From 03af2432e0eb9911f66d085f106aa0c9899280c4 Mon Sep 17 00:00:00 2001
From: Dmitry Kobets <dmitrykobets@microsoft.com>
Date: Thu, 2 Dec 2021 14:28:25 -0800
Subject: [PATCH] Re-work CI and error suppression

---
 pipelines/jobs.yml   | 11 +++++------
 pipelines/steps.yml  |  2 +-
 tests/CMakeLists.txt | 18 ++++++------------
 3 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/pipelines/jobs.yml b/pipelines/jobs.yml
index 3025fdc..dff2f9b 100644
--- a/pipelines/jobs.yml
+++ b/pipelines/jobs.yml
@@ -11,24 +11,23 @@ jobs:
     matrix:
       14_debug:
         GSL_CXX_STANDARD: '14'
-        CMAKE_CXX_STANDARD: '14'
         BUILD_TYPE: 'Debug'
       14_release:
         GSL_CXX_STANDARD: '14'
-        CMAKE_CXX_STANDARD: '14'
         BUILD_TYPE: 'Release'
       17_debug:
         GSL_CXX_STANDARD: '17'
-        CMAKE_CXX_STANDARD: '17'
         BUILD_TYPE: 'Debug'
       17_release:
         GSL_CXX_STANDARD: '17'
-        CMAKE_CXX_STANDARD: '17'
         BUILD_TYPE: 'Release'
+      # Note: Currently, only some C++20 features are supported by GSL
       20_debug:
-        GSL_CXX_STANDARD: '17'
-        CMAKE_CXX_STANDARD: '20'
+        GSL_CXX_STANDARD: '20'
         BUILD_TYPE: 'Debug'
+      20_release:
+        GSL_CXX_STANDARD: '20'
+        BUILD_TYPE: 'Release'
   continueOnError: false
   steps:
   - template: ./steps.yml
diff --git a/pipelines/steps.yml b/pipelines/steps.yml
index 6cc089b..b9a4e8c 100644
--- a/pipelines/steps.yml
+++ b/pipelines/steps.yml
@@ -3,7 +3,7 @@ steps:
     name: Configure
     inputs:
       workingDirectory: build
-      cmakeArgs: '-DCMAKE_CXX_STANDARD=$(CMAKE_CXX_STANDARD) -DCMAKE_BUILD_TYPE=$(BUILD_TYPE) -Werror=dev .. '
+      cmakeArgs: '-DGSL_CXX_STANDARD=$(GSL_CXX_STANDARD) -DCMAKE_BUILD_TYPE=$(BUILD_TYPE) -Werror=dev .. '
 
   - task: CMake@1
     name: Build
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index dbd36d3..77284b5 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -54,7 +54,7 @@ if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
     find_package(Microsoft.GSL REQUIRED)
 endif()
 
-if (MSVC AND (GSL_CXX_STANDARD EQUAL 17))
+if (MSVC AND (GSL_CXX_STANDARD GREATER_EQUAL 17))
     set(GSL_CPLUSPLUS_OPT -Zc:__cplusplus -permissive-)
 endif()
 
@@ -130,17 +130,16 @@ else()
             -Wno-unused-member-function
             -Wno-unused-variable
           >
-          $<$<BOOL:${CMAKE_CXX_STANDARD}>:
-            $<$<EQUAL:${CMAKE_CXX_STANDARD},20>:
-                -Wno-zero-as-null-pointer-constant # Very noisy, minor, and just so
-                -Wno-sign-conversion                                                                   # happens to trigger on googletest
-          >
-        >
         >
         $<$<CXX_COMPILER_ID:Clang>:
           $<$<AND:$<VERSION_GREATER:$<CXX_COMPILER_VERSION>,4.99>,$<VERSION_LESS:$<CXX_COMPILER_VERSION>,6>>:
             $<$<EQUAL:${GSL_CXX_STANDARD},17>:-Wno-undefined-func-template>
           >
+          $<$<AND:$<EQUAL:${GSL_CXX_STANDARD},20>,$<CXX_COMPILER_VERSION:11.0.0>>:
+              -Wno-zero-as-null-pointer-constant  # failing Clang Ubuntu 20.04 tests, seems to be a bug with clang 11.0.0
+                                                  # (operator< is being re-written by the compiler as operator<=> and
+                                                  # raising the warning)
+          >
         >
         $<$<CXX_COMPILER_ID:AppleClang>:
           $<$<AND:$<VERSION_GREATER:$<CXX_COMPILER_VERSION>,9.1>,$<VERSION_LESS:$<CXX_COMPILER_VERSION>,10>>:
@@ -238,11 +237,6 @@ else()
         -Wpedantic
         -Wshadow
         -Wsign-conversion
-        $<$<BOOL:${CMAKE_CXX_STANDARD}>:                                                           # happens to trigger on googletest
-          $<$<EQUAL:${CMAKE_CXX_STANDARD},20>:
-              -Wno-sign-conversion                                                                   # happens to trigger on googletest
-          >
-        >
         $<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>:
           -Weverything
           -Wno-c++98-compat