From c03229e60058cc823253fc310ded77926849515a Mon Sep 17 00:00:00 2001
From: Lionel Sambuc <lionel@minix3.org>
Date: Fri, 7 Mar 2014 15:06:33 +0100
Subject: [PATCH] LLVM Passe which fixes weak aliases overriden from bitcode

---
 .../passes/WeakAliasModuleOverride/Makefile   | 26 ++++++
 .../WeakAliasModuleOverride.cpp               | 86 +++++++++++++++++++
 2 files changed, 112 insertions(+)
 create mode 100644 external/bsd/llvm/passes/WeakAliasModuleOverride/Makefile
 create mode 100644 external/bsd/llvm/passes/WeakAliasModuleOverride/WeakAliasModuleOverride.cpp

diff --git a/external/bsd/llvm/passes/WeakAliasModuleOverride/Makefile b/external/bsd/llvm/passes/WeakAliasModuleOverride/Makefile
new file mode 100644
index 000000000..000d77cbb
--- /dev/null
+++ b/external/bsd/llvm/passes/WeakAliasModuleOverride/Makefile
@@ -0,0 +1,26 @@
+QUIET=@
+ECHO=echo
+CP=cp
+
+PASSLIBNAME:= WeakAliasModuleOverride.so
+
+LLVM_VERSION = $($LLVMPREFIX/bin/llvm-config --version | sed "s/[^0-9]//g")
+CFLAGS  += -Wno-long-long -Wall -W -Wno-unused-parameter -Wwrite-strings -DHAVE_EXCEPTIONS=0
+CFLAGS  += $(shell $(LLVMPREFIX)/bin/llvm-config --cxxflags) -g -DLLVM_VERSION=$(LLVM_VERSION)
+LDFLAGS += $(shell $(LLVMPREFIX)/bin/llvm-config --ldflags)
+OBJS= WeakAliasModuleOverride.o
+
+$(PASSLIBNAME): $(OBJS)
+	$(QUIET) $(ECHO) "  [LINK] $@"
+	$(QUIET) $(CXX) $(CFLAGS) -shared -o $@ $(CPPS) $(OBJS) $(LDFLAGS) $(LIBS)
+
+%.o: %.cpp $(HEADERS)
+	$(QUIET) $(ECHO)  "  [C++] $<"
+	$(QUIET) $(CXX) $(CFLAGS) $(INCLUDES) -c -o $@ $<
+
+install: $(PASSLIBNAME)
+	$(QUIET) -mkdir -p ../lib
+	$(QUIET) $(CP)  $(PASSLIBNAME) ../lib/$(PASSLIBNAME)
+
+clean:
+	-rm -f *.o *.so
diff --git a/external/bsd/llvm/passes/WeakAliasModuleOverride/WeakAliasModuleOverride.cpp b/external/bsd/llvm/passes/WeakAliasModuleOverride/WeakAliasModuleOverride.cpp
new file mode 100644
index 000000000..0d3a15120
--- /dev/null
+++ b/external/bsd/llvm/passes/WeakAliasModuleOverride/WeakAliasModuleOverride.cpp
@@ -0,0 +1,86 @@
+
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Regex.h"
+
+using namespace llvm;
+
+//#define passLog(M) (errs() << "WeakAliasModuleOverride: " << M << "\n")
+#define passLog(M) /* nothing */
+
+namespace {
+  class WeakAliasModuleOverride : public ModulePass {
+
+  public:
+    static char ID;
+    WeakAliasModuleOverride() : ModulePass(ID) {
+    }
+
+    virtual bool runOnModule(Module &M) {
+      const Module::FunctionListType &listFcts = M.getFunctionList();
+      const Module::GlobalListType &listGlobalVars = M.getGlobalList();
+
+      std::string Asm = M.getModuleInlineAsm();
+
+      passLog("ASM START\n"
+	  << Asm
+	  << "ASM END\n");
+
+      // Filter out Function symbols
+      for(Module::const_iterator it = listFcts.begin(), end=listFcts.end(); it!= end; ++it)
+      {
+	if (it->isDeclaration())
+	  continue;
+
+	// Filter out the assembly weak symbol as well as its default value
+        std::string symbolName = it->getName();
+        std::string matchWeak = "(^.weak.* " + symbolName + "\n)";
+        std::string matchAssignement = "(^" + symbolName + " .*=.*\n)";
+
+        Regex filterWeak(matchWeak, Regex::Newline);
+        Regex filterAssignement(matchAssignement, Regex::Newline);
+
+        while(filterWeak.match(Asm))
+          Asm = filterWeak.sub("", Asm);
+
+        while(filterAssignement.match(Asm))
+          Asm = filterAssignement.sub("", Asm);
+      }
+
+      // Filter out GlobalVariable symbols
+      for(Module::const_global_iterator it = listGlobalVars.begin(), end=listGlobalVars.end(); it!= end; ++it)
+      {
+	if (! it->hasInitializer())
+	  continue;
+
+	// Filter out the assembly weak symbol as well as its default value
+        std::string symbolName = it->getName();
+        std::string matchWeak = "(^.weak.* " + symbolName + "\n)";
+        std::string matchAssignement = "(^" + symbolName + " .*=.*\n)";
+
+        Regex filterWeak(matchWeak, Regex::Newline);
+        Regex filterAssignement(matchAssignement, Regex::Newline);
+
+        while(filterWeak.match(Asm))
+          Asm = filterWeak.sub("", Asm);
+
+        while(filterAssignement.match(Asm))
+          Asm = filterAssignement.sub("", Asm);
+      }
+
+      M.setModuleInlineAsm(Asm);
+
+      passLog("ASM START - registered\n"
+	  << M.getModuleInlineAsm()
+	  << "ASM END\n");
+
+      return true;
+    }
+  };
+}
+
+char WeakAliasModuleOverride::ID = 0;
+RegisterPass<WeakAliasModuleOverride> WEAK_ALIAS_MODULE_OVERRIDE("weak-alias-module-override", "Fix Weak Alias overrides");
-- 
2.44.0