[clang][AST] TextNodeDumper learned to output exception specifications

[strimo378]

Summary

Extended TextNodeDumper::VisitFunctionProtoType to output exception specifications

[shafik]

I think we at least need some tests for this, looks like we have the AST tests in clang/test/AST/ast-dump*

[strimo378]

There are many ast-dump tests about decls but there are nearly no other type tests.

[aaron.ballman]

In D155383#4507928, @strimo378 wrote:

There are many ast-dump tests about decls but there are nearly no other type tests.

We should still be adding tests for these changes, to ensure we don't regress the behavior later by accident. It also helps the code reviewers to see what the output looks like and whether we spot any concerns with it.

clang/lib/AST/TextNodeDumper.cpp

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[strimo378]

Added test cases and applied review comments.

[strimo378]

I added a test case for demonstrating NoexceptExpr and Exceptions output. I don't know how to produce a FunctionProtoType output with ExceptionSourceDecl and ExceptionSourceTemplate. typedef/using is the only way I know to output types for the current AST dump and all my attempts failed to produce an uninstantiated exception information within a typedef.

Here is an example from my (slightly extended) AST dump where I output every type stored within ASTContext:

FunctionProtoType #267 0x20c10fd58a0 'void ()' (canonical FunctionProtoType #210 0x20c10fd6580) exceptionspec_uninstantiated
|-ExceptionSourceDecl CXXConstructor 0x20c10fd5798 #266 'e' 'void () noexcept(b<__is_same(d<>, d<>)>::c && b<__is_same(d<>, d<>)>::c)'#286 cdecl
|-ExceptionSourceTemplate CXXConstructor 0x20c10fd6608 #212 'e' 'void () noexcept(b<__is_same(d<>, d<>)>::c && b<__is_same(d<>, d<f::c...>)>::c)'#251
`-BuiltinType #2 0x20c0f5bf7f0 'void'

[aaron.ballman]

In D155383#4576302, @strimo378 wrote:

I added a test case for demonstrating NoexceptExpr and Exceptions output. I don't know how to produce a FunctionProtoType output with ExceptionSourceDecl and ExceptionSourceTemplate. typedef/using is the only way I know to output types for the current AST dump and all my attempts failed to produce an uninstantiated exception information within a typedef.

Here is an example from my (slightly extended) AST dump where I output every type stored within ASTContext:

FunctionProtoType #267 0x20c10fd58a0 'void ()' (canonical FunctionProtoType #210 0x20c10fd6580) exceptionspec_uninstantiated
|-ExceptionSourceDecl CXXConstructor 0x20c10fd5798 #266 'e' 'void () noexcept(b<__is_same(d<>, d<>)>::c && b<__is_same(d<>, d<>)>::c)'#286 cdecl
|-ExceptionSourceTemplate CXXConstructor 0x20c10fd6608 #212 'e' 'void () noexcept(b<__is_same(d<>, d<>)>::c && b<__is_same(d<>, d<f::c...>)>::c)'#251
`-BuiltinType #2 0x20c0f5bf7f0 'void'

Then I'd say lets move forward with what you've got -- I recall running into similar issues when working on the JSON node dumper.

clang/lib/AST/TextNodeDumper.cpp

case RQ_None:
     break;
   case RQ_LValue:
     OS << " &";
     break;
   case RQ_RValue:
     OS << " &&";
     break;
   }
-  // FIXME: Exception specification.
+
+  switch (EPI.ExceptionSpec.Type) {
+  case EST_None:
+    break;
+  case EST_DynamicNone:
+    OS << " exceptionspec_dynamic_none";
+    break;
+  case EST_Dynamic:
+    OS << " exceptionspec_dynamic";
+    break;
+  case EST_MSAny:
+    OS << " exceptionspec_ms_any";
+    break;
+  case EST_NoThrow:
+    OS << " exceptionspec_nothrow";
+    break;
+  case EST_BasicNoexcept:
+    OS << " exceptionspec_basic_noexcept";
+    break;
+  case EST_DependentNoexcept:
+    OS << " exceptionspec_dependent_noexcept";
+    break;
+  case EST_NoexceptFalse:
+    OS << " exceptionspec_noexcept_false";
+    break;
+  case EST_NoexceptTrue:
+    OS << " exceptionspec_noexcept_true";
+    break;
+  case EST_Unevaluated:
+    OS << " exceptionspec_unevaluated";
+    break;
+  case EST_Uninstantiated:
+    OS << " exceptionspec_uninstantiated";
+    break;
+  case EST_Unparsed:
+    OS << " exceptionspec_unparsed";
+    break;
+  }
+  if (!EPI.ExceptionSpec.Exceptions.empty()) {
+    AddChild([=] {
+      OS << "Exceptions:";
+      for (unsigned I = 0, N = EPI.ExceptionSpec.Exceptions.size(); I != N;
+           ++I) {
+        if (I)
+          OS << ",";
+        dumpType(EPI.ExceptionSpec.Exceptions[I]);
+      }
+    });
+  }
+  if (EPI.ExceptionSpec.NoexceptExpr) {
+    AddChild([=] {
+      OS << "NoexceptExpr: ";
+      Visit(EPI.ExceptionSpec.NoexceptExpr);
+    });
+  }
+  dumpDeclRef(EPI.ExceptionSpec.SourceDecl, "ExceptionSourceDecl");
+  dumpDeclRef(EPI.ExceptionSpec.SourceTemplate, "ExceptionSourceTemplate");
+
   // FIXME: Consumed parameters.
   VisitFunctionType(T);
 }
 
 void TextNodeDumper::VisitUnresolvedUsingType(const UnresolvedUsingType *T) {
   dumpDeclRef(T->getDecl());
 }
 

clang/test/AST/ast-dump-functionprototype.cpp

+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -std=c++17 -Wno-dynamic-exception-spec -ast-dump %s | FileCheck -strict-whitespace %s
+
+struct A {};
+struct B {};
+
+typedef void (type1)() noexcept(10 > 5);
+
+// CHECK:      TypedefDecl {{.*}} type1 'void () noexcept(10 > 5)':'void () noexcept(10 > 5)'
+// CHECK-NEXT: `-ParenType {{.*}}
+// CHECK-NEXT:   `-FunctionProtoType {{.*}} 'void () noexcept(10 > 5)' exceptionspec_noexcept_true cdecl
+// CHECK-NEXT:     |-NoexceptExpr: ConstantExpr {{.*}} 'bool'
+// CHECK-NEXT:     | `-value: Int 1
+// CHECK-NEXT:     `-BuiltinType {{.*}} 'void'
+
+typedef void (type2)() throw(A, B);
+
+// CHECK:      TypedefDecl {{.*}} type2 'void () throw(A, B)':'void () throw(A, B)'
+// CHECK-NEXT: `-ParenType {{.*}}
+// CHECK-NEXT:   `-FunctionProtoType {{.*}} 'void () throw(A, B)' exceptionspec_dynamic cdecl
+// CHECK-NEXT:     |-Exceptions: 'A':'A', 'B':'B'
+// CHECK-NEXT:     `-BuiltinType {{.*}} 'void'
+