Fix setjmp/longjmp on native Windows (#1331)

* Add setjmp wrapper

* Add to projects

* Use wrapper on x64

* Always build on x64 and exclude on win32

* Fix signature

* Add comments

* Add comments for os-win32.h

* Add extern decleration

* Support cmake Windows build

* Fix for MinGW

CMakeLists.txt

@@ -859,6 +859,10 @@ if (MSVC)
         ${CMAKE_CURRENT_SOURCE_DIR}/msvc/unicorn/qapi-types.c
         ${CMAKE_CURRENT_SOURCE_DIR}/msvc/unicorn/qapi-visit.c
     )
+    if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+        enable_language(ASM_MASM)
+        set(UNICORN_SRCS ${UNICORN_SRCS} qemu/util/setjmp-wrapper-win32.asm)
+    endif()
 else()
     set(UNICORN_SRCS
         ${UNICORN_SRCS_COMMON}

msvc/unicorn/unicorn/unicorn.vcxproj

@@ -53,6 +53,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
+    <Import Project="$(VCTargetsPath)\BuildCustomizations\masm.props" />
   </ImportGroup>
   <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
@@ -357,7 +358,16 @@ copy "$(SolutionDir)..\include\unicorn\*.h" "$(SolutionDir)distro\include\unicor
     <ClInclude Include="..\qapi-types.h" />
     <ClInclude Include="..\qapi-visit.h" />
   </ItemGroup>
+  <ItemGroup>
+    <MASM Include="..\..\..\qemu\util\setjmp-wrapper-win32.asm">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</ExcludedFromBuild>
+    </MASM>
+  </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
+    <Import Project="$(VCTargetsPath)\BuildCustomizations\masm.targets" />
   </ImportGroup>
-</Project>
+</Project>

msvc/unicorn/unicorn/unicorn.vcxproj.filters

@@ -499,4 +499,7 @@
     <ClInclude Include="..\..\..\include\unicorn\unicorn.h" />
     <ClInclude Include="..\..\..\include\unicorn\x86.h" />
   </ItemGroup>
+  <ItemGroup>
+    <MASM Include="..\..\..\qemu\util\setjmp-wrapper-win32.asm" />
+  </ItemGroup>
 </Project>

msvc/unicorn/unicorn_static/unicorn_static.vcxproj

@@ -169,6 +169,14 @@
     <ClInclude Include="..\qapi-types.h" />
     <ClInclude Include="..\qapi-visit.h" />
   </ItemGroup>
+  <ItemGroup>
+    <MASM Include="..\..\..\qemu\util\setjmp-wrapper-win32.asm">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</ExcludedFromBuild>
+    </MASM>
+  </ItemGroup>
   <PropertyGroup Label="Globals">
     <ProjectGuid>{B6EFD6D7-C2D4-4FBB-B363-2E08CE09CC96}</ProjectGuid>
     <Keyword>Win32Proj</Keyword>
@@ -204,6 +212,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
+    <Import Project="$(VCTargetsPath)\BuildCustomizations\masm.props" />
   </ImportGroup>
   <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
@@ -363,5 +372,6 @@ copy "$(SolutionDir)..\include\unicorn\*.h" "$(SolutionDir)distro\include\unicor
   </ItemDefinitionGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
+    <Import Project="$(VCTargetsPath)\BuildCustomizations\masm.targets" />
   </ImportGroup>
-</Project>
+</Project>

msvc/unicorn/unicorn_static/unicorn_static.vcxproj.filters

@@ -498,4 +498,7 @@
       <Filter>qemu</Filter>
     </ClInclude>
   </ItemGroup>
+  <ItemGroup>
+    <MASM Include="..\..\..\qemu\util\setjmp-wrapper-win32.asm" />
+  </ItemGroup>
 </Project>

qemu/include/sysemu/os-win32.h

@@ -56,13 +56,27 @@
 # define EWOULDBLOCK  WSAEWOULDBLOCK
 #endif
 
-#if defined(_WIN64) && !defined(_MSC_VER)
+#if defined(_WIN64)
 /* On w64, setjmp is implemented by _setjmp which needs a second parameter.
  * If this parameter is NULL, longjump does no stack unwinding.
  * That is what we need for QEMU. Passing the value of register rsp (default)
  * lets longjmp try a stack unwinding which will crash with generated code. */
+
+#if defined(_MSC_VER) // MSVC
+
+// See qemu/include/utils/setjmp-wrapper-win32.asm for details.
+extern int _setjmp_wrapper(jmp_buf);
+
+# undef setjmp
+# define setjmp(env) _setjmp_wrapper(env)
+
+#else // MinGW
+
+// Original QEMU patch.
 # undef setjmp
 # define setjmp(env) _setjmp(env, NULL)
+#endif
+
 #endif
 /* QEMU uses sigsetjmp()/siglongjmp() as the portable way to specify
  * "longjmp and don't touch the signal masks". Since we know that the

qemu/util/setjmp-wrapper-win32.asm

@@ -0,0 +1,26 @@
+EXTERN _setjmp: proc
+PUBLIC _setjmp_wrapper
+
+_TEXT SEGMENT
+
+_setjmp_wrapper PROC
+
+; Why do we need this wrapper?
+; Short answer: Windows default implementation of setjmp/longjmp is incompatible with generated code.
+; A longer answer: https://blog.lazym.io/2020/09/21/Unicorn-Devblog-setjmp-longjmp-on-Windows/.
+
+; From qemu os-win32 comments:
+; > On w64, setjmp is implemented by _setjmp which needs a second parameter.
+; > If this parameter is NULL, longjump does no stack unwinding.
+; > That is what we need for QEMU. Passing the value of register rsp (default)
+; > lets longjmp try a stack unwinding which will crash with generated code.
+; It's true indeed, but MSVC doesn't has a setjmp signature which receives two arguements.
+; Therefore, we add a wrapper to keep the second argument zero.
+xor rdx, rdx
+jmp _setjmp
+
+_setjmp_wrapper ENDP
+
+_TEXT ENDS
+
+END