diff options
| -rw-r--r-- | clang/include/clang/Basic/Attr.td | 6 | ||||
| -rw-r--r-- | clang/include/clang/Basic/AttrDocs.td | 22 | ||||
| -rw-r--r-- | clang/lib/CodeGen/CodeGenModule.cpp | 14 | ||||
| -rw-r--r-- | clang/lib/Sema/SemaDeclAttr.cpp | 4 | ||||
| -rw-r--r-- | clang/test/CodeGen/stack-protector.c | 20 | ||||
| -rw-r--r-- | clang/test/Sema/no_stack_protector.c | 5 |
6 files changed, 65 insertions, 6 deletions
diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td index 9aa91b82fcb..9e6a5d6de55 100644 --- a/clang/include/clang/Basic/Attr.td +++ b/clang/include/clang/Basic/Attr.td @@ -1495,6 +1495,12 @@ def NotTailCalled : InheritableAttr { let Documentation = [NotTailCalledDocs]; } +def NoStackProtector : InheritableAttr { + let Spellings = [Clang<"no_stack_protector">]; + let Subjects = SubjectList<[Function]>; + let Documentation = [NoStackProtectorDocs]; +} + def NoThrow : InheritableAttr { let Spellings = [GCC<"nothrow">, Declspec<"nothrow">]; let Subjects = SubjectList<[Function]>; diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td index 6df0ffe26fa..1cb510560d0 100644 --- a/clang/include/clang/Basic/AttrDocs.td +++ b/clang/include/clang/Basic/AttrDocs.td @@ -2740,6 +2740,28 @@ The syntax of the declare target directive is as follows: }]; } +def NoStackProtectorDocs : Documentation { + let Category = DocCatFunction; + let Content = [{ +Clang supports the ``__attribute__((no_stack_protector))`` attribute which disables +the stack protector on the specified function. This attribute is useful for +selectively disabling the stack protector on some functions when building with +``-fstack-protector`` compiler option. + +For example, it disables the stack protector for the function ``foo`` but function +``bar`` will still be built with the stack protector with the ``-fstack-protector`` +option. + +.. code-block:: c + + int __attribute__((no_stack_protector)) + foo (int x); // stack protection will be disabled for foo. + + int bar(int y); // bar can be built with the stack protector. + + }]; +} + def NotTailCalledDocs : Documentation { let Category = DocCatFunction; let Content = [{ diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index bfdd1e65e2c..3a27d999352 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -1142,12 +1142,14 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, if (!hasUnwindExceptions(LangOpts)) B.addAttribute(llvm::Attribute::NoUnwind); - if (LangOpts.getStackProtector() == LangOptions::SSPOn) - B.addAttribute(llvm::Attribute::StackProtect); - else if (LangOpts.getStackProtector() == LangOptions::SSPStrong) - B.addAttribute(llvm::Attribute::StackProtectStrong); - else if (LangOpts.getStackProtector() == LangOptions::SSPReq) - B.addAttribute(llvm::Attribute::StackProtectReq); + if (!D || !D->hasAttr<NoStackProtectorAttr>()) { + if (LangOpts.getStackProtector() == LangOptions::SSPOn) + B.addAttribute(llvm::Attribute::StackProtect); + else if (LangOpts.getStackProtector() == LangOptions::SSPStrong) + B.addAttribute(llvm::Attribute::StackProtectStrong); + else if (LangOpts.getStackProtector() == LangOptions::SSPReq) + B.addAttribute(llvm::Attribute::StackProtectReq); + } if (!D) { // If we don't have a declaration to control inlining, the function isn't diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp index be69e15d6d7..e4532a7e678 100644 --- a/clang/lib/Sema/SemaDeclAttr.cpp +++ b/clang/lib/Sema/SemaDeclAttr.cpp @@ -6230,6 +6230,10 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D, case AttributeList::AT_NoInstrumentFunction: // Interacts with -pg. handleSimpleAttribute<NoInstrumentFunctionAttr>(S, D, AL); break; + case AttributeList::AT_NoStackProtector: + // Interacts with -fstack-protector options. + handleSimpleAttribute<NoStackProtectorAttr>(S, D, AL); + break; case AttributeList::AT_StdCall: case AttributeList::AT_CDecl: case AttributeList::AT_FastCall: diff --git a/clang/test/CodeGen/stack-protector.c b/clang/test/CodeGen/stack-protector.c index 7a45a2f4acf..5037a3e0d6f 100644 --- a/clang/test/CodeGen/stack-protector.c +++ b/clang/test/CodeGen/stack-protector.c @@ -22,6 +22,14 @@ void test1(const char *msg) { printf("%s\n", a); } +// DEF: define {{.*}}void @test2(i8* %msg) #[[B:.*]] { +__attribute__((no_stack_protector)) +void test2(const char *msg) { + char a[strlen(msg) + 1]; + strcpy(a, msg); + printf("%s\n", a); +} + // NOSSP-NOT: attributes #[[A]] = {{.*}} ssp // SSP: attributes #[[A]] = {{.*}} ssp{{ }} // SSPSTRONG: attributes #[[A]] = {{.*}} sspstrong @@ -33,3 +41,15 @@ void test1(const char *msg) { // SAFESTACK-SSP: attributes #[[A]] = {{.*}} safestack ssp{{ }} // SAFESTACK-SSPSTRONG: attributes #[[A]] = {{.*}} safestack sspstrong // SAFESTACK-SSPREQ: attributes #[[A]] = {{.*}} safestack sspreq + +// NOSSP-NOT: attributes #[[B]] = {{.*}} ssp +// SSP-NOT: attributes #[[B]] = {{.*}} ssp{{ }} +// SSPSTRONG-NOT: attributes #[[B]] = {{.*}} sspstrong +// SSPREQ-NOT: attributes #[[B]] = {{.*}} sspreq + +// SAFESTACK-SSP: attributes #[[B]] = {{.*}} safestack +// SAFESTACK-SSP-NOT: attributes #[[B]] = {{.*}} safestack ssp{{ }} +// SAFESTACK-SSPSTRONG: attributes #[[B]] = {{.*}} safestack +// SAFESTACK-SSPSTRONG-NOT: attributes #[[B]] = {{.*}} safestack sspstrong +// SAFESTACK-SSPREQ: attributes #[[B]] = {{.*}} safestack +// SAFESTACK-SSPREQ-NOT: attributes #[[B]] = {{.*}} safestack sspreq diff --git a/clang/test/Sema/no_stack_protector.c b/clang/test/Sema/no_stack_protector.c new file mode 100644 index 00000000000..8e52f0982f5 --- /dev/null +++ b/clang/test/Sema/no_stack_protector.c @@ -0,0 +1,5 @@ +// RUN: %clang_cc1 -fsyntax-only -verify %s + +void __attribute__((no_stack_protector)) foo() {} +int __attribute__((no_stack_protector)) var; // expected-warning {{'no_stack_protector' attribute only applies to functions}} +void __attribute__((no_stack_protector(2))) bar() {} // expected-error {{'no_stack_protector' attribute takes no arguments}} |
