From fcf701864a36394cfb2b8bcc0b5b8534fa79fc74 Mon Sep 17 00:00:00 2001
From: Olexa Bilaniuk <obilaniu@gmail.com>
Date: Fri, 12 Mar 2021 18:09:22 -0500
Subject: [PATCH] Strip host-compiler -std flag from NVCC line.

Closes #8523.
---
 mesonbuild/compilers/cuda.py            | 12 +++++++++++-
 test cases/cuda/16 multistd/main.cu     | 20 ++++++++++++++++++++
 test cases/cuda/16 multistd/meson.build |  4 ++++
 3 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 test cases/cuda/16 multistd/main.cu
 create mode 100644 test cases/cuda/16 multistd/meson.build

diff --git a/mesonbuild/compilers/cuda.py b/mesonbuild/compilers/cuda.py
index 411dff1a145c..aaa2b8e17dd2 100644
--- a/mesonbuild/compilers/cuda.py
+++ b/mesonbuild/compilers/cuda.py
@@ -616,8 +616,18 @@ def get_options(self) -> 'KeyedOptionDictType':
         return opts
 
     def _to_host_compiler_options(self, options: 'KeyedOptionDictType') -> 'KeyedOptionDictType':
+        """
+        Convert an NVCC Option set to a host compiler's option set.
+        """
+
+        # We must strip the -std option from the host compiler option set, as NVCC has
+        # its own -std flag that may not agree with the host compiler's.
         overrides = {name: opt.value for name, opt in options.items()}
-        return OptionOverrideProxy(overrides, self.host_compiler.get_options())
+        overrides.pop(OptionKey('std', machine=self.for_machine,
+                                       lang=self.host_compiler.language), None)
+        host_options = self.host_compiler.get_options().copy()
+        host_options.pop('std', '')
+        return OptionOverrideProxy(overrides, host_options)
 
     def get_option_compile_args(self, options: 'KeyedOptionDictType') -> T.List[str]:
         args = self.get_ccbin_args(options)
diff --git a/test cases/cuda/16 multistd/main.cu b/test cases/cuda/16 multistd/main.cu
new file mode 100644
index 000000000000..a2ffba4896c3
--- /dev/null
+++ b/test cases/cuda/16 multistd/main.cu	
@@ -0,0 +1,20 @@
+#include <cuda_runtime.h>
+#include <iostream>
+
+auto cuda_devices(void) {
+    int result = 0;
+    cudaGetDeviceCount(&result);
+    return result;
+}
+
+
+int main(void) {
+    int n = cuda_devices();
+    if (n == 0) {
+        std::cout << "No Cuda hardware found. Exiting.\n";
+        return 0;
+    }
+
+    std::cout << "Found " << n << "Cuda devices.\n";
+    return 0;
+}
diff --git a/test cases/cuda/16 multistd/meson.build b/test cases/cuda/16 multistd/meson.build
new file mode 100644
index 000000000000..4769a87dddd1
--- /dev/null
+++ b/test cases/cuda/16 multistd/meson.build	
@@ -0,0 +1,4 @@
+project('C++-CUDA multi-std', 'cpp', 'cuda', version : '1.0.0', default_options : ['cpp_std=c++17', 'cuda_std=c++14'])
+
+exe = executable('prog', 'main.cu')
+test('cudatest', exe)