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Allow register variables in naked functions. 

llvm-svn: 281298
This commit is contained in:
Nikola Smiljanic 2016-09-13 07:02:02 +00:00
parent 11cfa45bec
commit 98d2e59d72
2 changed files with 33 additions and 0 deletions
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15
clang/lib/Sema/SemaDecl.cpp
View File

@ -11818,6 +11818,21 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
if (FD && FD->hasAttr<NakedAttr>()) {
for (const Stmt *S : Body->children()) {
// Allow local register variables without initializer as they don't
// require prologue.
bool RegisterVariables = false;
if (auto *DS = dyn_cast<DeclStmt>(S)) {
for (const auto *Decl : DS->decls()) {
if (const auto *Var = dyn_cast<VarDecl>(Decl)) {
RegisterVariables =
Var->hasAttr<AsmLabelAttr>() && !Var->hasInit();
if (!RegisterVariables)
break;
}
}
}
if (RegisterVariables)
continue;
if (!isa<AsmStmt>(S) && !isa<NullStmt>(S)) {
Diag(S->getLocStart(), diag::err_non_asm_stmt_in_naked_function);
Diag(FD->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);

18
clang/test/Sema/attr-naked.c
View File

@ -48,3 +48,21 @@ __attribute__((naked)) void t9(int z) { // expected-note{{attribute is here}}
"r"(z) // expected-error{{parameter references not allowed in naked functions}}
);
}
__attribute__((naked)) void t10() { // expected-note{{attribute is here}}
int a; // expected-error{{non-ASM statement in naked function is not supported}}
}
__attribute__((naked)) void t11() { // expected-note{{attribute is here}}
register int a asm("eax") = x; // expected-error{{non-ASM statement in naked function is not supported}}
}
__attribute__((naked)) void t12() { // expected-note{{attribute is here}}
register int a asm("eax"), b asm("ebx") = x; // expected-error{{non-ASM statement in naked function is not supported}}
}
__attribute__((naked)) void t13() {
register int a asm("eax");
register int b asm("ebx"), c asm("ecx");
}