commit 07a5c22bb6fb0674c95205ae189365bf8e1b695e
author John McCall <rjmccall@apple.com> Sat Aug 15 02:09:25 2009 +0000
committer John McCall <rjmccall@apple.com> Sat Aug 15 02:09:25 2009 +0000
tree 65165508917e7a1e73b1edf3238c547bc1818744
parent 2cff7d16fe58e6d6447ec9cad2af083beb20d6b5

Disable all recognition of main() in -ffreestanding.  Addresses bug #4720.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@79070 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/AST/Decl.h

diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index 697c561..d603e67 100644
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -850,7 +850,7 @@
 
   /// \brief Determines whether this is a function "main", which is
   /// the entry point into an executable program.
-  bool isMain() const;
+  bool isMain(ASTContext &Context) const;
 
   /// \brief Determines whether this function is a function with
   /// external, C linkage.

lib/AST/Decl.cpp

diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 6d2f230..c91cb1d 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -414,8 +414,9 @@
     EndRangeLoc = B->getLocEnd();
 }
 
-bool FunctionDecl::isMain() const {
-  return getDeclContext()->getLookupContext()->isTranslationUnit() &&
+bool FunctionDecl::isMain(ASTContext &Context) const {
+  return !Context.getLangOptions().Freestanding &&
+    getDeclContext()->getLookupContext()->isTranslationUnit() &&
     getIdentifier() && getIdentifier()->isStr("main");
 }
 

lib/CodeGen/Mangle.cpp

diff --git a/lib/CodeGen/Mangle.cpp b/lib/CodeGen/Mangle.cpp
index 341e230..71b84e7 100644
--- a/lib/CodeGen/Mangle.cpp
+++ b/lib/CodeGen/Mangle.cpp
@@ -91,7 +91,7 @@
   // name mangling (always).
   if (!FD->hasAttr<OverloadableAttr>()) {
     // C functions are not mangled, and "main" is never mangled.
-    if (!Context.getLangOptions().CPlusPlus || FD->isMain())
+    if (!Context.getLangOptions().CPlusPlus || FD->isMain(Context))
       return false;
     
     // No mangling in an "implicit extern C" header. 

lib/Sema/SemaDecl.cpp

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index ab5578b..d75f322 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2766,7 +2766,7 @@
     return NewFD->setInvalidDecl();
   }
 
-  if (NewFD->isMain()) CheckMain(NewFD);
+  if (NewFD->isMain(Context)) CheckMain(NewFD);
 
   // Semantic checking for this function declaration (in isolation).
   if (getLangOptions().CPlusPlus) {
@@ -3542,7 +3542,7 @@
   //   definition itself provides a prototype. The aim is to detect
   //   global functions that fail to be declared in header files.
   if (!FD->isInvalidDecl() && FD->isGlobal() && !isa<CXXMethodDecl>(FD) &&
-      !FD->isMain()) {
+      !FD->isMain(Context)) {
     bool MissingPrototype = true;
     for (const FunctionDecl *Prev = FD->getPreviousDeclaration();
          Prev; Prev = Prev->getPreviousDeclaration()) {
@@ -3608,7 +3608,7 @@
   Stmt *Body = BodyArg.takeAs<Stmt>();
   if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) {
     FD->setBody(Body);
-    if (FD->isMain())
+    if (FD->isMain(Context))
       // C and C++ allow for main to automagically return 0.
       // Implements C++ [basic.start.main]p5 and C99 5.1.2.2.3.
       FD->setHasImplicitReturnZero(true);

test/Sema/freemain.c

diff --git a/test/Sema/freemain.c b/test/Sema/freemain.c
new file mode 100644
index 0000000..a2364df
--- /dev/null
+++ b/test/Sema/freemain.c
@@ -0,0 +1,9 @@
+// RUN: clang-cc -fsyntax-only -verify -ffreestanding %s
+
+// Tests that -ffreestanding disables all special treatment of main().
+
+void* allocate(long size);
+
+void* main(void* context, long size) {
+  if (context) return allocate(size);
+} // expected-warning {{control may reach end of non-void function}}