[clang] Warn when using msan on Android (PR #122540)

[Sharjeel Khan via cfe-commits]

https://github.com/Sharjeel-Khan created https://github.com/llvm/llvm-project/pull/122540

Msan is not supported on Android as mentioned in google/sanitizers#1381. We proactively give the warning saying it is unsupported to fix android/ndk#1958.

>From 4a1f619925d0b2e1003ffb69c5bcc2a28aba63c3 Mon Sep 17 00:00:00 2001
From: Sharjeel Khan <sharjeelkhan at google.com>
Date: Fri, 10 Jan 2025 20:07:52 +0000
Subject: [PATCH] Error when using msan on Android

Msan is not supported on Android as mentioned in google/sanitizers#1381.
We proactively give the warning saying it is unsupported to fix android/ndk#1958.
---
 clang/lib/Driver/SanitizerArgs.cpp | 10 ++++++++++
 clang/test/Driver/fsanitize.c      |  5 +++++
 2 files changed, 15 insertions(+)

diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
index a0d6919c6dc8d0..04b39d29e7342f 100644
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -530,6 +530,16 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
       }
       Add &= Supported;
 
+      // Msan is not supported on Android
+      if ((Add & SanitizerKind::Memory) && TC.getTriple().isAndroid()) {
+        if (DiagnoseErrors) {
+          D.Diag(diag::warn_drv_unsupported_option_for_target)
+                  << "-fsanitize=memory" << Triple.str();
+        }
+        DiagnosedKinds |= SanitizerKind::Memory;
+        Add &= ~SanitizerKind::Memory;
+      }
+
       // Test for -fno-rtti + explicit -fsanitizer=vptr before expanding groups
       // so we don't error out if -fno-rtti and -fsanitize=undefined were
       // passed.
diff --git a/clang/test/Driver/fsanitize.c b/clang/test/Driver/fsanitize.c
index 1d3caec748d77a..55b51ed29b0e65 100644
--- a/clang/test/Driver/fsanitize.c
+++ b/clang/test/Driver/fsanitize.c
@@ -399,6 +399,11 @@
 // RUN: %clang --target=arm-linux-androideabi %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ANDROID-NO-ASAN
 // CHECK-ANDROID-NO-ASAN: "-mrelocation-model" "pic"
 
+// RUN: %clang --target=aarch64-linux-android -fsanitize=memory %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-MSAN-ANDROID
+// RUN: %clang --target=i386-linux-android -fsanitize=memory %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-MSAN-ANDROID
+// RUN: %clang --target=x86_64-linux-android -fsanitize=memory %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-MSAN-ANDROID
+// CHECK-MSAN-ANDROID: ignoring '-fsanitize=memory' option as it is not currently supported for target
+
 // RUN: %clang --target=x86_64-linux-gnu %s -fsanitize=undefined -### 2>&1 | FileCheck %s --check-prefix=CHECK-RECOVER-UBSAN
 // RUN: %clang --target=x86_64-linux-gnu %s -fsanitize=undefined -fsanitize-recover -### 2>&1 | FileCheck %s --check-prefix=CHECK-RECOVER-UBSAN
 // RUN: %clang --target=x86_64-linux-gnu %s -fsanitize=undefined -fsanitize-recover=all -### 2>&1 | FileCheck %s --check-prefix=CHECK-RECOVER-UBSAN