From de54d1e18f6e5bed8cbca2cdddc8043081a4c8a2 Mon Sep 17 00:00:00 2001
From: "Ma, Rong" <rong.ma@intel.com>
Date: Tue, 12 Mar 2024 15:53:40 -0700
Subject: [PATCH] Allow binding fixed precision or scale for decimal type
 (#9044)

Summary:
Fixes https://github.com/facebookincubator/velox/issues/9029

Pull Request resolved: https://github.com/facebookincubator/velox/pull/9044

Reviewed By: Yuhta

Differential Revision: D54800731

Pulled By: mbasmanova

fbshipit-source-id: 7c15beb9c04c377f543612b1db6f2f0134c419b1
---
 velox/expression/SignatureBinder.cpp          |  3 +++
 .../expression/tests/SignatureBinderTest.cpp  | 25 +++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/velox/expression/SignatureBinder.cpp b/velox/expression/SignatureBinder.cpp
index 6ec60dcbe749..4ea670d4d195 100644
--- a/velox/expression/SignatureBinder.cpp
+++ b/velox/expression/SignatureBinder.cpp
@@ -138,6 +138,9 @@ bool SignatureBinder::tryBind() {
 bool SignatureBinderBase::checkOrSetIntegerParameter(
     const std::string& parameterName,
     int value) {
+  if (isPositiveInteger(parameterName)) {
+    return atoi(parameterName.c_str()) == value;
+  }
   if (!variables().count(parameterName)) {
     // Return false if the parameter is not found in the signature.
     return false;
diff --git a/velox/expression/tests/SignatureBinderTest.cpp b/velox/expression/tests/SignatureBinderTest.cpp
index 6c481ca4b35e..4eba91f38455 100644
--- a/velox/expression/tests/SignatureBinderTest.cpp
+++ b/velox/expression/tests/SignatureBinderTest.cpp
@@ -240,6 +240,31 @@ TEST(SignatureBinderTest, decimals) {
           "Type variables cannot have constraints");
     }
   }
+  // Scalar function signature with fixed scale.
+  {
+    {
+      auto signature = exec::FunctionSignatureBuilder()
+                           .integerVariable("precision")
+                           .returnType("boolean")
+                           .argumentType("DECIMAL(precision, 6)")
+                           .build();
+      testSignatureBinder(signature, {DECIMAL(11, 6)}, BOOLEAN());
+      assertCannotResolve(signature, {DECIMAL(11, 8)});
+    }
+    {
+      auto signature = exec::FunctionSignatureBuilder()
+                           .integerVariable("precision")
+                           .integerVariable("scale")
+                           .returnType("DECIMAL(precision, scale)")
+                           .argumentType("DECIMAL(precision, 6)")
+                           .argumentType("DECIMAL(18, scale)")
+                           .build();
+      testSignatureBinder(
+          signature, {DECIMAL(11, 6), DECIMAL(18, 4)}, DECIMAL(11, 4));
+      assertCannotResolve(signature, {DECIMAL(11, 6), DECIMAL(20, 4)});
+      assertCannotResolve(signature, {DECIMAL(11, 8), DECIMAL(18, 4)});
+    }
+  }
 }
 
 TEST(SignatureBinderTest, computation) {