From f23312294372f0b5d8da0182fce782711079a8d4 Mon Sep 17 00:00:00 2001
From: artur-zawlocki <artur.zawlocki@gmail.com>
Date: Thu, 16 Oct 2014 12:22:54 +0100
Subject: [PATCH] Added dumping of CFG to a .dot file [Delivers #80816506]

---
 evmcc/Compiler.cpp | 52 ++++++++++++++++++++++++++++++++++++++++++++++
 evmcc/Compiler.h   |  4 ++++
 evmcc/evmcc.cpp    | 18 ++++++++++++++--
 3 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/evmcc/Compiler.cpp b/evmcc/Compiler.cpp
index 77db366cf..a7e8ba483 100644
--- a/evmcc/Compiler.cpp
+++ b/evmcc/Compiler.cpp
@@ -929,6 +929,58 @@ void Compiler::linkBasicBlocks()
 	}
 }
 
+void Compiler::dumpBasicBlockGraph(std::ostream& out)
+{
+	out << "digraph BB {\n"
+	    << "  node [shape=record];\n"
+	    << "  entry [share=record, label=\"entry block\"];\n";
+
+	// std::map<std::string, BasicBlock*> blocksByName;
+	std::vector<BasicBlock*> blocks;
+	for (auto& pair : this->basicBlocks)
+	{
+		blocks.push_back(&pair.second);
+	}
+	blocks.push_back(m_jumpTableBlock.get());
+	blocks.push_back(m_badJumpBlock.get());
+
+	// Output nodes
+	for (auto bb : blocks)
+	{
+		std::string blockName = bb->llvm()->getName();
+		// blocksByName.insert(std::pair<std::string, BasicBlock*>(blockName, bb));
+
+		int numOfPhiNodes = 0;
+		auto firstNonPhiPtr = bb->llvm()->getFirstNonPHI();
+		for (auto instrIter = bb->llvm()->begin(); &*instrIter != firstNonPhiPtr; ++instrIter, ++numOfPhiNodes);
+
+		auto endStackSize = bb->getStack().size();
+
+		out << "  \"" << blockName  << "\" [shape=record, label=\""
+			<< std::to_string(numOfPhiNodes) << "|"
+			<< blockName << "|"
+			<< std::to_string(endStackSize)
+		<< "\"];\n";
+	}
+
+	out << "  entry -> \"Instr.0\";\n";
+
+	// Output edges
+	for (auto bb : blocks)
+	{
+		std::string blockName = bb->llvm()->getName();
+
+		auto end = llvm::succ_end(bb->llvm());
+		for (llvm::succ_iterator it = llvm::succ_begin(bb->llvm()); it != end; ++it)
+		{
+			std::string succName = it->getName();
+			out << "  \"" << blockName << "\" -> \"" << succName << "\";\n";
+		}
+	}
+
+	out << "}\n";
+}
+
 }
 }
 }
diff --git a/evmcc/Compiler.h b/evmcc/Compiler.h
index 1a0e61ca1..bda154689 100644
--- a/evmcc/Compiler.h
+++ b/evmcc/Compiler.h
@@ -24,6 +24,9 @@ public:
 
 	std::unique_ptr<llvm::Module> compile(const bytes& bytecode);
 
+	void dumpBasicBlockGraph(std::ostream& out);
+
+
 private:
 
 	void createBasicBlocks(const bytes& bytecode);
@@ -32,6 +35,7 @@ private:
 
 	void linkBasicBlocks();
 
+
 	llvm::IRBuilder<> m_builder;
 
 	/**
diff --git a/evmcc/evmcc.cpp b/evmcc/evmcc.cpp
index d8bf9438b..22ba1db50 100644
--- a/evmcc/evmcc.cpp
+++ b/evmcc/evmcc.cpp
@@ -1,6 +1,7 @@
 
 #include <iostream>
 #include <fstream>
+#include <ostream>
 #include <string>
 #include <vector>
 
@@ -22,6 +23,7 @@ void show_usage()
     std::cerr << "usage: evmcc (-b|-c|-d)+ <inputfile.bc>\n";
 }
 
+
 int main(int argc, char** argv)
 {
 
@@ -30,7 +32,8 @@ int main(int argc, char** argv)
     bool opt_show_bytes = false;
 	bool opt_compile = false;
 	bool opt_interpret = false;
-    bool opt_unknown = false;
+	bool opt_dump_graph = false;
+	bool opt_unknown = false;
 
     for (int i = 1; i < argc; i++)
     {
@@ -43,6 +46,8 @@ int main(int argc, char** argv)
 			opt_dissassemble = true;
 		else if (option == "-i")
 			opt_interpret = true;
+		else if (option == "-g")
+			opt_dump_graph = true;
 		else if (option[0] != '-' && input_file.empty())
 			input_file = option;
         else
@@ -89,9 +94,18 @@ int main(int argc, char** argv)
 
     if (opt_compile)
     {
-		auto module = eth::jit::Compiler().compile(bytecode);
+    	auto compiler = eth::jit::Compiler();
+		auto module = compiler.compile(bytecode);
 		llvm::raw_os_ostream out(std::cout);
 		module->print(out, nullptr);
+
+		if (opt_dump_graph)
+		{
+			std::ofstream ofs("blocks.dot");
+			compiler.dumpBasicBlockGraph(ofs);
+			ofs.close();
+			std::cout << "Basic blocks graph written to block.dot\n";
+		}
     }
 
 	if (opt_interpret)