From a5003c0c6a0d557b0e3716813fc7bb2702ff6546 Mon Sep 17 00:00:00 2001
From: Roman Sirokov <roman.sirokov@amd.com>
Date: Mon, 24 Aug 2026 10:42:52 +0000
Subject: [PATCH] fix(cli): accept negative float flag values in space form

The space form of negative-number float flags (e.g. `serve --temperature
-1`) was rejected by clap with a confusing "unexpected argument '-1'"
error, because clap parsed the leading-dash token as a flag rather than a
value. Only the equals form (`--temperature=-1`) reached the range
validator that reports the valid range.

Enable `allow_negative_numbers` on the affected float flags
(`--temperature` and `--top-p` on both `chat` and `serve`) so the space
form reaches the value parser and both forms validate identically,
surfacing a clear range-validation message instead of an unexpected
argument error.

Add regression tests covering both the space and equals forms for
`--temperature` and `--top-p` on `chat` and `serve`.

Signed-off-by: Roman Sirokov <roman.sirokov@amd.com>
---
 apps/rocm/src/main.rs | 56 +++++++++++++++++++++++++++++++++++++++----
 1 file changed, 52 insertions(+), 4 deletions(-)

diff --git a/apps/rocm/src/main.rs b/apps/rocm/src/main.rs
index 5b4ac58a..79b07211 100644
--- a/apps/rocm/src/main.rs
+++ b/apps/rocm/src/main.rs
@@ -257,10 +257,13 @@ echo \"Summarize this\" | rocm chat --provider anthropic")]
         #[arg(long)]
         prompt: Option<String>,
         /// Sampling temperature to send with the request (>= 0.0). Higher is more random.
-        #[arg(long, value_parser = parse_non_negative_temperature)]
+        // `allow_negative_numbers` lets the space form (`--temperature -1`) reach
+        // `parse_non_negative_temperature` for a clear range error, instead of clap
+        // rejecting `-1` as an unexpected argument.
+        #[arg(long, allow_negative_numbers = true, value_parser = parse_non_negative_temperature)]
         temperature: Option<f32>,
         /// Nucleus sampling probability to send with the request (0.0-1.0).
-        #[arg(long = "top-p", value_parser = parse_unit_interval)]
+        #[arg(long = "top-p", allow_negative_numbers = true, value_parser = parse_unit_interval)]
         top_p: Option<f32>,
         /// Maximum number of tokens to generate in the response.
         #[arg(long = "max-tokens", value_parser = parse_positive_u32)]
@@ -398,10 +401,13 @@ rocm serve qwen2.5-7b-instruct --verbose --device gpu_required")]
         #[arg(long, value_name = "FRACTION", allow_hyphen_values = true)]
         gpu_memory_utilization: Option<String>,
         /// Default sampling temperature for generation (>= 0.0).
-        #[arg(long, value_parser = parse_non_negative_temperature)]
+        // `allow_negative_numbers` lets the space form (`--temperature -1`) reach
+        // `parse_non_negative_temperature` for a clear range error, instead of clap
+        // rejecting `-1` as an unexpected argument.
+        #[arg(long, allow_negative_numbers = true, value_parser = parse_non_negative_temperature)]
         temperature: Option<f32>,
         /// Default nucleus sampling probability for generation (0.0-1.0).
-        #[arg(long = "top-p", value_parser = parse_unit_interval)]
+        #[arg(long = "top-p", allow_negative_numbers = true, value_parser = parse_unit_interval)]
         top_p: Option<f32>,
         /// Default maximum number of tokens to generate per response.
         #[arg(long = "max-tokens", value_parser = parse_positive_u32)]
@@ -18253,6 +18259,48 @@ mod tests {
         );
     }
 
+    #[test]
+    fn serve_negative_sampling_space_form_reaches_range_validator() {
+        // The space form (`--temperature -1`) must reach the range validator and
+        // report a range error, not be rejected by clap as an unexpected argument.
+        // This is the classic negative-number-as-flag gotcha; `allow_negative_numbers`
+        // makes both forms validate identically.
+        for args in [
+            &["--temperature", "-1"][..],
+            &["--temperature=-1"][..],
+            &["--top-p", "-0.5"][..],
+            &["--top-p=-0.5"][..],
+        ] {
+            assert_eq!(
+                parse_serve(args)
+                    .expect_err("negative sampling value is rejected")
+                    .kind(),
+                clap::error::ErrorKind::ValueValidation,
+                "expected range validation for {args:?}"
+            );
+        }
+    }
+
+    #[test]
+    fn chat_negative_sampling_space_form_reaches_range_validator() {
+        for args in [
+            &["--temperature", "-1"][..],
+            &["--temperature=-1"][..],
+            &["--top-p", "-0.5"][..],
+            &["--top-p=-0.5"][..],
+        ] {
+            let mut argv = vec!["rocm", "chat", "--prompt", "hi"];
+            argv.extend_from_slice(args);
+            assert_eq!(
+                Cli::try_parse_from(argv)
+                    .expect_err("negative sampling value is rejected")
+                    .kind(),
+                clap::error::ErrorKind::ValueValidation,
+                "expected range validation for {args:?}"
+            );
+        }
+    }
+
     #[test]
     fn chat_parses_generation_flags() {
         let cli = Cli::try_parse_from([