From a9a93f37779bbab41d73142aa5e4beb43089696e Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Fri, 8 Nov 2002 20:34:02 +0000
Subject: [PATCH] Add a method "getMainFunction()" that efficiently locates
'main' in a module
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4629 91177308-0d34-0410-b5e6-96231b3b80d8
---
include/llvm/Module.h | 6 +++++
lib/VMCore/Module.cpp | 52 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 58 insertions(+)
diff --git a/include/llvm/Module.h b/include/llvm/Module.h
index 2b8c0ab5d0e..6f7a14f410b 100644
--- a/include/llvm/Module.h
+++ b/include/llvm/Module.h
@@ -80,6 +80,12 @@ public:
///
Function *getFunction(const std::string &Name, const FunctionType *Ty);
+ /// getMainFunction - This function looks up main efficiently. This is such a
+ /// common case, that it is a method in Module. If main cannot be found, a
+ /// null pointer is returned.
+ ///
+ Function *getMainFunction();
+
/// addTypeName - Insert an entry in the symbol table mapping Str to Type. If
/// there is already an entry for this name, true is returned and the symbol
/// table is not modified.
diff --git a/lib/VMCore/Module.cpp b/lib/VMCore/Module.cpp
index 397b5e28341..fec6fec77d3 100644
--- a/lib/VMCore/Module.cpp
+++ b/lib/VMCore/Module.cpp
@@ -139,6 +139,58 @@ bool Module::addTypeName(const std::string &Name, const Type *Ty) {
return false;
}
+/// getMainFunction - This function looks up main efficiently. This is such a
+/// common case, that it is a method in Module. If main cannot be found, a
+/// null pointer is returned.
+///
+Function *Module::getMainFunction() {
+ std::vector<const Type*> Params;
+
+ // int main(void)...
+ if (Function *F = getFunction("main", FunctionType::get(Type::IntTy,
+ Params, false)))
+ return F;
+
+ // void main(void)...
+ if (Function *F = getFunction("main", FunctionType::get(Type::VoidTy,
+ Params, false)))
+ return F;
+
+ Params.push_back(Type::IntTy);
+
+ // int main(int argc)...
+ if (Function *F = getFunction("main", FunctionType::get(Type::IntTy,
+ Params, false)))
+ return F;
+
+ // void main(int argc)...
+ if (Function *F = getFunction("main", FunctionType::get(Type::VoidTy,
+ Params, false)))
+ return F;
+
+ for (unsigned i = 0; i != 2; ++i) { // Check argv and envp
+ Params.push_back(PointerType::get(PointerType::get(Type::SByteTy)));
+
+ // int main(int argc, char **argv)...
+ if (Function *F = getFunction("main", FunctionType::get(Type::IntTy,
+ Params, false)))
+ return F;
+
+ // void main(int argc, char **argv)...
+ if (Function *F = getFunction("main", FunctionType::get(Type::VoidTy,
+ Params, false)))
+ return F;
+ }
+
+ // Loop over all of the methods, trying to find main the hard way...
+ for (iterator I = begin(), E = end(); I != E; ++I)
+ if (I->getName() == "main")
+ return I;
+ return 0; // Main not found...
+}
+
+
+
// getTypeName - If there is at least one entry in the symbol table for the
// specified type, return it.
//