[Sanitizer] Write a slightly better implementation of GetEnv() function on Windows
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@177051 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/sanitizer_common/sanitizer_win.cc b/lib/sanitizer_common/sanitizer_win.cc
index d627219..c657341 100644
--- a/lib/sanitizer_common/sanitizer_win.cc
+++ b/lib/sanitizer_common/sanitizer_win.cc
@@ -111,19 +111,38 @@
UNIMPLEMENTED();
}
+static const kMaxEnvNameLength = 128;
+static const kMaxEnvValueLength = 32767;
+
+namespace {
+
+struct EnvVariable {
+ char name[kMaxEnvNameLength];
+ char value[kMaxEnvValueLength];
+};
+
+} // namespace
+
+static const int kEnvVariables = 5;
+static EnvVariable env_vars[kEnvVariables];
+static int num_env_vars;
+
const char *GetEnv(const char *name) {
- static char env_buffer[32767] = {};
-
- // Note: this implementation stores the result in a static buffer so we only
- // allow it to be called just once.
- static bool called_once = false;
- if (called_once)
- UNIMPLEMENTED();
- called_once = true;
-
- DWORD rv = GetEnvironmentVariableA(name, env_buffer, sizeof(env_buffer));
- if (rv > 0 && rv < sizeof(env_buffer))
- return env_buffer;
+ // Note: this implementation caches the values of the environment variables
+ // and limits their quantity.
+ for (int i = 0; i < num_env_vars; i++) {
+ if (0 == internal_strcmp(name, env_vars[i].name))
+ return env_vars[i].value;
+ }
+ CHECK_LT(num_env_vars, kEnvVariables);
+ DWORD rv = GetEnvironmentVariableA(name, env_vars[num_env_vars].value,
+ kMaxEnvValueLength);
+ if (rv > 0 && rv < kMaxEnvValueLength) {
+ CHECK_LT(internal_strlen(name), kMaxEnvNameLength);
+ internal_strncpy(env_vars[num_env_vars].name, name, kMaxEnvNameLength);
+ num_env_vars++;
+ return env_vars[num_env_vars - 1].value;
+ }
return 0;
}
