<commit_before>//===- CallGraph.cpp - Build a Module's call graph ------------------------===//
// 
//                     The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
// 
//===----------------------------------------------------------------------===//
//
// This interface is used to build and manipulate a call graph, which is a very 
// useful tool for interprocedural optimization.
//
// Every function in a module is represented as a node in the call graph.  The
// callgraph node keeps track of which functions the are called by the function
// corresponding to the node.
//
// A call graph will contain nodes where the function that they correspond to is
// null.  This 'external' node is used to represent control flow that is not
// represented (or analyzable) in the module.  As such, the external node will
// have edges to functions with the following properties:
//   1. All functions in the module without internal linkage, since they could
//      be called by functions outside of the our analysis capability.
//   2. All functions whose address is used for something more than a direct
//      call, for example being stored into a memory location.  Since they may
//      be called by an unknown caller later, they must be tracked as such.
//
// Similarly, functions have a call edge to the external node iff:
//   1. The function is external, reflecting the fact that they could call
//      anything without internal linkage or that has its address taken.
//   2. The function contains an indirect function call.
//
// As an extension in the future, there may be multiple nodes with a null
// function.  These will be used when we can prove (through pointer analysis)
// that an indirect call site can call only a specific set of functions.
//
// Because of these properties, the CallGraph captures a conservative superset
// of all of the caller-callee relationships, which is useful for
// transformations.
//
// The CallGraph class also attempts to figure out what the root of the
// CallGraph is, which is currently does by looking for a function named 'main'.
// If no function named 'main' is found, the external node is used as the entry
// node, reflecting the fact that any function without internal linkage could
// be called into (which is common for libraries).
//
//===----------------------------------------------------------------------===//

#include "llvm/Analysis/CallGraph.h"
#include "llvm/Module.h"
#include "llvm/iOther.h"
#include "llvm/iTerminators.h"
#include "Support/STLExtras.h"
#include <algorithm>

static RegisterAnalysis<CallGraph> X("callgraph", "Call Graph Construction");

// getNodeFor - Return the node for the specified function or create one if it
// does not already exist.
//
CallGraphNode *CallGraph::getNodeFor(Function *F) {
  CallGraphNode *&CGN = FunctionMap[F];
  if (CGN) return CGN;

  assert((!F || F->getParent() == Mod) && "Function not in current module!");
  return CGN = new CallGraphNode(F);
}

// addToCallGraph - Add a function to the call graph, and link the node to all
// of the functions that it calls.
//
void CallGraph::addToCallGraph(Function *F) {
  CallGraphNode *Node = getNodeFor(F);

  // If this function has external linkage, anything could call it...
  if (!F->hasInternalLinkage()) {
    ExternalNode->addCalledFunction(Node);

    // Found the entry point?
    if (F->getName() == "main") {
      if (Root)
        Root = ExternalNode;  // Found multiple external mains?  Don't pick one.
      else
        Root = Node;          // Found a main, keep track of it!
    }
  }
  
  // If this function is not defined in this translation unit, it could call
  // anything.
  if (F->isExternal())
    Node->addCalledFunction(ExternalNode);

  // Loop over all of the users of the function... looking for callers...
  //
  for (Value::use_iterator I = F->use_begin(), E = F->use_end(); I != E; ++I) {
    User *U = *I;
    if (CallInst *CI = dyn_cast<CallInst>(U))
      getNodeFor(CI->getParent()->getParent())->addCalledFunction(Node);
    else if (InvokeInst *II = dyn_cast<InvokeInst>(U))
      getNodeFor(II->getParent()->getParent())->addCalledFunction(Node);
    else                         // Can't classify the user!
      ExternalNode->addCalledFunction(Node);
  }

  // Look for an indirect function call...
  for (Function::iterator BB = F->begin(), BBE = F->end(); BB != BBE; ++BB)
    for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE; ++II){
      Instruction &I = *II;

      if (CallInst *CI = dyn_cast<CallInst>(&I)) {
        if (CI->getCalledFunction() == 0)
          Node->addCalledFunction(ExternalNode);<commit_msg>This is a disgusting hack that improves code substantially, by making callgraphSCC passes more effective.<commit_after>//===- CallGraph.cpp - Build a Module's call graph ------------------------===//
// 
//                     The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
// 
//===----------------------------------------------------------------------===//
//
// This interface is used to build and manipulate a call graph, which is a very 
// useful tool for interprocedural optimization.
//
// Every function in a module is represented as a node in the call graph.  The
// callgraph node keeps track of which functions the are called by the function
// corresponding to the node.
//
// A call graph will contain nodes where the function that they correspond to is
// null.  This 'external' node is used to represent control flow that is not
// represented (or analyzable) in the module.  As such, the external node will
// have edges to functions with the following properties:
//   1. All functions in the module without internal linkage, since they could
//      be called by functions outside of the our analysis capability.
//   2. All functions whose address is used for something more than a direct
//      call, for example being stored into a memory location.  Since they may
//      be called by an unknown caller later, they must be tracked as such.
//
// Similarly, functions have a call edge to the external node iff:
//   1. The function is external, reflecting the fact that they could call
//      anything without internal linkage or that has its address taken.
//   2. The function contains an indirect function call.
//
// As an extension in the future, there may be multiple nodes with a null
// function.  These will be used when we can prove (through pointer analysis)
// that an indirect call site can call only a specific set of functions.
//
// Because of these properties, the CallGraph captures a conservative superset
// of all of the caller-callee relationships, which is useful for
// transformations.
//
// The CallGraph class also attempts to figure out what the root of the
// CallGraph is, which is currently does by looking for a function named 'main'.
// If no function named 'main' is found, the external node is used as the entry
// node, reflecting the fact that any function without internal linkage could
// be called into (which is common for libraries).
//
//===----------------------------------------------------------------------===//

#include "llvm/Analysis/CallGraph.h"
#include "llvm/Module.h"
#include "llvm/iOther.h"
#include "llvm/iTerminators.h"
#include "Support/STLExtras.h"

static RegisterAnalysis<CallGraph> X("callgraph", "Call Graph Construction");

static const char * const KnownExternalFunctions[] = {
  // Low-level system calls
  "open",
  "read",
  "write",
  "writev",
  "lseek",
  "poll",
  "ioctl",

  // Low-level stdc library functions
  "abort",
  "getenv",
  "putenv",
  
  // Standard IO functions
  "printf",
  "sprintf",
  "fopen",
  "freopen",
  "fclose",
  "fwrite",
  "puts",
  "fputs",
  "getc",
  "ungetc",
  "putc",
  "putchar",
  "fread",
  "fileno",
  "ftell",
  "fflush",
  "fseek",
  "fileno",
  "ferror",
  "feof",
  "fdopen",
  "__fxstat",
  "setbuf",
  "setbuffer",
  "etlinebuf",
  "setvbuf",

  // Memory functions
  "malloc",
  "free",
  "realloc",
  "calloc",
  "memalign",
  
  // String functions
  "atoi",
  "memmove",
  "memset",
  "memchr",
  "memcmp",
  "strchr",
  "strncpy",
  "strncmp",
  "strcmp",
  "__strcoll_l",
  "__strxfrm_l",
  "__strftime_l",
  "__strtol_l",
  "__strtoul_l",
  "__strtoll_l",
  "__strtoull_l",
  "__strtof_l",
  "__strtod_l",
  "__strtold_l",

  // Locale functions
  "__uselocale",
  "__newlocale",
  "__freelocale",
  "__duplocale",
  "__nl_langinfo_l",

  // gettext functions used by libstdc++
  "gettext",
  "dgettext",
  "dcgettext",
  "textdomain",
  "bindtextdomain",
  
  // Random stuff
  "__assert_fail",
  "__errno_location",
};


/// ExternalFunctionDoesntCallIntoProgram - This hack is used to indicate to the
/// call graph that the specified external function is _KNOWN_ to not call back
/// into the program.  This is important, because otherwise functions which call
/// "printf" for example, end up in a great big SCC that goes from the function
/// through main.
///
static bool ExternalFunctionDoesntCallIntoProgram(const std::string &Name) {
  static std::vector<std::string> Funcs;

  // First time this is called?
  if (Funcs.empty()) {
    // Add a whole bunch of functions which are often used...
    Funcs.insert(Funcs.end(), KnownExternalFunctions,
                 KnownExternalFunctions+
              sizeof(KnownExternalFunctions)/sizeof(KnownExternalFunctions[0]));
    // Sort the list for efficient access
    std::sort(Funcs.begin(), Funcs.end());
  }

  // Binary search for the function name...
  std::vector<std::string>::iterator I =
    std::lower_bound(Funcs.begin(), Funcs.end(), Name);

  // Found it?
  return I != Funcs.end() && *I == Name;
}



// getNodeFor - Return the node for the specified function or create one if it
// does not already exist.
//
CallGraphNode *CallGraph::getNodeFor(Function *F) {
  CallGraphNode *&CGN = FunctionMap[F];
  if (CGN) return CGN;

  assert((!F || F->getParent() == Mod) && "Function not in current module!");
  return CGN = new CallGraphNode(F);
}

// addToCallGraph - Add a function to the call graph, and link the node to all
// of the functions that it calls.
//
void CallGraph::addToCallGraph(Function *F) {
  CallGraphNode *Node = getNodeFor(F);

  // If this function has external linkage, anything could call it...
  if (!F->hasInternalLinkage()) {
    ExternalNode->addCalledFunction(Node);

    // Found the entry point?
    if (F->getName() == "main") {
      if (Root)
        Root = ExternalNode;  // Found multiple external mains?  Don't pick one.
      else
        Root = Node;          // Found a main, keep track of it!
    }
  }
  
  // If this function is not defined in this translation unit, it could call
  // anything.
  if (F->isExternal() && !F->getIntrinsicID() && 
      !ExternalFunctionDoesntCallIntoProgram(F->getName()))
    Node->addCalledFunction(ExternalNode);

  // Loop over all of the users of the function... looking for callers...
  //
  for (Value::use_iterator I = F->use_begin(), E = F->use_end(); I != E; ++I) {
    User *U = *I;
    if (CallInst *CI = dyn_cast<CallInst>(U))
      getNodeFor(CI->getParent()->getParent())->addCalledFunction(Node);
    else if (InvokeInst *II = dyn_cast<InvokeInst>(U))
      getNodeFor(II->getParent()->getParent())->addCalledFunction(Node);
    else                         // Can't classify the user!
      ExternalNode->addCalledFunction(Node);
  }

  // Look for an indirect function call...
  for (Function::iterator BB = F->begin(), BBE = F->end(); BB != BBE; ++BB)
    for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE; ++II){
      Instruction &I = *II;

      if (CallInst *CI = dyn_cast<CallInst>(&I)) {
        if (CI->getCalledFunction() == 0)
          Node->addCalledFunction(ExternalNode);
{'fraction_non_alphanumeric': 0.14421881475341897, 'fraction_numerical': 0.0009117281392457522, 'mean_word_length': 2.8123222748815166, 'pattern_counts': {'":': 0, '<': 14, '<?xml version=': 0, '>': 58, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '7634670', 'n_tokens_mistral': 3451, 'n_tokens_neox': 3402, 'n_words': 1362}