Avoid leaking internal headers for ppc (#164)

include/cpuinfo_ppc.h

@@ -17,7 +17,6 @@
 
 #include "cpu_features_cache_info.h"
 #include "cpu_features_macros.h"
-#include "internal/hwcaps.h"
 
 CPU_FEATURES_START_CPP_NAMESPACE
 
@@ -74,12 +73,17 @@ typedef struct {
 // This function is guaranteed to be malloc, memset and memcpy free.
 PPCInfo GetPPCInfo(void);
 
+typedef struct {
+  char platform[64];       // 0 terminated string
+  char base_platform[64];  // 0 terminated string
+} PPCPlatformTypeStrings;
+
 typedef struct {
   char platform[64];  // 0 terminated string
   char model[64];     // 0 terminated string
   char machine[64];   // 0 terminated string
   char cpu[64];       // 0 terminated string
-  PlatformType type;
+  PPCPlatformTypeStrings type;
 } PPCPlatformStrings;
 
 PPCPlatformStrings GetPPCPlatformStrings(void);

include/internal/hwcaps.h

@@ -171,16 +171,19 @@ typedef struct {
   unsigned long hwcaps2;
 } HardwareCapabilities;
 
+// Retrieves values from auxiliary vector for types AT_HWCAP and AT_HWCAP2.
+// First tries to call getauxval(), if not available falls back to reading
+// "/proc/self/auxv".
 HardwareCapabilities CpuFeatures_GetHardwareCapabilities(void);
+
+// Checks whether value for AT_HWCAP (or AT_HWCAP2) match hwcaps_mask.
 bool CpuFeatures_IsHwCapsSet(const HardwareCapabilities hwcaps_mask,
                              const HardwareCapabilities hwcaps);
 
-typedef struct {
-  char platform[64];       // 0 terminated string
-  char base_platform[64];  // 0 terminated string
-} PlatformType;
-
-PlatformType CpuFeatures_GetPlatformType(void);
+// Get pointer for the AT_PLATFORM type.
+const char* CpuFeatures_GetPlatformPointer(void);
+// Get pointer for the AT_BASE_PLATFORM type.
+const char* CpuFeatures_GetBasePlatformPointer(void);
 
 CPU_FEATURES_END_CPP_NAMESPACE