[Frontend] Introduce getDirectiveCategory for ACC/OMP directives (#94689)

The categories are primarily meant for OpenMP, where the spec assigns a
category to each directive. It's one of declarative, executable,
informational, meta, subsidiary, and utility.

These will be used in clang to avoid listing directives belonging to
certain categories by hand.

---------

Co-authored-by: Valentin Clement (バレンタイン クレメン) <clementval@gmail.com>

Author: kparzysz

llvm/include/llvm/Frontend/Directive/DirectiveBase.td

@@ -156,6 +156,18 @@ def AS_FromLeaves : Association<"FromLeaves"> {}    // See below
 // The name "AS_FromLeaves" is recognized by TableGen, and there is no enum
 // generated for it.
 
+// Kinds of directive categories.
+class Category<string n> {
+  string name = n;  // Name of the enum value in enum class Category.
+}
+
+def CA_Declarative: Category<"Declarative"> {}
+def CA_Executable: Category<"Executable"> {}
+def CA_Informational: Category<"Informational"> {}
+def CA_Meta: Category<"Meta"> {}
+def CA_Subsidiary: Category<"Subsidiary"> {}
+def CA_Utility: Category<"Utility"> {}
+
 // Information about a specific directive.
 class Directive<string d> {
   // Name of the directive. Can be composite directive sepearted by whitespace.
@@ -190,4 +202,7 @@ class Directive<string d> {
 
   // What the directive is associated with.
   Association association = AS_FromLeaves;
+
+  // The category of the directive.
+  Category category = ?;
 }

llvm/include/llvm/Frontend/OpenACC/ACC.td

@@ -268,6 +268,7 @@ def ACCC_Unknown : Clause<"unknown"> {
 // 2.12
 def ACC_Atomic : Directive<"atomic"> {
   let association = AS_Block;
+  let category = CA_Executable;
 }
 
 // 2.6.5
@@ -293,6 +294,7 @@ def ACC_Data : Directive<"data"> {
     VersionedClause<ACCC_Present>
   ];
   let association = AS_Block;
+  let category = CA_Executable;
 }
 
 // 2.13
@@ -308,6 +310,7 @@ def ACC_Declare : Directive<"declare"> {
     VersionedClause<ACCC_Link>
   ];
   let association = AS_None;
+  let category = CA_Declarative;
 }
 
 // 2.5.3
@@ -334,6 +337,7 @@ def ACC_Kernels : Directive<"kernels"> {
     VersionedClause<ACCC_VectorLength>
   ];
   let association = AS_Block;
+  let category = CA_Executable;
 }
 
 // 2.5.1
@@ -363,6 +367,7 @@ def ACC_Parallel : Directive<"parallel"> {
     VersionedClause<ACCC_Self>
   ];
   let association = AS_Block;
+  let category = CA_Executable;
 }
 
 // 2.5.2
@@ -391,6 +396,7 @@ def ACC_Serial : Directive<"serial"> {
     VersionedClause<ACCC_Self>
   ];
   let association = AS_Block;
+  let category = CA_Executable;
 }
 
 // 2.9
@@ -411,11 +417,13 @@ def ACC_Loop : Directive<"loop"> {
     VersionedClause<ACCC_Seq>
   ];
   let association = AS_Loop;
+  let category = CA_Executable;
 }
 
 // 2.10
 def ACC_Cache : Directive<"cache"> {
   let association = AS_None;
+  let category = CA_Executable;
 }
 
 // 2.14.1
@@ -426,6 +434,7 @@ def ACC_Init : Directive<"init"> {
     VersionedClause<ACCC_If>
   ];
   let association = AS_None;
+  let category = CA_Executable;
 }
 
 // 2.15.1
@@ -442,6 +451,7 @@ def ACC_Routine : Directive<"routine"> {
     VersionedClause<ACCC_NoHost>
   ];
   let association = AS_Declaration;
+  let category = CA_Declarative;
 }
 
 // 2.14.3
@@ -461,6 +471,7 @@ def ACC_Set : Directive<"set"> {
     VersionedClause<ACCC_DeviceType>
   ];
   let association = AS_None;
+  let category = CA_Executable;
 }
 
 // 2.14.2
@@ -471,6 +482,7 @@ def ACC_Shutdown : Directive<"shutdown"> {
     VersionedClause<ACCC_If>
   ];
   let association = AS_None;
+  let category = CA_Executable;
 }
 
 // 2.14.4
@@ -490,6 +502,7 @@ def ACC_Update : Directive<"update"> {
     VersionedClause<ACCC_Self>
   ];
   let association = AS_None;
+  let category = CA_Executable;
 }
 
 // 2.16.3
@@ -499,6 +512,7 @@ def ACC_Wait : Directive<"wait"> {
     VersionedClause<ACCC_If>
   ];
   let association = AS_None;
+  let category = CA_Executable;
 }
 
 // 2.14.6
@@ -516,6 +530,7 @@ def ACC_EnterData : Directive<"enter data"> {
     VersionedClause<ACCC_Copyin>
   ];
   let association = AS_None;
+  let category = CA_Executable;
 }
 
 // 2.14.7
@@ -534,6 +549,7 @@ def ACC_ExitData : Directive<"exit data"> {
     VersionedClause<ACCC_Detach>
   ];
   let association = AS_None;
+  let category = CA_Executable;
 }
 
 // 2.8
@@ -546,6 +562,7 @@ def ACC_HostData : Directive<"host_data"> {
     VersionedClause<ACCC_UseDevice>
   ];
   let association = AS_Block;
+  let category = CA_Executable;
 }
 
 // 2.11
@@ -584,6 +601,7 @@ def ACC_KernelsLoop : Directive<"kernels loop"> {
     VersionedClause<ACCC_Seq>
   ];
   let leafConstructs = [ACC_Kernels, ACC_Loop];
+  let category = CA_Executable;
 }
 
 // 2.11
@@ -623,6 +641,7 @@ def ACC_ParallelLoop : Directive<"parallel loop"> {
     VersionedClause<ACCC_Seq>
   ];
   let leafConstructs = [ACC_Parallel, ACC_Loop];
+  let category = CA_Executable;
 }
 
 // 2.11
@@ -659,9 +678,11 @@ def ACC_SerialLoop : Directive<"serial loop"> {
     VersionedClause<ACCC_Seq>
   ];
   let leafConstructs = [ACC_Serial, ACC_Loop];
+  let category = CA_Executable;
 }
 
 def ACC_Unknown : Directive<"unknown"> {
   let isDefault = true;
   let association = AS_None;
+  let category = CA_Utility;
 }