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-rw-r--r--include/clang/Basic/DiagnosticSemaKinds.td3
-rw-r--r--lib/CodeGen/CodeGenModule.cpp34
-rw-r--r--lib/CodeGen/CodeGenModule.h2
-rw-r--r--test/CodeGen/alias.c5
-rw-r--r--test/Sema/attr-alias-elf.c8
5 files changed, 41 insertions, 11 deletions
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 7c4f988353..eadf4e747c 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2106,6 +2106,9 @@ def err_alias_to_undefined : Error<
def warn_alias_to_weak_alias : Warning<
"alias will always resolve to %0 even if weak definition of alias %1 is overridden">,
InGroup<IgnoredAttributes>;
+def warn_alias_with_section : Warning<
+ "alias will not be in section '%0' but in the same section as the aliasee">,
+ InGroup<IgnoredAttributes>;
def err_duplicate_mangled_name : Error<
"definition with same mangled name as another definition">;
def err_cyclic_alias : Error<
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index caa4f24899..9c60eb55f8 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -238,11 +238,6 @@ void CodeGenModule::checkAliases() {
Diags.Report(AA->getLocation(), diag::err_alias_to_undefined);
}
- // We have to handle alias to weak aliases in here. LLVM itself disallows
- // this since the object semantics would not match the IL one. For
- // compatibility with gcc we implement it by just pointing the alias
- // to its aliasee's aliasee. We also warn, since the user is probably
- // expecting the link to be weak.
llvm::Constant *Aliasee = Alias->getAliasee();
llvm::GlobalValue *AliaseeGV;
if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee)) {
@@ -253,6 +248,19 @@ void CodeGenModule::checkAliases() {
} else {
AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
}
+
+ if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
+ StringRef AliasSection = SA->getName();
+ if (AliasSection != AliaseeGV->getSection())
+ Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
+ << AliasSection;
+ }
+
+ // We have to handle alias to weak aliases in here. LLVM itself disallows
+ // this since the object semantics would not match the IL one. For
+ // compatibility with gcc we implement it by just pointing the alias
+ // to its aliasee's aliasee. We also warn, since the user is probably
+ // expecting the link to be weak.
if (auto GA = dyn_cast<llvm::GlobalAlias>(AliaseeGV)) {
if (GA->mayBeOverridden()) {
Diags.Report(AA->getLocation(), diag::warn_alias_to_weak_alias)
@@ -585,7 +593,7 @@ CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
/// variables (these details are set in EmitGlobalVarDefinition for variables).
void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D,
llvm::GlobalValue *GV) {
- SetCommonAttributes(D, GV);
+ setNonAliasAttributes(D, GV);
}
void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
@@ -711,13 +719,17 @@ void CodeGenModule::SetCommonAttributes(const Decl *D,
if (D->hasAttr<UsedAttr>())
addUsedGlobal(GV);
+}
+
+void CodeGenModule::setNonAliasAttributes(const Decl *D,
+ llvm::GlobalValue *GV) {
+ assert(!isa<llvm::GlobalAlias>(GV));
+ SetCommonAttributes(D, GV);
if (const SectionAttr *SA = D->getAttr<SectionAttr>())
GV->setSection(SA->getName());
- // Alias cannot have attributes. Filter them here.
- if (!isa<llvm::GlobalAlias>(GV))
- getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this);
+ getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this);
}
void CodeGenModule::SetInternalFunctionAttributes(const Decl *D,
@@ -728,7 +740,7 @@ void CodeGenModule::SetInternalFunctionAttributes(const Decl *D,
F->setLinkage(llvm::Function::InternalLinkage);
- SetCommonAttributes(D, F);
+ setNonAliasAttributes(D, F);
}
static void setLinkageAndVisibilityForGV(llvm::GlobalValue *GV,
@@ -1879,7 +1891,7 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
// common vars aren't constant even if declared const.
GV->setConstant(false);
- SetCommonAttributes(D, GV);
+ setNonAliasAttributes(D, GV);
// Emit the initializer function if necessary.
if (NeedsGlobalCtor || NeedsGlobalDtor)
diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index 419324d7d8..4a1573b849 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -1050,6 +1050,8 @@ private:
/// NOTE: This should only be called for definitions.
void SetCommonAttributes(const Decl *D, llvm::GlobalValue *GV);
+ void setNonAliasAttributes(const Decl *D, llvm::GlobalValue *GV);
+
/// SetFunctionDefinitionAttributes - Set attributes for a global definition.
void SetFunctionDefinitionAttributes(const FunctionDecl *D,
llvm::GlobalValue *GV);
diff --git a/test/CodeGen/alias.c b/test/CodeGen/alias.c
index 4a89b13be9..98449d36ed 100644
--- a/test/CodeGen/alias.c
+++ b/test/CodeGen/alias.c
@@ -16,6 +16,7 @@ extern void f1(void) __attribute((alias("f0")));
// CHECKBASIC-DAG: @f1 = alias void ()* @f0
// CHECKBASIC-DAG: @test8_foo = alias weak bitcast (void ()* @test8_bar to void (...)*)
// CHECKBASIC-DAG: @test8_zed = alias bitcast (void ()* @test8_bar to void (...)*)
+// CHECKBASIC-DAG: @test9_zed = alias void ()* @test9_bar
// CHECKBASIC: define void @f0() [[NUW:#[0-9]+]] {
// Make sure that aliases cause referenced values to be emitted.
@@ -54,3 +55,7 @@ int outer_weak(int a) { return inner_weak_a(a); }
void test8_bar() {}
void test8_foo() __attribute__((weak, alias("test8_bar")));
void test8_zed() __attribute__((alias("test8_foo")));
+
+void test9_bar(void) { }
+void test9_zed(void) __attribute__((section("test")));
+void test9_zed(void) __attribute__((alias("test9_bar")));
diff --git a/test/Sema/attr-alias-elf.c b/test/Sema/attr-alias-elf.c
index 01bc1879dc..04d13924ac 100644
--- a/test/Sema/attr-alias-elf.c
+++ b/test/Sema/attr-alias-elf.c
@@ -56,3 +56,11 @@ typedef int b4;
void test2_bar() {}
void test2_foo() __attribute__((weak, alias("test2_bar")));
void test2_zed() __attribute__((alias("test2_foo"))); // expected-warning {{alias will always resolve to test2_bar even if weak definition of alias test2_foo is overridden}}
+
+void test3_bar() { }
+void test3_foo() __attribute__((section("test"))); // expected-warning {{alias will not be in section 'test' but in the same section as the aliasee}}
+void test3_foo() __attribute__((alias("test3_bar")));
+
+__attribute__((section("test"))) void test4_bar() { }
+void test4_foo() __attribute__((section("test")));
+void test4_foo() __attribute__((alias("test4_bar")));
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-17 07:42:38 +0000