fix: address argument parsing silent drops

ddprof-lib/src/main/cpp/arguments.cpp

@@ -119,6 +119,32 @@ static const Multiplier UNIVERSAL[] = {
 //     alluser            - include only user-mode events
 //
 
+// Parses the y/yes,t/true,1 vs n/no,f/false,0 boolean convention. A NULL value
+// (bare option, no '=') enables the flag, matching the documented no-value-means-
+// enable convention shared by every boolean option in this file. Returns false
+// (leaving out untouched) when a non-NULL value matches none of the above, so the
+// caller can raise "Invalid <option> value" instead of coercing garbage to a
+// default. Takes out by reference since every caller passes a real bool.
+static bool parseBoolOption(const char *value, bool &out) {
+  if (value == nullptr) {
+    out = true;
+    return true;
+  }
+  if (strcmp(value, "y") == 0 || strcmp(value, "yes") == 0 ||
+      strcmp(value, "t") == 0 || strcmp(value, "true") == 0 ||
+      strcmp(value, "1") == 0) {
+    out = true;
+    return true;
+  }
+  if (strcmp(value, "n") == 0 || strcmp(value, "no") == 0 ||
+      strcmp(value, "f") == 0 || strcmp(value, "false") == 0 ||
+      strcmp(value, "0") == 0) {
+    out = false;
+    return true;
+  }
+  return false;
+}
+
 Error Arguments::parse(const char *args) {
   if (args == NULL) {
     return Error::OK;
@@ -255,7 +281,9 @@ Error Arguments::parse(const char *args) {
       }
 
       CASE("generations")
-      _gc_generations = value != NULL && strcmp(value, "true") == 0;
+      if (!parseBoolOption(value, _gc_generations)) {
+        msg = "Invalid generations value";
+      }
       if (_gc_generations && _memory <= 0) {
         _memory =
             4 * 1024 *
@@ -327,8 +355,10 @@ Error Arguments::parse(const char *args) {
           _cstack = CSTACK_VM;
           _features.mixed = 1;
           _features.carrier_frames = 1;
-        } else {
+        } else if (strcmp(value, "no") == 0) {
           _cstack = CSTACK_NO;
+        } else {
+          msg = "Invalid cstack value";
         }
       }
 
@@ -345,104 +375,48 @@ Error Arguments::parse(const char *args) {
       }
 
       CASE("lightweight")
-      if (value != NULL) {
-        switch (value[0]) {
-        case 'y': // yes
-        case 't': // true
-          _lightweight = true;
-          break;
-        default:
-          _lightweight = false;
-        }
+      if (value != NULL && !parseBoolOption(value, _lightweight)) {
+        msg = "Invalid lightweight value";
       }
 
       CASE("mcleanup")
-      if (value != NULL) {
-        switch (value[0]) {
-        case 'n': // no
-        case 'f': // false
-        case '0': // 0
-          _enable_method_cleanup = false;
-          break;
-        case 'y': // yes
-        case 't': // true
-        case '1': // 1
-        default:
-          _enable_method_cleanup = true;
-        }
-      } else {
-        // No value means enable
-        _enable_method_cleanup = true;
+      // No value means enable.
+      if (!parseBoolOption(value, _enable_method_cleanup)) {
+        msg = "Invalid mcleanup value";
       }
 
       CASE("remotesym")
-      if (value != NULL) {
-        switch (value[0]) {
-        case 'n': // no
-        case 'f': // false
-        case '0': // 0
-          _remote_symbolication = false;
-          break;
-        case 'y': // yes
-        case 't': // true
-        case '1': // 1
-        default:
-          _remote_symbolication = true;
-        }
-      } else {
-        // No value means enable
-        _remote_symbolication = true;
+      // No value means enable.
+      if (!parseBoolOption(value, _remote_symbolication)) {
+        msg = "Invalid remotesym value";
       }
 
       CASE("jvmtistacks")
-      if (value != NULL) {
-        switch (value[0]) {
-        case 'y': // yes
-        case 't': // true
-        case '1': // 1
-          _jvmtistacks = true;
-          break;
-        default:
-          _jvmtistacks = false;
-        }
-      } else {
-        _jvmtistacks = true;
+      if (!parseBoolOption(value, _jvmtistacks)) {
+        msg = "Invalid jvmtistacks value";
       }
 
       CASE("wallprecheck")
-      if (value != NULL) {
-        _wall_precheck = strcmp(value, "false") != 0 && strcmp(value, "0") != 0;
-      } else {
-        // No value means enable
-        _wall_precheck = true;
+      // No value means enable.
+      if (!parseBoolOption(value, _wall_precheck)) {
+        msg = "Invalid wallprecheck value";
       }
 
       CASE("wallsampler")
       if (value != NULL) {
-          switch (value[0]) {
-              case 'j':
-                  _wallclock_sampler = JVMTI;
-                  break;
-              case 'a':
-              default:
-                  _wallclock_sampler = ASGCT;
+          if (strcasecmp(value, "jvmti") == 0) {
+              _wallclock_sampler = JVMTI;
+          } else if (strcasecmp(value, "asgct") == 0) {
+              _wallclock_sampler = ASGCT;
+          } else {
+              msg = "Invalid wallsampler value";
           }
       }
 
       CASE("nosanity")
-      if (value != NULL) {
-        switch (value[0]) {
-        case 'n': // no
-        case 'f': // false
-        case '0': // 0
-          _skip_sanity_checks = false;
-          break;
-        default:
-          _skip_sanity_checks = true;
-        }
-      } else {
-        // A bare 'nosanity' with no value skips the checks.
-        _skip_sanity_checks = true;
+      // A bare 'nosanity' with no value skips the checks.
+      if (!parseBoolOption(value, _skip_sanity_checks)) {
+        msg = "Invalid nosanity value";
       }
 
       CASE("nativemem")
@@ -474,18 +448,9 @@ Error Arguments::parse(const char *args) {
         if (config) {
           *(config++) = 0;
         }
-        if (value != NULL) {
-          switch (value[0]) {
-          case 'n': // no
-          case 'f': // false
-          case '0': // 0
-            _reference_chains = false;
-            break;
-          default:
-            _reference_chains = true;
-          }
-        } else {
-          _reference_chains = true;
+        // A bare 'referencechains' with no value means enable.
+        if (!parseBoolOption(value, _reference_chains)) {
+          msg = "Invalid referencechains value";
         }
         char *cursor = config;
         while (cursor != NULL) {
@@ -528,15 +493,18 @@ Error Arguments::parse(const char *args) {
               _reference_chains_first_pass_budget = std::min(
                   std::max(atoi(eq), 0), MAX_REFERENCE_CHAINS_FIRST_PASS_BUDGET);
               _reference_chains_tuned_mask |= REF_CHAINS_TUNED_FIRST_PASS_BUDGET;
+            } else {
+              _unknown_args.push_back(cursor);
             }
+          } else if (*cursor != 0) {
+            _unknown_args.push_back(cursor);
           }
           cursor = next;
         }
       }
 
       DEFAULT()
-      if (_unknown_arg == NULL)
-        _unknown_arg = arg;
+      _unknown_args.push_back(arg);
     }
   }
 

ddprof-lib/src/main/cpp/arguments.h

@@ -201,9 +201,9 @@ class Error {
 
   explicit Error(const char *message) : _message(message) {}
 
-  const char *message() { return _message; }
+  const char *message() const { return _message; }
 
-  operator bool() { return _message != NULL; }
+  operator bool() const { return _message != NULL; }
 };
 
 class Arguments {
@@ -260,7 +260,7 @@ class Arguments {
   const char* _file;
   const char* _log;
   const char* _loglevel;
-  const char* _unknown_arg;
+  std::vector<std::string> _unknown_args;
   const char* _filter;
   CStack _cstack;
   Clock _clock;
@@ -311,7 +311,7 @@ class Arguments {
         _file(NULL),
         _log(NULL),
         _loglevel(NULL),
-        _unknown_arg(NULL),
+        _unknown_args({}),
         _filter(NULL),
         _cstack(CSTACK_DEFAULT),
         _clock(CLK_DEFAULT),

ddprof-lib/src/main/cpp/javaApi.cpp

@@ -115,13 +115,13 @@ Java_com_datadoghq_profiler_JavaProfiler_execute0(JNIEnv *env, jobject unused,
   JniString command_str(env, command);
   Error error = args.parse(command_str.c_str());
 
+  Log::open(args);
+
   if (error) {
     throwNew(env, "java/lang/IllegalArgumentException", error.message());
     return NULL;
   }
 
-  Log::open(args);
-
   std::ostringstream out;
 
   // Attach ProfiledThread

ddprof-lib/src/main/cpp/log.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright 2021 Andrei Pangin
+ * Copyright 2026, Datadog, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,12 +28,20 @@ LogLevel Log::_level = LOG_NONE;
 void Log::open(Arguments &args) {
   open(args._log, args._loglevel);
 
-  if (args._unknown_arg != NULL) {
-    warn("Unknown argument: %s", args._unknown_arg);
+  for (const std::string &arg : args._unknown_args) {
+    warn("Unknown argument: %s", arg.c_str());
   }
 }
 
 void Log::open(const char *file_name, const char *level) {
+  if (file_name == NULL && level == NULL) {
+    // Nothing to reconfigure. In particular, this keeps a rejected execute0()
+    // command (which parses to _log == NULL, _loglevel == NULL when the
+    // caller didn't ask to change logging) from resetting an active custom
+    // log file back to stdout/LOG_NONE before the parse error is thrown.
+    return;
+  }
+
   if (_file != stdout && _file != stderr) {
     fclose(_file);
   }