Add support for Meson build system

Tested on:
 - Linux/x86* with gcc
 - Android armv7 arm64 x86 x86_64 with clang
 - Windows x86 x86_64 with Visual Studio 2017
 - Windows x86 x86_64 with MinGW
 - macOS x86_64 with clang
 - iOS arm64 x86_64 with clang

Co-authored by: Nirbheek Chauhan <nirbheek@centricular.com>

https://gitlab.xiph.org/xiph/opus/-/merge_requests/13

2 files changed, 82 insertions, 0 deletions

diff --git a/celt/meson.build b/celt/meson.build
new file mode 100644
index 00000000..370ea1fe
--- /dev/null
+++ b/celt/meson.build
@@ -0,0 +1,63 @@
+celt_sources = sources['CELT_SOURCES']
+
+celt_sse_sources = sources['CELT_SOURCES_SSE']
+
+celt_sse2_sources = sources['CELT_SOURCES_SSE2']
+
+celt_sse4_1_sources = sources['CELT_SOURCES_SSE4_1']
+
+celt_neon_intr_sources = sources['CELT_SOURCES_ARM_NEON_INTR']
+
+celt_static_libs = []
+
+foreach intr_name : ['sse', 'sse2', 'sse4_1', 'neon_intr']
+  have_intr = get_variable('have_' + intr_name)
+  if not have_intr
+    continue
+  endif
+
+  intr_sources = get_variable('celt_@0@_sources'.format(intr_name))
+  intr_args = get_variable('opus_@0@_args'.format(intr_name), [])
+  celt_static_libs += static_library('celt_' + intr_name, intr_sources,
+      c_args: intr_args,
+      include_directories: opus_includes,
+      install: false)
+endforeach
+
+have_arm_intrinsics_or_asm = have_arm_ne10
+if (intrinsics_support.length() + asm_optimization.length() + inline_optimization.length()) > 0
+  have_arm_intrinsics_or_asm = true
+endif
+
+if host_cpu_family in ['arm', 'aarch64'] and have_arm_intrinsics_or_asm
+  celt_sources +=  sources['CELT_SOURCES_ARM']
+  if have_arm_ne10
+    celt_sources += sources['CELT_SOURCES_ARM_NE10']
+  endif
+  if opus_arm_external_asm
+    arm2gnu = [find_program('arm/arm2gnu.pl')] + arm2gnu_args
+    celt_sources_arm_asm = configure_file(input: 'arm/celt_pitch_xcorr_arm.s',
+      output: '@BASENAME@-gnu.S',
+      command: arm2gnu + ['@INPUT@'],
+      capture: true)
+    celt_arm_armopts_s = configure_file(input: 'arm/armopts.s.in',
+      output: 'arm/armopts.s',
+      configuration: opus_conf)
+    celt_static_libs += static_library('celt-armasm',
+      celt_arm_armopts_s, celt_sources_arm_asm,
+      install: false)
+  endif
+endif
+
+celt_c_args = []
+if host_system == 'windows'
+  celt_c_args += ['-DDLL_EXPORT']
+endif
+
+celt_lib = static_library('opus-celt',
+  celt_sources,
+  c_args: celt_c_args,
+  include_directories: opus_includes,
+  link_whole: celt_static_libs,
+  dependencies: libm,
+  install: false)
diff --git a/celt/tests/meson.build b/celt/tests/meson.build
new file mode 100644
index 00000000..0e6d2e62
--- /dev/null
+++ b/celt/tests/meson.build
@@ -0,0 +1,19 @@
+tests = [
+  'test_unit_types',
+  'test_unit_mathops',
+  'test_unit_entropy',
+  'test_unit_laplace',
+  'test_unit_dft',
+  'test_unit_mdct',
+  'test_unit_rotation',
+  'test_unit_cwrs32',
+]
+
+foreach test_name : tests
+  exe = executable(test_name, '@0@.c'.format(test_name),
+                   include_directories : opus_includes,
+                   link_with : [celt_lib, celt_static_libs],
+                   dependencies : libm,
+                   install : false)
+  test(test_name, exe)
+endforeach