Compiler "Optimizes" Out Object Initialization Function - c++

Question

I have an object that I need to populate before using called pipelineInfo. To populate the object I use a function called createPipelineInfo. This works perfectly well when I use visual studios to compile a debug build but when I try to compile a release build the compiler "optimizes" out the entire createPipelineInfo function.
Here is the call to initialize the object and its use:
VkGraphicsPipelineCreateInfo pipelineInfo = createPipelineInfo(shaderStages, vertexInputInfo, inputAssembly, viewportState, rasterizer,
multisampling, colorBlending, pipelineLayout, renderPass);
if (vkCreateGraphicsPipelines(logicalDevice, VK_NULL_HANDLE, 1, &pipelineInfo, nullptr, &graphicsPipeline) != VK_SUCCESS) {
throw std::runtime_error("failed to create graphics pipeline!");
}
The following is the createPipelineInfo function:
inline static VkGraphicsPipelineCreateInfo createPipelineInfo(
const std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages,
const VkPipelineVertexInputStateCreateInfo& vertexInputInfo,
const VkPipelineInputAssemblyStateCreateInfo& inputAssembly,
const VkPipelineViewportStateCreateInfo& viewportState,
const VkPipelineRasterizationStateCreateInfo& rasterizer,
const VkPipelineMultisampleStateCreateInfo& multisampling,
const VkPipelineColorBlendStateCreateInfo& colorBlending,
const VkPipelineLayout& pipelineLayout,
const VkRenderPass& renderPass) {
VkGraphicsPipelineCreateInfo pipelineInfo{};
//Shader Stage
pipelineInfo.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
pipelineInfo.stageCount = 2;
pipelineInfo.pStages = shaderStages.data();
//Fixed Pipeline Stage
pipelineInfo.pVertexInputState = &vertexInputInfo;
pipelineInfo.pInputAssemblyState = &inputAssembly;
pipelineInfo.pViewportState = &viewportState;
pipelineInfo.pRasterizationState = &rasterizer;
pipelineInfo.pMultisampleState = &multisampling;
//pipelineInfo.pDepthStencilState = &depthStencil;
pipelineInfo.pColorBlendState = &colorBlending;
pipelineInfo.pDynamicState = nullptr; // Optional
//Pipeline Layout
pipelineInfo.layout = pipelineLayout;
pipelineInfo.renderPass = renderPass;
pipelineInfo.subpass = 0;
pipelineInfo.basePipelineHandle = VK_NULL_HANDLE;
return pipelineInfo;
}
On the other hand if I copy the body of the function and dump it in place of the function call everything works perfectly fine.
VkGraphicsPipelineCreateInfo pipelineInfo{};
//Shader Stage
pipelineInfo.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
pipelineInfo.stageCount = 2;
pipelineInfo.pStages = shaderStages.data();
//Fixed Pipeline Stage
pipelineInfo.pVertexInputState = &vertexInputInfo;
pipelineInfo.pInputAssemblyState = &inputAssembly;
pipelineInfo.pViewportState = &viewportState;
pipelineInfo.pRasterizationState = &rasterizer;
pipelineInfo.pMultisampleState = &multisampling;
//pipelineInfo.pDepthStencilState = &depthStencil;
pipelineInfo.pColorBlendState = &colorBlending;
pipelineInfo.pDynamicState = nullptr; // Optional
//Pipeline Layout
pipelineInfo.layout = pipelineLayout;
pipelineInfo.renderPass = renderPass;
pipelineInfo.subpass = 0;
pipelineInfo.basePipelineHandle = VK_NULL_HANDLE;
if (vkCreateGraphicsPipelines(logicalDevice, VK_NULL_HANDLE, 1, &pipelineInfo, nullptr, &graphicsPipeline) != VK_SUCCESS) {
throw std::runtime_error("failed to create graphics pipeline!");
}
I'm trying to figure out why the compiler is optimizing out the function call and failing that trying to develop a work around that doesn't involve dumping the body of the function in place of every call to the function.

Answer 1

wild guess: this parameter is passed by copy
const std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages
so when taking the address of its contents here with data method call:
pipelineInfo.pStages = shaderStages.data();
you invoke undefined behaviour. The compiler isn't smart enough to 1) warn you about taking a reference to temporary because of the complexity of the calls, and 2) it doesn't automatically perform copy elision on parameter passing.
Fix: pass it by reference (note that all other parameters use a by reference mode for a reason)
const std::array<VkPipelineShaderStageCreateInfo, 2> &shaderStages