Support compilers that don't have the "inline" keyword

Use AC_C_INLINE autoconf macro, include config.h where needed, and add
a define of JSON_INLINE to jansson.h that has the correct "inline"
keyword.

.gitignore

@@ -23,3 +23,4 @@ missing
 stamp-h1
 *.pyc
 *.pc
+/src/jansson.h

configure.ac

@@ -17,13 +17,22 @@ AC_PROG_LIBTOOL
 # Checks for typedefs, structures, and compiler characteristics.
 AC_TYPE_INT32_T
 
+AC_C_INLINE
+case $ac_cv_c_inline in
+    yes) json_inline=inline;;
+    no) json_inline=;;
+    *) json_inline=$ac_cv_c_inline;;
+esac
+AC_SUBST([json_inline])
+
 # Checks for library functions.
 
 AC_CONFIG_FILES([
         jansson.pc
         Makefile
         doc/Makefile
         src/Makefile
+        src/jansson.h
         test/Makefile
         test/bin/Makefile
         test/suites/Makefile

src/hashtable.c

@@ -5,6 +5,8 @@
  * it under the terms of the MIT license. See LICENSE for details.
  */
 
+#include <config.h>
+
 #include <stdlib.h>
 #include "hashtable.h"
 

src/jansson.h → src/jansson.h.in

@@ -10,7 +10,10 @@
 
 #include <stdio.h>
 
-#ifdef __cplusplus
+#ifndef __cplusplus
+#define JSON_INLINE @json_inline@
+#else
+#define JSON_INLINE inline
 extern "C" {
 #endif
 
@@ -56,7 +59,8 @@ json_t *json_true(void);
 json_t *json_false(void);
 json_t *json_null(void);
 
-static inline json_t *json_incref(json_t *json)
+static JSON_INLINE
+json_t *json_incref(json_t *json)
 {
     if(json && json->refcount != (unsigned int)-1)
         ++json->refcount;
@@ -66,7 +70,8 @@ static inline json_t *json_incref(json_t *json)
 /* do not call json_delete directly */
 void json_delete(json_t *json);
 
-static inline void json_decref(json_t *json)
+static JSON_INLINE
+void json_decref(json_t *json)
 {
     if(json && json->refcount != (unsigned int)-1 && --json->refcount == 0)
         json_delete(json);
@@ -87,13 +92,13 @@ void *json_object_iter_next(json_t *object, void *iter);
 const char *json_object_iter_key(void *iter);
 json_t *json_object_iter_value(void *iter);
 
-static inline
+static JSON_INLINE
 int json_object_set(json_t *object, const char *key, json_t *value)
 {
     return json_object_set_new(object, key, json_incref(value));
 }
 
-static inline
+static JSON_INLINE
 int json_object_set_nocheck(json_t *object, const char *key, json_t *value)
 {
     return json_object_set_new_nocheck(object, key, json_incref(value));
@@ -108,19 +113,19 @@ int json_array_remove(json_t *array, unsigned int index);
 int json_array_clear(json_t *array);
 int json_array_extend(json_t *array, json_t *other);
 
-static inline
+static JSON_INLINE
 int json_array_set(json_t *array, unsigned int index, json_t *value)
 {
     return json_array_set_new(array, index, json_incref(value));
 }
 
-static inline
+static JSON_INLINE
 int json_array_append(json_t *array, json_t *value)
 {
     return json_array_append_new(array, json_incref(value));
 }
 
-static inline
+static JSON_INLINE
 int json_array_insert(json_t *array, unsigned int index, json_t *value)
 {
     return json_array_insert_new(array, index, json_incref(value));

src/value.c

@@ -6,6 +6,9 @@
  */
 
 #define _GNU_SOURCE
+
+#include <config.h>
+
 #include <stdlib.h>
 #include <string.h>