[cfe-commits] r148207 - in /cfe/trunk: lib/AST/Decl.cpp test/SemaCXX/linkage.cpp
Eli Friedman
eli.friedman at gmail.com
Sat Jan 14 17:23:58 PST 2012
Author: efriedma
Date: Sat Jan 14 19:23:58 2012
New Revision: 148207
URL: http://llvm.org/viewvc/llvm-project?rev=148207&view=rev
Log:
Change linkage computation so it doesn't depend on FunctionDecl::isExternC or VarDecl::isExternC, and instead queries what it actually cares about: whether the given declaration is inside an extern "C" context. Fundamentally, figuring out whether a function/variable uses C linkage requires knowing the linkage, and the logic in FunctionDecl::isExternC and VarDecl::isExternC was getting it wrong. Given that, fix FunctionDecl::isExternC and VarDecl::isExternC to use much simpler implementations that depend on the fixed linkage computation.
Fixes a regression to test/SemaCXX/linkage.cpp caused by a new warning exposing the fact that the internal state was wrong.
Modified:
cfe/trunk/lib/AST/Decl.cpp
cfe/trunk/test/SemaCXX/linkage.cpp
Modified: cfe/trunk/lib/AST/Decl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Decl.cpp?rev=148207&r1=148206&r2=148207&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Decl.cpp (original)
+++ cfe/trunk/lib/AST/Decl.cpp Sat Jan 14 19:23:58 2012
@@ -269,7 +269,8 @@
if (D->isInAnonymousNamespace()) {
const VarDecl *Var = dyn_cast<VarDecl>(D);
const FunctionDecl *Func = dyn_cast<FunctionDecl>(D);
- if ((!Var || !Var->isExternC()) && (!Func || !Func->isExternC()))
+ if ((!Var || !Var->getDeclContext()->isExternCContext()) &&
+ (!Func || !Func->getDeclContext()->isExternCContext()))
return LinkageInfo::uniqueExternal();
}
@@ -330,7 +331,8 @@
//
// Note that we don't want to make the variable non-external
// because of this, but unique-external linkage suits us.
- if (Context.getLangOptions().CPlusPlus && !Var->isExternC()) {
+ if (Context.getLangOptions().CPlusPlus &&
+ !Var->getDeclContext()->isExternCContext()) {
LinkageInfo TypeLV = getLVForType(Var->getType());
if (TypeLV.linkage() != ExternalLinkage)
return LinkageInfo::uniqueExternal();
@@ -400,7 +402,8 @@
// unique-external linkage, it's not legally usable from outside
// this translation unit. However, we should use the C linkage
// rules instead for extern "C" declarations.
- if (Context.getLangOptions().CPlusPlus && !Function->isExternC() &&
+ if (Context.getLangOptions().CPlusPlus &&
+ !Function->getDeclContext()->isExternCContext() &&
Function->getType()->getLinkage() == UniqueExternalLinkage)
return LinkageInfo::uniqueExternal();
@@ -762,7 +765,8 @@
// external linkage.
if (D->getLexicalDeclContext()->isFunctionOrMethod()) {
if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
- if (Function->isInAnonymousNamespace() && !Function->isExternC())
+ if (Function->isInAnonymousNamespace() &&
+ !Function->getDeclContext()->isExternCContext())
return LinkageInfo::uniqueExternal();
LinkageInfo LV;
@@ -783,7 +787,8 @@
if (const VarDecl *Var = dyn_cast<VarDecl>(D))
if (Var->getStorageClass() == SC_Extern ||
Var->getStorageClass() == SC_PrivateExtern) {
- if (Var->isInAnonymousNamespace() && !Var->isExternC())
+ if (Var->isInAnonymousNamespace() &&
+ !Var->getDeclContext()->isExternCContext())
return LinkageInfo::uniqueExternal();
LinkageInfo LV;
@@ -1167,27 +1172,17 @@
}
bool VarDecl::isExternC() const {
- ASTContext &Context = getASTContext();
- if (!Context.getLangOptions().CPlusPlus)
- return (getDeclContext()->isTranslationUnit() &&
- getStorageClass() != SC_Static) ||
- (getDeclContext()->isFunctionOrMethod() && hasExternalStorage());
+ if (getLinkage() != ExternalLinkage)
+ return false;
const DeclContext *DC = getDeclContext();
- if (DC->isFunctionOrMethod())
+ if (DC->isRecord())
return false;
- for (; !DC->isTranslationUnit(); DC = DC->getParent()) {
- if (const LinkageSpecDecl *Linkage = dyn_cast<LinkageSpecDecl>(DC)) {
- if (Linkage->getLanguage() == LinkageSpecDecl::lang_c)
- return getStorageClass() != SC_Static;
-
- break;
- }
-
- }
-
- return false;
+ ASTContext &Context = getASTContext();
+ if (!Context.getLangOptions().CPlusPlus)
+ return true;
+ return DC->isExternCContext();
}
VarDecl *VarDecl::getCanonicalDecl() {
@@ -1687,27 +1682,21 @@
}
bool FunctionDecl::isExternC() const {
- ASTContext &Context = getASTContext();
- // In C, any non-static, non-overloadable function has external
- // linkage.
- if (!Context.getLangOptions().CPlusPlus)
- return getStorageClass() != SC_Static && !getAttr<OverloadableAttr>();
+ if (getLinkage() != ExternalLinkage)
+ return false;
+
+ if (getAttr<OverloadableAttr>())
+ return false;
const DeclContext *DC = getDeclContext();
if (DC->isRecord())
return false;
- for (; !DC->isTranslationUnit(); DC = DC->getParent()) {
- if (const LinkageSpecDecl *Linkage = dyn_cast<LinkageSpecDecl>(DC)) {
- if (Linkage->getLanguage() == LinkageSpecDecl::lang_c)
- return getStorageClass() != SC_Static &&
- !getAttr<OverloadableAttr>();
-
- break;
- }
- }
+ ASTContext &Context = getASTContext();
+ if (!Context.getLangOptions().CPlusPlus)
+ return true;
- return isMain();
+ return isMain() || DC->isExternCContext();
}
bool FunctionDecl::isGlobal() const {
@@ -2352,8 +2341,7 @@
return MFK_Strndup;
default:
- if (getLinkage() == ExternalLinkage &&
- (!getASTContext().getLangOptions().CPlusPlus || isExternC())) {
+ if (isExternC()) {
if (FnInfo->isStr("memset"))
return MFK_Memset;
else if (FnInfo->isStr("memcpy"))
Modified: cfe/trunk/test/SemaCXX/linkage.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/linkage.cpp?rev=148207&r1=148206&r2=148207&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/linkage.cpp (original)
+++ cfe/trunk/test/SemaCXX/linkage.cpp Sat Jan 14 19:23:58 2012
@@ -76,15 +76,13 @@
struct X {
int f() {
extern int g();
- // FIXME: We don't compute the correct linkage for this variable
- // at the moment
- // extern int a;
+ extern int a;
// Test both for mangling in the code generation and warnings from use
// of internal, undefined names via -Werror.
// CHECK: call i32 @g(
- // FIXME: load i32* @a,
- return g();// + a;
+ // CHECK: load i32* @a,
+ return g() + a;
}
};
}
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