[clang] [clang] Do not allow unorderable features in [[gnu::target{,_clones}]] (PR #98426)

[Dan Klishch via cfe-commits]

https://github.com/DanShaders updated https://github.com/llvm/llvm-project/pull/98426

>From 723205411efe18dbe8bb154839525b59963b1638 Mon Sep 17 00:00:00 2001
From: Dan Klishch <danilklishch at gmail.com>
Date: Wed, 10 Jul 2024 23:39:42 -0400
Subject: [PATCH 1/2] [clang] Do not allow unorderable features in
 [[gnu::target{,_clones}]]

This partially addresses #98244.
---
 clang/lib/Sema/SemaDecl.cpp          |  4 +++-
 clang/lib/Sema/SemaDeclAttr.cpp      |  3 ++-
 clang/test/Sema/attr-target-clones.c |  3 +++
 clang/test/Sema/attr-target-mv.c     | 14 ++++++++++++++
 clang/test/Sema/attr-target.c        |  2 ++
 5 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 5b7275c316f74a..e03e66f23e9a1e 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11108,7 +11108,9 @@ static bool CheckMultiVersionValue(Sema &S, const FunctionDecl *FD) {
       }
 
       if (!TargetInfo.validateCpuSupports(BareFeat) ||
-          !TargetInfo.isValidFeatureName(BareFeat)) {
+          !TargetInfo.isValidFeatureName(BareFeat) ||
+          (BareFeat != "default" &&
+           TargetInfo.multiVersionSortPriority(BareFeat) == 0)) {
         S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
             << Feature << BareFeat;
         return true;
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index bb4d33560b93b8..256188e65d8aaa 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3289,7 +3289,8 @@ bool Sema::checkTargetClonesAttrString(
       } else if (Cur == "default") {
         DefaultIsDupe = HasDefault;
         HasDefault = true;
-      } else if (!Context.getTargetInfo().isValidFeatureName(Cur))
+      } else if (!Context.getTargetInfo().isValidFeatureName(Cur) ||
+                 Context.getTargetInfo().multiVersionSortPriority(Cur) == 0)
         return Diag(CurLoc, diag::warn_unsupported_target_attribute)
                << Unsupported << None << Cur << TargetClones;
       if (llvm::is_contained(StringsBuffer, Cur) || DefaultIsDupe)
diff --git a/clang/test/Sema/attr-target-clones.c b/clang/test/Sema/attr-target-clones.c
index e287fce7699b77..4597ea54d02bfe 100644
--- a/clang/test/Sema/attr-target-clones.c
+++ b/clang/test/Sema/attr-target-clones.c
@@ -122,3 +122,6 @@ void good_overload5(int) __attribute__((target_clones("mmx", "sse4.2", "default"
 void good_isa_level(int) __attribute__((target_clones("default", "arch=x86-64", "arch=x86-64-v2", "arch=x86-64-v3", "arch=x86-64-v4")));
 // expected-warning at +1 {{unsupported CPU 'x86-64-v5' in the 'target_clones' attribute string; 'target_clones' attribute ignored}}
 void bad_isa_level(int) __attribute__((target_clones("default", "arch=x86-64-v5")));
+
+// expected-warning at +1 {{unsupported 'sha' in the 'target_clones' attribute string; 'target_clones' attribute ignored}}
+void bad_feature(void) __attribute__((target_clones("default", "sse4.2", "sha")));
diff --git a/clang/test/Sema/attr-target-mv.c b/clang/test/Sema/attr-target-mv.c
index 8218771275e1bd..ddb1d82b02f098 100644
--- a/clang/test/Sema/attr-target-mv.c
+++ b/clang/test/Sema/attr-target-mv.c
@@ -170,3 +170,17 @@ int __attribute__((__overloadable__)) __attribute__((target("arch=sandybridge"))
 
 int __attribute__((__overloadable__)) __attribute__((target("sse4.2"))) good_overload7(void);
 int __attribute__((target("arch=sandybridge"))) good_overload7(int);
+
+// expected-error at +2 {{function multiversioning doesn't support feature 'sha'}}
+// expected-note at +2 {{function multiversioning caused by this declaration}}
+int __attribute__((target("sha"))) no_priority1(void);
+int __attribute__((target("default"))) no_priority1(void);
+
+int __attribute__((target("default"))) no_priority2(void);
+// expected-error at +1 {{function multiversioning doesn't support feature 'sha'}}
+int __attribute__((target("sha"))) no_priority2(void);
+
+int __attribute__((target("default"))) no_priority3(void);
+int __attribute__((target("avx2"))) no_priority3(void);
+// expected-error at +1 {{function multiversioning doesn't support feature 'sha'}}
+int __attribute__((target("sha"))) no_priority3(void);
diff --git a/clang/test/Sema/attr-target.c b/clang/test/Sema/attr-target.c
index 5328f056507a71..65ece3c27d2990 100644
--- a/clang/test/Sema/attr-target.c
+++ b/clang/test/Sema/attr-target.c
@@ -33,6 +33,8 @@ void __attribute__((target("x86-64"))) baseline(void) {}
 //expected-warning at +1 {{unsupported 'x86-64-v2' in the 'target' attribute string}}
 void __attribute__((target("x86-64-v2"))) v2(void) {}
 
+int __attribute__((target("sha"))) good_target_but_not_for_fmv() { return 5; }
+
 #elifdef __aarch64__
 
 int __attribute__((target("sve,arch=armv8-a"))) foo(void) { return 4; }

>From 7378d6241f4e829a3b69af2ceb9a70c9c0bcc56a Mon Sep 17 00:00:00 2001
From: Dan Klishch <danilklishch at gmail.com>
Date: Mon, 13 Jan 2025 16:57:19 -0500
Subject: [PATCH 2/2] fixup after #116257

---
 clang/lib/Sema/SemaDecl.cpp     | 3 +--
 clang/lib/Sema/SemaDeclAttr.cpp | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index e03e66f23e9a1e..ccfaf273dc7683 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11109,8 +11109,7 @@ static bool CheckMultiVersionValue(Sema &S, const FunctionDecl *FD) {
 
       if (!TargetInfo.validateCpuSupports(BareFeat) ||
           !TargetInfo.isValidFeatureName(BareFeat) ||
-          (BareFeat != "default" &&
-           TargetInfo.multiVersionSortPriority(BareFeat) == 0)) {
+          (BareFeat != "default" && TargetInfo.getFMVPriority(BareFeat) == 0)) {
         S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
             << Feature << BareFeat;
         return true;
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 256188e65d8aaa..0a1f2535a7d0c5 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3290,7 +3290,7 @@ bool Sema::checkTargetClonesAttrString(
         DefaultIsDupe = HasDefault;
         HasDefault = true;
       } else if (!Context.getTargetInfo().isValidFeatureName(Cur) ||
-                 Context.getTargetInfo().multiVersionSortPriority(Cur) == 0)
+                 Context.getTargetInfo().getFMVPriority(Cur) == 0)
         return Diag(CurLoc, diag::warn_unsupported_target_attribute)
                << Unsupported << None << Cur << TargetClones;
       if (llvm::is_contained(StringsBuffer, Cur) || DefaultIsDupe)