use environ on posix systems to read environment variables before the C runtime is initialized (issue
@@ -400,6 +400,14 @@ static void mi_strlcat(char* dest, const char* src, size_t dest_size) {
dest[dest_size - 1] = 0;
}
+static inline int mi_strnicmp(const char* s, const char* t, size_t n) {
+ if (n==0) return 0;
+ for (; *s != 0 && *t != 0 && n > 0; s++, t++, n--) {
+ if (toupper(*s) != toupper(*t)) break;
+ }
+ return (n==0 ? 0 : *s - *t);
+}
+
#if defined _WIN32
// On Windows use GetEnvironmentVariable instead of getenv to work
// reliably even when this is invoked before the C runtime is initialized.
@@ -411,11 +419,45 @@ static bool mi_getenv(const char* name, char* result, size_t result_size) {
size_t len = GetEnvironmentVariableA(name, result, (DWORD)result_size);
return (len > 0 && len < result_size);
}
+#elif !defined(MI_USE_ENVIRON) || (MI_USE_ENVIRON!=0)
+// On Posix systemsr use `environ` to acces environment variables
+// even before the C runtime is initialized.
+#if defined(__APPLE__)
+#include <crt_externs.h>
+static char** mi_get_environ(void) {
+ return (*_NSGetEnviron());
+}
#else
+extern char** environ;
+static char** mi_get_environ(void) {
+ return environ;
+}
+#endif
static bool mi_getenv(const char* name, char* result, size_t result_size) {
+ if (name==NULL) return false;
+ const size_t len = strlen(name);
+ if (len == 0) return false;
+ char** env = mi_get_environ();
+ if (env == NULL) return false;
+ // compare all entries
+ for (; *env != NULL; env++) {
+ const char* s = *env;
+ if (mi_strnicmp(name, s, len) == 0 && s[len] == '=') { // case insensitive
+ // found it
+ mi_strlcpy(result, s + len + 1, result_size);
+ return true;
+ }
+ }
+ return false;
+}
+#else
+// fallback: use standard C `getenv` but this cannot be used while initializing the C runtime
+static bool mi_getenv(const char* name, char* result, size_t result_size) {
+ // cannot call getenv() when still initializing the C runtime.
+ if (_mi_preloading()) return false;
const char* s = getenv(name);
if (s == NULL) {
- // in unix environments we check the upper case name too.
+ // we check the upper case name too.
char buf[64+1];
size_t len = strlen(name);
if (len >= sizeof(buf)) len = sizeof(buf) - 1;
@@ -434,11 +476,8 @@ static bool mi_getenv(const char* name, char* result, size_t result_size) {
}
}
#endif
+
static void mi_option_init(mi_option_desc_t* desc) {
- #ifndef _WIN32
- // cannot call getenv() when still initializing the C runtime.
- if (_mi_preloading()) return;
- #endif
// Read option value from the environment
char buf[64+1];
mi_strlcpy(buf, "mimalloc_", sizeof(buf));
@@ -471,9 +510,9 @@ static void mi_option_init(mi_option_desc_t* desc) {
desc->init = DEFAULTED;
}
}
+ mi_assert_internal(desc->init != UNINIT);
}
- else {
+ else if (!_mi_preloading()) {
desc->init = DEFAULTED;
}
- mi_assert_internal(desc->init != UNINIT);
}
