[asan, myriad] Support environment variables

[alekseyshl]

compiler-rt/lib/sanitizer_common/sanitizer_rtems.cc

257 ↗

(On Diff #150576)

What if name_len > env_len - 2?

261 ↗

(On Diff #150576)

name == "" and env="=x\0" will work and return "x", but maybe it's not that a bad thing.

[vitalybuka]

compiler-rt/lib/sanitizer_common/sanitizer_rtems.cc

39 ↗

(On Diff #150576)

why?

41 ↗

(On Diff #150576)

Howe about making it static and add __sanitizer::SetEnvForTest()

253 ↗

(On Diff #150576)

how this can happen?

259 ↗

(On Diff #150576)

for (uptr i = 0; i <= end; i += internal_strlen(env) + 1)

[waltl]

Sorry for the overly complicated initial patch. We've decided to get
setenv() to work in our test enviroment (using similar approach to the
initial patch here), so now the sanitizer run-time can just call that.

compiler-rt/trunk/lib/sanitizer_common/sanitizer_rtems.cc

 void ReleaseMemoryPagesToOS(uptr beg, uptr end) {}
 void DumpProcessMap() {}
 
 // There is no page protection so everything is "accessible."
 bool IsAccessibleMemoryRange(uptr beg, uptr size) {
   return true;
 }
 
-char **GetArgv() { return NULL; }
-const char *GetEnv(const char *name) { return NULL; }
+char **GetArgv() { return nullptr; }
+
+const char *GetEnv(const char *name) {
+  return getenv(name);
+}
 
 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
   internal_strncpy(buf, "StubBinaryName", buf_len);
   return internal_strlen(buf);
 }
 
 uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
   internal_strncpy(buf, "StubProcessName", buf_len);