[clang] [clang] Don't pass sanitizers' rtlibs to linker with `-r` (PR #147905)

[Dmitry Chestnykh via cfe-commits]

https://github.com/chestnykh updated https://github.com/llvm/llvm-project/pull/147905

>From 86dc26e3947d2d53e9b86d700946e7f381f71a7a Mon Sep 17 00:00:00 2001
From: Dmitry Chestnykh <dm.chestnykh at gmail.com>
Date: Thu, 10 Jul 2025 10:19:31 +0300
Subject: [PATCH 1/2] [clang] Don't pass sanitizers' rtlibs to linker with `-r`

If clang is invoked with `-r` (relocatable linking)
then we shouldn't construct sanitizer arguments and
then pass sanitizer runtime libs to the linker
GCC also skips runtime linking if `-r` is also here
---
 clang/lib/Driver/SanitizerArgs.cpp |  3 ++-
 clang/test/Driver/sanitizer-ld.c   | 16 ++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
index 4bd61c2f8deef..6547e3bd07a77 100644
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -1159,7 +1159,8 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
 
   LinkRuntimes =
       Args.hasFlag(options::OPT_fsanitize_link_runtime,
-                   options::OPT_fno_sanitize_link_runtime, LinkRuntimes);
+                   options::OPT_fno_sanitize_link_runtime, LinkRuntimes) &&
+      !Args.hasArg(options::OPT_r);
 
   // Parse -link-cxx-sanitizer flag.
   LinkCXXRuntimes = D.CCCIsCXX();
diff --git a/clang/test/Driver/sanitizer-ld.c b/clang/test/Driver/sanitizer-ld.c
index d2e4877e89d78..5144dbc2007d3 100644
--- a/clang/test/Driver/sanitizer-ld.c
+++ b/clang/test/Driver/sanitizer-ld.c
@@ -1369,3 +1369,19 @@
 // CHECK-DSO-SHARED-HWASAN-AARCH64-LINUX-NOT: "-lresolv"
 // CHECK-DSO-SHARED-HWASAN-AARCH64-LINUX-NOT: "--export-dynamic"
 // CHECK-DSO-SHARED-HWASAN-AARCH64-LINUX-NOT: "--dynamic-list"
+
+// RUN: %clang -fsanitize=address,undefined -r -### %s 2>&1 \
+// RUN:     --target=x86_64-unknown-linux -fuse-ld=ld \
+// RUN:     -resource-dir=%S/Inputs/resource_dir \
+// RUN:     --sysroot=%S/Inputs/basic_linux_tree \
+// RUN:   | %{filecheck} --check-prefix=CHECK-RELOCATABLE-LINK-ASAN-UBSAN-RTLIB
+//
+// CHECK-RELOCATABLE-LINK-ASAN-UBSAN-RTLIB-NOT: "{{.*}}(asan|ubsan){{.*}}"
+
+// RUN: %clang -fsanitize=thread -r -### %s 2>&1 \
+// RUN:     --target=x86_64-unknown-linux -fuse-ld=ld \
+// RUN:     -resource-dir=%S/Inputs/resource_dir \
+// RUN:     --sysroot=%S/Inputs/basic_linux_tree \
+// RUN:   | %{filecheck} --check-prefix=CHECK-RELOCATABLE-LINK-TSAN-RTLIB
+//
+// CHECK-RELOCATABLE-LINK-TSAN-RTLIB-NOT: "{{.*}}tsan{{.*}}"

>From 47f92e6c4a0cb4fc32e4bda4db1b0f9e9dd0ccf0 Mon Sep 17 00:00:00 2001
From: Dmitry Chestnykh <dm.chestnykh at gmail.com>
Date: Sat, 12 Jul 2025 07:39:18 +0300
Subject: [PATCH 2/2] Force link sanitizer rtlib with `-fsnaitize-link-runtime`

---
 clang/lib/Driver/SanitizerArgs.cpp | 3 ++-
 clang/test/Driver/sanitizer-ld.c   | 8 ++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
index 6547e3bd07a77..de9a016d643e6 100644
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -1160,7 +1160,8 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
   LinkRuntimes =
       Args.hasFlag(options::OPT_fsanitize_link_runtime,
                    options::OPT_fno_sanitize_link_runtime, LinkRuntimes) &&
-      !Args.hasArg(options::OPT_r);
+      Args.hasFlag(options::OPT_fsanitize_link_runtime, options::OPT_r,
+                   LinkRuntimes);
 
   // Parse -link-cxx-sanitizer flag.
   LinkCXXRuntimes = D.CCCIsCXX();
diff --git a/clang/test/Driver/sanitizer-ld.c b/clang/test/Driver/sanitizer-ld.c
index 5144dbc2007d3..ac1851286af63 100644
--- a/clang/test/Driver/sanitizer-ld.c
+++ b/clang/test/Driver/sanitizer-ld.c
@@ -1378,6 +1378,14 @@
 //
 // CHECK-RELOCATABLE-LINK-ASAN-UBSAN-RTLIB-NOT: "{{.*}}(asan|ubsan){{.*}}"
 
+// RUN: %clang -fsanitize=address -r -fsanitize-link-runtime -### %s 2>&1 \
+// RUN:     --target=x86_64-unknown-linux -fuse-ld=ld \
+// RUN:     -resource-dir=%S/Inputs/resource_dir \
+// RUN:     --sysroot=%S/Inputs/basic_linux_tree \
+// RUN:   | FileCheck %s --check-prefix=CHECK-RELOCATABLE-LINK-FORCE-LINK-ASAN
+//
+// CHECK-RELOCATABLE-LINK-FORCE-LINK-ASAN: "{{.*}}asan{{.*}}"
+
 // RUN: %clang -fsanitize=thread -r -### %s 2>&1 \
 // RUN:     --target=x86_64-unknown-linux -fuse-ld=ld \
 // RUN:     -resource-dir=%S/Inputs/resource_dir \