https://github.com/abhishek-kaushik22 created
https://github.com/llvm/llvm-project/pull/154801
Fixes #149866
>From 359de1e5786a413f3bfca6b09b60bd2fd67dbb1f Mon Sep 17 00:00:00 2001
From: Abhishek Kaushik <abhishek.kaus...@intel.com>
Date: Thu, 21 Aug 2025 22:59:21 +0530
Subject: [PATCH] [Clang]Throw frontend error for target feature mismatch when
using flatten attribute
Fixes #149866
---
clang/docs/ReleaseNotes.rst | 3 ++
.../clang/Basic/DiagnosticFrontendKinds.td | 5 +++
clang/lib/CodeGen/CGCall.cpp | 9 ++--
clang/lib/CodeGen/CodeGenFunction.cpp | 45 +++++++++++++------
clang/test/CodeGen/target-features-error-3.c | 12 +++++
clang/test/CodeGen/target-features-error-4.c | 12 +++++
clang/test/CodeGen/target-features-error-5.c | 12 +++++
.../test/CodeGen/target-features-no-error-2.c | 12 +++++
8 files changed, 93 insertions(+), 17 deletions(-)
create mode 100644 clang/test/CodeGen/target-features-error-3.c
create mode 100644 clang/test/CodeGen/target-features-error-4.c
create mode 100644 clang/test/CodeGen/target-features-error-5.c
create mode 100644 clang/test/CodeGen/target-features-no-error-2.c
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index fe1dd15c6f885..ebd5b7621ef91 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -229,6 +229,9 @@ Bug Fixes in This Version
cast chain. (#GH149967).
- Fixed a crash with incompatible pointer to integer conversions in designated
initializers involving string literals. (#GH154046)
+- Clang now emits a frontend error when a function marked with the `flatten`
attribute
+ calls another function that requires target features not enabled in the
caller. This
+ prevents a fatal error in the backend.
Bug Fixes to Compiler Builtins
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/Basic/DiagnosticFrontendKinds.td
b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
index 8a8db27490f06..a3b918842f53e 100644
--- a/clang/include/clang/Basic/DiagnosticFrontendKinds.td
+++ b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
@@ -287,6 +287,11 @@ def err_function_needs_feature : Error<
"always_inline function %1 requires target feature '%2', but would "
"be inlined into function %0 that is compiled without support for '%2'">;
+def err_flatten_function_needs_feature
+ : Error<"flatten function %0 calls %1 which requires target feature '%2', "
+ "but the "
+ "caller is compiled without support for '%2'">;
+
let CategoryName = "Codegen ABI Check" in {
def err_function_always_inline_attribute_mismatch : Error<
"always_inline function %1 and its caller %0 have mismatching %2
attributes">;
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 466546b2f1309..9c4fa12f18b20 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -5261,9 +5261,12 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo
&CallInfo,
// since otherwise we could be making a conditional call after a check for
// the proper cpu features (and it won't cause code generation issues due
to
// function based code generation).
- if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
- (TargetDecl->hasAttr<TargetAttr>() ||
- (CurFuncDecl && CurFuncDecl->hasAttr<TargetAttr>())))
+ if ((TargetDecl->hasAttr<AlwaysInlineAttr>() &&
+ (TargetDecl->hasAttr<TargetAttr>() ||
+ (CurFuncDecl && CurFuncDecl->hasAttr<TargetAttr>()))) ||
+ (CurFuncDecl && CurFuncDecl->hasAttr<FlattenAttr>() &&
+ (CurFuncDecl->hasAttr<TargetAttr>() ||
+ TargetDecl->hasAttr<TargetAttr>())))
checkTargetFeatures(Loc, FD);
}
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp
b/clang/lib/CodeGen/CodeGenFunction.cpp
index 652fe672f15e3..9854dae33d6f3 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -2827,6 +2827,9 @@ void CodeGenFunction::checkTargetFeatures(SourceLocation
Loc,
if (!FD)
return;
+ bool IsAlwaysInline = TargetDecl->hasAttr<AlwaysInlineAttr>();
+ bool IsFlatten = FD && FD->hasAttr<FlattenAttr>();
+
// Grab the required features for the call. For a builtin this is listed in
// the td file with the default cpu, for an always_inline function this is
any
// listed cpu and any listed features.
@@ -2869,25 +2872,39 @@ void
CodeGenFunction::checkTargetFeatures(SourceLocation Loc,
if (F.getValue())
ReqFeatures.push_back(F.getKey());
}
- if (!llvm::all_of(ReqFeatures, [&](StringRef Feature) {
- if (!CallerFeatureMap.lookup(Feature)) {
- MissingFeature = Feature.str();
- return false;
- }
- return true;
- }) && !IsHipStdPar)
- CGM.getDiags().Report(Loc, diag::err_function_needs_feature)
- << FD->getDeclName() << TargetDecl->getDeclName() << MissingFeature;
+ if (!llvm::all_of(ReqFeatures,
+ [&](StringRef Feature) {
+ if (!CallerFeatureMap.lookup(Feature)) {
+ MissingFeature = Feature.str();
+ return false;
+ }
+ return true;
+ }) &&
+ !IsHipStdPar) {
+ if (IsAlwaysInline)
+ CGM.getDiags().Report(Loc, diag::err_function_needs_feature)
+ << FD->getDeclName() << TargetDecl->getDeclName() <<
MissingFeature;
+ else if (IsFlatten)
+ CGM.getDiags().Report(Loc, diag::err_flatten_function_needs_feature)
+ << FD->getDeclName() << TargetDecl->getDeclName() <<
MissingFeature;
+ }
+
} else if (!FD->isMultiVersion() && FD->hasAttr<TargetAttr>()) {
llvm::StringMap<bool> CalleeFeatureMap;
CGM.getContext().getFunctionFeatureMap(CalleeFeatureMap, TargetDecl);
for (const auto &F : CalleeFeatureMap) {
- if (F.getValue() && (!CallerFeatureMap.lookup(F.getKey()) ||
- !CallerFeatureMap.find(F.getKey())->getValue()) &&
- !IsHipStdPar)
- CGM.getDiags().Report(Loc, diag::err_function_needs_feature)
- << FD->getDeclName() << TargetDecl->getDeclName() << F.getKey();
+ if (F.getValue() &&
+ (!CallerFeatureMap.lookup(F.getKey()) ||
+ !CallerFeatureMap.find(F.getKey())->getValue()) &&
+ !IsHipStdPar) {
+ if (IsAlwaysInline)
+ CGM.getDiags().Report(Loc, diag::err_function_needs_feature)
+ << FD->getDeclName() << TargetDecl->getDeclName() << F.getKey();
+ else if (IsFlatten)
+ CGM.getDiags().Report(Loc, diag::err_flatten_function_needs_feature)
+ << FD->getDeclName() << TargetDecl->getDeclName() << F.getKey();
+ }
}
}
}
diff --git a/clang/test/CodeGen/target-features-error-3.c
b/clang/test/CodeGen/target-features-error-3.c
new file mode 100644
index 0000000000000..ff4866ac69ca0
--- /dev/null
+++ b/clang/test/CodeGen/target-features-error-3.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -emit-llvm -verify -o /dev/null
+
+typedef double __v2df __attribute__((__vector_size__(16)));
+
+__v2df __attribute__((target("sse4.1"))) foo() {
+ __v2df v = {0.0, 0.0};
+ return __builtin_ia32_roundpd(v, 2);
+}
+
+__v2df __attribute__((flatten)) bar() {
+ return foo(); // expected-error {{flatten function 'bar' calls 'foo' which
requires target feature 'sse4.1', but the caller is compiled without support
for 'sse4.1'}}
+}
diff --git a/clang/test/CodeGen/target-features-error-4.c
b/clang/test/CodeGen/target-features-error-4.c
new file mode 100644
index 0000000000000..fe4879e03b660
--- /dev/null
+++ b/clang/test/CodeGen/target-features-error-4.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -emit-llvm -verify -o /dev/null
+
+typedef double __v2df __attribute__((__vector_size__(16)));
+
+__v2df __attribute__((target("sse4.1"))) foo() {
+ __v2df v = {0.0, 0.0};
+ return __builtin_ia32_roundpd(v, 2);
+}
+
+__v2df __attribute__((target("no-sse4.1"), flatten)) bar() {
+ return foo(); // expected-error {{flatten function 'bar' calls 'foo' which
requires target feature 'sse4.1', but the caller is compiled without support
for 'sse4.1'}}
+}
diff --git a/clang/test/CodeGen/target-features-error-5.c
b/clang/test/CodeGen/target-features-error-5.c
new file mode 100644
index 0000000000000..8bc3ba193463d
--- /dev/null
+++ b/clang/test/CodeGen/target-features-error-5.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -target-feature +sse4.1
-emit-llvm -verify -o /dev/null
+
+typedef double __v2df __attribute__((__vector_size__(16)));
+
+__v2df foo() {
+ __v2df v = {0.0, 0.0};
+ return __builtin_ia32_roundpd(v, 2);
+}
+
+__v2df __attribute__((target("no-sse4.1"), flatten)) bar() {
+ return foo(); // expected-error {{flatten function 'bar' calls 'foo' which
requires target feature 'sse4.1', but the caller is compiled without support
for 'sse4.1'}}
+}
diff --git a/clang/test/CodeGen/target-features-no-error-2.c
b/clang/test/CodeGen/target-features-no-error-2.c
new file mode 100644
index 0000000000000..eeec3f3d05d7b
--- /dev/null
+++ b/clang/test/CodeGen/target-features-no-error-2.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -emit-llvm -verify -o /dev/null
+
+typedef double __v2df __attribute__((__vector_size__(16)));
+
+__v2df __attribute__((target("sse4.1"))) foo() {
+ __v2df v = {0.0, 0.0};
+ return __builtin_ia32_roundpd(v, 2);
+}
+
+__v2df __attribute__((target("sse4.1"), flatten)) bar() {
+ return foo(); // expected-no-diagnostics
+}
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
