add C++ include guards to header files which are missing them

Fixes https://github.com/espressif/esp-idf/issues/628

components/esp32/include/esp_dport_access.h

@@ -15,6 +15,10 @@
 #ifndef _ESP_DPORT_ACCESS_H_
 #define _ESP_DPORT_ACCESS_H_
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 void esp_dport_access_stall_other_cpu_start(void);
 void esp_dport_access_stall_other_cpu_end(void);
 void esp_dport_access_int_init(void);
@@ -27,4 +31,8 @@ void esp_dport_access_int_init(void);
 #define DPORT_STALL_OTHER_CPU_END()     esp_dport_access_stall_other_cpu_end()
 #endif
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* _ESP_DPORT_ACCESS_H_ */

components/esp32/include/esp_heap_alloc_caps.h

@@ -14,6 +14,10 @@
 #ifndef HEAP_ALLOC_CAPS_H
 #define HEAP_ALLOC_CAPS_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * @brief Flags to indicate the capabilities of the various memory systems
  */
@@ -99,5 +103,8 @@ static inline bool  esp_ptr_dma_capable( const void *ptr )
     return ( (int)ptr >= 0x3FFAE000 && (int)ptr < 0x40000000 );
 }
 
-
+#ifdef __cplusplus
+}
 #endif
+
+#endif //HEAP_ALLOC_CAPS_H

components/esp32/include/esp_ipc.h

@@ -17,6 +17,10 @@
 
 #include <esp_err.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef void (*esp_ipc_func_t)(void* arg);
 
 /**
@@ -84,5 +88,8 @@ esp_err_t esp_ipc_call(uint32_t cpu_id, esp_ipc_func_t func, void* arg);
 esp_err_t esp_ipc_call_blocking(uint32_t cpu_id, esp_ipc_func_t func, void* arg);
 
 
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* __ESP_IPC_H__ */

components/fatfs/src/esp_vfs_fat.h

@@ -21,6 +21,10 @@
 #include "ff.h"
 #include "wear_levelling.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * @brief Register FATFS with VFS component
  *
@@ -173,3 +177,7 @@ esp_err_t esp_vfs_fat_spiflash_mount(const char* base_path,
  *      - ESP_ERR_INVALID_STATE if esp_vfs_fat_spiflash_mount hasn't been called
  */
  esp_err_t esp_vfs_fat_spiflash_unmount(const char* base_path, wl_handle_t wl_handle);
+
+#ifdef __cplusplus
+}
+#endif

components/soc/esp32/include/soc/dport_access.h

@@ -19,6 +19,10 @@
 #include "esp_attr.h"
 #include "esp_dport_access.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 //Registers Operation {{
 
 //Register read macros with an underscore prefix access DPORT memory directly. In IDF apps, use the non-underscore versions to be SMP-safe.
@@ -114,5 +118,8 @@ static inline uint32_t IRAM_ATTR DPORT_READ_PERI_REG(uint32_t addr)
 #define DPORT_GET_PERI_REG_BITS2(reg, mask,shift)      ((DPORT_READ_PERI_REG(reg)>>(shift))&(mask))
 //}}
 
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* _DPORT_ACCESS_H_ */