Minor cc_cmake_snapshot touch-ups

- Partial support for arm64 hosts (no prebuilts yet)
- Replace incorrect template function use MATCHES with STREQUAL
- Add more ignored system libs
- No need to explicitly add libc++ prebuilt

Bug: 285204695
Test: m binder_sdk
Change-Id: Id6508cc9f9ee6328c95c2821c325629f84eda138

cc/cmake_ext_add_aidl_library.txt

@@ -25,7 +25,7 @@ function(add_aidl_library NAME LANG AIDLROOT SOURCES AIDLFLAGS)
         endif()
 
         set(DEPFILE_ARG)
-        if (NOT ${CMAKE_GENERATOR} MATCHES "Unix Makefiles")
+        if (NOT ${CMAKE_GENERATOR} STREQUAL "Unix Makefiles")
             set(DEPFILE_ARG DEPFILE "${GEN_SOURCE}.d")
         endif()
 
@@ -57,7 +57,7 @@ function(add_aidl_library NAME LANG AIDLROOT SOURCES AIDLFLAGS)
         "${GEN_DIR}/include"
     )
 
-    if (${LANG} MATCHES "ndk")
+    if (${LANG} STREQUAL "ndk")
         set(BINDER_LIB_NAME "libbinder_ndk_sdk")
     else()
         set(BINDER_LIB_NAME "libbinder_sdk")

cc/cmake_main.txt

@@ -11,7 +11,11 @@ if (NOT ANDROID_BUILD_TOP)
     set(ANDROID_BUILD_TOP "${CMAKE_CURRENT_SOURCE_DIR}")
 endif()
 
-set(PREBUILTS_BIN_DIR "${CMAKE_CURRENT_SOURCE_DIR}/prebuilts/host/linux-x86/bin")
+if ("${CMAKE_HOST_SYSTEM_PROCESSOR}" MATCHES "^(arm|aarch)")
+    set(PREBUILTS_BIN_DIR "${CMAKE_CURRENT_SOURCE_DIR}/prebuilts/host/linux_musl-arm64/bin")
+else()
+    set(PREBUILTS_BIN_DIR "${CMAKE_CURRENT_SOURCE_DIR}/prebuilts/host/linux-x86/bin")
+endif()
 if (NOT AIDL_BIN)
     find_program(AIDL_BIN aidl REQUIRED HINTS "${PREBUILTS_BIN_DIR}")
 endif()

cc/cmake_snapshot.go

@@ -61,8 +61,13 @@ var defaultUnportableFlags []string = []string{
 }
 
 var ignoredSystemLibs []string = []string{
+	"crtbegin_dynamic",
+	"crtend_android",
+	"libc",
 	"libc++",
 	"libc++_static",
+	"libdl",
+	"libm",
 	"prebuilt_libclang_rt.builtins",
 	"prebuilt_libclang_rt.ubsan_minimal",
 }
@@ -267,7 +272,11 @@ func (m *CmakeSnapshot) DepsMutator(ctx android.BottomUpMutatorContext) {
 		{"arch", "x86_64"},
 	}
 	ctx.AddVariationDependencies(variations, cmakeSnapshotModuleTag, m.Properties.Modules...)
-	ctx.AddVariationDependencies(variations, cmakeSnapshotPrebuiltTag, m.Properties.Prebuilts...)
+
+	if len(m.Properties.Prebuilts) > 0 {
+		prebuilts := append(m.Properties.Prebuilts, "libc++")
+		ctx.AddVariationDependencies(variations, cmakeSnapshotPrebuiltTag, prebuilts...)
+	}
 }
 
 func (m *CmakeSnapshot) GenerateAndroidBuildActions(ctx android.ModuleContext) {