[OpenMP] Try to find an existing base for `omp begin/end declare vari…

…ant` If we have a function definition in `omp begin/end declare variant` it is a specialization of a base function with the same name and "compatible" type. Before, we just created a declaration for the base. With this patch we try to find an existing declaration first and only create a new one if we did not find any with a compatible type. This is preferable as we can tolerate slight mismatches, especially if the specialized version is "more constrained", e.g., constexpr. Reviewed By: mikerice Differential Revision: https://reviews.llvm.org/D77252
llvm · Apr 8, 2020 · 8f0aa3f · 8f0aa3f
1 parent 3cb1f35
commit 8f0aa3f
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Showing 15 changed files with 1,437 additions and 606 deletions.
diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
@@ -2535,7 +2535,7 @@ class ASTContext : public RefCountedBase<ASTContext> {
   QualType mergeTypes(QualType, QualType, bool OfBlockPointer=false,
                       bool Unqualified = false, bool BlockReturnType = false);
   QualType mergeFunctionTypes(QualType, QualType, bool OfBlockPointer=false,
-                              bool Unqualified = false);
+                              bool Unqualified = false, bool AllowCXX = false);
   QualType mergeFunctionParameterTypes(QualType, QualType,
                                        bool OfBlockPointer = false,
                                        bool Unqualified = false);

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
@@ -8856,8 +8856,8 @@ QualType ASTContext::mergeFunctionParameterTypes(QualType lhs, QualType rhs,
 }
 
 QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
-                                        bool OfBlockPointer,
-                                        bool Unqualified) {
+                                        bool OfBlockPointer, bool Unqualified,
+                                        bool AllowCXX) {
   const auto *lbase = lhs->castAs<FunctionType>();
   const auto *rbase = rhs->castAs<FunctionType>();
   const auto *lproto = dyn_cast<FunctionProtoType>(lbase);
@@ -8931,7 +8931,8 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
   FunctionType::ExtInfo einfo = lbaseInfo.withNoReturn(NoReturn);
 
   if (lproto && rproto) { // two C99 style function prototypes
-    assert(!lproto->hasExceptionSpec() && !rproto->hasExceptionSpec() &&
+    assert((AllowCXX ||
+            (!lproto->hasExceptionSpec() && !rproto->hasExceptionSpec())) &&
            "C++ shouldn't be here");
     // Compatible functions must have the same number of parameters
     if (lproto->getNumParams() != rproto->getNumParams())
@@ -8995,7 +8996,7 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
 
   const FunctionProtoType *proto = lproto ? lproto : rproto;
   if (proto) {
-    assert(!proto->hasExceptionSpec() && "C++ shouldn't be here");
+    assert((AllowCXX || !proto->hasExceptionSpec()) && "C++ shouldn't be here");
     if (proto->isVariadic())
       return {};
     // Check that the types are compatible with the types that

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
@@ -5554,7 +5554,45 @@ Sema::OMPDeclareVariantScope::OMPDeclareVariantScope(OMPTraitInfo &TI)
 FunctionDecl *
 Sema::ActOnStartOfFunctionDefinitionInOpenMPDeclareVariantScope(Scope *S,
                                                                 Declarator &D) {
-  auto *BaseFD = cast<FunctionDecl>(ActOnDeclarator(S, D));
+  IdentifierInfo *BaseII = D.getIdentifier();
+  LookupResult Lookup(*this, DeclarationName(BaseII), D.getIdentifierLoc(),
+                      LookupOrdinaryName);
+  LookupParsedName(Lookup, S, &D.getCXXScopeSpec());
+
+  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
+  QualType FType = TInfo->getType();
+
+  bool IsConstexpr = D.getDeclSpec().getConstexprSpecifier() == CSK_constexpr;
+  bool IsConsteval = D.getDeclSpec().getConstexprSpecifier() == CSK_consteval;
+
+  FunctionDecl *BaseFD = nullptr;
+  for (auto *Candidate : Lookup) {
+    auto *UDecl = dyn_cast<FunctionDecl>(Candidate->getUnderlyingDecl());
+    if (!UDecl)
+      continue;
+
+    // Don't specialize constexpr/consteval functions with
+    // non-constexpr/consteval functions.
+    if (UDecl->isConstexpr() && !IsConstexpr)
+      continue;
+    if (UDecl->isConsteval() && !IsConsteval)
+      continue;
+
+    QualType NewType = Context.mergeFunctionTypes(
+        FType, UDecl->getType(), /* OfBlockPointer */ false,
+        /* Unqualified */ false, /* AllowCXX */ true);
+    if (NewType.isNull())
+      continue;
+
+    // Found a base!
+    BaseFD = UDecl;
+    break;
+  }
+  if (!BaseFD) {
+    BaseFD = cast<FunctionDecl>(ActOnDeclarator(S, D));
+    BaseFD->setImplicit(true);
+  }
+
   OMPDeclareVariantScope &DVScope = OMPDeclareVariantScopes.back();
   std::string MangledName;
   MangledName += D.getIdentifier()->getName();
@@ -5583,8 +5621,6 @@ void Sema::ActOnFinishedFunctionDefinitionInOpenMPDeclareVariantScope(
   auto *OMPDeclareVariantA = OMPDeclareVariantAttr::CreateImplicit(
       Context, VariantFuncRef, DVScope.TI);
   BaseFD->addAttr(OMPDeclareVariantA);
-
-  BaseFD->setImplicit(true);
 }
 
 ExprResult Sema::ActOnOpenMPCall(ExprResult Call, Scope *Scope,

diff --git a/clang/test/AST/ast-dump-openmp-begin-declare-variant_10.c b/clang/test/AST/ast-dump-openmp-begin-declare-variant_10.c
diff --git a/clang/test/AST/ast-dump-openmp-begin-declare-variant_11.c b/clang/test/AST/ast-dump-openmp-begin-declare-variant_11.c
diff --git a/clang/test/AST/ast-dump-openmp-begin-declare-variant_12.c b/clang/test/AST/ast-dump-openmp-begin-declare-variant_12.c
diff --git a/clang/test/AST/ast-dump-openmp-begin-declare-variant_2.c b/clang/test/AST/ast-dump-openmp-begin-declare-variant_2.c
@@ -34,49 +34,46 @@ int test() {
 //  - we pick the right callees
 
 // CHECK:      |-FunctionDecl [[ADDR_0:0x[a-z0-9]*]] <{{.*}}, col:21> col:5 implicit used also_before 'int ({{.*}})'
-// CHECK-NEXT: | `-OMPDeclareVariantAttr [[ADDR_1:0x[a-z0-9]*]] <<invalid sloc>> Implicit device={kind(cpu)}
-// CHECK-NEXT: |   `-DeclRefExpr [[ADDR_2:0x[a-z0-9]*]] <col:1> 'int ({{.*}})' Function [[ADDR_3:0x[a-z0-9]*]] 'also_before[device={kind(cpu)}]' 'int ({{.*}})'
-// CHECK-NEXT: |-FunctionDecl [[ADDR_3]] <col:1, line:8:1> line:6:1 also_before[device={kind(cpu)}] 'int ({{.*}})'
-// CHECK-NEXT: | `-CompoundStmt [[ADDR_4:0x[a-z0-9]*]] <col:23, line:8:1>
-// CHECK-NEXT: |   `-ReturnStmt [[ADDR_5:0x[a-z0-9]*]] <line:7:3, col:10>
-// CHECK-NEXT: |     `-IntegerLiteral [[ADDR_6:0x[a-z0-9]*]] <col:10> 'int' 0
-// CHECK-NEXT: |-FunctionDecl [[ADDR_7:0x[a-z0-9]*]] <line:12:1, col:20> col:5 implicit used also_after 'int ({{.*}})'
-// CHECK-NEXT: | `-OMPDeclareVariantAttr [[ADDR_8:0x[a-z0-9]*]] <<invalid sloc>> Implicit implementation={vendor(score(100): llvm)}
-// CHECK-NEXT: |   `-DeclRefExpr [[ADDR_9:0x[a-z0-9]*]] <col:1> 'int ({{.*}})' Function [[ADDR_10:0x[a-z0-9]*]] 'also_after[implementation={vendor(llvm)}]' 'int ({{.*}})'
-// CHECK-NEXT: |-FunctionDecl [[ADDR_10]] <col:1, line:14:1> line:12:1 also_after[implementation={vendor(llvm)}] 'int ({{.*}})'
-// CHECK-NEXT: | `-CompoundStmt [[ADDR_11:0x[a-z0-9]*]] <col:22, line:14:1>
-// CHECK-NEXT: |   `-ReturnStmt [[ADDR_12:0x[a-z0-9]*]] <line:13:3, col:10>
-// CHECK-NEXT: |     `-IntegerLiteral [[ADDR_13:0x[a-z0-9]*]] <col:10> 'int' 0
-// CHECK-NEXT: |-FunctionDecl [[ADDR_14:0x[a-z0-9]*]] prev [[ADDR_0]] <line:17:1, col:21> col:5 implicit used also_before 'int ({{.*}})'
-// CHECK-NEXT: | |-OMPDeclareVariantAttr [[ADDR_15:0x[a-z0-9]*]] <<invalid sloc>> Inherited Implicit device={kind(cpu)}
-// CHECK-NEXT: | | `-DeclRefExpr [[ADDR_2]] <line:6:1> 'int ({{.*}})' Function [[ADDR_3]] 'also_before[device={kind(cpu)}]' 'int ({{.*}})'
-// CHECK-NEXT: | `-OMPDeclareVariantAttr [[ADDR_16:0x[a-z0-9]*]] <<invalid sloc>> Implicit implementation={vendor(score(0): llvm)}
-// CHECK-NEXT: |   `-DeclRefExpr [[ADDR_17:0x[a-z0-9]*]] <line:17:1> 'int ({{.*}})' Function [[ADDR_18:0x[a-z0-9]*]] 'also_before[implementation={vendor(llvm)}]' 'int ({{.*}})'
-// CHECK-NEXT: |-FunctionDecl [[ADDR_18]] <col:1, line:19:1> line:17:1 also_before[implementation={vendor(llvm)}] 'int ({{.*}})'
-// CHECK-NEXT: | `-CompoundStmt [[ADDR_19:0x[a-z0-9]*]] <col:23, line:19:1>
-// CHECK-NEXT: |   `-ReturnStmt [[ADDR_20:0x[a-z0-9]*]] <line:18:3, col:10>
-// CHECK-NEXT: |     `-IntegerLiteral [[ADDR_21:0x[a-z0-9]*]] <col:10> 'int' 1
-// CHECK-NEXT: |-FunctionDecl [[ADDR_22:0x[a-z0-9]*]] prev [[ADDR_7]] <line:22:1, line:24:1> line:22:5 used also_after 'int ({{.*}})'
-// CHECK-NEXT: | |-CompoundStmt [[ADDR_23:0x[a-z0-9]*]] <col:22, line:24:1>
-// CHECK-NEXT: | | `-ReturnStmt [[ADDR_24:0x[a-z0-9]*]] <line:23:3, col:10>
-// CHECK-NEXT: | |   `-IntegerLiteral [[ADDR_25:0x[a-z0-9]*]] <col:10> 'int' 2
-// CHECK-NEXT: | `-OMPDeclareVariantAttr [[ADDR_26:0x[a-z0-9]*]] <<invalid sloc>> Inherited Implicit implementation={vendor(score(100): llvm)}
-// CHECK-NEXT: |   `-DeclRefExpr [[ADDR_9]] <line:12:1> 'int ({{.*}})' Function [[ADDR_10]] 'also_after[implementation={vendor(llvm)}]' 'int ({{.*}})'
-// CHECK-NEXT: `-FunctionDecl [[ADDR_27:0x[a-z0-9]*]] <line:26:1, line:29:1> line:26:5 test 'int ({{.*}})'
-// CHECK-NEXT:   `-CompoundStmt [[ADDR_28:0x[a-z0-9]*]] <col:12, line:29:1>
-// CHECK-NEXT:     `-ReturnStmt [[ADDR_29:0x[a-z0-9]*]] <line:28:3, col:37>
-// CHECK-NEXT:       `-BinaryOperator [[ADDR_30:0x[a-z0-9]*]] <col:10, col:37> 'int' '+'
-// CHECK-NEXT:         |-PseudoObjectExpr [[ADDR_31:0x[a-z0-9]*]] <col:10, col:21> 'int'
-// CHECK-NEXT:         | |-CallExpr [[ADDR_32:0x[a-z0-9]*]] <col:10, col:21> 'int'
-// CHECK-NEXT:         | | `-ImplicitCastExpr [[ADDR_33:0x[a-z0-9]*]] <col:10> 'int (*)({{.*}})' <FunctionToPointerDecay>
-// CHECK-NEXT:         | |   `-DeclRefExpr [[ADDR_34:0x[a-z0-9]*]] <col:10> 'int ({{.*}})' {{.*}}Function [[ADDR_22]] 'also_after' 'int ({{.*}})'
-// CHECK-NEXT:         | `-CallExpr [[ADDR_35:0x[a-z0-9]*]] <line:12:1, line:28:21> 'int'
-// CHECK-NEXT:         |   `-ImplicitCastExpr [[ADDR_36:0x[a-z0-9]*]] <line:12:1> 'int (*)({{.*}})' <FunctionToPointerDecay>
-// CHECK-NEXT:         |     `-DeclRefExpr [[ADDR_9]] <col:1> 'int ({{.*}})' Function [[ADDR_10]] 'also_after[implementation={vendor(llvm)}]' 'int ({{.*}})'
-// CHECK-NEXT:         `-PseudoObjectExpr [[ADDR_37:0x[a-z0-9]*]] <line:28:25, col:37> 'int'
-// CHECK-NEXT:           |-CallExpr [[ADDR_38:0x[a-z0-9]*]] <col:25, col:37> 'int'
-// CHECK-NEXT:           | `-ImplicitCastExpr [[ADDR_39:0x[a-z0-9]*]] <col:25> 'int (*)({{.*}})' <FunctionToPointerDecay>
-// CHECK-NEXT:           |   `-DeclRefExpr [[ADDR_40:0x[a-z0-9]*]] <col:25> 'int ({{.*}})' {{.*}}Function [[ADDR_14]] 'also_before' 'int ({{.*}})'
-// CHECK-NEXT:           `-CallExpr [[ADDR_41:0x[a-z0-9]*]] <line:6:1, line:28:37> 'int'
-// CHECK-NEXT:             `-ImplicitCastExpr [[ADDR_42:0x[a-z0-9]*]] <line:6:1> 'int (*)({{.*}})' <FunctionToPointerDecay>
+// CHECK-NEXT: | |-OMPDeclareVariantAttr [[ADDR_1:0x[a-z0-9]*]] <<invalid sloc>> Implicit device={kind(cpu)}
+// CHECK-NEXT: | | `-DeclRefExpr [[ADDR_2:0x[a-z0-9]*]] <col:1> 'int ({{.*}})' Function [[ADDR_3:0x[a-z0-9]*]] 'also_before[device={kind(cpu)}]' 'int ({{.*}})'
+// CHECK-NEXT: | `-OMPDeclareVariantAttr [[ADDR_4:0x[a-z0-9]*]] <<invalid sloc>> Implicit implementation={vendor(score(0): llvm)}
+// CHECK-NEXT: |   `-DeclRefExpr [[ADDR_5:0x[a-z0-9]*]] <line:17:1> 'int ({{.*}})' Function [[ADDR_6:0x[a-z0-9]*]] 'also_before[implementation={vendor(llvm)}]' 'int ({{.*}})'
+// CHECK-NEXT: |-FunctionDecl [[ADDR_3]] <line:6:1, line:8:1> line:6:1 also_before[device={kind(cpu)}] 'int ({{.*}})'
+// CHECK-NEXT: | `-CompoundStmt [[ADDR_7:0x[a-z0-9]*]] <col:23, line:8:1>
+// CHECK-NEXT: |   `-ReturnStmt [[ADDR_8:0x[a-z0-9]*]] <line:7:3, col:10>
+// CHECK-NEXT: |     `-IntegerLiteral [[ADDR_9:0x[a-z0-9]*]] <col:10> 'int' 0
+// CHECK-NEXT: |-FunctionDecl [[ADDR_10:0x[a-z0-9]*]] <line:12:1, col:20> col:5 implicit used also_after 'int ({{.*}})'
+// CHECK-NEXT: | `-OMPDeclareVariantAttr [[ADDR_11:0x[a-z0-9]*]] <<invalid sloc>> Implicit implementation={vendor(score(100): llvm)}
+// CHECK-NEXT: |   `-DeclRefExpr [[ADDR_12:0x[a-z0-9]*]] <col:1> 'int ({{.*}})' Function [[ADDR_13:0x[a-z0-9]*]] 'also_after[implementation={vendor(llvm)}]' 'int ({{.*}})'
+// CHECK-NEXT: |-FunctionDecl [[ADDR_13]] <col:1, line:14:1> line:12:1 also_after[implementation={vendor(llvm)}] 'int ({{.*}})'
+// CHECK-NEXT: | `-CompoundStmt [[ADDR_14:0x[a-z0-9]*]] <col:22, line:14:1>
+// CHECK-NEXT: |   `-ReturnStmt [[ADDR_15:0x[a-z0-9]*]] <line:13:3, col:10>
+// CHECK-NEXT: |     `-IntegerLiteral [[ADDR_16:0x[a-z0-9]*]] <col:10> 'int' 0
+// CHECK-NEXT: |-FunctionDecl [[ADDR_6]] <line:17:1, line:19:1> line:17:1 also_before[implementation={vendor(llvm)}] 'int ({{.*}})'
+// CHECK-NEXT: | `-CompoundStmt [[ADDR_17:0x[a-z0-9]*]] <col:23, line:19:1>
+// CHECK-NEXT: |   `-ReturnStmt [[ADDR_18:0x[a-z0-9]*]] <line:18:3, col:10>
+// CHECK-NEXT: |     `-IntegerLiteral [[ADDR_19:0x[a-z0-9]*]] <col:10> 'int' 1
+// CHECK-NEXT: |-FunctionDecl [[ADDR_20:0x[a-z0-9]*]] prev [[ADDR_10]] <line:22:1, line:24:1> line:22:5 used also_after 'int ({{.*}})'
+// CHECK-NEXT: | |-CompoundStmt [[ADDR_21:0x[a-z0-9]*]] <col:22, line:24:1>
+// CHECK-NEXT: | | `-ReturnStmt [[ADDR_22:0x[a-z0-9]*]] <line:23:3, col:10>
+// CHECK-NEXT: | |   `-IntegerLiteral [[ADDR_23:0x[a-z0-9]*]] <col:10> 'int' 2
+// CHECK-NEXT: | `-OMPDeclareVariantAttr [[ADDR_24:0x[a-z0-9]*]] <<invalid sloc>> Inherited Implicit implementation={vendor(score(100): llvm)}
+// CHECK-NEXT: |   `-DeclRefExpr [[ADDR_12]] <line:12:1> 'int ({{.*}})' Function [[ADDR_13]] 'also_after[implementation={vendor(llvm)}]' 'int ({{.*}})'
+// CHECK-NEXT: `-FunctionDecl [[ADDR_25:0x[a-z0-9]*]] <line:26:1, line:29:1> line:26:5 test 'int ({{.*}})'
+// CHECK-NEXT:   `-CompoundStmt [[ADDR_26:0x[a-z0-9]*]] <col:12, line:29:1>
+// CHECK-NEXT:     `-ReturnStmt [[ADDR_27:0x[a-z0-9]*]] <line:28:3, col:37>
+// CHECK-NEXT:       `-BinaryOperator [[ADDR_28:0x[a-z0-9]*]] <col:10, col:37> 'int' '+'
+// CHECK-NEXT:         |-PseudoObjectExpr [[ADDR_29:0x[a-z0-9]*]] <col:10, col:21> 'int'
+// CHECK-NEXT:         | |-CallExpr [[ADDR_30:0x[a-z0-9]*]] <col:10, col:21> 'int'
+// CHECK-NEXT:         | | `-ImplicitCastExpr [[ADDR_31:0x[a-z0-9]*]] <col:10> 'int (*)({{.*}})' <FunctionToPointerDecay>
+// CHECK-NEXT:         | |   `-DeclRefExpr [[ADDR_32:0x[a-z0-9]*]] <col:10> 'int ({{.*}})' {{.*}}Function [[ADDR_20]] 'also_after' 'int ({{.*}})'
+// CHECK-NEXT:         | `-CallExpr [[ADDR_33:0x[a-z0-9]*]] <line:12:1, line:28:21> 'int'
+// CHECK-NEXT:         |   `-ImplicitCastExpr [[ADDR_34:0x[a-z0-9]*]] <line:12:1> 'int (*)({{.*}})' <FunctionToPointerDecay>
+// CHECK-NEXT:         |     `-DeclRefExpr [[ADDR_12]] <col:1> 'int ({{.*}})' Function [[ADDR_13]] 'also_after[implementation={vendor(llvm)}]' 'int ({{.*}})'
+// CHECK-NEXT:         `-PseudoObjectExpr [[ADDR_35:0x[a-z0-9]*]] <line:28:25, col:37> 'int'
+// CHECK-NEXT:           |-CallExpr [[ADDR_36:0x[a-z0-9]*]] <col:25, col:37> 'int'
+// CHECK-NEXT:           | `-ImplicitCastExpr [[ADDR_37:0x[a-z0-9]*]] <col:25> 'int (*)({{.*}})' <FunctionToPointerDecay>
+// CHECK-NEXT:           |   `-DeclRefExpr [[ADDR_38:0x[a-z0-9]*]] <col:25> 'int ({{.*}})' {{.*}}Function [[ADDR_0]] 'also_before' 'int ({{.*}})'
+// CHECK-NEXT:           `-CallExpr [[ADDR_39:0x[a-z0-9]*]] <line:6:1, line:28:37> 'int'
+// CHECK-NEXT:             `-ImplicitCastExpr [[ADDR_40:0x[a-z0-9]*]] <line:6:1> 'int (*)({{.*}})' <FunctionToPointerDecay>
 // CHECK-NEXT:               `-DeclRefExpr [[ADDR_2]] <col:1> 'int ({{.*}})' Function [[ADDR_3]] 'also_before[device={kind(cpu)}]' 'int ({{.*}})'