[liba] Add a bridge for incomplete libc

For example, GLIBC doesn't provide strlcpy which we want to use

Change-Id: Iebbadfd42ca8e5dc089a8fe0b670fef843a10027

Makefile

@@ -53,6 +53,7 @@ info:
 	@echo "==============================="
 
 ifeq ($(USE_LIBA),0)
+include liba/Makefile.bridge
 else
 SFLAGS += -ffreestanding -nostdinc -nostdlib
 include liba/Makefile

apps/graph/function.cpp

@@ -11,12 +11,7 @@ Graph::Function::Function(const char * text, KDColor color) :
 }
 
 void Graph::Function::setContent(const char * c) {
-#if __GLIBC__
-  // FIXME: This is ugly.
-  strncpy(m_text, c, sizeof(m_text));
-#else
   strlcpy(m_text, c, sizeof(m_text));
-#endif
   if (m_expression != nullptr) {
     delete m_expression;
   }

liba/Makefile.bridge

@@ -0,0 +1,3 @@
+SFLAGS += -Iliba/include/bridge
+
+objs += liba/src/bridge.o

liba/include/bridge/string.h

@@ -0,0 +1,16 @@
+#ifndef LIBA_BRIDGE_STRING_H
+#define LIBA_BRIDGE_STRING_H
+
+#include_next <string.h>
+
+#include "../private/macros.h"
+
+LIBA_BEGIN_DECLS
+
+#if __GLIBC__
+size_t strlcpy(char * dst, const char * src, size_t len);
+#endif
+
+LIBA_END_DECLS
+
+#endif

liba/src/bridge.c

@@ -0,0 +1,5 @@
+#include <string.h>
+
+#if __GLIBC__
+#include "strlcpy.c"
+#endif