[release/6.0] Fix build with Clang 13 (#63314)

* Fix clang 13 induced runtime issues (#62170)

The clang 13 optimizer started to assume that "this" pointer is always
properly aligned. That lead to elimination of some code that was actually
needed.
It also takes pointer aliasing rules more strictly in one place in jit.
That caused the optimizer to falsely assume that a callee with an argument
passed by reference is not modifying that argument and used a stale
copy of the original value at the caller site.

This change fixes both of the issues. With this fix, runtime compiled
using clang 13 seems to be fully functional.

* Fix build with clang 13 (#60328)

diff --git a/eng/native/configurecompiler.cmake b/eng/native/configurecompiler.cmake
index c22469f567b726f41e09a963324452873c5d3c7f..502d432f17bb3fc510e81c1b63c4f5adb94e91a7 100644 (file)
--- a/eng/native/configurecompiler.cmake
+++ b/eng/native/configurecompiler.cmake
@@ -340,15 +340,17 @@ if (CLR_CMAKE_HOST_UNIX)
   #These seem to indicate real issues
   add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-Wno-invalid-offsetof>)
 
-  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  add_compile_options(-Wno-unused-but-set-variable)
+
+  if (CMAKE_C_COMPILER_ID MATCHES "Clang")
+    add_compile_options(-Wno-unknown-warning-option)
+
     # The -ferror-limit is helpful during the porting, it makes sure the compiler doesn't stop
     # after hitting just about 20 errors.
     add_compile_options(-ferror-limit=4096)
 
     # Disabled warnings
     add_compile_options(-Wno-unused-private-field)
-    # Explicit constructor calls are not supported by clang (this->ClassName::ClassName())
-    add_compile_options(-Wno-microsoft)
     # There are constants of type BOOL used in a condition. But BOOL is defined as int
     # and so the compiler thinks that there is a mistake.
     add_compile_options(-Wno-constant-logical-operand)
@@ -363,8 +365,9 @@ if (CLR_CMAKE_HOST_UNIX)
     # to a struct or a class that has virtual members or a base class. In that case, clang
     # may not generate the same object layout as MSVC.
     add_compile_options(-Wno-incompatible-ms-struct)
+
+    add_compile_options(-Wno-reserved-identifier)
   else()
-    add_compile_options(-Wno-unused-but-set-variable)
     add_compile_options(-Wno-unknown-pragmas)
     add_compile_options(-Wno-uninitialized)
     add_compile_options(-Wno-strict-aliasing)

diff --git a/src/coreclr/inc/corhlpr.h b/src/coreclr/inc/corhlpr.h
index 450514da95c180b21264b9399418f6bf82045239..427e8cdc0ff5c5ac1d3206b9149113195a894df3 100644 (file)
--- a/src/coreclr/inc/corhlpr.h
+++ b/src/coreclr/inc/corhlpr.h
@@ -336,7 +336,7 @@ struct COR_ILMETHOD_SECT
     const COR_ILMETHOD_SECT* Next() const
     {
         if (!More()) return(0);
-        return ((COR_ILMETHOD_SECT*)(((BYTE *)this) + DataSize()))->Align();
+        return ((COR_ILMETHOD_SECT*)Align(((BYTE *)this) + DataSize()));
     }
 
     const BYTE* Data() const
@@ -374,9 +374,9 @@ struct COR_ILMETHOD_SECT
         return((AsSmall()->Kind & CorILMethod_Sect_FatFormat) != 0);
     }
 
-    const COR_ILMETHOD_SECT* Align() const
+    static const void* Align(const void* p)
     {
-        return((COR_ILMETHOD_SECT*) ((((UINT_PTR) this) + 3) & ~3));
+        return((void*) ((((UINT_PTR) p) + 3) & ~3));
     }
 
 protected:
@@ -579,7 +579,7 @@ typedef struct tagCOR_ILMETHOD_FAT : IMAGE_COR_ILMETHOD_FAT
 
     const COR_ILMETHOD_SECT* GetSect() const {
         if (!More()) return (0);
-        return(((COR_ILMETHOD_SECT*) (GetCode() + GetCodeSize()))->Align());
+        return(((COR_ILMETHOD_SECT*) COR_ILMETHOD_SECT::Align(GetCode() + GetCodeSize())));
     }
 } COR_ILMETHOD_FAT;
 

diff --git a/src/coreclr/jit/bitsetasshortlong.h b/src/coreclr/jit/bitsetasshortlong.h
index dce54d6a5ca3ab7786752fecc489fb1ffeeb7369..365cf346a10ac2197dfe8fee079a45d68566324b 100644 (file)
--- a/src/coreclr/jit/bitsetasshortlong.h
+++ b/src/coreclr/jit/bitsetasshortlong.h
@@ -345,7 +345,7 @@ public:
     {
         if (IsShort(env))
         {
-            (size_t&)out = (size_t)out & ((size_t)gen | (size_t)in);
+            out = (BitSetShortLongRep)((size_t)out & ((size_t)gen | (size_t)in));
         }
         else
         {
@@ -361,7 +361,7 @@ public:
     {
         if (IsShort(env))
         {
-            (size_t&)in = (size_t)use | ((size_t)out & ~(size_t)def);
+            in = (BitSetShortLongRep)((size_t)use | ((size_t)out & ~(size_t)def));
         }
         else
         {

diff --git a/src/coreclr/jit/inlinepolicy.h b/src/coreclr/jit/inlinepolicy.h
index 466e17fe0e11274051d03eeeabe26908cdd15437..e604fd57a36ed5633d177cafdc6350d9a23960fe 100644 (file)
--- a/src/coreclr/jit/inlinepolicy.h
+++ b/src/coreclr/jit/inlinepolicy.h
@@ -185,7 +185,7 @@ protected:
 class ExtendedDefaultPolicy : public DefaultPolicy
 {
 public:
-    ExtendedDefaultPolicy::ExtendedDefaultPolicy(Compiler* compiler, bool isPrejitRoot)
+    ExtendedDefaultPolicy(Compiler* compiler, bool isPrejitRoot)
         : DefaultPolicy(compiler, isPrejitRoot)
         , m_ProfileFrequency(0.0)
         , m_BinaryExprWithCns(0)

diff --git a/src/libraries/Native/Unix/CMakeLists.txt b/src/libraries/Native/Unix/CMakeLists.txt
index 31cea57a629380e0175ac4a8f012f92ad0e8a4d5..6fae902369c0e81a565b32f0feb620afbaf3518b 100644 (file)
--- a/src/libraries/Native/Unix/CMakeLists.txt
+++ b/src/libraries/Native/Unix/CMakeLists.txt
@@ -36,6 +36,8 @@ add_compile_options(-Wno-cast-align)
 add_compile_options(-Wno-typedef-redefinition)
 add_compile_options(-Wno-c11-extensions)
 add_compile_options(-Wno-unknown-pragmas)
+add_compile_options(-Wno-unknown-warning-option)
+add_compile_options(-Wno-unused-but-set-variable)
 
 check_c_compiler_flag(-Wimplicit-fallthrough COMPILER_SUPPORTS_W_IMPLICIT_FALLTHROUGH)
 if (COMPILER_SUPPORTS_W_IMPLICIT_FALLTHROUGH)
@@ -48,6 +50,7 @@ add_compile_options(-g)
 if(CMAKE_C_COMPILER_ID STREQUAL Clang)
     add_compile_options(-Wthread-safety)
     add_compile_options(-Wno-thread-safety-analysis)
+    add_compile_options(-Wno-reserved-identifier)
 elseif(CMAKE_C_COMPILER_ID STREQUAL GNU)
     add_compile_options(-Wno-stringop-truncation)
 endif()

diff --git a/src/libraries/Native/Unix/System.Native/pal_process.c b/src/libraries/Native/Unix/System.Native/pal_process.c
index 5e97d958f74d176d209583fdfb04bfa917306020..fabdfae76187caf36bba9ea1294055aac0ec0faf 100644 (file)
--- a/src/libraries/Native/Unix/System.Native/pal_process.c
+++ b/src/libraries/Native/Unix/System.Native/pal_process.c
@@ -191,6 +191,24 @@ static int SetGroups(uint32_t* userGroups, int32_t userGroupsLength, uint32_t* p
     return rv;
 }
 
+typedef void (*VoidIntFn)(int);
+
+static
+VoidIntFn
+handler_from_sigaction (struct sigaction *sa)
+{
+    if (((unsigned int)sa->sa_flags) & SA_SIGINFO)
+    {
+        // work around -Wcast-function-type
+        void (*tmp)(void) = (void (*)(void))sa->sa_sigaction;
+        return (void (*)(int))tmp;
+    }
+    else
+    {
+        return sa->sa_handler;
+    }
+}
+
 int32_t SystemNative_ForkAndExecProcess(const char* filename,
                                       char* const argv[],
                                       char* const envp[],
@@ -371,7 +389,7 @@ int32_t SystemNative_ForkAndExecProcess(const char* filename,
             }
             if (!sigaction(sig, NULL, &sa_old))
             {
-                void (*oldhandler)(int) = (((unsigned int)sa_old.sa_flags) & SA_SIGINFO) ? (void (*)(int))sa_old.sa_sigaction : sa_old.sa_handler;
+                void (*oldhandler)(int) = handler_from_sigaction (&sa_old);
                 if (oldhandler != SIG_IGN && oldhandler != SIG_DFL)
                 {
                     // It has a custom handler, put the default handler back.