[compiler-rt] [sanitizer] Lift AsanDoesNotSupportStaticLinkage to sanitizer_common.h. NFC (PR #80948)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Fangrui Song (MaskRay)

<details>
<summary>Changes</summary>

The `_DYNAMIC` reference from `AsanDoesNotSupportStaticLinkage` ensures
that `clang++ -fsanitize=address -static` gets a linker error. Move the
function to sanitizer_common.h to be used by more sanitizers on ELF
platforms.

Fuchsia opts out the check as its AsanDoesNotSupportStaticLinkage is a
no-op.


---
Full diff: https://github.com/llvm/llvm-project/pull/80948.diff


10 Files Affected:

- (modified) compiler-rt/lib/asan/asan_fuchsia.cpp (-2) 
- (modified) compiler-rt/lib/asan/asan_internal.h (-1) 
- (modified) compiler-rt/lib/asan/asan_linux.cpp (-7) 
- (modified) compiler-rt/lib/asan/asan_mac.cpp (-5) 
- (modified) compiler-rt/lib/asan/asan_rtl.cpp (+2-3) 
- (modified) compiler-rt/lib/asan/asan_win.cpp (-2) 
- (modified) compiler-rt/lib/memprof/memprof_internal.h (-1) 
- (modified) compiler-rt/lib/memprof/memprof_linux.cpp (-7) 
- (modified) compiler-rt/lib/memprof/memprof_rtl.cpp (+1-1) 
- (modified) compiler-rt/lib/sanitizer_common/sanitizer_common.h (+11) 


``````````diff
diff --git a/compiler-rt/lib/asan/asan_fuchsia.cpp b/compiler-rt/lib/asan/asan_fuchsia.cpp
index 12625e9d75833..dbc4342e83388 100644
--- a/compiler-rt/lib/asan/asan_fuchsia.cpp
+++ b/compiler-rt/lib/asan/asan_fuchsia.cpp
@@ -57,8 +57,6 @@ void AsanCheckDynamicRTPrereqs() {}
 void AsanCheckIncompatibleRT() {}
 void InitializeAsanInterceptors() {}
 
-void *AsanDoesNotSupportStaticLinkage() { return nullptr; }
-
 void InitializePlatformExceptionHandlers() {}
 void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
   UNIMPLEMENTED();
diff --git a/compiler-rt/lib/asan/asan_internal.h b/compiler-rt/lib/asan/asan_internal.h
index 2944ebe213b5d..06dfc4b177339 100644
--- a/compiler-rt/lib/asan/asan_internal.h
+++ b/compiler-rt/lib/asan/asan_internal.h
@@ -80,7 +80,6 @@ void ReplaceSystemMalloc();
 
 // asan_linux.cpp / asan_mac.cpp / asan_win.cpp
 uptr FindDynamicShadowStart();
-void *AsanDoesNotSupportStaticLinkage();
 void AsanCheckDynamicRTPrereqs();
 void AsanCheckIncompatibleRT();
 
diff --git a/compiler-rt/lib/asan/asan_linux.cpp b/compiler-rt/lib/asan/asan_linux.cpp
index 37d3bad1b1ec6..cdc1912a6d832 100644
--- a/compiler-rt/lib/asan/asan_linux.cpp
+++ b/compiler-rt/lib/asan/asan_linux.cpp
@@ -51,11 +51,9 @@ extern "C" void *_DYNAMIC;
 #  elif SANITIZER_NETBSD
 #    include <link_elf.h>
 #    include <ucontext.h>
-extern Elf_Dyn _DYNAMIC;
 #  else
 #    include <link.h>
 #    include <sys/ucontext.h>
-extern ElfW(Dyn) _DYNAMIC[];
 #  endif
 
 typedef enum {
@@ -76,11 +74,6 @@ void InitializePlatformInterceptors() {}
 void InitializePlatformExceptionHandlers() {}
 bool IsSystemHeapAddress(uptr addr) { return false; }
 
-void *AsanDoesNotSupportStaticLinkage() {
-  // This will fail to link with -static.
-  return &_DYNAMIC;
-}
-
 #  if ASAN_PREMAP_SHADOW
 uptr FindPremappedShadowStart(uptr shadow_size_bytes) {
   uptr granularity = GetMmapGranularity();
diff --git a/compiler-rt/lib/asan/asan_mac.cpp b/compiler-rt/lib/asan/asan_mac.cpp
index 1b0e9b3fe0060..b250f796e165f 100644
--- a/compiler-rt/lib/asan/asan_mac.cpp
+++ b/compiler-rt/lib/asan/asan_mac.cpp
@@ -49,11 +49,6 @@ void InitializePlatformInterceptors() {}
 void InitializePlatformExceptionHandlers() {}
 bool IsSystemHeapAddress (uptr addr) { return false; }
 
-// No-op. Mac does not support static linkage anyway.
-void *AsanDoesNotSupportStaticLinkage() {
-  return 0;
-}
-
 uptr FindDynamicShadowStart() {
   return MapDynamicShadow(MemToShadowSize(kHighMemEnd), ASAN_SHADOW_SCALE,
                           /*min_shadow_base_alignment*/ 0, kHighMemEnd);
diff --git a/compiler-rt/lib/asan/asan_rtl.cpp b/compiler-rt/lib/asan/asan_rtl.cpp
index a61deed7382b0..dbfad57955c75 100644
--- a/compiler-rt/lib/asan/asan_rtl.cpp
+++ b/compiler-rt/lib/asan/asan_rtl.cpp
@@ -410,6 +410,8 @@ static bool AsanInitInternal() {
     return false;
   }
 
+  // Make sure we are not statically linked.
+  DoesNotSupportStaticLinking();
   AsanCheckIncompatibleRT();
   AsanCheckDynamicRTPrereqs();
   AvoidCVE_2016_2143();
@@ -421,9 +423,6 @@ static bool AsanInitInternal() {
 
   InitializeHighMemEnd();
 
-  // Make sure we are not statically linked.
-  AsanDoesNotSupportStaticLinkage();
-
   // Install tool-specific callbacks in sanitizer_common.
   AddDieCallback(AsanDie);
   SetCheckUnwindCallback(CheckUnwind);
diff --git a/compiler-rt/lib/asan/asan_win.cpp b/compiler-rt/lib/asan/asan_win.cpp
index 8507e675684ed..cda1f7a91e140 100644
--- a/compiler-rt/lib/asan/asan_win.cpp
+++ b/compiler-rt/lib/asan/asan_win.cpp
@@ -266,8 +266,6 @@ void PlatformTSDDtor(void *tsd) { AsanThread::TSDDtor(tsd); }
 // }}}
 
 // ---------------------- Various stuff ---------------- {{{
-void *AsanDoesNotSupportStaticLinkage() { return 0; }
-
 uptr FindDynamicShadowStart() {
   return MapDynamicShadow(MemToShadowSize(kHighMemEnd), ASAN_SHADOW_SCALE,
                           /*min_shadow_base_alignment*/ 0, kHighMemEnd);
diff --git a/compiler-rt/lib/memprof/memprof_internal.h b/compiler-rt/lib/memprof/memprof_internal.h
index 990e62ce1a55d..ad61d829d72ca 100644
--- a/compiler-rt/lib/memprof/memprof_internal.h
+++ b/compiler-rt/lib/memprof/memprof_internal.h
@@ -61,7 +61,6 @@ void ReplaceSystemMalloc();
 
 // memprof_linux.cpp
 uptr FindDynamicShadowStart();
-void *MemprofDoesNotSupportStaticLinkage();
 
 // memprof_thread.cpp
 MemprofThread *CreateMainThread();
diff --git a/compiler-rt/lib/memprof/memprof_linux.cpp b/compiler-rt/lib/memprof/memprof_linux.cpp
index fcb6f662a82e5..26a2b456b874e 100644
--- a/compiler-rt/lib/memprof/memprof_linux.cpp
+++ b/compiler-rt/lib/memprof/memprof_linux.cpp
@@ -38,8 +38,6 @@
 #include <unistd.h>
 #include <unwind.h>
 
-extern ElfW(Dyn) _DYNAMIC[];
-
 typedef enum {
   MEMPROF_RT_VERSION_UNDEFINED = 0,
   MEMPROF_RT_VERSION_DYNAMIC,
@@ -57,11 +55,6 @@ namespace __memprof {
 void InitializePlatformInterceptors() {}
 void InitializePlatformExceptionHandlers() {}
 
-void *MemprofDoesNotSupportStaticLinkage() {
-  // This will fail to link with -static.
-  return &_DYNAMIC;
-}
-
 uptr FindDynamicShadowStart() {
   uptr shadow_size_bytes = MemToShadowSize(kHighMemEnd);
   return MapDynamicShadow(shadow_size_bytes, SHADOW_SCALE,
diff --git a/compiler-rt/lib/memprof/memprof_rtl.cpp b/compiler-rt/lib/memprof/memprof_rtl.cpp
index 5e2e7bc2be3f7..83e377f8e4307 100644
--- a/compiler-rt/lib/memprof/memprof_rtl.cpp
+++ b/compiler-rt/lib/memprof/memprof_rtl.cpp
@@ -162,7 +162,7 @@ static void MemprofInitInternal() {
   InitializeHighMemEnd();
 
   // Make sure we are not statically linked.
-  MemprofDoesNotSupportStaticLinkage();
+  DoesNotSupportStaticLinking();
 
   // Install tool-specific callbacks in sanitizer_common.
   AddDieCallback(MemprofDie);
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common.h b/compiler-rt/lib/sanitizer_common/sanitizer_common.h
index b99c0cffcbb11..999ddb2f82dbc 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common.h
@@ -290,6 +290,17 @@ bool SetEnv(const char *name, const char *value);
 
 u32 GetUid();
 void ReExec();
+
+#if defined(__ELF__) && !SANITIZER_FUCHSIA
+extern uptr kDynamic[] asm("_DYNAMIC");
+inline void DoesNotSupportStaticLinking() {
+  // This will fail to link with -static. However, -static-pie is not detected.
+  [[maybe_unused]] volatile auto x = &kDynamic;
+}
+#else
+inline void DoesNotSupportStaticLinking() {}
+#endif
+
 void CheckASLR();
 void CheckMPROTECT();
 char **GetArgv();

``````````

</details>


https://github.com/llvm/llvm-project/pull/80948