Add OPENEXR_CORE_USE_NAMESPACE to build OpenEXRCore with C++

.github/workflows/ci_steps.yml

@@ -53,6 +53,8 @@ on:
         type: string
       OPENEXR_FORCE_INTERNAL_OPENJPH:
         type: string
+      OPENEXR_CORE_USE_NAMESPACE:
+        type: string
       CMAKE_OSX_ARCHITECTURES:
         type: string
       BUILD_TESTING:
@@ -222,6 +224,7 @@ jobs:
           cmake_args+=("-DOPENEXR_FORCE_INTERNAL_DEFLATE=${{ inputs.OPENEXR_FORCE_INTERNAL_DEFLATE }}")
           cmake_args+=("-DOPENEXR_FORCE_INTERNAL_OPENJPH=${{ inputs.OPENEXR_FORCE_INTERNAL_OPENJPH }}")
           cmake_args+=("-DBUILD_TESTING=${{ inputs.BUILD_TESTING }}")
+          cmake_args+=("-DOPENEXR_CORE_USE_NAMESPACE=${{ inputs.OPENEXR_CORE_USE_NAMESPACE }}")
           cmake_args+=("-DOPENEXR_RUN_FUZZ_TESTS=OFF")
           cmake_args+=("-DCMAKE_VERBOSE_MAKEFILE=ON")
           if [ -n "${{ inputs.namespace }}" ]; then

.github/workflows/ci_workflow.yml

@@ -80,6 +80,7 @@ jobs:
       OPENEXR_FORCE_INTERNAL_IMATH: ${{ matrix.OPENEXR_FORCE_INTERNAL_IMATH || 'OFF' }}
       OPENEXR_FORCE_INTERNAL_DEFLATE: ${{ matrix.OPENEXR_FORCE_INTERNAL_DEFLATE || 'OFF' }}
       OPENEXR_FORCE_INTERNAL_OPENJPH: ${{ matrix.OPENEXR_FORCE_INTERNAL_OPENJPH || 'OFF' }}
+      OPENEXR_CORE_USE_NAMESPACE: ${{ matrix.OPENEXR_CORE_USE_NAMESPACE || 'OFF' }}
       BUILD_TESTING: ${{ matrix.BUILD_TESTING || 'ON' }}
       RUN_TESTING: ${{ matrix.RUN_TESTING || 'ON' }}
       namespace: ${{ matrix.namespace }}
@@ -147,6 +148,11 @@ jobs:
             RUN_TESTING: OFF
             validate_install: OFF
 
+          - build: 12
+            label: OPENEXR_CORE_USE_NAMESPACE
+            OPENEXR_CORE_USE_NAMESPACE: ON
+            validate_install: OFF
+
   macOS:
     name: 'macOS.${{ matrix.build}}: ${{ matrix.label }}'
     uses: ./.github/workflows/ci_steps.yml
@@ -169,6 +175,7 @@ jobs:
       OPENEXR_FORCE_INTERNAL_IMATH: ${{ matrix.OPENEXR_FORCE_INTERNAL_IMATH || 'OFF' }}
       OPENEXR_FORCE_INTERNAL_DEFLATE: ${{ matrix.OPENEXR_FORCE_INTERNAL_DEFLATE || 'OFF' }}
       OPENEXR_FORCE_INTERNAL_OPENJPH: ${{ matrix.OPENEXR_FORCE_INTERNAL_OPENJPH || 'OFF' }}
+      OPENEXR_CORE_USE_NAMESPACE: ${{ matrix.OPENEXR_CORE_USE_NAMESPACE || 'OFF' }}
       CMAKE_OSX_ARCHITECTURES: ${{ matrix.CMAKE_OSX_ARCHITECTURES }}
       BUILD_TESTING: ${{ matrix.BUILD_TESTING || 'ON' }}
       RUN_TESTING: ${{ matrix.RUN_TESTING || 'ON' }}
@@ -231,6 +238,11 @@ jobs:
             RUN_TESTING: OFF
             validate_install: OFF
 
+          - build: 11
+            label: OPENEXR_CORE_USE_NAMESPACE
+            OPENEXR_CORE_USE_NAMESPACE: ON
+            validate_install: OFF
+
   windows:
     name: 'Windows.${{ matrix.build}}: ${{ matrix.label }}'
     uses: ./.github/workflows/ci_steps.yml
@@ -251,6 +263,7 @@ jobs:
       OPENEXR_FORCE_INTERNAL_IMATH: ${{ matrix.OPENEXR_FORCE_INTERNAL_IMATH || 'OFF' }}
       OPENEXR_FORCE_INTERNAL_DEFLATE: ${{ matrix.OPENEXR_FORCE_INTERNAL_DEFLATE || 'OFF' }}
       OPENEXR_FORCE_INTERNAL_OPENJPH: ${{ matrix.OPENEXR_FORCE_INTERNAL_OPENJPH || 'OFF' }}
+      OPENEXR_CORE_USE_NAMESPACE: ${{ matrix.OPENEXR_CORE_USE_NAMESPACE || 'OFF' }}
       msystem: ${{ matrix.msystem }}
       BUILD_TESTING: ${{ matrix.BUILD_TESTING || 'ON' }}
       RUN_TESTING: ${{ matrix.RUN_TESTING || 'ON' }}
@@ -317,3 +330,7 @@ jobs:
             RUN_TESTING: OFF
             validate_install: OFF
 
+          - build: 12
+            label: OPENEXR_CORE_USE_NAMESPACE
+            OPENEXR_CORE_USE_NAMESPACE: ON
+            validate_install: OFF

BUILD.bazel

@@ -63,6 +63,7 @@ expand_template(
         "@OPENEXR_VERSION_PATCH@": "0",
         "#cmakedefine OPENEXR_ENABLE_API_VISIBILITY": "#define OPENEXR_ENABLE_API_VISIBILITY",
         "#cmakedefine OPENEXR_HAVE_LARGE_STACK 1": "/* #undef OPENEXR_HAVE_LARGE_STACK */",
+        "#cmakedefine OPENEXR_CORE_USE_NAMESPACE @OPENEXR_CORE_USE_NAMESPACE@": "/* #undef OPENEXR_CORE_USE_NAMESPACE */",
     },
     template = "cmake/OpenEXRConfig.h.in",
 )

cmake/OpenEXRConfig.h.in

@@ -62,6 +62,33 @@
 #define OPENEXR_IMF_NAMESPACE_CUSTOM @OPENEXR_NAMESPACE_CUSTOM@
 #define OPENEXR_IMF_NAMESPACE @OPENEXR_IMF_NAMESPACE@
 
+//
+// Option to build OpenEXRCore in a namespace using C++ instead of C
+//
+// All code in OpenEXRCore is bracketed by ENTER/EXIT pairs. Some of the code
+// needs 'extern "C" {' directives, but when compiling with C++, this must
+// revert to 'namespace OPENEXR_IMF_INTERNAL_NAMESPACE {'. In C, the NAMESPACE
+// ENTER/EXIT pairs degenerate to no-ops.
+//
+#cmakedefine OPENEXR_CORE_USE_NAMESPACE @OPENEXR_CORE_USE_NAMESPACE@
+#if __cplusplus
+#  ifdef OPENEXR_CORE_USE_NAMESPACE
+#    define OPENEXR_CORE_NAMESPACE_ENTER namespace OPENEXR_IMF_INTERNAL_NAMESPACE {
+#    define OPENEXR_CORE_NAMESPACE_EXIT }
+#    define OPENEXR_CORE_EXTERN_C_ENTER namespace OPENEXR_IMF_INTERNAL_NAMESPACE {
+#  else
+#    define OPENEXR_CORE_NAMESPACE_ENTER
+#    define OPENEXR_CORE_NAMESPACE_EXIT
+#    define OPENEXR_CORE_EXTERN_C_ENTER extern "C" {
+#  endif
+#  define OPENEXR_CORE_EXTERN_C_EXIT }
+#else
+#  define OPENEXR_CORE_NAMESPACE_ENTER 
+#  define OPENEXR_CORE_NAMESPACE_EXIT 
+#  define OPENEXR_CORE_EXTERN_C_ENTER
+#  define OPENEXR_CORE_EXTERN_C_EXIT
+#endif
+
 //
 // Version string for runtime access
 //

cmake/OpenEXRSetup.cmake

@@ -74,6 +74,8 @@ option(OPENEXR_BUILD_EXAMPLES "Build and install OpenEXR examples" ON)
 
 option(OPENEXR_BUILD_PYTHON "Build python bindings" OFF)
 
+option(OPENEXR_CORE_USE_NAMESPACE "Build the OpenEXRCore library using C++ in a namespace" OFF)
+
 option(OPENEXR_BUILD_OSS_FUZZ "Build the oss-fuzz fuzzers" OFF)
 if (OPENEXR_BUILD_OSS_FUZZ)
   # If building the oss-fuzz fuzzers, accept the comiler/options from

external/deflate/lib/adler32.c

@@ -158,5 +158,5 @@ libdeflate_adler32(u32 adler, const void *buffer, size_t len)
 {
 	if (buffer == NULL) /* Return initial value. */
 		return 1;
-	return adler32_impl(adler, buffer, len);
+	return adler32_impl(adler, (const u8*) buffer, len);
 }

external/deflate/lib/decompress_template.h

@@ -47,13 +47,13 @@ FUNCNAME(struct libdeflate_decompressor * restrict d,
 	 void * restrict out, size_t out_nbytes_avail,
 	 size_t *actual_in_nbytes_ret, size_t *actual_out_nbytes_ret)
 {
-	u8 *out_next = out;
+        u8 *out_next = (u8*) out;
 	u8 * const out_end = out_next + out_nbytes_avail;
 	u8 * const out_fastloop_end =
 		out_end - MIN(out_nbytes_avail, FASTLOOP_MAX_BYTES_WRITTEN);
 
 	/* Input bitstream state; see deflate_decompress.c for documentation */
-	const u8 *in_next = in;
+	const u8 *in_next = (const u8*) in;
 	const u8 * const in_end = in_next + in_nbytes;
 	const u8 * const in_fastloop_end =
 		in_end - MIN(in_nbytes, FASTLOOP_MAX_BYTES_READ);

external/deflate/lib/deflate_compress.c

@@ -2988,7 +2988,10 @@ static const struct {
 	u8 len_sym_cost;
 } default_litlen_costs[] = {
 	{ /* match_prob = 0.25 */
-		.used_lits_to_lit_cost = {
+#ifndef __cplusplus
+		.used_lits_to_lit_cost = 
+#endif
+		{
 			6, 6, 22, 32, 38, 43, 48, 51,
 			54, 57, 59, 61, 64, 65, 67, 69,
 			70, 72, 73, 74, 75, 76, 77, 79,
@@ -3023,9 +3026,15 @@ static const struct {
 			133, 134, 134, 134, 134, 134, 134, 134,
 			134,
 		},
-		.len_sym_cost = 109,
+#ifndef __cplusplus
+		.len_sym_cost =
+#endif
+                109,
 	}, { /* match_prob = 0.5 */
-		.used_lits_to_lit_cost = {
+#ifndef __cplusplus
+		.used_lits_to_lit_cost =
+#endif
+                {
 			16, 16, 32, 41, 48, 53, 57, 60,
 			64, 66, 69, 71, 73, 75, 76, 78,
 			80, 81, 82, 83, 85, 86, 87, 88,
@@ -3060,9 +3069,15 @@ static const struct {
 			143, 143, 143, 143, 143, 143, 143, 143,
 			144,
 		},
-		.len_sym_cost = 93,
+#ifndef __cplusplus
+		.len_sym_cost =
+#endif
+                93,
 	}, { /* match_prob = 0.75 */
-		.used_lits_to_lit_cost = {
+#ifndef __cplusplus
+		.used_lits_to_lit_cost =
+#endif
+                {
 			32, 32, 48, 57, 64, 69, 73, 76,
 			80, 82, 85, 87, 89, 91, 92, 94,
 			96, 97, 98, 99, 101, 102, 103, 104,
@@ -3097,7 +3112,10 @@ static const struct {
 			159, 159, 159, 159, 159, 159, 159, 159,
 			160,
 		},
-		.len_sym_cost = 84,
+#ifndef __cplusplus
+                .len_sym_cost =
+#endif
+		84,
 	},
 };
 
@@ -3900,7 +3918,7 @@ libdeflate_alloc_compressor_ex(int compression_level,
 			size += sizeof(c->p.f);
 	}
 
-	c = libdeflate_aligned_malloc(options->malloc_func ?
+	c = (struct libdeflate_compressor *) libdeflate_aligned_malloc(options->malloc_func ?
 				      options->malloc_func :
 				      libdeflate_default_malloc_func,
 				      MATCHFINDER_MEM_ALIGNMENT, size);
@@ -4015,7 +4033,10 @@ LIBDEFLATEAPI struct libdeflate_compressor *
 libdeflate_alloc_compressor(int compression_level)
 {
 	static const struct libdeflate_options defaults = {
-		.sizeof_options = sizeof(defaults),
+#ifndef __cplusplus
+		.sizeof_options =
+#endif
+                sizeof(defaults), NULL, NULL
 	};
 	return libdeflate_alloc_compressor_ex(compression_level, &defaults);
 }
@@ -4032,18 +4053,18 @@ libdeflate_deflate_compress(struct libdeflate_compressor *c,
 	 * uncompressed blocks.
 	 */
 	if (unlikely(in_nbytes <= c->max_passthrough_size))
-		return deflate_compress_none(in, in_nbytes,
-					     out, out_nbytes_avail);
+            return deflate_compress_none((const u8*) in, in_nbytes,
+                                         (u8*) out, out_nbytes_avail);
 
 	/* Initialize the output bitstream structure. */
 	os.bitbuf = 0;
 	os.bitcount = 0;
-	os.next = out;
+	os.next = (u8*) out;
 	os.end = os.next + out_nbytes_avail;
 	os.overflow = false;
 
 	/* Call the actual compression function. */
-	(*c->impl)(c, in, in_nbytes, &os);
+	(*c->impl)(c, (u8*) in, in_nbytes, &os);
 
 	/* Return 0 if the output buffer is too small. */
 	if (os.overflow)

external/deflate/lib/deflate_decompress.c

@@ -1164,7 +1164,7 @@ libdeflate_alloc_decompressor_ex(const struct libdeflate_options *options)
 	if (options->sizeof_options != sizeof(*options))
 		return NULL;
 
-	d = (options->malloc_func ? options->malloc_func :
+	d = (struct libdeflate_decompressor *) (options->malloc_func ? options->malloc_func :
 	     libdeflate_default_malloc_func)(sizeof(*d));
 	if (d == NULL)
 		return NULL;
@@ -1195,7 +1195,9 @@ LIBDEFLATEAPI struct libdeflate_decompressor *
 libdeflate_alloc_decompressor(void)
 {
 	static const struct libdeflate_options defaults = {
-		.sizeof_options = sizeof(defaults),
+		sizeof(struct libdeflate_options),
+		NULL,
+		NULL
 	};
 	return libdeflate_alloc_decompressor_ex(&defaults);
 }

external/deflate/lib/x86/adler32_template.h

@@ -63,8 +63,8 @@
 #  else
 #    define VDPBUSD(a, b, c)	_mm_dpbusd_avx_epi32((a), (b), (c))
 #  endif
-#  define VLOAD(p)		_mm_load_si128((const void *)(p))
-#  define VLOADU(p)		_mm_loadu_si128((const void *)(p))
+#  define VLOAD(p)		_mm_load_si128((const __m128i *)(p))
+#  define VLOADU(p)		_mm_loadu_si128((const __m128i *)(p))
 #  define VMADD16(a, b)		_mm_madd_epi16((a), (b))
 #  define VMASKZ_LOADU(mask, p) _mm_maskz_loadu_epi8((mask), (p))
 #  define VMULLO32(a, b)	_mm_mullo_epi32((a), (b))
@@ -87,8 +87,8 @@
 #  else
 #    define VDPBUSD(a, b, c)	_mm256_dpbusd_avx_epi32((a), (b), (c))
 #  endif
-#  define VLOAD(p)		_mm256_load_si256((const void *)(p))
-#  define VLOADU(p)		_mm256_loadu_si256((const void *)(p))
+#  define VLOAD(p)		_mm256_load_si256((const __m256i *)(p))
+#  define VLOADU(p)		_mm256_loadu_si256((const __m256i *)(p))
 #  define VMADD16(a, b)		_mm256_madd_epi16((a), (b))
 #  define VMASKZ_LOADU(mask, p) _mm256_maskz_loadu_epi8((mask), (p))
 #  define VMULLO32(a, b)	_mm256_mullo_epi32((a), (b))
@@ -107,8 +107,8 @@
 #  define VADD16(a, b)		_mm512_add_epi16((a), (b))
 #  define VADD32(a, b)		_mm512_add_epi32((a), (b))
 #  define VDPBUSD(a, b, c)	_mm512_dpbusd_epi32((a), (b), (c))
-#  define VLOAD(p)		_mm512_load_si512((const void *)(p))
-#  define VLOADU(p)		_mm512_loadu_si512((const void *)(p))
+#  define VLOAD(p)		_mm512_load_si512((const __m512i *)(p))
+#  define VLOADU(p)		_mm512_loadu_si512((const __m512i *)(p))
 #  define VMADD16(a, b)		_mm512_madd_epi16((a), (b))
 #  define VMASKZ_LOADU(mask, p) _mm512_maskz_loadu_epi8((mask), (p))
 #  define VMULLO32(a, b)	_mm512_mullo_epi32((a), (b))

external/deflate/lib/zlib_compress.c

@@ -33,7 +33,7 @@ libdeflate_zlib_compress(struct libdeflate_compressor *c,
 			 const void *in, size_t in_nbytes,
 			 void *out, size_t out_nbytes_avail)
 {
-	u8 *out_next = out;
+        u8 *out_next = (u8*) out;
 	u16 hdr;
 	unsigned compression_level;
 	unsigned level_hint;

external/deflate/lib/zlib_decompress.c

@@ -35,7 +35,7 @@ libdeflate_zlib_decompress_ex(struct libdeflate_decompressor *d,
 			      size_t *actual_in_nbytes_ret,
 			      size_t *actual_out_nbytes_ret)
 {
-	const u8 *in_next = in;
+        const u8 *in_next = (const u8*) in;
 	const u8 * const in_end = in_next + in_nbytes;
 	u16 hdr;
 	size_t actual_in_nbytes;

src/bin/exrinfo/CMakeLists.txt

@@ -2,3 +2,7 @@
 # Copyright Contributors to the OpenEXR Project.
 
 add_openexr_bin_program(exrinfo SOURCES main.c)
+
+if (OPENEXR_CORE_USE_NAMESPACE)
+  set_source_files_properties(main.c PROPERTIES LANGUAGE CXX)
+endif()

src/bin/exrinfo/main.c

@@ -17,6 +17,10 @@
 
 #include <stdlib.h>
 
+#if __cplusplus
+using namespace OPENEXR_IMF_INTERNAL_NAMESPACE;
+#endif
+
 static void
 usage (FILE* stream, const char* argv0, int verbose)
 {

src/lib/OpenEXRCore/CMakeLists.txt

@@ -110,6 +110,26 @@ openexr_define_library(OpenEXRCore
     Imath::Imath
   )
 
+if (OPENEXR_CORE_USE_NAMESPACE)
+  message(STATUS "Building OpenEXRCore as C++")
+  get_target_property(OPENEXR_CORE_SOURCES OpenEXRCore SOURCES)
+  list(FILTER OPENEXR_CORE_SOURCES INCLUDE REGEX "\\.c$")
+
+  # clang++ defaults to interpreting .c files as c code, for force
+  # language to c++ 
+  if (CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
+    set(core_compile_options "/TP")
+  else()
+    set(core_compile_options "-xc++")
+  endif()
+  set_source_files_properties(${OPENEXR_CORE_SOURCES} PROPERTIES
+    LANGUAGE CXX
+    COMPILE_OPTIONS ${core_compile_options}
+  )
+else()
+  message(STATUS "Building OpenEXRCore as C")
+endif()
+
 if (DEFINED EXR_DEFLATE_LIB)
   if (BUILD_SHARED_LIBS)
     target_link_libraries(OpenEXRCore PRIVATE ${EXR_DEFLATE_LIB})

src/lib/OpenEXRCore/attributes.c

@@ -3,13 +3,16 @@
 ** Copyright Contributors to the OpenEXR Project.
 */
 
+#include "OpenEXRConfig.h"
 #include "internal_attr.h"
 
 #include "internal_constants.h"
 #include "internal_structs.h"
 
 #include <string.h>
 
+OPENEXR_CORE_NAMESPACE_ENTER
+
 struct _internal_exr_attr_map
 {
     const char*          name;
@@ -1131,3 +1134,6 @@ exr_attr_list_remove (
 
     return attr_destroy (ctxt, attr);
 }
+
+OPENEXR_CORE_NAMESPACE_EXIT
+