Clean up build configuration

12 files changed, 94 insertions, 44 deletions

diff --git a/.clang-tidy b/.clang-tidy
index 6fe5d7a..db23eed 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -3,9 +3,6 @@ Checks: >
   -*-magic-numbers,
   -*-uppercase-literal-suffix,
   -altera-*,
-  -bugprone-reserved-identifier,
-  -cert-dcl37-c,
-  -cert-dcl51-cpp,
   -clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,
   -hicpp-multiway-paths-covered,
   -llvmlibc-*,
diff --git a/benchmark/.clang-tidy b/benchmark/.clang-tidy
index 3ebd18e..2aa1e4f 100644
--- a/benchmark/.clang-tidy
+++ b/benchmark/.clang-tidy
@@ -5,9 +5,6 @@ Checks: >
   -altera-*,
   -android-cloexec-fopen,
   -bugprone-easily-swappable-parameters,
-  -bugprone-reserved-identifier,
-  -cert-dcl37-c,
-  -cert-dcl51-cpp,
   -clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,
   -hicpp-multiway-paths-covered,
   -llvm-header-guard,
diff --git a/benchmark/bench.h b/benchmark/bench.h
index c07e211..bcfe077 100644
--- a/benchmark/bench.h
+++ b/benchmark/bench.h
@@ -4,8 +4,6 @@
 #ifndef BENCH_H
 #define BENCH_H
 
-#define _POSIX_C_SOURCE 199309L
-
 #include <time.h>
 
 typedef struct timespec BenchmarkTime;
diff --git a/benchmark/warnings.h b/benchmark/warnings.h
index 59f479d..43e740e 100644
--- a/benchmark/warnings.h
+++ b/benchmark/warnings.h
@@ -9,7 +9,8 @@
 #  define ZIX_DISABLE_GLIB_WARNINGS                                         \
     _Pragma("clang diagnostic push")                                        \
     _Pragma("clang diagnostic ignored \"-Wdocumentation-unknown-command\"") \
-    _Pragma("clang diagnostic ignored \"-Wdocumentation\"")
+    _Pragma("clang diagnostic ignored \"-Wdocumentation\"")                 \
+    _Pragma("clang diagnostic ignored \"-Wreserved-id-macro\"")
 
 #  define ZIX_RESTORE_WARNINGS _Pragma("clang diagnostic pop")
 
diff --git a/meson.build b/meson.build
index e6f17b4..92525e8 100644
--- a/meson.build
+++ b/meson.build
@@ -26,20 +26,49 @@ cc = meson.get_compiler('c')
 # Set global warning flags
 if get_option('strict') and not meson.is_subproject()
   subdir('meson/warnings')
+  add_project_arguments(all_c_warnings, language: ['c'])
 endif
 subdir('meson/suppressions')
+add_project_arguments(c_suppressions, language: ['c'])
 
-add_project_arguments(all_c_warnings + c_suppressions, language: ['c'])
+##########################
+# Platform Configuration #
+##########################
 
-################
-# Dependencies #
-################
+platform_c_args = []
 
-# Check for mlock() (used by ZixRing)
-mlock_fragment = '''#include <sys/mman.h>
-                     int main(void) { return mlock(0, 0); }'''
-if cc.compiles(mlock_fragment, name: 'mlock')
-  add_project_arguments(['-DHAVE_MLOCK'], language: 'c')
+# Determine whether to use POSIX
+no_posix = get_option('posix').disabled() or host_machine.system() == 'windows'
+if no_posix
+  platform_c_args += ['-DZIX_NO_POSIX']
+else
+  platform_c_args += ['-D_POSIX_C_SOURCE=200809L']
+endif
+
+# Check for platform features with the build system
+if get_option('checks')
+  platform_c_args += ['-DZIX_NO_DEFAULT_CONFIG']
+
+  mlock_code = '''#include <sys/mman.h>
+int main(void) { return mlock(0, 0); }'''
+
+  posix_memalign_code = '''#include <stdlib.h>
+int main(void) { void* mem; posix_memalign(&mem, 8, 8); }'''
+
+  platform_c_args += '-DHAVE_MLOCK=@0@'.format(
+    cc.compiles(mlock_code,
+                args: platform_c_args,
+                name: 'mlock').to_int())
+
+  platform_c_args += '-DHAVE_POSIX_MEMALIGN=@0@'.format(
+    cc.compiles(posix_memalign_code,
+                args: platform_c_args,
+                name: 'posix_memalign').to_int())
+endif
+
+# Build as C++ on MSVC
+if cc.get_id() == 'msvc'
+  add_project_arguments(['/TP'], language: ['c'])
 endif
 
 ###########
@@ -81,7 +110,7 @@ if get_option('default_library') == 'static'
 endif
 
 # Set any additional arguments required for building libraries or programs
-library_c_args = ['-DZIX_INTERNAL']
+library_c_args = platform_c_args + ['-DZIX_INTERNAL']
 library_link_args = []
 program_c_args = []
 program_link_args = []
@@ -215,15 +244,15 @@ if not get_option('benchmarks').disabled()
 
   if glib_dep.found()
     build_benchmarks = true
+    benchmark_c_args = platform_c_args
 
-    benchmark_c_args = []
     if cc.get_id() == 'clang'
-      benchmark_c_args += [
+      benchmark_c_suppressions = [
         '-Wno-reserved-identifier',
       ]
-    endif
 
-    benchmark_c_args = cc.get_supported_arguments(benchmark_c_args)
+      benchmark_c_args += cc.get_supported_arguments(benchmark_c_suppressions)
+    endif
 
     foreach benchmark : benchmarks
       benchmark(benchmark,
diff --git a/meson/suppressions/meson.build b/meson/suppressions/meson.build
index 2f96751..e5d5cf3 100644
--- a/meson/suppressions/meson.build
+++ b/meson/suppressions/meson.build
@@ -21,7 +21,6 @@ if is_variable('cc')
         '-Wno-c11-extensions', # Glib
         '-Wno-implicit-fallthrough', # Really for clang < 12
         '-Wno-padded',
-        '-Wno-reserved-id-macro',
       ]
 
     elif cc.get_id() == 'gcc'
diff --git a/meson_options.txt b/meson_options.txt
index 4f5c9b4..ef032fb 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -1,8 +1,14 @@
 option('benchmarks', type: 'feature', value: 'auto', yield: true,
        description: 'Build benchmarks')
 
+option('checks', type: 'boolean', value: true, yield: true,
+       description: 'Check for features with the build system')
+
 option('strict', type: 'boolean', value: false, yield: true,
        description: 'Enable ultra-strict warnings')
 
 option('tests', type: 'feature', value: 'auto', yield: true,
        description: 'Build tests')
+
+option('posix', type: 'feature', value: 'auto', yield: true,
+       description: 'Use POSIX system facilities')
diff --git a/src/.clang-tidy b/src/.clang-tidy
index bcf65be..66ba28d 100644
--- a/src/.clang-tidy
+++ b/src/.clang-tidy
@@ -4,9 +4,6 @@ Checks: >
   -*-uppercase-literal-suffix,
   -altera-*,
   -bugprone-easily-swappable-parameters,
-  -bugprone-reserved-identifier,
-  -cert-dcl37-c,
-  -cert-dcl51-cpp,
   -clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,
   -hicpp-multiway-paths-covered,
   -llvm-header-guard,
diff --git a/src/allocator.c b/src/allocator.c
index 2df0b90..ca91803 100644
--- a/src/allocator.c
+++ b/src/allocator.c
@@ -1,13 +1,12 @@
 // Copyright 2011-2021 David Robillard <d@drobilla.net>
 // SPDX-License-Identifier: ISC
 
-#define _POSIX_C_SOURCE 200809L
-
-#include "zix_config.h"
-
 #include "zix/allocator.h"
+
 #include "zix/attributes.h"
 
+#include "zix_config.h"
+
 #ifdef _WIN32
 #  define WIN32_LEAN_AND_MEAN 1
 #  include <malloc.h>
diff --git a/src/ring.c b/src/ring.c
index a464428..d5b942b 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -3,10 +3,12 @@
 
 #include "zix/ring.h"
 
+#include "zix_config.h"
+
 #include <stdlib.h>
 #include <string.h>
 
-#ifdef HAVE_MLOCK
+#if USE_MLOCK
 #  include <sys/mman.h>
 #  define ZIX_MLOCK(ptr, size) mlock((ptr), (size))
 #elif defined(_WIN32)
diff --git a/src/zix_config.h b/src/zix_config.h
index 832b50f..7be46e4 100644
--- a/src/zix_config.h
+++ b/src/zix_config.h
@@ -1,15 +1,26 @@
-// Copyright 2021 David Robillard <d@drobilla.net>
+// Copyright 2021-2022 David Robillard <d@drobilla.net>
 // SPDX-License-Identifier: ISC
 
 /*
   Configuration header that defines reasonable defaults at compile time.
 
-  This allows compile-time configuration from the command line (typically via
-  the build system) while still allowing the source to be built without any
-  configuration.  The build system can define ZIX_NO_DEFAULT_CONFIG to disable
-  defaults, in which case it must define things like HAVE_FEATURE to enable
-  features.  The design here ensures that compiler warnings or
-  include-what-you-use will catch any mistakes.
+  This allows compile-time configuration from the command line, while still
+  allowing the source to be built "as-is" without any configuration.  The idea
+  is to support an advanced build system with configuration checks, while still
+  allowing the code to be simply "thrown at a compiler" with features
+  determined from the compiler or system headers.  Everything can be
+  overridden, so it should never be necessary to edit this file to build
+  successfully.
+
+  To ensure that all configure checks are performed, the build system can
+  define ZIX_NO_DEFAULT_CONFIG to disable defaults.  In this case, it must
+  define all HAVE_FEATURE symbols below to 1 or 0 to enable or disable
+  features.  Any missing definitions will generate a compiler warning.
+
+  To ensure that this header is always included properly, all code that uses
+  configuration variables includes this header and checks their value with #if
+  (not #ifdef).  Variables like USE_FEATURE are internal and should never be
+  defined on the command line.
 */
 
 #ifndef ZIX_CONFIG_H
@@ -28,10 +39,21 @@
 #    endif
 #  endif
 
+// POSIX.1-2001: mlock()
+#  ifndef HAVE_MLOCK
+#    if defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L
+#      define HAVE_MLOCK 1
+#    else
+#      define HAVE_MLOCK 0
+#    endif
+#  endif
+
 // POSIX.1-2001: posix_memalign()
 #  ifndef HAVE_POSIX_MEMALIGN
 #    if defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L
-#      define HAVE_POSIX_MEMALIGN
+#      define HAVE_POSIX_MEMALIGN 1
+#    else
+#      define HAVE_POSIX_MEMALIGN 0
 #    endif
 #  endif
 
@@ -45,7 +67,13 @@
   if the build system defines them all.
 */
 
-#ifdef HAVE_POSIX_MEMALIGN
+#if HAVE_MLOCK
+#  define USE_MLOCK 1
+#else
+#  define USE_MLOCK 0
+#endif
+
+#if HAVE_POSIX_MEMALIGN
 #  define USE_POSIX_MEMALIGN 1
 #else
 #  define USE_POSIX_MEMALIGN 0
diff --git a/test/.clang-tidy b/test/.clang-tidy
index 9f98471..e490926 100644
--- a/test/.clang-tidy
+++ b/test/.clang-tidy
@@ -5,9 +5,6 @@ Checks: >
   -altera-*,
   -android-cloexec-fopen,
   -bugprone-easily-swappable-parameters,
-  -bugprone-reserved-identifier,
-  -cert-dcl37-c,
-  -cert-dcl51-cpp,
   -clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,
   -cppcoreguidelines-avoid-non-const-global-variables,
   -google-readability-casting,