feat: add device support probe ABI

Expose a baseline-safe capability query for AArch32 NEON/VFPv4 requirements, bump the compatible ABI minor version, and cover HWCAP combinations plus package usage.

Author: NicoIer

CMakeLists.txt

@@ -33,7 +33,7 @@ endif()
 
 project(
     soc
-    VERSION 3.0.0
+    VERSION 3.1.0
     DESCRIPTION "CPU software rasterization and occlusion culling library"
     LANGUAGES C
 )

include/soc/soc.h

@@ -34,6 +34,15 @@ extern "C" {
 
 SOC_API uint32_t SOC_CALL soc_get_abi_version(void);
 
+/*
+ * Safe to call immediately after loading the library, before any other SOC
+ * operation. Returns SOC_TRUE when this library's ISA requirements are
+ * available to the current process. If it returns SOC_FALSE, only this
+ * function and soc_get_abi_version() may be called; all other SOC operations
+ * are unsupported.
+ */
+SOC_API soc_bool SOC_CALL soc_device_is_supported(void);
+
 /*
  * config->worker_count is the total execution lane count, including the
  * thread which calls build. Zero selects the online logical CPU count (clamped

include/soc/soc_types.h

@@ -5,7 +5,7 @@
 #include <stdint.h>
 
 #define SOC_ABI_VERSION_MAJOR 3u
-#define SOC_ABI_VERSION_MINOR 0u
+#define SOC_ABI_VERSION_MINOR 1u
 #define SOC_ABI_VERSION \
     ((SOC_ABI_VERSION_MAJOR << 16u) | SOC_ABI_VERSION_MINOR)
 

src/CMakeLists.txt

@@ -22,6 +22,50 @@ if(_soc_build_aarch32_neon_fma)
     )
 endif()
 
+add_library(
+    soc_device_support
+    OBJECT
+        abi/soc_device_support.c
+)
+target_include_directories(
+    soc_device_support
+    PRIVATE
+        "${PROJECT_SOURCE_DIR}/include"
+        "${CMAKE_CURRENT_SOURCE_DIR}"
+)
+target_compile_features(soc_device_support PRIVATE c_std_17)
+set_target_properties(
+    soc_device_support
+    PROPERTIES
+        C_VISIBILITY_PRESET hidden
+        INTERPROCEDURAL_OPTIMIZATION FALSE
+        POSITION_INDEPENDENT_CODE ON
+)
+soc_enable_warnings(soc_device_support)
+if(SOC_BUILD_SHARED)
+    target_compile_definitions(
+        soc_device_support
+        PRIVATE SOC_BUILDING_LIBRARY
+    )
+else()
+    target_compile_definitions(soc_device_support PRIVATE SOC_STATIC)
+endif()
+if(_soc_build_aarch32_neon_fma)
+    target_compile_definitions(
+        soc_device_support
+        PRIVATE
+            $<$<CONFIG:Release>:SOC_ABI_REQUIRES_ARM32_NEON_VFPV4=1>
+    )
+    target_compile_options(
+        soc_device_support
+        PRIVATE
+            $<$<CONFIG:Release>:-march=armv7-a>
+            $<$<CONFIG:Release>:-mfpu=vfpv3-d16>
+            $<$<CONFIG:Release>:-mfloat-abi=softfp>
+            $<$<CONFIG:Release>:-fno-lto>
+    )
+endif()
+
 add_library(
     soc_core
     OBJECT
@@ -123,6 +167,7 @@ if(SOC_BUILD_SHARED)
         soc
         SHARED
             abi/soc_api.c
+            $<TARGET_OBJECTS:soc_device_support>
             $<TARGET_OBJECTS:soc_core>
     )
     target_compile_definitions(soc PRIVATE SOC_BUILDING_LIBRARY)
@@ -131,6 +176,7 @@ else()
         soc
         STATIC
             abi/soc_api.c
+            $<TARGET_OBJECTS:soc_device_support>
             $<TARGET_OBJECTS:soc_core>
     )
     target_compile_definitions(soc PUBLIC SOC_STATIC)

src/abi/soc_device_support.c

@@ -0,0 +1,19 @@
+#include <soc/soc.h>
+
+#include "abi/soc_device_support.h"
+
+#if defined(SOC_ABI_REQUIRES_ARM32_NEON_VFPV4)
+    #if !defined(__ANDROID__) || !defined(__arm__)
+        #error "ARM32 NEON/VFPv4 support probe requires Android AArch32"
+    #endif
+    #include <sys/auxv.h>
+#endif
+
+soc_bool SOC_CALL soc_device_is_supported(void)
+{
+#if defined(SOC_ABI_REQUIRES_ARM32_NEON_VFPV4)
+    return soc_arm32_neon_vfpv4_is_supported(getauxval(AT_HWCAP));
+#else
+    return SOC_TRUE;
+#endif
+}

src/abi/soc_device_support.h

@@ -0,0 +1,19 @@
+#ifndef SOC_DEVICE_SUPPORT_H_INCLUDED
+#define SOC_DEVICE_SUPPORT_H_INCLUDED
+
+#include <soc/soc.h>
+
+#define SOC_ARM32_HWCAP_NEON (1ul << 12u)
+#define SOC_ARM32_HWCAP_VFPV4 (1ul << 16u)
+
+static inline soc_bool soc_arm32_neon_vfpv4_is_supported(
+    unsigned long hwcap
+)
+{
+    const unsigned long required =
+        SOC_ARM32_HWCAP_NEON | SOC_ARM32_HWCAP_VFPV4;
+
+    return (hwcap & required) == required ? SOC_TRUE : SOC_FALSE;
+}
+
+#endif

tests/CMakeLists.txt

@@ -5,6 +5,17 @@ soc_enable_warnings(soc_test_abi)
 
 add_test(NAME soc.abi COMMAND soc_test_abi)
 
+add_executable(soc_test_device_support test_device_support.c)
+target_link_libraries(soc_test_device_support PRIVATE soc::soc)
+target_include_directories(
+    soc_test_device_support
+    PRIVATE "${PROJECT_SOURCE_DIR}/src"
+)
+target_compile_features(soc_test_device_support PRIVATE c_std_17)
+soc_enable_warnings(soc_test_device_support)
+
+add_test(NAME soc.device_support COMMAND soc_test_device_support)
+
 add_executable(soc_test_types test_types.c)
 target_link_libraries(soc_test_types PRIVATE soc::soc)
 target_compile_features(soc_test_types PRIVATE c_std_17)

tests/package-consumer/main.c

@@ -8,6 +8,18 @@ int main(void)
     soc_build_stats build_stats = {0};
     soc_query_stats query_stats = {0};
     soc_snapshot* snapshot = NULL;
+    const soc_bool device_supported = soc_device_is_supported();
+
+    if (soc_get_abi_version() != SOC_ABI_VERSION ||
+        SOC_ABI_VERSION_MAJOR != 3u) {
+        return 1;
+    }
+    if (device_supported == SOC_FALSE) {
+        return 0;
+    }
+    if (device_supported != SOC_TRUE) {
+        return 1;
+    }
 
     group.flags = SOC_OCCLUDER_GROUP_FLAG_NONE;
     build.struct_size = sizeof(build);
@@ -22,9 +34,7 @@ int main(void)
 
     soc_snapshot_destroy(snapshot);
 
-    return soc_get_abi_version() == SOC_ABI_VERSION &&
-        SOC_ABI_VERSION_MAJOR == 3u &&
-        SOC_OCCLUDER_GROUP_SIZE_V1 <= sizeof(group) &&
+    return SOC_OCCLUDER_GROUP_SIZE_V1 <= sizeof(group) &&
         SOC_OCCLUSION_BUILD_DESC_SIZE_V1 <= sizeof(build) &&
         SOC_BUILD_STATS_SIZE_V1 <= sizeof(build_stats) &&
         SOC_QUERY_STATS_SIZE_V1 <= sizeof(query_stats)

tests/test_abi.c

@@ -228,9 +228,17 @@ static int test_invalid_arguments(void)
 
 int main(void)
 {
+    const soc_bool device_supported = soc_device_is_supported();
+
     if (test_version() != 0) {
         return 1;
     }
+    if (device_supported == SOC_FALSE) {
+        return 0;
+    }
+    if (device_supported != SOC_TRUE) {
+        return 1;
+    }
     if (test_context_lifetime() != 0) {
         return 1;
     }

tests/test_device_support.c

@@ -0,0 +1,29 @@
+#include <soc/soc.h>
+
+#include "abi/soc_device_support.h"
+
+#define CHECK(condition) \
+    do { \
+        if (!(condition)) { \
+            return 1; \
+        } \
+    } while (0)
+
+int main(void)
+{
+    CHECK(soc_arm32_neon_vfpv4_is_supported(0ul) == SOC_FALSE);
+    CHECK(soc_arm32_neon_vfpv4_is_supported(
+        SOC_ARM32_HWCAP_NEON
+    ) == SOC_FALSE);
+    CHECK(soc_arm32_neon_vfpv4_is_supported(
+        SOC_ARM32_HWCAP_VFPV4
+    ) == SOC_FALSE);
+    CHECK(soc_arm32_neon_vfpv4_is_supported(
+        SOC_ARM32_HWCAP_NEON | SOC_ARM32_HWCAP_VFPV4
+    ) == SOC_TRUE);
+    CHECK(soc_arm32_neon_vfpv4_is_supported(~0ul) == SOC_TRUE);
+
+    const soc_bool supported = soc_device_is_supported();
+    CHECK(supported == SOC_FALSE || supported == SOC_TRUE);
+    return 0;
+}