[dxbc,d3d11] Don't access shex chunk if it is not defined

src/d3d11/d3d11_shader.cpp

@@ -20,8 +20,6 @@ namespace dxvk {
       reinterpret_cast<const char*>(pShaderBytecode),
       BytecodeLength);
     
-    DxbcModule module(reader);
-    
     // If requested by the user, dump both the raw DXBC
     // shader and the compiled SPIR-V module to a file.
     const std::string& dumpPath = pDevice->GetOptions()->shaderDumpPath;
@@ -30,14 +28,21 @@ namespace dxvk {
       reader.store(std::ofstream(str::topath(str::format(dumpPath, "/", name, ".dxbc").c_str()).c_str(),
         std::ios_base::binary | std::ios_base::trunc));
     }
-    
+
+    // Error out if the shader is invalid
+    DxbcModule module(reader);
+    auto programInfo = module.programInfo();
+
+    if (!programInfo)
+      throw DxvkError("Invalid shader binary.");
+
     // Decide whether we need to create a pass-through
     // geometry shader for vertex shader stream output
     bool passthroughShader = pDxbcModuleInfo->xfb != nullptr
-      && (module.programInfo().type() == DxbcProgramType::VertexShader
-       || module.programInfo().type() == DxbcProgramType::DomainShader);
+      && (programInfo->type() == DxbcProgramType::VertexShader
+       || programInfo->type() == DxbcProgramType::DomainShader);
 
-    if (module.programInfo().shaderStage() != pShaderKey->type() && !passthroughShader)
+    if (programInfo->shaderStage() != pShaderKey->type() && !passthroughShader)
       throw DxvkError("Mismatching shader type.");
 
     m_shader = passthroughShader

src/dxbc/dxbc_module.h

@@ -35,7 +35,10 @@ namespace dxvk {
      * \brief Shader type
      * \returns Shader type
      */
-    DxbcProgramInfo programInfo() const {
+    std::optional<DxbcProgramInfo> programInfo() const {
+      if (m_shexChunk == nullptr)
+        return std::nullopt;
+
       return m_shexChunk->programInfo();
     }