build: switch from c90 to c11 (#4743)

bnoordhuis · web-flow · commit bb706f5fe718 · 2025-03-24T08:01:25.000+01:00
After 14 years that should be fairly safe, right? Right!? Not safe enough for Windows Server 2016 apparently; there are build errors coming from system headers. The GHA images are slated for removal in a month anyway so upgrade them to Windows Server 2025. Fixes: #4742
diff --git a/.github/workflows/CI-win.yml b/.github/workflows/CI-win.yml
@@ -21,13 +21,12 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - {toolchain: Visual Studio 16 2019, arch: Win32, server: 2019}
-          - {toolchain: Visual Studio 16 2019, arch: x64, server: 2019}
           - {toolchain: Visual Studio 17 2022, arch: Win32, server: 2022}
           - {toolchain: Visual Studio 17 2022, arch: x64, server: 2022}
           - {toolchain: Visual Studio 17 2022, arch: x64, server: 2022, config: ASAN}
           - {toolchain: Visual Studio 17 2022, arch: x64, server: 2022, config: UBSAN}
           - {toolchain: Visual Studio 17 2022, arch: arm64, server: 2022}
+          - {toolchain: Visual Studio 17 2022, arch: x64, server: 2025}
     steps:
       - uses: actions/checkout@v4
       - name: Build
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -20,7 +20,7 @@ include(CTest)
 set(CMAKE_C_VISIBILITY_PRESET hidden)
 set(CMAKE_C_STANDARD_REQUIRED ON)
 set(CMAKE_C_EXTENSIONS ON)
-set(CMAKE_C_STANDARD 90)
+set(CMAKE_C_STANDARD 11)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
diff --git a/SUPPORTED_PLATFORMS.md b/SUPPORTED_PLATFORMS.md
@@ -4,7 +4,7 @@
 |---|---|---|---|
 | GNU/Linux | Tier 1 | Linux >= 3.10 with glibc >= 2.17 | |
 | macOS | Tier 1 | macOS >= 11 | Currently supported macOS releases |
-| Windows | Tier 1 | >= Windows 10 | VS 2015 and later are supported |
+| Windows | Tier 1 | >= Windows 10 | VS 2017 and later are supported |
 | FreeBSD | Tier 2 | >= 12 | |
 | AIX | Tier 2 | >= 6 | Maintainers: @libuv/aix |
 | IBM i | Tier 2 | >= IBM i 7.2 | Maintainers: @libuv/ibmi |
diff --git a/configure.ac b/configure.ac
@@ -33,7 +33,7 @@ CC_ATTRIBUTE_VISIBILITY([default], [
 # we exclude -fno-strict-aliasing for xlc
 CC_CHECK_FLAG_SUPPORTED_APPEND([-fno-strict-aliasing])
 CC_CHECK_CFLAGS_APPEND([-g])
-CC_CHECK_CFLAGS_APPEND([-std=gnu89])
+CC_CHECK_CFLAGS_APPEND([-std=gnu11])
 CC_CHECK_CFLAGS_APPEND([-Wall])
 CC_CHECK_CFLAGS_APPEND([-Wextra])
 CC_CHECK_CFLAGS_APPEND([-Wno-long-long])
