Select stub/impl per apex variant

Create a select statement for every api_domain a library could be
included in. The stub/impl
selection heuristics per apex domain are
1. If dep has stubs and the api domain appears in dep's apex_available, use
   impl
2. If dep has stubs and the api domain does not appear in dep's
   apex_available, use stubs

(Category 3: If dep does not have stubs and the apex does not appear in
dep's apex_available, then a separate apex_available validation in Bazel
will emit an error).

Platform variants have been special-cased for now to use equality of
apex_available for stub/impl selection

Test: go test ./bp2build
Bug: 272378496

Change-Id: Ibd29efd763c8863c7e6d2a9af0da30bbde07175d

bazel/configurability.go

@@ -69,8 +69,8 @@ const (
 
 	productVariableBazelPackage = "//build/bazel/product_variables"
 
-	AndroidAndInApex  = "android-in_apex"
+	AndroidAndInApex = "android-in_apex"
-	AndroidAndNonApex = "android-non_apex"
+	AndroidPlatform  = "system"
 
 	InApex  = "in_apex"
 	NonApex = "non_apex"
@@ -202,7 +202,7 @@ var (
 
 	osAndInApexMap = map[string]string{
 		AndroidAndInApex:           "//build/bazel/rules/apex:android-in_apex",
-		AndroidAndNonApex:          "//build/bazel/rules/apex:android-non_apex",
+		AndroidPlatform:            "//build/bazel/rules/apex:system",
 		osDarwin:                   "//build/bazel/platforms/os:darwin",
 		osLinux:                    "//build/bazel/platforms/os:linux_glibc",
 		osLinuxMusl:                "//build/bazel/platforms/os:linux_musl",

bp2build/build_conversion_test.go

@@ -1941,7 +1941,7 @@ func TestPrettyPrintSelectMapEqualValues(t *testing.T) {
 	libFooImplLabel := bazel.Label{
 		Label: ":libfoo.impl",
 	}
-	lla.SetSelectValue(bazel.OsAndInApexAxis, bazel.AndroidAndNonApex, bazel.MakeLabelList([]bazel.Label{libFooImplLabel}))
+	lla.SetSelectValue(bazel.OsAndInApexAxis, bazel.AndroidPlatform, bazel.MakeLabelList([]bazel.Label{libFooImplLabel}))
 	lla.SetSelectValue(bazel.OsAndInApexAxis, bazel.ConditionsDefaultConfigKey, bazel.MakeLabelList([]bazel.Label{libFooImplLabel}))
 	actual, _ := prettyPrintAttribute(lla, 0)
 	android.AssertStringEquals(t, "Print the common value if all keys in an axis have the same value", `[":libfoo.impl"]`, actual)

bp2build/cc_library_conversion_test.go

@@ -3042,7 +3042,8 @@ cc_library {
 }`,
 		ExpectedBazelTargets: makeCcLibraryTargets("foolib", AttrNameToString{
 			"implementation_dynamic_deps": `select({
-        "//build/bazel/rules/apex:android-in_apex": ["@api_surfaces//module-libapi/current:barlib"],
+        "//build/bazel/rules/apex:foo": ["@api_surfaces//module-libapi/current:barlib"],
+        "//build/bazel/rules/apex:system": ["@api_surfaces//module-libapi/current:barlib"],
         "//conditions:default": [":barlib"],
     })`,
 			"local_includes": `["."]`,
@@ -3096,7 +3097,11 @@ cc_library {
         "//build/bazel/platforms/os:linux_glibc": [":quxlib"],
         "//build/bazel/platforms/os:linux_musl": [":quxlib"],
         "//build/bazel/platforms/os:windows": [":quxlib"],
-        "//build/bazel/rules/apex:android-in_apex": [
+        "//build/bazel/rules/apex:foo": [
+            "@api_surfaces//module-libapi/current:barlib",
+            "@api_surfaces//module-libapi/current:quxlib",
+        ],
+        "//build/bazel/rules/apex:system": [
             "@api_surfaces//module-libapi/current:barlib",
             "@api_surfaces//module-libapi/current:quxlib",
         ],
@@ -4139,44 +4144,34 @@ cc_library {
 	name: "barlib",
 	stubs: { symbol_file: "bar.map.txt", versions: ["28", "29", "current"] },
 	bazel_module: { bp2build_available: false },
+	apex_available: ["//apex_available:platform",],
 }
 cc_library {
 	name: "bazlib",
 	stubs: { symbol_file: "bar.map.txt", versions: ["28", "29", "current"] },
 	bazel_module: { bp2build_available: false },
+	apex_available: ["//apex_available:platform",],
 }
 cc_library {
     name: "foo",
 	  shared_libs: ["barlib", "bazlib"],
     export_shared_lib_headers: ["bazlib"],
     apex_available: [
-        "apex_available:platform",
+        "//apex_available:platform",
     ],
 }`,
 		ExpectedBazelTargets: []string{
 			MakeBazelTarget("cc_library_static", "foo_bp2build_cc_library_static", AttrNameToString{
-				"implementation_dynamic_deps": `select({
+				"implementation_dynamic_deps": `[":barlib"]`,
-        "//build/bazel/rules/apex:android-in_apex": ["@api_surfaces//module-libapi/current:barlib"],
+				"dynamic_deps":                `[":bazlib"]`,
-        "//conditions:default": [":barlib"],
+				"local_includes":              `["."]`,
-    })`,
+				"tags":                        `["apex_available=//apex_available:platform"]`,
-				"dynamic_deps": `select({
-        "//build/bazel/rules/apex:android-in_apex": ["@api_surfaces//module-libapi/current:bazlib"],
-        "//conditions:default": [":bazlib"],
-    })`,
-				"local_includes": `["."]`,
-				"tags":           `["apex_available=apex_available:platform"]`,
 			}),
 			MakeBazelTarget("cc_library_shared", "foo", AttrNameToString{
-				"implementation_dynamic_deps": `select({
+				"implementation_dynamic_deps": `[":barlib"]`,
-        "//build/bazel/rules/apex:android-in_apex": ["@api_surfaces//module-libapi/current:barlib"],
+				"dynamic_deps":                `[":bazlib"]`,
-        "//conditions:default": [":barlib"],
+				"local_includes":              `["."]`,
-    })`,
+				"tags":                        `["apex_available=//apex_available:platform"]`,
-				"dynamic_deps": `select({
-        "//build/bazel/rules/apex:android-in_apex": ["@api_surfaces//module-libapi/current:bazlib"],
-        "//conditions:default": [":bazlib"],
-    })`,
-				"local_includes": `["."]`,
-				"tags":           `["apex_available=apex_available:platform"]`,
 			}),
 		},
 	})

bp2build/cc_library_shared_conversion_test.go

@@ -609,7 +609,8 @@ cc_library_shared {
 		ExpectedBazelTargets: []string{
 			MakeBazelTarget("cc_library_shared", "b", AttrNameToString{
 				"implementation_dynamic_deps": `select({
-        "//build/bazel/rules/apex:android-in_apex": ["@api_surfaces//module-libapi/current:a"],
+        "//build/bazel/rules/apex:apex_b": ["@api_surfaces//module-libapi/current:a"],
+        "//build/bazel/rules/apex:system": ["@api_surfaces//module-libapi/current:a"],
         "//conditions:default": [":a"],
     })`,
 				"tags": `["apex_available=apex_b"]`,
@@ -618,6 +619,64 @@ cc_library_shared {
 	})
 }
 
+// Tests that library in apexfoo links against stubs of platform_lib and otherapex_lib
+func TestCcLibrarySharedStubs_UseStubsFromMultipleApiDomains(t *testing.T) {
+	runCcLibrarySharedTestCase(t, Bp2buildTestCase{
+		Description:                "cc_library_shared stubs",
+		ModuleTypeUnderTest:        "cc_library_shared",
+		ModuleTypeUnderTestFactory: cc.LibrarySharedFactory,
+		Blueprint: soongCcLibrarySharedPreamble + `
+cc_library_shared {
+	name: "libplatform_stable",
+	stubs: { symbol_file: "libplatform_stable.map.txt", versions: ["28", "29", "current"] },
+	apex_available: ["//apex_available:platform"],
+	bazel_module: { bp2build_available: false },
+	include_build_directory: false,
+}
+cc_library_shared {
+	name: "libapexfoo_stable",
+	stubs: { symbol_file: "libapexfoo_stable.map.txt", versions: ["28", "29", "current"] },
+	apex_available: ["apexfoo"],
+	bazel_module: { bp2build_available: false },
+	include_build_directory: false,
+}
+cc_library_shared {
+	name: "libutils",
+	shared_libs: ["libplatform_stable", "libapexfoo_stable",],
+	apex_available: ["//apex_available:platform", "apexfoo", "apexbar"],
+	include_build_directory: false,
+}
+`,
+		ExpectedBazelTargets: []string{
+			MakeBazelTarget("cc_library_shared", "libutils", AttrNameToString{
+				"implementation_dynamic_deps": `select({
+        "//build/bazel/rules/apex:apexbar": [
+            "@api_surfaces//module-libapi/current:libplatform_stable",
+            "@api_surfaces//module-libapi/current:libapexfoo_stable",
+        ],
+        "//build/bazel/rules/apex:apexfoo": [
+            "@api_surfaces//module-libapi/current:libplatform_stable",
+            ":libapexfoo_stable",
+        ],
+        "//build/bazel/rules/apex:system": [
+            "@api_surfaces//module-libapi/current:libplatform_stable",
+            "@api_surfaces//module-libapi/current:libapexfoo_stable",
+        ],
+        "//conditions:default": [
+            ":libplatform_stable",
+            ":libapexfoo_stable",
+        ],
+    })`,
+				"tags": `[
+        "apex_available=//apex_available:platform",
+        "apex_available=apexfoo",
+        "apex_available=apexbar",
+    ]`,
+			}),
+		},
+	})
+}
+
 func TestCcLibrarySharedStubs_IgnorePlatformAvailable(t *testing.T) {
 	runCcLibrarySharedTestCase(t, Bp2buildTestCase{
 		Description:                "cc_library_shared stubs",
@@ -641,7 +700,8 @@ cc_library_shared {
 		ExpectedBazelTargets: []string{
 			MakeBazelTarget("cc_library_shared", "b", AttrNameToString{
 				"implementation_dynamic_deps": `select({
-        "//build/bazel/rules/apex:android-in_apex": ["@api_surfaces//module-libapi/current:a"],
+        "//build/bazel/rules/apex:apex_b": ["@api_surfaces//module-libapi/current:a"],
+        "//build/bazel/rules/apex:system": ["@api_surfaces//module-libapi/current:a"],
         "//conditions:default": [":a"],
     })`,
 				"tags": `[
@@ -653,6 +713,34 @@ cc_library_shared {
 	})
 }
 
+func TestCcLibraryDoesNotDropStubDepIfNoVariationAcrossAxis(t *testing.T) {
+	runCcLibrarySharedTestCase(t, Bp2buildTestCase{
+		Description:                "cc_library depeends on impl for all configurations",
+		ModuleTypeUnderTest:        "cc_library_shared",
+		ModuleTypeUnderTestFactory: cc.LibrarySharedFactory,
+		Blueprint: soongCcLibrarySharedPreamble + `
+cc_library_shared {
+	name: "a",
+	stubs: { symbol_file: "a.map.txt", versions: ["28", "29", "current"] },
+	bazel_module: { bp2build_available: false },
+	apex_available: ["//apex_available:platform"],
+}
+cc_library_shared {
+	name: "b",
+	shared_libs: [":a"],
+	include_build_directory: false,
+	apex_available: ["//apex_available:platform"],
+}
+`,
+		ExpectedBazelTargets: []string{
+			MakeBazelTarget("cc_library_shared", "b", AttrNameToString{
+				"implementation_dynamic_deps": `[":a"]`,
+				"tags":                        `["apex_available=//apex_available:platform"]`,
+			}),
+		},
+	})
+}
+
 func TestCcLibrarySharedStubs_MultipleApexAvailable(t *testing.T) {
 	runCcLibrarySharedTestCase(t, Bp2buildTestCase{
 		ModuleTypeUnderTest:        "cc_library_shared",
@@ -682,7 +770,7 @@ cc_library_shared {
 		ExpectedBazelTargets: []string{
 			MakeBazelTarget("cc_library_shared", "b", AttrNameToString{
 				"implementation_dynamic_deps": `select({
-        "//build/bazel/rules/apex:android-in_apex": ["@api_surfaces//module-libapi/current:a"],
+        "//build/bazel/rules/apex:system": ["@api_surfaces//module-libapi/current:a"],
         "//conditions:default": [":a"],
     })`,
 				"tags": `[

bp2build/cc_library_static_conversion_test.go

@@ -1504,6 +1504,7 @@ cc_library {
         versions: ["current"],
     },
     bazel_module: { bp2build_available: false },
+    apex_available: ["com.android.runtime"],
 }
 
 cc_library_static {
@@ -1561,7 +1562,8 @@ cc_library_static {
 			}),
 			MakeBazelTarget("cc_library_static", "keep_with_stubs", AttrNameToString{
 				"implementation_dynamic_deps": `select({
-        "//build/bazel/rules/apex:android-in_apex": ["@api_surfaces//module-libapi/current:libm"],
+        "//build/bazel/rules/apex:foo": ["@api_surfaces//module-libapi/current:libm"],
+        "//build/bazel/rules/apex:system": ["@api_surfaces//module-libapi/current:libm"],
         "//conditions:default": [":libm"],
     })`,
 				"system_dynamic_deps": `[]`,

cc/bp2build.go

@@ -1269,7 +1269,7 @@ func createInApexConfigSetting(ctx android.TopDownMutatorContext, apexName strin
 
 func inApexConfigSetting(apexAvailable string) string {
 	if apexAvailable == android.AvailableToPlatform {
-		return bazel.AndroidAndNonApex
+		return bazel.AndroidPlatform
 	}
 	if apexAvailable == android.AvailableToAnyApex {
 		return bazel.AndroidAndInApex
@@ -1278,58 +1278,99 @@ func inApexConfigSetting(apexAvailable string) string {
 	return "//build/bazel/rules/apex:" + apiDomain
 }
 
+// Inputs to stub vs impl selection.
+type stubSelectionInfo struct {
+	// Label of the implementation library (e.g. //bionic/libc:libc)
+	impl bazel.Label
+	// Axis containing the implementation library
+	axis bazel.ConfigurationAxis
+	// Axis key containing the implementation library
+	config string
+	// API domain of the apex
+	// For test apexes (test_com.android.foo), this will be the source apex (com.android.foo)
+	apiDomain string
+	// List of dep labels
+	dynamicDeps *bazel.LabelListAttribute
+	// Boolean value for determining if the dep is in the same api domain
+	// If false, the label will be rewritten to to the stub label
+	sameApiDomain bool
+}
+
+func useStubOrImplInApexWithName(ssi stubSelectionInfo) {
+	lib := ssi.impl
+	if !ssi.sameApiDomain {
+		lib = bazel.Label{
+			Label: apiSurfaceModuleLibCurrentPackage + strings.TrimPrefix(lib.OriginalModuleName, ":"),
+		}
+	}
+	// Create a select statement specific to this apex
+	inApexSelectValue := ssi.dynamicDeps.SelectValue(bazel.OsAndInApexAxis, inApexConfigSetting(ssi.apiDomain))
+	(&inApexSelectValue).Append(bazel.MakeLabelList([]bazel.Label{lib}))
+	ssi.dynamicDeps.SetSelectValue(bazel.OsAndInApexAxis, inApexConfigSetting(ssi.apiDomain), bazel.FirstUniqueBazelLabelList(inApexSelectValue))
+	// Delete the library from the common config for this apex
+	implDynamicDeps := ssi.dynamicDeps.SelectValue(ssi.axis, ssi.config)
+	implDynamicDeps = bazel.SubtractBazelLabelList(implDynamicDeps, bazel.MakeLabelList([]bazel.Label{ssi.impl}))
+	ssi.dynamicDeps.SetSelectValue(ssi.axis, ssi.config, implDynamicDeps)
+	if ssi.axis == bazel.NoConfigAxis {
+		// Set defaults. Defaults (i.e. host) should use impl and not stubs.
+		defaultSelectValue := ssi.dynamicDeps.SelectValue(bazel.OsAndInApexAxis, bazel.ConditionsDefaultConfigKey)
+		(&defaultSelectValue).Append(bazel.MakeLabelList([]bazel.Label{ssi.impl}))
+		ssi.dynamicDeps.SetSelectValue(bazel.OsAndInApexAxis, bazel.ConditionsDefaultConfigKey, bazel.FirstUniqueBazelLabelList(defaultSelectValue))
+	}
+}
+
 func setStubsForDynamicDeps(ctx android.BazelConversionPathContext, axis bazel.ConfigurationAxis,
 	config string, apexAvailable []string, dynamicLibs bazel.LabelList, dynamicDeps *bazel.LabelListAttribute, ind int, buildNonApexWithStubs bool) {
 
-	depsWithStubs := []bazel.Label{}
-	for _, l := range dynamicLibs.Includes {
-		dep, _ := ctx.ModuleFromName(l.OriginalModuleName)
-		if d, ok := dep.(*Module); ok && d.HasStubsVariants() {
-			depApexAvailable := d.ApexAvailable()
-			if !availableToSameApexes(apexAvailable, depApexAvailable) {
-				depsWithStubs = append(depsWithStubs, l)
-			}
-		}
-	}
-	if len(depsWithStubs) > 0 {
-		implDynamicDeps := bazel.SubtractBazelLabelList(dynamicLibs, bazel.MakeLabelList(depsWithStubs))
-		dynamicDeps.SetSelectValue(axis, config, implDynamicDeps)
-
-		stubLibLabels := []bazel.Label{}
-		for _, l := range depsWithStubs {
-			stubLabelInApiSurfaces := bazel.Label{
-				Label: apiSurfaceModuleLibCurrentPackage + strings.TrimPrefix(l.OriginalModuleName, ":"),
-			}
-			stubLibLabels = append(stubLibLabels, stubLabelInApiSurfaces)
-		}
-		inApexSelectValue := dynamicDeps.SelectValue(bazel.OsAndInApexAxis, bazel.AndroidAndInApex)
-		nonApexSelectValue := dynamicDeps.SelectValue(bazel.OsAndInApexAxis, bazel.AndroidAndNonApex)
-		defaultSelectValue := dynamicDeps.SelectValue(bazel.OsAndInApexAxis, bazel.ConditionsDefaultConfigKey)
-		nonApexDeps := depsWithStubs
-		if buildNonApexWithStubs {
-			nonApexDeps = stubLibLabels
-		}
-		if axis == bazel.NoConfigAxis {
-			(&inApexSelectValue).Append(bazel.MakeLabelList(stubLibLabels))
-			(&nonApexSelectValue).Append(bazel.MakeLabelList(nonApexDeps))
-			(&defaultSelectValue).Append(bazel.MakeLabelList(depsWithStubs))
-			dynamicDeps.SetSelectValue(bazel.OsAndInApexAxis, bazel.AndroidAndInApex, bazel.FirstUniqueBazelLabelList(inApexSelectValue))
-			dynamicDeps.SetSelectValue(bazel.OsAndInApexAxis, bazel.AndroidAndNonApex, bazel.FirstUniqueBazelLabelList(nonApexSelectValue))
-			dynamicDeps.SetSelectValue(bazel.OsAndInApexAxis, bazel.ConditionsDefaultConfigKey, bazel.FirstUniqueBazelLabelList(defaultSelectValue))
-		} else if config == bazel.OsAndroid {
-			(&inApexSelectValue).Append(bazel.MakeLabelList(stubLibLabels))
-			(&nonApexSelectValue).Append(bazel.MakeLabelList(nonApexDeps))
-			dynamicDeps.SetSelectValue(bazel.OsAndInApexAxis, bazel.AndroidAndInApex, bazel.FirstUniqueBazelLabelList(inApexSelectValue))
-			dynamicDeps.SetSelectValue(bazel.OsAndInApexAxis, bazel.AndroidAndNonApex, bazel.FirstUniqueBazelLabelList(nonApexSelectValue))
-		}
-	}
-
 	// Create a config_setting for each apex_available.
 	// This will be used to select impl of a dep if dep is available to the same apex.
 	for _, aa := range apexAvailable {
 		createInApexConfigSetting(ctx.(android.TopDownMutatorContext), aa)
 	}
 
+	apiDomainForSelects := []string{}
+	for _, apex := range apexAvailable {
+		apiDomainForSelects = append(apiDomainForSelects, GetApiDomain(apex))
+	}
+	// Always emit a select statement for the platform variant.
+	// This ensures that b build //foo --config=android works
+	// Soong always creates a platform variant even when the library might not be available to platform.
+	if !android.InList(android.AvailableToPlatform, apiDomainForSelects) {
+		apiDomainForSelects = append(apiDomainForSelects, android.AvailableToPlatform)
+	}
+	apiDomainForSelects = android.SortedUniqueStrings(apiDomainForSelects)
+
+	// Create a select for each apex this library could be included in.
+	for _, l := range dynamicLibs.Includes {
+		dep, _ := ctx.ModuleFromName(l.OriginalModuleName)
+		if c, ok := dep.(*Module); !ok || !c.HasStubsVariants() {
+			continue
+		}
+		// TODO (b/280339069): Decrease the verbosity of the generated BUILD files
+		for _, apiDomain := range apiDomainForSelects {
+			var sameApiDomain bool
+			if apiDomain == android.AvailableToPlatform {
+				// Platform variants in Soong use equality of apex_available for stub/impl selection.
+				// https://cs.android.com/android/_/android/platform/build/soong/+/316b0158fe57ee7764235923e7c6f3d530da39c6:cc/cc.go;l=3393-3404;drc=176271a426496fa2688efe2b40d5c74340c63375;bpv=1;bpt=0
+				// One of the factors behind this design choice is cc_test
+				// Tests only have a platform variant, and using equality of apex_available ensures
+				// that tests of an apex library gets its implementation and not stubs.
+				// TODO (b/280343104): Discuss if we can drop this special handling for platform variants.
+				sameApiDomain = availableToSameApexes(apexAvailable, dep.(*Module).ApexAvailable())
+			} else {
+				sameApiDomain = android.InList(apiDomain, dep.(*Module).ApexAvailable())
+			}
+			ssi := stubSelectionInfo{
+				impl:          l,
+				axis:          axis,
+				config:        config,
+				apiDomain:     apiDomain,
+				dynamicDeps:   dynamicDeps,
+				sameApiDomain: sameApiDomain,
+			}
+			useStubOrImplInApexWithName(ssi)
+		}
+	}
 }
 
 func (la *linkerAttributes) convertStripProps(ctx android.BazelConversionPathContext, module *Module) {
@@ -1424,7 +1465,6 @@ func (la *linkerAttributes) finalize(ctx android.BazelConversionPathContext) {
 		la.implementationDynamicDeps.Exclude(bazel.OsConfigurationAxis, "linux_bionic", toRemove)
 
 		la.implementationDynamicDeps.Exclude(bazel.OsAndInApexAxis, bazel.ConditionsDefaultConfigKey, toRemove)
-		la.implementationDynamicDeps.Exclude(bazel.OsAndInApexAxis, bazel.AndroidAndNonApex, toRemove)
 		stubsToRemove := make([]bazel.Label, 0, len(la.usedSystemDynamicDepAsDynamicDep))
 		for _, lib := range toRemove.Includes {
 			stubLabelInApiSurfaces := bazel.Label{
@@ -1432,7 +1472,12 @@ func (la *linkerAttributes) finalize(ctx android.BazelConversionPathContext) {
 			}
 			stubsToRemove = append(stubsToRemove, stubLabelInApiSurfaces)
 		}
-		la.implementationDynamicDeps.Exclude(bazel.OsAndInApexAxis, bazel.AndroidAndInApex, bazel.MakeLabelList(stubsToRemove))
+		// system libraries (e.g. libc, libm, libdl) belong the com.android.runtime api domain
+		// dedupe the stubs of these libraries from the other api domains (platform, other_apexes...)
+		for _, aa := range ctx.Module().(*Module).ApexAvailable() {
+			la.implementationDynamicDeps.Exclude(bazel.OsAndInApexAxis, inApexConfigSetting(aa), bazel.MakeLabelList(stubsToRemove))
+		}
+		la.implementationDynamicDeps.Exclude(bazel.OsAndInApexAxis, bazel.AndroidPlatform, bazel.MakeLabelList(stubsToRemove))
 	}
 
 	la.deps.ResolveExcludes()