commit 5e071a18ce88d93fcffaebb9e0f62524ae504908
author Elliott Hughes <enh@google.com> Thu Aug 11 15:02:45 2016 -0700
committer Elliott Hughes <enh@google.com> Thu Aug 11 15:02:45 2016 -0700
tree 39f8f753321a562b980e0134dbe98e4400f4be24
parent f5042cab109f7136191fd316be1471532d2ddf71

dlerror returns char*, not const char*.

http://pubs.opengroup.org/onlinepubs/9699919799/functions/dlerror.html:

    char *dlerror(void);
    ...
    The application shall not modify the string returned.

Change-Id: I5e684bfd3930c39a2a30ea6fd005a5d5d3e5b181

libc/include/dlfcn.h

diff --git a/libc/include/dlfcn.h b/libc/include/dlfcn.h
index a53f664..9aa4a1f 100644
--- a/libc/include/dlfcn.h
+++ b/libc/include/dlfcn.h
@@ -51,7 +51,7 @@
 
 void* dlopen(const char* filename, int flag);
 int dlclose(void* _Nonnull handle);
-const char* dlerror(void);
+char* dlerror(void);
 void* dlsym(void* handle, const char* _Nonnull symbol);
 void* dlvsym(void* handle, const char* _Nonnull symbol, const char* _Nonnull version) __INTRODUCED_IN(24);
 int dladdr(const void* addr, Dl_info* _Nonnull info);

libdl/libdl.c

diff --git a/libdl/libdl.c b/libdl/libdl.c
index b62ee5c..4cc4dea 100644
--- a/libdl/libdl.c
+++ b/libdl/libdl.c
@@ -25,7 +25,7 @@
 
 void* dlopen(const char* filename __unused, int flag __unused) { return 0; }
 
-const char* dlerror(void) { return 0; }
+char* dlerror(void) { return 0; }
 
 void* dlsym(void* handle __unused, const char* symbol __unused) { return 0; }
 

linker/dlfcn.cpp

diff --git a/linker/dlfcn.cpp b/linker/dlfcn.cpp
index 4d9a218..3ac61d7 100644
--- a/linker/dlfcn.cpp
+++ b/linker/dlfcn.cpp
@@ -33,10 +33,10 @@
 
 static pthread_mutex_t g_dl_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
 
-static const char* __bionic_set_dlerror(char* new_value) {
+static char* __bionic_set_dlerror(char* new_value) {
   char** dlerror_slot = &reinterpret_cast<char**>(__get_tls())[TLS_SLOT_DLERROR];
 
-  const char* old_value = *dlerror_slot;
+  char* old_value = *dlerror_slot;
   *dlerror_slot = new_value;
   return old_value;
 }
@@ -52,8 +52,8 @@
   __bionic_set_dlerror(buffer);
 }
 
-const char* dlerror() {
-  const char* old_value = __bionic_set_dlerror(nullptr);
+char* dlerror() {
+  char* old_value = __bionic_set_dlerror(nullptr);
   return old_value;
 }