Android: Add buildId option to the ndk for the linker

Allow to overwrite default value (sha1) for the --build-id linker flag.

Task-number: QBS-1668
Change-Id: Ib26904019eb68c94d345d0e33648b04ccf830de1
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

4 files changed, 29 insertions, 3 deletions

diff --git a/doc/reference/modules/android-ndk-module.qdoc b/doc/reference/modules/android-ndk-module.qdoc
index 4740480b3..d3b16e2bf 100644
--- a/doc/reference/modules/android-ndk-module.qdoc
+++ b/doc/reference/modules/android-ndk-module.qdoc
@@ -78,6 +78,17 @@
 */
 
 /*!
+    \qmlproperty string Android.ndk::buildId
+
+    Value to pass to the --build-id linker flag.
+    Plain --build-id option is used when buildId property is empty.
+
+    \since Qbs 1.21
+
+    \defaultvalue \c "sha1"
+*/
+
+/*!
     \qmlproperty string Android.ndk::appStl
 
     The library to use for C++. The possible values are:
diff --git a/share/qbs/modules/Android/ndk/ndk.qbs b/share/qbs/modules/Android/ndk/ndk.qbs
index 39042c086..3b223e4fb 100644
--- a/share/qbs/modules/Android/ndk/ndk.qbs
+++ b/share/qbs/modules/Android/ndk/ndk.qbs
@@ -50,6 +50,20 @@ Module {
         description: "Supported Android ABIs"
         allowedValues: ["arm64-v8a", "armeabi-v7a", "x86", "x86_64"]
     }
+    // From https://android.googlesource.com/platform/ndk/+/refs/heads/ndk-release-r21/docs/BuildSystemMaintainers.md
+    // Android Studio‘s LLDB debugger uses a binary’s build ID to locate debug information. To
+    // ensure that LLDB works with a binary, pass an option like -Wl,--build-id=sha1 to Clang when
+    // linking. Other --build-id= modes are OK, but avoid a plain --build-id argument when using
+    // LLD, because Android Studio‘s version of LLDB doesn’t recognize LLD's default 8-byte build
+    // ID. See Issue 885.
+
+    // Plain --build-id option is nevertheless implemented when buildId property is empty.
+
+    // Possible values (from man page of ld.lld — ELF linker from the LLVM project):
+    // one of fast, md5, sha1, tree, uuid, 0xhex-string, and none. tree is an alias for sha1.
+    // Build-IDs of type fast, md5, sha1, and tree are calculated from the object contents. fast is
+    // not intended to be cryptographically secure.
+    property string buildId: "sha1"
 
     // See https://developer.android.com/ndk/guides/cpp-support.html
     property string appStl: "c++_shared"
diff --git a/share/qbs/modules/Android/ndk/utils.js b/share/qbs/modules/Android/ndk/utils.js
index e763ed9b6..ab312921e 100644
--- a/share/qbs/modules/Android/ndk/utils.js
+++ b/share/qbs/modules/Android/ndk/utils.js
@@ -96,8 +96,9 @@ function commonCompilerFlags(toolchain, buildVariant, ndk) {
     return flags;
 }
 
-function commonLinkerFlags(abi) {
-    return ["-z", "noexecstack", "-z", "relro", "-z", "now", "--build-id=sha1", "--gc-sections" ];
+function commonLinkerFlags(ndk) {
+    var buildId = (ndk.buildId) ? "--build-id=" + ndk.buildId : "--build-id";
+    return ["-z", "noexecstack", "-z", "relro", "-z", "now", buildId, "--gc-sections"];
 }
 
 function stlFileName(prefix, ndk, suffix) {
diff --git a/share/qbs/modules/cpp/android-gcc.qbs b/share/qbs/modules/cpp/android-gcc.qbs
index 17e1f72ed..a5061e166 100644
--- a/share/qbs/modules/cpp/android-gcc.qbs
+++ b/share/qbs/modules/cpp/android-gcc.qbs
@@ -100,7 +100,7 @@ LinuxGCC {
 
     commonCompilerFlags: NdkUtils.commonCompilerFlags(qbs.toolchain, qbs.buildVariant, Android.ndk)
 
-    linkerFlags: NdkUtils.commonLinkerFlags(Android.ndk.abi);
+    linkerFlags: NdkUtils.commonLinkerFlags(Android.ndk);
     driverLinkerFlags: {
         var flags = ["-fuse-ld=lld", "-Wl,--exclude-libs,libgcc.a", "-nostdlib++"];
         // See https://android.googlesource.com/platform/ndk/+/ndk-release-r21/docs/BuildSystemMaintainers.md#Unwinding