Merge changes I6f7d40b7,I25654032

* changes:
  add a library to report build numbers without causing rebuilds
  Rewrite symbol_inject to be testable

cc/binary.go

@@ -323,6 +323,12 @@ func (binary *binaryDecorator) link(ctx ModuleContext,
 			flagsToBuilderFlags(flags), afterPrefixSymbols)
 	}
 
+	if Bool(binary.baseLinker.Properties.Use_version_lib) && ctx.Host() {
+		versionedOutputFile := outputFile
+		outputFile = android.PathForModuleOut(ctx, "unversioned", fileName)
+		binary.injectVersionSymbol(ctx, outputFile, versionedOutputFile)
+	}
+
 	linkerDeps = append(linkerDeps, deps.SharedLibsDeps...)
 	linkerDeps = append(linkerDeps, deps.LateSharedLibsDeps...)
 	linkerDeps = append(linkerDeps, objs.tidyFiles...)

cc/libbuildversion/Android.bp

@@ -0,0 +1,12 @@
+cc_library_static {
+    name: "libbuildversion",
+    host_supported: true,
+    srcs: ["libbuildversion.cpp"],
+    export_include_dirs: ["include"],
+    cflags: ["-fvisibility=hidden"],
+    target: {
+        windows: {
+            enabled: true,
+        },
+    },
+}

cc/libbuildversion/include/build/version.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef BUILD_VERSION_H
+#define BUILD_VERSION_H
+
+#include <string>
+
+namespace android {
+namespace build {
+
+std::string GetBuildNumber();
+
+} // namespace build
+} // namespace android
+
+#endif  // BUILD_VERSION_H

cc/libbuildversion/libbuildversion.cpp

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <build/version.h>
+
+#ifdef __ANDROID__
+#include <sys/system_properties.h>
+#endif
+
+namespace android {
+namespace build {
+
+#ifdef __ANDROID__
+
+std::string GetBuildNumber() {
+  const prop_info* pi = __system_property_find("ro.build.version.incremental");
+  if (pi == nullptr) return "";
+
+  std::string property_value;
+  __system_property_read_callback(pi,
+                                  [](void* cookie, const char*, const char* value, unsigned) {
+                                    auto property_value = reinterpret_cast<std::string*>(cookie);
+                                    *property_value = value;
+                                  },
+                                  &property_value);
+
+  return property_value;
+}
+
+#else
+
+extern "C" {
+  char soong_build_number[128] = "SOONG BUILD NUMBER PLACEHOLDER";
+}
+
+std::string GetBuildNumber() {
+  return soong_build_number;
+}
+
+#endif
+}  // namespace build
+}  // namespace android

cc/libbuildversion/tests/Android.bp

@@ -0,0 +1,35 @@
+cc_defaults {
+    name: "build_version_test_defaults",
+    use_version_lib: true,
+    host_supported: true,
+    target: {
+        windows: {
+            enabled: true,
+        },
+    },
+}
+
+cc_test {
+    name: "build_version_test",
+    defaults: ["build_version_test_defaults"],
+    srcs: ["build_version_test.cpp"],
+    target: {
+        android: {
+            shared_libs: ["libbuild_version_test"],
+        },
+        not_windows: {
+            shared_libs: ["libbuild_version_test"],
+        },
+    },
+}
+
+cc_library_shared {
+    name: "libbuild_version_test",
+    defaults: ["build_version_test_defaults"],
+    srcs: ["build_version_test_lib.cpp"],
+    target: {
+        windows: {
+            enabled: false,
+        },
+    },
+}

cc/libbuildversion/tests/build_version_test.cpp

@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+
+#include <gtest/gtest.h>
+
+#include <build/version.h>
+
+#include "build_version_test_lib.h"
+
+TEST(BuildNumber, binary) {
+  printf("binary version: %s\n", android::build::GetBuildNumber().c_str());
+  EXPECT_NE(android::build::GetBuildNumber(), "SOONG BUILD NUMBER PLACEHOLDER");
+}
+
+  // symbol_inject doesn't support dlls
+#ifndef __WIN32__
+TEST(BuildNumber, library) {
+  printf("shared library version: %s\n", LibGetBuildNumber().c_str());
+  EXPECT_NE(LibGetBuildNumber(), "SOONG BUILD NUMBER PLACEHOLDER");
+}
+#endif

cc/libbuildversion/tests/build_version_test_lib.cpp

@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <build/version.h>
+
+#include "build_version_test_lib.h"
+
+std::string LibGetBuildNumber() {
+  return android::build::GetBuildNumber();
+}

cc/libbuildversion/tests/build_version_test_lib.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef BUILD_VERSION_TEST_LIB_H_
+#define BUILD_VERSION_TEST_LIB_H_
+
+#include <string>
+
+std::string __attribute__((visibility("default"))) LibGetBuildNumber();
+
+#endif // BUILD_VERSION_TEST_LIB_H_

cc/library.go

@@ -492,10 +492,16 @@ func (library *libraryDecorator) linkStatic(ctx ModuleContext,
 	library.objects = deps.WholeStaticLibObjs.Copy()
 	library.objects = library.objects.Append(objs)
 
-	outputFile := android.PathForModuleOut(ctx,
-		ctx.ModuleName()+library.MutatedProperties.VariantName+staticLibraryExtension)
+	fileName := ctx.ModuleName() + library.MutatedProperties.VariantName + staticLibraryExtension
+	outputFile := android.PathForModuleOut(ctx, fileName)
 	builderFlags := flagsToBuilderFlags(flags)
 
+	if Bool(library.baseLinker.Properties.Use_version_lib) && ctx.Host() {
+		versionedOutputFile := outputFile
+		outputFile = android.PathForModuleOut(ctx, "unversioned", fileName)
+		library.injectVersionSymbol(ctx, outputFile, versionedOutputFile)
+	}
+
 	TransformObjToStaticLib(ctx, library.objects.objFiles, builderFlags, outputFile, objs.tidyFiles)
 
 	library.coverageOutputFile = TransformCoverageFilesToLib(ctx, library.objects, builderFlags,
@@ -585,6 +591,12 @@ func (library *libraryDecorator) linkShared(ctx ModuleContext,
 		library.stripper.strip(ctx, outputFile, strippedOutputFile, builderFlags)
 	}
 
+	if Bool(library.baseLinker.Properties.Use_version_lib) && ctx.Host() {
+		versionedOutputFile := outputFile
+		outputFile = android.PathForModuleOut(ctx, "unversioned", fileName)
+		library.injectVersionSymbol(ctx, outputFile, versionedOutputFile)
+	}
+
 	sharedLibs := deps.SharedLibs
 	sharedLibs = append(sharedLibs, deps.LateSharedLibs...)
 

cc/linker.go

@@ -18,6 +18,7 @@ import (
 	"android/soong/android"
 	"fmt"
 
+	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 )
 
@@ -95,6 +96,9 @@ type BaseLinkerProperties struct {
 			Exclude_static_libs []string
 		}
 	}
+
+	// make android::build:GetBuildNumber() available containing the build ID.
+	Use_version_lib *bool `android:"arch_variant"`
 }
 
 func NewBaseLinker() *baseLinker {
@@ -136,6 +140,10 @@ func (linker *baseLinker) linkerDeps(ctx BaseModuleContext, deps Deps) Deps {
 	deps.ReexportSharedLibHeaders = append(deps.ReexportSharedLibHeaders, linker.Properties.Export_shared_lib_headers...)
 	deps.ReexportGeneratedHeaders = append(deps.ReexportGeneratedHeaders, linker.Properties.Export_generated_headers...)
 
+	if Bool(linker.Properties.Use_version_lib) {
+		deps.WholeStaticLibs = append(deps.WholeStaticLibs, "libbuildversion")
+	}
+
 	if ctx.useVndk() {
 		deps.SharedLibs = removeListFromList(deps.SharedLibs, linker.Properties.Target.Vendor.Exclude_shared_libs)
 		deps.ReexportSharedLibHeaders = removeListFromList(deps.ReexportSharedLibHeaders, linker.Properties.Target.Vendor.Exclude_shared_libs)
@@ -278,3 +286,31 @@ func (linker *baseLinker) link(ctx ModuleContext,
 	flags Flags, deps PathDeps, objs Objects) android.Path {
 	panic(fmt.Errorf("baseLinker doesn't know how to link"))
 }
+
+// Injecting version symbols
+// Some host modules want a version number, but we don't want to rebuild it every time.  Optionally add a step
+// after linking that injects a constant placeholder with the current version number.
+
+func init() {
+	pctx.HostBinToolVariable("symbolInjectCmd", "symbol_inject")
+}
+
+var injectVersionSymbol = pctx.AndroidStaticRule("injectVersionSymbol",
+	blueprint.RuleParams{
+		Command: "$symbolInjectCmd -i $in -o $out -s soong_build_number " +
+			"-from 'SOONG BUILD NUMBER PLACEHOLDER' -v $buildNumberFromFile",
+		CommandDeps: []string{"$symbolInjectCmd"},
+	},
+	"buildNumberFromFile")
+
+func (linker *baseLinker) injectVersionSymbol(ctx ModuleContext, in android.Path, out android.WritablePath) {
+	ctx.Build(pctx, android.BuildParams{
+		Rule:        injectVersionSymbol,
+		Description: "inject version symbol",
+		Input:       in,
+		Output:      out,
+		Args: map[string]string{
+			"buildNumberFromFile": ctx.Config().BuildNumberFromFile(),
+		},
+	})
+}