[TableGen] Print record location when record asserts fail (llvm#111029)

When record assertions fail, print an error message with the record's
location, so it's easier to see where the record that caused the assert
to fail was instantiated. This is useful when the assert condition in a
class depends on a template parameter, so we need to know the context of
the definition to determine why the assert failed.

Also enhanced the assert.td test to check for these context messages,
and also add checks for some assert failures that were missing in the
test.

Author: jurahul

llvm/include/llvm/TableGen/Error.h

@@ -48,7 +48,8 @@ void PrintError(const RecordVal *RecVal, const Twine &Msg);
 [[noreturn]] void PrintFatalError(const RecordVal *RecVal, const Twine &Msg);
 [[noreturn]] void PrintFatalError(function_ref<void(raw_ostream &OS)> PrintMsg);
 
-void CheckAssert(SMLoc Loc, Init *Condition, Init *Message);
+// Returns true if the assert failed.
+bool CheckAssert(SMLoc Loc, Init *Condition, Init *Message);
 void dumpMessage(SMLoc Loc, Init *Message);
 
 extern SourceMgr SrcMgr;

llvm/lib/TableGen/Error.cpp

@@ -160,18 +160,22 @@ void PrintFatalError(const RecordVal *RecVal, const Twine &Msg) {
 
 // Check an assertion: Obtain the condition value and be sure it is true.
 // If not, print a nonfatal error along with the message.
-void CheckAssert(SMLoc Loc, Init *Condition, Init *Message) {
+bool CheckAssert(SMLoc Loc, Init *Condition, Init *Message) {
   auto *CondValue = dyn_cast_or_null<IntInit>(Condition->convertInitializerTo(
       IntRecTy::get(Condition->getRecordKeeper())));
-  if (!CondValue)
+  if (!CondValue) {
     PrintError(Loc, "assert condition must of type bit, bits, or int.");
-  else if (!CondValue->getValue()) {
+    return true;
+  }
+  if (!CondValue->getValue()) {
     PrintError(Loc, "assertion failed");
     if (auto *MessageInit = dyn_cast<StringInit>(Message))
       PrintNote(MessageInit->getValue());
     else
       PrintNote("(assert message is not a string)");
+    return true;
   }
+  return false;
 }
 
 // Dump a message to stderr.

llvm/lib/TableGen/Record.cpp

@@ -3182,11 +3182,19 @@ void Record::checkRecordAssertions() {
   RecordResolver R(*this);
   R.setFinal(true);
 
+  bool AnyFailed = false;
   for (const auto &Assertion : getAssertions()) {
     Init *Condition = Assertion.Condition->resolveReferences(R);
     Init *Message = Assertion.Message->resolveReferences(R);
-    CheckAssert(Assertion.Loc, Condition, Message);
+    AnyFailed |= CheckAssert(Assertion.Loc, Condition, Message);
   }
+
+  if (!AnyFailed)
+    return;
+
+  // If any of the record assertions failed, print some context that will
+  // help see where the record that caused these assert failures is defined.
+  PrintError(this, "assertion failed in this record");
 }
 
 void Record::emitRecordDumps() {

llvm/test/TableGen/assert.td

@@ -1,6 +1,8 @@
-// RUN: not llvm-tblgen %s 2>&1 | FileCheck %s
+// RUN: not llvm-tblgen %s 2>&1 | FileCheck %s -DFILE=%s
 
+// -----------------------------------------------------------------------------
 // Test the assert statement at top level.
+// -----------------------------------------------------------------------------
 
 // CHECK: assertion failed
 // CHECK-NOT: note: primary name is too short
@@ -48,33 +50,35 @@ foreach i = 1...3 in {
   def bar_ # i;
 }
 
+// -----------------------------------------------------------------------------
 // Test the assert statement in a record definition.
+// -----------------------------------------------------------------------------
 
-// CHECK: assertion failed
+// CHECK: [[FILE]]:[[@LINE+8]]:10: error: assertion failed
 // CHECK-NOT: primary first name is not "Grace"
-// CHECK: primary first name is not "Grack"
-// CHECK: assertion failed
-// CHECK: foo field should be
-
+// CHECK: note: primary first name is not "Grack"
+// CHECK: [[FILE]]:[[@LINE+7]]:10: error: assertion failed
+// CHECK: note: foo field should be
+// CHECK: [[FILE]]:[[@LINE+1]]:5: error: assertion failed in this record
 def Rec10 {
   assert !eq(!substr(Name, 0, 5), "Grace"), "primary first name is not \"Grace\"";
   assert !eq(!substr(Name, 0, 5), "Grack"), "primary first name is not \"Grack\"";
   string foo = "Foo";
   assert !eq(foo, "foo"), "foo field should be \"Foo\"";
 }
 
-// CHECK: assertion failed
+// CHECK: [[FILE]]:[[@LINE+5]]:10: error: assertion failed
 // CHECK: note: magic field is incorrect: 42
-
+// CHECK: [[FILE]]:[[@LINE+1]]:5: error: assertion failed in this record
 def Rec11 {
   int magic = 13;
   assert !eq(magic, 13), "magic field is incorrect: " # magic;
   let magic = 42;       
 }
 
-// CHECK: assertion failed
+// CHECK: [[FILE]]:[[@LINE+6]]:10: error: assertion failed
 // CHECK: note: var field has wrong value
-
+// CHECK: [[FILE]]:[[@LINE+1]]:5: error: assertion failed in this record
 def Rec12 {
   defvar prefix = "foo_";
   string var = prefix # "snork";
@@ -83,25 +87,27 @@ def Rec12 {
 
 // CHECK: assertion failed
 // CHECK: note: kind field has wrong value
-
 class Kind {
   int kind = 7;
 }
 
+// CHECK: [[FILE]]:[[@LINE+1]]:5: error: assertion failed in this record
 def Rec13 : Kind {
   let kind = 8;
   assert !eq(kind, 7), "kind field has wrong value: " # kind;
 }
 
 // CHECK: assertion failed
 // CHECK: note: double_result should be
-
+// CHECK: [[FILE]]:[[@LINE+1]]:5: error: assertion failed in this record
 def Rec14 : Cube<3> {
   int double_result = !mul(result, 2);
   assert !eq(double_result, 53), "double_result should be 54";
 }
 
+// -----------------------------------------------------------------------------
 // Test the assert statement in a class definition.
+// -----------------------------------------------------------------------------
 
 class PersonName<string name> {
   assert !le(!size(name), 32), "person name is too long: " # name;
@@ -118,32 +124,39 @@ def Rec20 : Person<"Donald Knuth", 60>;
 
 // CHECK: assertion failed
 // CHECK: note: person name is too long
-
+// CHECK: [[FILE]]:[[@LINE+1]]:5: error: assertion failed in this record
 def Rec21 : Person<"Donald Uh Oh This Name Is Too Long Knuth", 50>;
 
 // CHECK: assertion failed
 // CHECK: note: person age is invalid
-
+// CHECK: [[FILE]]:[[@LINE+1]]:5: error: assertion failed in this record
 def Rec22 : Person<"Donald Knuth", 150>;
 
 // Test the assert statement in an anonymous class invocation.
-
 def Rec30 {
   string Name = Person<"Margaret Heafield Hamilton", 25>.Name;
   int Age = Person<"Margaret Heafield Hamilton", 25>.Age;
 }
 
+// CHECK: assertion failed
+// CHECK: note: person name is too long
+// CHECK: [[FILE]]:[[@LINE+2]]:17: error: assertion failed in this record
 def Rec31 {
   string Name = Person<"Margaret Heafield And More Middle Names Hamilton", 25>.Name;
   int Age = Person<"Margaret Heafield Hamilton", 25>.Age;
 }
 
+// CHECK: assertion failed
+// CHECK: note: person age is invalid: 0
+// CHECK: [[FILE]]:[[@LINE+3]]:13: error: assertion failed in this record
 def Rec32 {
   string Name = Person<"Margaret Heafield Hamilton", 25>.Name;
   int Age = Person<"Margaret Heafield Hamilton", 0>.Age;
 }
 
+// -----------------------------------------------------------------------------
 // Test the assert statement in a multiclass.
+// -----------------------------------------------------------------------------
 
 // CHECK: assertion failed
 // CHECK: note: MC1 id string is too long