[clang] 97b2f20 - Change error for storage-class to mean linkage, fix lang-linkage diag

[Erich Keane via cfe-commits]

Author: Erich Keane
Date: 2021-09-22T10:51:05-07:00
New Revision: 97b2f20a446e54f4354d8f950dfab62c37e6ddf4

URL: https://github.com/llvm/llvm-project/commit/97b2f20a446e54f4354d8f950dfab62c37e6ddf4
DIFF: https://github.com/llvm/llvm-project/commit/97b2f20a446e54f4354d8f950dfab62c37e6ddf4.diff

LOG: Change error for storage-class to mean linkage, fix lang-linkage diag

Allow multiversioning declarations to match when the actual formal
linkage matches, not just when the storage class is identical.
Additionally, change the ambiguous 'linkage' mismatch to be more
specific and say 'language linkage'.

Added: 
    

Modified: 
    clang/include/clang/Basic/DiagnosticSemaKinds.td
    clang/lib/Sema/SemaDecl.cpp
    clang/test/SemaCXX/attr-cpuspecific.cpp
    clang/test/SemaCXX/attr-target-mv.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 3cadd986b8ae..0e803ee028ce 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -11208,8 +11208,8 @@ def err_multiversion_mismatched_attrs
             "%0 %select{is missing|has 
diff erent arguments}1">;
 def err_multiversion_
diff  : Error<
   "multiversioned function declaration has a 
diff erent %select{calling convention"
-  "|return type|constexpr specification|inline specification|storage class|"
-  "linkage}0">;
+  "|return type|constexpr specification|inline specification|linkage|"
+  "language linkage}0">;
 def err_multiversion_doesnt_support : Error<
   "attribute '%select{target|cpu_specific|cpu_dispatch}0' multiversioned functions do not "
   "yet support %select{function templates|virtual functions|"

diff  --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 13389ebdd72f..79080098026c 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -10322,8 +10322,8 @@ bool Sema::areMultiversionVariantFunctionsCompatible(
     ReturnType = 1,
     ConstexprSpec = 2,
     InlineSpec = 3,
-    StorageClass = 4,
-    Linkage = 5,
+    Linkage = 4,
+    LanguageLinkage = 5,
   };
 
   if (NoProtoDiagID.getDiagID() != 0 && OldFD &&
@@ -10397,11 +10397,11 @@ bool Sema::areMultiversionVariantFunctionsCompatible(
     if (OldFD->isInlineSpecified() != NewFD->isInlineSpecified())
       return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << InlineSpec;
 
-    if (OldFD->getStorageClass() != NewFD->getStorageClass())
-      return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << StorageClass;
+    if (OldFD->getFormalLinkage() != NewFD->getFormalLinkage())
+      return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << Linkage;
 
     if (!CLinkageMayDiffer && OldFD->isExternC() != NewFD->isExternC())
-      return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << Linkage;
+      return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << LanguageLinkage;
 
     if (CheckEquivalentExceptionSpec(
             OldFD->getType()->getAs<FunctionProtoType>(), OldFD->getLocation(),

diff  --git a/clang/test/SemaCXX/attr-cpuspecific.cpp b/clang/test/SemaCXX/attr-cpuspecific.cpp
index 861711b46383..fe4635816654 100644
--- a/clang/test/SemaCXX/attr-cpuspecific.cpp
+++ b/clang/test/SemaCXX/attr-cpuspecific.cpp
@@ -34,9 +34,19 @@ int __attribute__((cpu_specific(sandybridge))) foo2(void);
 constexpr int __attribute__((cpu_specific(ivybridge))) foo2(void);
 
 static int __attribute__((cpu_specific(sandybridge))) bar(void);
-//expected-error at +1 {{multiversioned function declaration has a 
diff erent storage class}}
+//expected-error at +1 {{multiversioned function declaration has a 
diff erent linkage}}
 int __attribute__((cpu_dispatch(ivybridge))) bar(void) {}
 
+// OK
+extern int __attribute__((cpu_specific(sandybridge))) bar2(void);
+int __attribute__((cpu_dispatch(ivybridge))) bar2(void) {}
+
+namespace {
+int __attribute__((cpu_specific(sandybridge))) bar3(void);
+static int __attribute__((cpu_dispatch(ivybridge))) bar3(void) {}
+}
+
+
 inline int __attribute__((cpu_specific(sandybridge))) baz(void);
 //expected-error at +1 {{multiversioned function declaration has a 
diff erent inline specification}}
 int __attribute__((cpu_specific(ivybridge))) baz(void) {return 1;}
@@ -74,7 +84,7 @@ struct S {
 extern "C" {
 int __attribute__((cpu_specific(atom))) 
diff _mangle(void) { return 0; }
 }
-//expected-error at +1 {{multiversioned function declaration has a 
diff erent linkage}}
+//expected-error at +1 {{multiversioned function declaration has a 
diff erent language linkage}}
 int __attribute__((cpu_specific(sandybridge))) 
diff _mangle(void) { return 0; }
 
 __attribute__((cpu_specific(atom))) void DiffDecl();

diff  --git a/clang/test/SemaCXX/attr-target-mv.cpp b/clang/test/SemaCXX/attr-target-mv.cpp
index 5ef1d398d2d8..5b2f0fc825f3 100644
--- a/clang/test/SemaCXX/attr-target-mv.cpp
+++ b/clang/test/SemaCXX/attr-target-mv.cpp
@@ -27,17 +27,26 @@ int __attribute__((target("default"))) foo2(void) { return 2; }
 
 static int __attribute__((target("sse4.2"))) bar(void) { return 0; }
 static int __attribute__((target("arch=sandybridge"))) bar(void);
-//expected-error at +1 {{multiversioned function declaration has a 
diff erent storage class}}
+//expected-error at +1 {{multiversioned function declaration has a 
diff erent linkage}}
 int __attribute__((target("arch=ivybridge"))) bar(void) {return 1;}
 static int __attribute__((target("default"))) bar(void) { return 2; }
 
 int __attribute__((target("sse4.2"))) bar2(void) { return 0; }
-//expected-error at +1 {{multiversioned function declaration has a 
diff erent storage class}}
+//expected-error at +1 {{multiversioned function declaration has a 
diff erent linkage}}
 static int __attribute__((target("arch=sandybridge"))) bar2(void);
 int __attribute__((target("arch=ivybridge"))) bar2(void) {return 1;}
 int __attribute__((target("default"))) bar2(void) { return 2; }
 
 
+// no diagnostic, since this doesn't change the linkage.
+int __attribute__((target("sse4.2"))) bar3(void) { return 0; }
+extern int __attribute__((target("arch=sandybridge"))) bar2(void);
+
+namespace {
+int __attribute__((target("sse4.2"))) bar4(void) { return 0; }
+static int __attribute__((target("arch=sandybridge"))) bar4(void);
+}
+
 inline int __attribute__((target("sse4.2"))) baz(void) { return 0; }
 inline int __attribute__((target("arch=sandybridge"))) baz(void);
 //expected-error at +1 {{multiversioned function declaration has a 
diff erent inline specification}}
@@ -102,7 +111,7 @@ struct S {
 extern "C" {
 int __attribute__((target("sse4.2"))) 
diff _mangle(void) { return 0; }
 }
-//expected-error at +1 {{multiversioned function declaration has a 
diff erent linkage}}
+//expected-error at +1 {{multiversioned function declaration has a 
diff erent language linkage}}
 int __attribute__((target("arch=sandybridge"))) 
diff _mangle(void) { return 0; }
 
 // expected-error at +1 {{multiversioned functions do not yet support deduced return types}}