From 6661ea505ab6562fe8738024cde9ac2be12a125d Mon Sep 17 00:00:00 2001
From: bdr7fv <bdr7fv@git.zephyr-software.com>
Date: Tue, 29 May 2012 01:55:01 +0000
Subject: [PATCH] More comment cleanup for PNTransformDriver.cpp
Former-commit-id: b785fed302e131895847afcec75f73311832f45c
---
tools/transforms/PNTransformDriver.cpp | 240 -------------------------
1 file changed, 240 deletions(-)
diff --git a/tools/transforms/PNTransformDriver.cpp b/tools/transforms/PNTransformDriver.cpp
index b737a87f5..2e803127d 100644
--- a/tools/transforms/PNTransformDriver.cpp
+++ b/tools/transforms/PNTransformDriver.cpp
@@ -1338,247 +1338,7 @@ inline bool PNTransformDriver::Instruction_Rewrite(PNStackLayout *layout, Instru
return true;
}
-/*
-//TODO: this is a naive rewrite, more analysis is needed
-//TODO: check if pmatch actually has a match
-bool PNTransformDriver::Rewrite(PNStackLayout *layout, Function_t *func)
-{
- //TODO: handle this better
- assert(layout != NULL);
- assert(func != NULL);
-
- cerr<<"PNTransformDriver: Rewriting Function = "<<func->GetName()<<endl;
-
- int max = PNRegularExpressions::MAX_MATCHES;
- regmatch_t pmatch[max];
- memset(pmatch, 0,sizeof(regmatch_t) * max);
-
- //TODO: if no stack allocation is seen before a stack access, ignore, don't abort?
-
- //rewrite instructions
- bool stack_alloc = false;
- for(
- set<Instruction_t*>::const_iterator it=func->GetInstructions().begin();
- it!=func->GetInstructions().end();
- ++it
- )
- {
- Instruction_t* instr=*it;
- string matched ="";
- string disasm_str = "";
- DISASM disasm;
-
- instr->Disassemble(disasm);
- disasm_str = disasm.CompleteInstr;
-
- cerr << "PNTransformDriver: Looking at Instruction = " << disasm_str << endl;
-
- //the disassmebly of lea has extra tokens not accepted by nasm, remove those tokens
- if(regexec(&(pn_regex.regex_lea_hack), disasm_str.c_str(), max, pmatch, 0)==0)
- {
- cerr<<"PNTransformDriver: Transforming LEA Instruction"<<endl;
- matched = "";
- for (int k = 1; k < 5; ++k)
- {
- if (pmatch[k].rm_so >= 0 && pmatch[k].rm_eo >= 0)
- {
- int mlen = pmatch[k].rm_eo - pmatch[k].rm_so;
- matched.append(disasm_str.substr(pmatch[k].rm_so,mlen));
- }
- }
- disasm_str = matched;
- cerr<<"PNTransformDriver: New LEA Instruction = "<<disasm_str<<endl;
- matched = "";
- }
-
-
- if(regexec(&(pn_regex.regex_stack_alloc), disasm_str.c_str(), 5, pmatch, 0)==0)
- {
- cerr << "PNTransformDriver: Transforming Stack Alloc"<<endl;
-
- //TODO: what should I do in this case?
- //TODO: transform the instruction but never decrease the size of the allocation
- if(stack_alloc)
- {
- cerr <<"PNTransformDriver: Stack Alloc Previously Found, Ignoring Instruction"<<endl;
- continue;
- }
-
- stringstream ss;
- ss << hex << layout->GetAlteredAllocSize();
-
- disasm_str = "sub esp, 0x"+ss.str();
-
- cerr<<"PNTransformDriver: New Instruction = "<<disasm_str<<endl;
- undo_list[instr] = instr->GetDataBits();
- if(!instr->Assemble(disasm_str))
- return false;
-
- stack_alloc = true;
- }
- else if(regexec(&(pn_regex.regex_esp_only), disasm_str.c_str(), max, pmatch, 0)==0)
- {
- cerr<<"PNTransformDriver: Transforming ESP Only Instruction ([esp])"<<endl;
-
- PNRange *closest = layout->GetClosestRangeESP(0);
-
- if(closest == NULL)
- {
- //There should always be a closet range to esp+0
- assert(false);
- }
-
- int new_offset = closest->GetDisplacement();
-
- assert(new_offset >= 0);
-
- if(new_offset == 0)
- {
- cerr<<"PNTransformDriver: Displacement of [esp] is Zero, Ignoring Transformation"<<endl;
- continue;
- }
-
- stringstream ss;
- ss<<hex<<new_offset;
-
- matched = "esp+0x"+ss.str();
- int mlen = pmatch[1].rm_eo - pmatch[1].rm_so;
- disasm_str.replace(pmatch[1].rm_so,mlen,matched);
-
- cerr<<"PNTransformDriver: New Instruction = "<<disasm_str<<endl;
- undo_list[instr] = instr->GetDataBits();
- if(!instr->Assemble(disasm_str.c_str()))
- return false;
-
- }
-//TODO: the regular expression order does matter, scaled must come first, change the regex so this doesn't matter
- else if(regexec(&(pn_regex.regex_esp_scaled), disasm_str.c_str(), 5, pmatch, 0)==0 ||
- regexec(&(pn_regex.regex_esp_direct), disasm_str.c_str(), 5, pmatch, 0)==0)
- {
- cerr<<"PNTransformDriver: Transforming ESP Relative Instruction"<<endl;
- int mlen = pmatch[1].rm_eo - pmatch[1].rm_so;
- matched = disasm_str.substr(pmatch[1].rm_so,mlen);
-
- // extract displacement
- int offset = strtol(matched.c_str(),NULL,0);
-
- //TODO: I don't think this can happen but just in case
- assert(offset >= 0);
-
- int new_offset = layout->GetNewOffsetESP(offset);
-
- stringstream ss;
- ss<<hex<<new_offset;
-
- matched = "0x"+ss.str();
-
- disasm_str.replace(pmatch[1].rm_so,mlen,matched);
-
- cerr<<"PNTransformDriver: New Instruction = "<<disasm_str<<endl;
- undo_list[instr] = instr->GetDataBits();
- if(!instr->Assemble(disasm_str.c_str()))
- return false;
- }
- //TODO: the regular expression order does matter, scaled must come first, change the regex so this doesn't matter
- else if(regexec(&(pn_regex.regex_ebp_scaled), disasm_str.c_str(), 5, pmatch, 0)==0 ||
- regexec(&(pn_regex.regex_ebp_direct), disasm_str.c_str(), 5, pmatch, 0)==0)
- {
- cerr<<"PNTransformDriver: Transforming EBP Relative Instruction"<<endl;
-
- int mlen = pmatch[1].rm_eo - pmatch[1].rm_so;
- matched = disasm_str.substr(pmatch[1].rm_so,mlen);
-
- // extract displacement
- int offset = strtol(matched.c_str(),NULL,0);
-
- cerr<<"PNTransformDriver: Offset = "<<offset<<endl;
-
- int new_offset = layout->GetNewOffsetEBP(offset);
-
- if(new_offset == offset)
- {
- cerr<<"PNTransformDriver: No offset transformation necessary, skipping instruction"<<endl;
- continue;
- }
-
- stringstream ss;
- ss<<hex<<new_offset;
-
- matched = "0x"+ss.str();
-
- disasm_str.replace(pmatch[1].rm_so,mlen,matched);
-
- cerr<<"PNTransformDriver: New Instruction = "<<disasm_str<<endl;
- undo_list[instr] = instr->GetDataBits();
- if(!instr->Assemble(disasm_str.c_str()))
- return false;
-
- }
-
- else if(regexec(&(pn_regex.regex_stack_dealloc), disasm_str.c_str(), 5, pmatch, 0)==0)
- {
- cerr<<"PNTransformDriver: Transforming Stack Dealloc Instruction"<<endl;
-
- //Check if the dealloc amount is 0. In unoptimized code, sometimes the
- //compiler will reset esp, and then add 0 to esp
- //In this case, do not deallocate the stack
-
- int mlen = pmatch[1].rm_eo - pmatch[1].rm_so;
- matched = disasm_str.substr(pmatch[1].rm_so,mlen);
-
- // extract displacement
- int offset = strtol(matched.c_str(),NULL,0);
-
- cerr<<"PNTransformDriver: Dealloc Amount = "<<offset<<endl;
-
- if(offset == 0)
- {
- cerr<<"PNTransformDriver: Dealloc of 0 detected, ignoring instruction"<<endl;
- continue;
- }
-
- stringstream ss;
- ss << hex <<layout->GetAlteredAllocSize();
-
- disasm_str = "add esp, 0x"+ss.str();
-
- undo_list[instr] = instr->GetDataBits();
- cerr<<"PNTransformDriver: New Instruction = "<<disasm_str<<endl;
- if (!instr->Assemble(disasm_str))
- return false;
- }
- else
- cerr<<"PNTransformDriver: No Pattern Match"<<endl;
- }
-
- //If you get here assume the transform was successfully made
- return true;
-}
-
-*/
-
- /*
-void PNTransformDriver::undo(map<Instruction_t*, string> undo_list, Function_t *func)
-{
- //rollback any changes
- cerr<<"PNTransformDriver: Undo Transform: "<<undo_list.size()<<" instructions to rollback for function "<<func->GetName()<<endl;
- for(
- map<Instruction_t*, std::string>::const_iterator mit=undo_list.begin();
- mit != undo_list.end();
- ++mit)
- {
- Instruction_t* insn = mit->first;
- std::string dataBits = mit->second;
-
- DISASM disasm;
- insn->Disassemble(disasm);
- insn->SetDataBits(dataBits);
- }
-
- undo_list.clear();
-}
-*/
//TODO: there is a memory leak, I need to write a undo_list clear to properly cleanup
//void PNTransformDriver::undo(map<Instruction_t*, Instruction_t*> undo_list, Function_t *func)
--
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