Improve error message when select types do not match (p4lang#3352)

* Improve error message when select types do not match Signed-off-by: Mihai Budiu <mbudiu@vmware.com> * Changed reference output Signed-off-by: Mihai Budiu <mbudiu@vmware.com>
github-sajan · May 26, 2022 · 393f3c0 · 393f3c0
1 parent c7aacc0
commit 393f3c0
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Showing 6 changed files with 42 additions and 5 deletions.
diff --git a/frontends/p4/typeChecking/typeChecker.cpp b/frontends/p4/typeChecking/typeChecker.cpp
@@ -3610,9 +3610,10 @@ TypeInference::matchCase(const IR::SelectExpression* select, const IR::Type_Base
         }
         useSelType = selectType->components.at(0);
     }
-    auto tvs = unify(select, useSelType, caseType,
-                     "'match' case label type '%1%' does not match expected type '%2%'",
-                     { caseType, useSelType });
+    auto tvs = unify(
+        select, useSelType, caseType,
+        "'match' case label '%1%' has type '%2%' which does not match the expected type '%3%'",
+        { selectCase->keyset, caseType, useSelType });
     if (tvs == nullptr)
         return nullptr;
     ConstantTypeSubstitution cts(tvs, refMap, typeMap, this);

diff --git a/testdata/p4_16_errors/issue3345.p4 b/testdata/p4_16_errors/issue3345.p4
@@ -0,0 +1,8 @@
+parser MyParser2(in bool t) {
+  state start {
+    transition select(t) {
+     1w1: accept;
+     _: reject;
+   }
+ }
+}
diff --git a/testdata/p4_16_errors_outputs/issue1986-1.p4-stderr b/testdata/p4_16_errors_outputs/issue1986-1.p4-stderr
@@ -4,4 +4,6 @@ issue1986-1.p4(22): [--Werror=type-error] error: SelectExpression
   ---- Actual error:
   Cannot unify type 'bit<0>' with type 'bit<2>'
   ---- Originating from:
-  'match' case label type 'bit<0>' does not match expected type 'bit<2>'
+issue1986-1.p4(23): 'match' case label '0' has type 'bit<0>' which does not match the expected type 'bit<2>'
+              0w0: parse_h2;
+              ^^^
diff --git a/testdata/p4_16_errors_outputs/issue1986.p4-stderr b/testdata/p4_16_errors_outputs/issue1986.p4-stderr
@@ -4,7 +4,10 @@ issue1986.p4(17): [--Werror=type-error] error: SelectExpression
   ---- Actual error:
   Cannot unify type 'bit<0>' with type 'bit<1>'
   ---- Originating from:
-issue1986.p4(18): 'match' case label type 'tuple<bit<0>>' does not match expected type 'tuple<bit<1>>'
+issue1986.p4(18): 'match' case label 'ListExpression' has type 'tuple<bit<0>>' which does not match the expected type 'tuple<bit<1>>'
+             {0w0}: accept;
+             ^^^^^
+issue1986.p4(18)
              {0w0}: accept;
              ^^^^^
 issue1986.p4(17)

diff --git a/testdata/p4_16_errors_outputs/issue3345.p4 b/testdata/p4_16_errors_outputs/issue3345.p4
@@ -0,0 +1,9 @@
+parser MyParser2(in bool t) {
+    state start {
+        transition select(t) {
+            1w1: accept;
+            default: reject;
+        }
+    }
+}
+
diff --git a/testdata/p4_16_errors_outputs/issue3345.p4-stderr b/testdata/p4_16_errors_outputs/issue3345.p4-stderr
@@ -0,0 +1,14 @@
+issue3345.p4(3): [--Werror=type-error] error: SelectExpression
+    transition select(t) {
+               ^
+  ---- Actual error:
+issue3345.p4(1): Cannot unify type 'bit<1>' with type 'bool'
+  parser MyParser2(in bool t) {
+                      ^^^^
+  ---- Originating from:
+issue3345.p4(4): 'match' case label '1w1' has type 'bit<1>' which does not match the expected type 'bool'
+       1w1: accept;
+       ^^^
+issue3345.p4(1)
+  parser MyParser2(in bool t) {
+                      ^^^^