minix/llvm/passes/WeakAliasModuleOverride/WeakAliasModuleOverride.cpp

   1
   2 #include "llvm/IR/GlobalVariable.h"
   3 #include "llvm/IR/Module.h"
   4 #include "llvm/Pass.h"
   5
   6 #include "llvm/Support/raw_ostream.h"
   7 #include "llvm/Support/Regex.h"
   8
   9 using namespace llvm;
  10
  11 //#define passLog(M) (errs() << "WeakAliasModuleOverride: " << M << "\n")
  12 #define passLog(M) /* nothing */
  13
  14 namespace {
  15   class WeakAliasModuleOverride : public ModulePass {
  16
  17   public:
  18     static char ID;
  19     WeakAliasModuleOverride() : ModulePass(ID) {
  20     }
  21
  22     virtual bool runOnModule(Module &M) {
  23       const Module::FunctionListType &listFcts = M.getFunctionList();
  24       const Module::GlobalListType &listGlobalVars = M.getGlobalList();
  25
  26       std::string Asm = M.getModuleInlineAsm();
  27
  28       passLog("ASM START\n"
  29           << Asm
  30           << "ASM END\n");
  31
  32       // Filter out Function symbols
  33       for(Module::const_iterator it = listFcts.begin(), end=listFcts.end(); it!= end; ++it)
  34       {
  35         if (it->isDeclaration())
  36           continue;
  37
  38         // Filter out the assembly weak symbol as well as its default value
  39         std::string symbolName = it->getName();
  40         std::string matchWeak = "(^.weak.* " + symbolName + "\n)";
  41         std::string matchAssignement = "(^" + symbolName + " .*=.*\n)";
  42
  43         Regex filterWeak(matchWeak, Regex::Newline);
  44         Regex filterAssignement(matchAssignement, Regex::Newline);
  45
  46         while(filterWeak.match(Asm))
  47           Asm = filterWeak.sub("", Asm);
  48
  49         while(filterAssignement.match(Asm))
  50           Asm = filterAssignement.sub("", Asm);
  51       }
  52
  53       // Filter out GlobalVariable symbols
  54       for(Module::const_global_iterator it = listGlobalVars.begin(), end=listGlobalVars.end(); it!= end; ++it)
  55       {
  56         if (! it->hasInitializer())
  57           continue;
  58
  59         // Filter out the assembly weak symbol as well as its default value
  60         std::string symbolName = it->getName();
  61         std::string matchWeak = "(^.weak.* " + symbolName + "\n)";
  62         std::string matchAssignement = "(^" + symbolName + " .*=.*\n)";
  63
  64         Regex filterWeak(matchWeak, Regex::Newline);
  65         Regex filterAssignement(matchAssignement, Regex::Newline);
  66
  67         while(filterWeak.match(Asm))
  68           Asm = filterWeak.sub("", Asm);
  69
  70         while(filterAssignement.match(Asm))
  71           Asm = filterAssignement.sub("", Asm);
  72       }
  73
  74       M.setModuleInlineAsm(Asm);
  75
  76       passLog("ASM START - registered\n"
  77           << M.getModuleInlineAsm()
  78           << "ASM END\n");
  79
  80       return true;
  81     }
  82   };
  83 }
  84
  85 char WeakAliasModuleOverride::ID = 0;
  86 RegisterPass<WeakAliasModuleOverride> WEAK_ALIAS_MODULE_OVERRIDE("weak-alias-module-override", "Fix Weak Alias overrides");