cc/bp2build.go b/cc/bp2build.go
index d41aa00..598e350 100644
--- a/cc/bp2build.go
+++ b/cc/bp2build.go
@@ -393,6 +393,8 @@
 	features bazel.StringListAttribute
 
 	suffix bazel.StringAttribute
+
+	fdoProfile bazel.LabelAttribute
 }
 
 type filterOutFn func(string) bool
@@ -777,6 +779,13 @@
 	(&compilerAttrs).srcs.Add(&convertedLSrcs.srcName)
 	(&compilerAttrs).cSrcs.Add(&convertedLSrcs.cSrcName)
 
+	if module.afdo != nil && module.afdo.Properties.Afdo {
+		fdoProfileDep := bp2buildFdoProfile(ctx, module)
+		if fdoProfileDep != nil {
+			(&compilerAttrs).fdoProfile.SetValue(*fdoProfileDep)
+		}
+	}
+
 	if !compilerAttrs.syspropSrcs.IsEmpty() {
 		(&linkerAttrs).wholeArchiveDeps.Add(bp2buildCcSysprop(ctx, module.Name(), module.Properties.Min_sdk_version, compilerAttrs.syspropSrcs))
 	}
@@ -793,6 +802,37 @@
 	}
 }
 
+type fdoProfileAttributes struct {
+	Absolute_path_profile string
+}
+
+func bp2buildFdoProfile(
+	ctx android.Bp2buildMutatorContext,
+	m *Module,
+) *bazel.Label {
+	for _, project := range globalAfdoProfileProjects {
+		// We handcraft a BUILD file with fdo_profile targets that use the existing profiles in the project
+		// This implementation is assuming that every afdo profile in globalAfdoProfileProjects already has
+		// an associated fdo_profile target declared in the same package.
+		// TODO(b/260714900): Handle arch-specific afdo profiles (e.g. `<module-name>-arm<64>.afdo`)
+		path := android.ExistentPathForSource(ctx, project, m.Name()+".afdo")
+		if path.Valid() {
+			// FIXME: Some profiles only exist internally and are not released to AOSP.
+			// When generated BUILD files are checked in, we'll run into merge conflict.
+			// The cc_library_shared target in AOSP won't have reference to an fdo_profile target because
+			// the profile doesn't exist. Internally, the same cc_library_shared target will
+			// have reference to the fdo_profile.
+			// For more context, see b/258682955#comment2
+			fdoProfileLabel := "//" + strings.TrimSuffix(project, "/") + ":" + m.Name()
+			return &bazel.Label{
+				Label: fdoProfileLabel,
+			}
+		}
+	}
+
+	return nil
+}
+
 func bp2buildCcAidlLibrary(
 	ctx android.Bp2buildMutatorContext,
 	m *Module,
diff --git a/cc/library.go b/cc/library.go
index 7059023..ed0ed01 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -417,6 +417,8 @@
 		Strip:                             stripAttrsFromLinkerAttrs(&linkerAttrs),
 		Features:                          baseAttributes.features,
 		bazelCcHeaderAbiCheckerAttributes: bp2buildParseAbiCheckerProps(ctx, m),
+
+		Fdo_profile: compilerAttrs.fdoProfile,
 	}
 
 	if compilerAttrs.stubsSymbolFile != nil && len(compilerAttrs.stubsVersions.Value) > 0 {
@@ -2930,6 +2932,8 @@
 			Suffix: compilerAttrs.suffix,
 
 			bazelCcHeaderAbiCheckerAttributes: bp2buildParseAbiCheckerProps(ctx, module),
+
+			Fdo_profile: compilerAttrs.fdoProfile,
 		}
 		if compilerAttrs.stubsSymbolFile != nil && len(compilerAttrs.stubsVersions.Value) > 0 {
 			hasStubs := true
@@ -3020,6 +3024,8 @@
 	Suffix bazel.StringAttribute
 
 	bazelCcHeaderAbiCheckerAttributes
+
+	Fdo_profile bazel.LabelAttribute
 }
 
 type bazelCcStubSuiteAttributes struct {