Fix host call to nohost function with host variant.

clang/lib/Sema/SemaOpenMP.cpp

@@ -2702,6 +2702,24 @@ void Sema::finalizeOpenMPDelayedAnalysis(const FunctionDecl *Caller,
   }
   if (!LangOpts.OpenMPIsDevice && !LangOpts.OpenMPOffloadMandatory && DevTy &&
       *DevTy == OMPDeclareTargetDeclAttr::DT_NoHost) {
+    // In OpenMP 5.2 or later, if the function has a host variant then allow
+    // that to be called instead
+    auto &&HasHostAttr = [](const FunctionDecl *Callee) {
+      for (OMPDeclareVariantAttr *A :
+           Callee->specific_attrs<OMPDeclareVariantAttr>()) {
+        auto *DeclRefVariant = cast<DeclRefExpr>(A->getVariantFuncRef());
+        auto *VariantFD = cast<FunctionDecl>(DeclRefVariant->getDecl());
+        Optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy =
+            OMPDeclareTargetDeclAttr::getDeviceType(
+                VariantFD->getMostRecentDecl());
+        if (!DevTy || *DevTy == OMPDeclareTargetDeclAttr::DT_Host)
+          return true;
+      }
+      return false;
+    };
+    if (getLangOpts().OpenMP >= 52 &&
+        Callee->hasAttr<OMPDeclareVariantAttr>() && HasHostAttr(Callee))
+      return;
     // Diagnose nohost function called during host codegen.
     StringRef NoHostDevTy = getOpenMPSimpleClauseTypeName(
         OMPC_device_type, OMPC_DEVICE_TYPE_nohost);

clang/test/OpenMP/declare_target_messages.cpp

@@ -11,10 +11,12 @@
 // RUN: %clang_cc1 -triple x86_64-apple-macos10.7.0 -verify=expected,omp51 -fopenmp-version=51 -fopenmp-simd -fnoopenmp-use-tls -ferror-limit 100 -o - %s
 // RUN: %clang_cc1 -triple x86_64-apple-macos10.7.0 -verify=expected,omp51 -fopenmp-version=51 -fopenmp-simd -fnoopenmp-use-tls -ferror-limit 100 -o - %s
 
+// RUN: %clang_cc1 -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -fopenmp-version=52 -DVERBOSE_MODE=1 -verify=expected,omp52 -fnoopenmp-use-tls -ferror-limit 100 -o - %s
+
 // RUN: %clang_cc1 -triple x86_64-apple-macos10.7.0 -verify=expected,omp5 -fopenmp -fnoopenmp-use-tls -ferror-limit 100 -o - %s
 #pragma omp end declare target // expected-error {{unexpected OpenMP directive '#pragma omp end declare target'}}
 
-int a, b, z; // omp5-error {{variable captured in declare target region must appear in a to clause}} // omp51-error {{variable captured in declare target region must appear in a to clause}}
+int a, b, z; // omp5-error {{variable captured in declare target region must appear in a to clause}} // omp51-error {{variable captured in declare target region must appear in a to clause}} omp52-error {{variable captured in declare target region must appear in a to clause}}
 __thread int t; // expected-note {{defined as threadprivate or thread local}}
 
 #pragma omp declare target . // expected-error {{expected '(' after 'declare target'}}
@@ -23,16 +25,16 @@ __thread int t; // expected-note {{defined as threadprivate or thread local}}
 void f();
 #pragma omp end declare target shared(a) // expected-warning {{extra tokens at the end of '#pragma omp end declare target' are ignored}}
 
-#pragma omp declare target map(a) // omp45-error {{expected at least one 'to' or 'link' clause}} omp5-error {{expected at least one 'to' or 'link' clause}} omp51-error {{expected at least one 'to', 'link' or 'indirect' clause}} omp45-error {{unexpected 'map' clause, only 'to' or 'link' clauses expected}} omp5-error {{unexpected 'map' clause, only 'to', 'link' or 'device_type' clauses expected}} omp51-error {{unexpected 'map' clause, only 'to', 'link', 'device_type' or 'indirect' clauses expected}}
+#pragma omp declare target map(a) // omp45-error {{expected at least one 'to' or 'link' clause}} omp5-error {{expected at least one 'to' or 'link' clause}} omp51-error {{expected at least one 'to', 'link' or 'indirect' clause}} omp45-error {{unexpected 'map' clause, only 'to' or 'link' clauses expected}} omp5-error {{unexpected 'map' clause, only 'to', 'link' or 'device_type' clauses expected}} omp51-error {{unexpected 'map' clause, only 'to', 'link', 'device_type' or 'indirect' clauses expected}} omp52-error {{unexpected 'map' clause, only 'enter', 'link', 'device_type' or 'indirect' clauses expected}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 
-#pragma omp declare target to(foo1) // expected-error {{use of undeclared identifier 'foo1'}}
+#pragma omp declare target to(foo1) // omp45-error {{use of undeclared identifier 'foo1'}} omp5-error {{use of undeclared identifier 'foo1'}} omp51-error {{use of undeclared identifier 'foo1'}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 
 #pragma omp declare target link(foo2) // expected-error {{use of undeclared identifier 'foo2'}}
 
-#pragma omp declare target to(f) device_type(host) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} dev5-note {{marked as 'device_type(host)' here}}
+#pragma omp declare target to(f) device_type(host) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} dev5-note {{marked as 'device_type(host)' here}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 
 void q();
-#pragma omp declare target to(q) device_type(any) device_type(any) device_type(host) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} omp5-warning {{more than one 'device_type' clause is specified}} // omp51-warning {{more than one 'device_type' clause is specified}}
+#pragma omp declare target to(q) device_type(any) device_type(any) device_type(host) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} omp5-warning {{more than one 'device_type' clause is specified}} // omp51-warning {{more than one 'device_type' clause is specified}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 
 #if _OPENMP == 202011
 // omp51-error@+1 {{directive '#pragma omp declare target' cannot contain more than one 'indirect' clause}}
@@ -67,11 +69,11 @@ void c();
 
 void func() {} // expected-note {{'func' defined here}}
 
-#pragma omp declare target link(func) allocate(a) // expected-error {{function name is not allowed in 'link' clause}} omp45-error {{unexpected 'allocate' clause, only 'to' or 'link' clauses expected}} omp5-error {{unexpected 'allocate' clause, only 'to', 'link' or 'device_type' clauses expected}} omp51-error {{unexpected 'allocate' clause, only 'to', 'link', 'device_type' or 'indirect' clauses expected}}
+#pragma omp declare target link(func) allocate(a) // expected-error {{function name is not allowed in 'link' clause}} omp45-error {{unexpected 'allocate' clause, only 'to' or 'link' clauses expected}} omp5-error {{unexpected 'allocate' clause, only 'to', 'link' or 'device_type' clauses expected}} omp51-error {{unexpected 'allocate' clause, only 'to', 'link', 'device_type' or 'indirect' clauses expected}} omp52-error {{unexpected 'allocate' clause, only 'enter', 'link', 'device_type' or 'indirect' clauses expected}}
 
 void bar();
 void baz() {bar();}
-#pragma omp declare target(bar) // omp5-warning {{declaration marked as declare target after first use, it may lead to incorrect results}} // omp51-warning {{declaration marked as declare target after first use, it may lead to incorrect results}}
+#pragma omp declare target(bar) // omp5-warning {{declaration marked as declare target after first use, it may lead to incorrect results}} // omp51-warning {{declaration marked as declare target after first use, it may lead to incorrect results}} omp52-warning {{declaration marked as declare target after first use, it may lead to incorrect results}}
 
 extern int b;
 
@@ -162,7 +164,7 @@ void foo(int p) {
 }
 #pragma omp declare target
 void foo1() {
-  [&](){ (void)(b+z);}(); // omp5-note {{variable 'z' is captured here}} //omp51-note {{variable 'z' is captured here}}
+  [&](){ (void)(b+z);}(); // omp5-note {{variable 'z' is captured here}} //omp51-note {{variable 'z' is captured here}} omp52-note {{variable 'z' is captured here}}
 }
 #pragma omp end declare target
 
@@ -197,22 +199,22 @@ namespace {
 #pragma omp declare target link(S) // expected-error {{'S' used in declare target directive is not a variable or a function name}}
 
 #pragma omp declare target (x, x) // expected-error {{'x' appears multiple times in clauses on the same declare target directive}}
-#pragma omp declare target to(x) to(x) // expected-error {{'x' appears multiple times in clauses on the same declare target directive}}
+#pragma omp declare target to(x) to(x) // omp45-error {{'x' appears multiple times in clauses on the same declare target directive}} omp5-error {{'x' appears multiple times in clauses on the same declare target directive}} omp51-error {{'x' appears multiple times in clauses on the same declare target directive}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 #pragma omp declare target link(x) // expected-error {{'x' must not appear in both clauses 'to' and 'link'}}
 
 void bazz() {}
-#pragma omp declare target to(bazz) device_type(nohost) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} host5-note 3{{marked as 'device_type(nohost)' here}}
+#pragma omp declare target to(bazz) device_type(nohost) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} host5-note 3{{marked as 'device_type(nohost)' here}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 void bazzz() {bazz();}
-#pragma omp declare target to(bazzz) device_type(nohost) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}}
+#pragma omp declare target to(bazzz) device_type(nohost) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 void any() {bazz();} // host5-error {{function with 'device_type(nohost)' is not available on host}}
 void host1() {bazz();} // host5-error {{function with 'device_type(nohost)' is not available on host}}
-#pragma omp declare target to(host1) device_type(host) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} dev5-note 3 {{marked as 'device_type(host)' here}}
+#pragma omp declare target to(host1) device_type(host) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} dev5-note 3 {{marked as 'device_type(host)' here}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 void host2() {bazz();} //host5-error {{function with 'device_type(nohost)' is not available on host}}
-#pragma omp declare target to(host2)
+#pragma omp declare target to(host2) // omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 void device() {host1();} // dev5-error {{function with 'device_type(host)' is not available on device}}
-#pragma omp declare target to(device) device_type(nohost) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} host5-note 2 {{marked as 'device_type(nohost)' here}}
+#pragma omp declare target to(device) device_type(nohost) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} host5-note 2 {{marked as 'device_type(nohost)' here}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 void host3() {host1();} // dev5-error {{function with 'device_type(host)' is not available on device}}
-#pragma omp declare target to(host3)
+#pragma omp declare target to(host3) // omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 
 #pragma omp declare target
 void any1() {any();}
@@ -227,9 +229,9 @@ void any7() {device();} // host5-error {{function with 'device_type(nohost)' is
 void any8() {any2();}
 
 int MultiDevTy;
-#pragma omp declare target to(MultiDevTy) device_type(any)    // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}}
-#pragma omp declare target to(MultiDevTy) device_type(host)   // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} omp5-error {{'device_type(host)' does not match previously specified 'device_type(any)' for the same declaration}} omp51-error {{'device_type(host)' does not match previously specified 'device_type(any)' for the same declaration}}
-#pragma omp declare target to(MultiDevTy) device_type(nohost) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} omp5-error {{'device_type(nohost)' does not match previously specified 'device_type(any)' for the same declaration}} // omp51-error {{'device_type(nohost)' does not match previously specified 'device_type(any)' for the same declaration}}
+#pragma omp declare target to(MultiDevTy) device_type(any)    // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
+#pragma omp declare target to(MultiDevTy) device_type(host)   // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} omp5-error {{'device_type(host)' does not match previously specified 'device_type(any)' for the same declaration}} omp51-error {{'device_type(host)' does not match previously specified 'device_type(any)' for the same declaration}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
+#pragma omp declare target to(MultiDevTy) device_type(nohost) // omp45-error {{unexpected 'device_type' clause, only 'to' or 'link' clauses expected}} omp5-error {{'device_type(nohost)' does not match previously specified 'device_type(any)' for the same declaration}} // omp51-error {{'device_type(nohost)' does not match previously specified 'device_type(any)' for the same declaration}} omp52-error {{unexpected 'to' clause, use 'enter' instead}} omp52-error {{expected at least one 'enter', 'link' or 'indirect' clause}}
 
 #if TESTENDINC
 #include "unterminated_declare_target_include.h"
@@ -240,3 +242,11 @@ int MultiDevTy;
 // expected-warning@+1 {{expected '#pragma omp end declare target' at end of file to match '#pragma omp begin declare target'}}
 #pragma omp begin declare target
 #endif
+
+void fun();
+void host_function();
+#pragma omp declare target enter(fun) device_type(nohost) // omp45-error {{unexpected 'enter' clause, use 'to' instead}} omp45-error {{expected at least one 'to' or 'link' clause}} omp5-error {{unexpected 'enter' clause, use 'to' instead}} omp5-error {{expected at least one 'to' or 'link' clause}} omp51-error {{expected at least one 'to', 'link' or 'indirect' clause}} omp51-error {{unexpected 'enter' clause, use 'to' instead}}
+#pragma omp declare variant(host_function) match(device={kind(host)})
+void fun() {}
+void host_function() {}
+void call_host_function() { fun(); }

clang/test/OpenMP/declare_target_nohost_variant_messages.cpp

@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -fopenmp-version=52 -DVERBOSE_MODE=1 -verify=omp52 -fnoopenmp-use-tls -ferror-limit 100 -fopenmp-targets=amdgcn-amd-amdhsa -o - %s
+
+void fun();
+void not_a_host_function();
+#pragma omp declare target enter(fun) device_type(nohost) // omp52-note {{marked as 'device_type(nohost)' here}}
+#pragma omp declare variant(not_a_host_function) match(device={kind(host)}) // omp52-error {{function with 'device_type(nohost)' is not available on host}}
+void fun() {}
+#pragma omp begin declare target device_type(nohost) // omp52-note {{marked as 'device_type(nohost)' here}}
+void not_a_host_function() {}
+#pragma omp end declare target
+void failed_call_to_host_function() { fun(); } // omp52-error {{function with 'device_type(nohost)' is not available on host}}
+
+void fun2();
+void host_function();
+#pragma omp declare target enter(fun2) device_type(nohost)
+#pragma omp declare variant(host_function) match(device={kind(host)})
+void fun2() {}
+#pragma omp begin declare target device_type(host)
+void host_function() {}
+#pragma omp end declare target
+void call_to_host_function() { fun2(); }