ninja.cc - platform/build/kati - Gitiles

 // Copyright 2015 Google Inc. All rights reserved
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 // +build ignore

 #include "ninja.h"

 #include <stdio.h>
 #include <sys/stat.h>
 #include <unistd.h>

 #include <map>
 #include <memory>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>

 #include "command.h"
 #include "dep.h"
 #include "eval.h"
 #include "file_cache.h"
 #include "fileutil.h"
 #include "flags.h"
 #include "log.h"
 #include "string_piece.h"
 #include "stringprintf.h"
 #include "strutil.h"
 #include "var.h"
 #include "version.h"

 static size_t FindCommandLineFlag(StringPiece cmd, StringPiece name) {
   const size_t found = cmd.find(name);
   if (found == string::npos || found == 0)
     return string::npos;
   return found;
 }

 static StringPiece FindCommandLineFlagWithArg(StringPiece cmd,
                                               StringPiece name) {
   size_t index = FindCommandLineFlag(cmd, name);
   if (index == string::npos)
     return StringPiece();

   StringPiece val = TrimLeftSpace(cmd.substr(index + name.size()));
   index = val.find(name);
   while (index != string::npos) {
     val = TrimLeftSpace(val.substr(index + name.size()));
     index = val.find(name);
   }

   index = val.find_first_of(" \t");
   return val.substr(0, index);
 }

 static bool StripPrefix(StringPiece p, StringPiece* s) {
   if (!HasPrefix(*s, p))
     return false;
   *s = s->substr(p.size());
   return true;
 }

 size_t GetGomaccPosForAndroidCompileCommand(StringPiece cmdline) {
   size_t index = cmdline.find(' ');
   if (index == string::npos)
     return string::npos;
   StringPiece cmd = cmdline.substr(0, index);
   if (HasSuffix(cmd, "ccache")) {
     index++;
     size_t pos = GetGomaccPosForAndroidCompileCommand(cmdline.substr(index));
     return pos == string::npos ? string::npos : pos + index;
   }
   if (!StripPrefix("prebuilts/", &cmd))
     return string::npos;
   if (!StripPrefix("gcc/", &cmd) && !StripPrefix("clang/", &cmd))
     return string::npos;
   if (!HasSuffix(cmd, "gcc") && !HasSuffix(cmd, "g++") &&
       !HasSuffix(cmd, "clang") && !HasSuffix(cmd, "clang++")) {
     return string::npos;
   }

   StringPiece rest = cmdline.substr(index);
   return rest.find(" -c ") != string::npos ? 0 : string::npos;
 }

 static bool GetDepfileFromCommandImpl(StringPiece cmd, string* out) {
   if ((FindCommandLineFlag(cmd, " -MD") == string::npos &&
        FindCommandLineFlag(cmd, " -MMD") == string::npos) ||
       FindCommandLineFlag(cmd, " -c") == string::npos) {
     return false;
   }

   StringPiece mf = FindCommandLineFlagWithArg(cmd, " -MF");
   if (!mf.empty()) {
     mf.AppendToString(out);
     return true;
   }

   StringPiece o = FindCommandLineFlagWithArg(cmd, " -o");
   if (o.empty()) {
     ERROR("Cannot find the depfile in %s", cmd.as_string().c_str());
     return false;
   }

   StripExt(o).AppendToString(out);
   *out += ".d";
   return true;
 }

 bool GetDepfileFromCommand(string* cmd, string* out) {
   CHECK(!cmd->empty());
   if (!GetDepfileFromCommandImpl(*cmd, out))
     return false;

   // A hack for Android - llvm-rs-cc seems not to emit a dep file.
   if (cmd->find("bin/llvm-rs-cc ") != string::npos) {
     return false;
   }

   // TODO: A hack for Makefiles generated by automake.

   // A hack for Android to get .P files instead of .d.
   string p;
   StripExt(*out).AppendToString(&p);
   p += ".P";
   if (cmd->find(p) != string::npos) {
     const string rm_f = "; rm -f " + *out;
     const size_t found = cmd->find(rm_f);
     if (found == string::npos) {
       ERROR("Cannot find removal of .d file: %s", cmd->c_str());
     }
     cmd->erase(found, rm_f.size());
     return true;
   }

   // A hack for Android. For .s files, GCC does not use C
   // preprocessor, so it ignores -MF flag.
   string as = "/";
   StripExt(Basename(*out)).AppendToString(&as);
   as += ".s";
   if (cmd->find(as) != string::npos) {
     return false;
   }

   *cmd += "&& cp ";
   *cmd += *out;
   *cmd += ' ';
   *cmd += *out;
   *cmd += ".tmp ";
   *out += ".tmp";
   return true;
 }

 class NinjaGenerator {
  public:
   NinjaGenerator(const char* ninja_suffix, const char* ninja_dir, Evaluator* ev)
       : ce_(ev), ev_(ev), fp_(NULL), rule_id_(0) {
     ev_->set_avoid_io(true);
     shell_ = ev->EvalVar(kShellSym);
     if (g_goma_dir)
       gomacc_ = StringPrintf("%s/gomacc ", g_goma_dir);
     if (ninja_suffix) {
       ninja_suffix_ = ninja_suffix;
     }
     if (ninja_dir) {
       ninja_dir_ = ninja_dir;
     } else {
       ninja_dir_ = ".";
     }

     for (Symbol e : Vars::used_env_vars()) {
       shared_ptr<string> val = ev_->EvalVar(e);
       used_envs_.emplace(e.str(), *val);
     }

     if (g_gen_regen_rule)
       GetExecutablePath(&kati_binary_);
   }

   ~NinjaGenerator() {
     ev_->set_avoid_io(false);
   }

   void Generate(const vector<DepNode*>& nodes,
                 bool build_all_targets,
                 const string& orig_args) {
     GenerateEnvlist();
     GenerateNinja(nodes, build_all_targets, orig_args);
     GenerateShell();
   }

  private:
   string GenRuleName() {
     return StringPrintf("rule%d", rule_id_++);
   }

   StringPiece TranslateCommand(const char* in, string* cmd_buf) {
     const size_t orig_size = cmd_buf->size();
     bool prev_backslash = false;
     // Set space as an initial value so the leading comment will be
     // stripped out.
     char prev_char = ' ';
     char quote = 0;
     for (; *in; in++) {
       switch (*in) {
         case '#':
           if (quote == 0 && isspace(prev_char)) {
             while (in[1] && *in != '\n')
               in++;
           } else {
             *cmd_buf += *in;
           }
           break;

         case '\'':
         case '"':
         case '`':
           if (quote) {
             if (quote == *in)
               quote = 0;
           } else if (!prev_backslash) {
             quote = *in;
           }
           *cmd_buf += *in;
           break;

         case '$':
           *cmd_buf += "$$";
           break;

         case '\n':
           if (prev_backslash) {
             cmd_buf->resize(cmd_buf->size()-1);
           } else {
             *cmd_buf += ' ';
           }
           break;

         case '\\':
           *cmd_buf += '\\';
           break;

         default:
           *cmd_buf += *in;
       }

       if (*in == '\\') {
         prev_backslash = !prev_backslash;
       } else {
         prev_backslash = false;
       }

       prev_char = *in;
     }

     while (true) {
       char c = (*cmd_buf)[cmd_buf->size()-1];
       if (!isspace(c) && c != ';')
         break;
       cmd_buf->resize(cmd_buf->size() - 1);
     }

     return StringPiece(cmd_buf->data() + orig_size,
                        cmd_buf->size() - orig_size);
   }

   bool GetDescriptionFromCommand(StringPiece cmd, string *out) {
     if (!HasPrefix(cmd, "echo ")) {
       return false;
     }
     cmd = cmd.substr(5, cmd.size());

     bool prev_backslash = false;
     char quote = 0;
     string out_buf;

     // Strip outer quotes, and fail if it is not a single echo command
     for (StringPiece::iterator in = cmd.begin(); in != cmd.end(); in++) {
       if (prev_backslash) {
         prev_backslash = false;
         out_buf += *in;
       } else if (*in == '\\') {
         prev_backslash = true;
         out_buf += *in;
       } else if (quote) {
         if (*in == quote) {
           quote = 0;
         } else {
           out_buf += *in;
         }
       } else {
         switch (*in) {
         case '\'':
         case '"':
         case '`':
           quote = *in;
           break;

         case '<':
         case '>':
         case '&':
         case '|':
         case ';':
           return false;

         default:
           out_buf += *in;
         }
       }
     }

     *out = out_buf;
     return true;
   }

   bool GenShellScript(const vector<Command*>& commands,
                       string* cmd_buf,
                       string* description) {
     bool got_descritpion = false;
     bool use_gomacc = false;
     bool should_ignore_error = false;
     for (const Command* c : commands) {
       if (!cmd_buf->empty()) {
         if (should_ignore_error) {
           *cmd_buf += " ; ";
         } else {
           *cmd_buf += " && ";
         }
       }
       should_ignore_error = c->ignore_error;

       const char* in = c->cmd->c_str();
       while (isspace(*in))
         in++;

       bool needs_subshell = commands.size() > 1;
       if (*in == '(') {
         needs_subshell = false;
       }

       if (needs_subshell)
         *cmd_buf += '(';

       size_t cmd_start = cmd_buf->size();
       StringPiece translated = TranslateCommand(in, cmd_buf);
       if (g_detect_android_echo && !got_descritpion && !c->echo &&
           GetDescriptionFromCommand(translated, description)) {
         got_descritpion = true;
         cmd_buf->resize(cmd_start);
         translated.clear();
       }
       if (translated.empty()) {
         *cmd_buf += "true";
       } else if (g_goma_dir) {
         size_t pos = GetGomaccPosForAndroidCompileCommand(translated);
         if (pos != string::npos) {
           cmd_buf->insert(cmd_start + pos, gomacc_);
           use_gomacc = true;
         }
       }

       if (c == commands.back() && c->ignore_error) {
         *cmd_buf += " ; true";
       }

       if (needs_subshell)
         *cmd_buf += ')';
     }
     return g_goma_dir && !use_gomacc;
   }

   void EmitDepfile(string* cmd_buf) {
     *cmd_buf += ' ';
     string depfile;
     bool result = GetDepfileFromCommand(cmd_buf, &depfile);
     cmd_buf->resize(cmd_buf->size()-1);
     if (!result)
       return;
     fprintf(fp_, " depfile = %s\n", depfile.c_str());
     fprintf(fp_, " deps = gcc\n");
   }

   void EmitNode(DepNode* node) {
     auto p = done_.insert(node->output);
     if (!p.second)
       return;

     // Removing this will fix auto_vars.mk, build_once.mk, and
     // command_vars.mk. However, this change will make
     // ninja_normalized_path2.mk fail and cause a lot of warnings for
     // Android build.
     if (node->cmds.empty() &&
         node->deps.empty() && node->order_onlys.empty() && !node->is_phony) {
       return;
     }

     StringPiece base = Basename(node->output.str());
     if (base != node->output.str()) {
       auto p = short_names_.emplace(Intern(base), node->output);
       if (!p.second) {
         // We generate shortcuts only for targets whose basename are unique.
         p.first->second = kEmptySym;
       }
     }

     vector<Command*> commands;
     ce_.Eval(node, &commands);

     string rule_name = "phony";
     bool use_local_pool = false;
     if (!commands.empty()) {
       rule_name = GenRuleName();
       fprintf(fp_, "rule %s\n", rule_name.c_str());

       string description = "build $out";
       string cmd_buf;
       use_local_pool |= GenShellScript(commands, &cmd_buf, &description);
       fprintf(fp_, " description = %s\n", description.c_str());
       EmitDepfile(&cmd_buf);

       // It seems Linux is OK with ~130kB and Mac's limit is ~250kB.
       // TODO: Find this number automatically.
       if (cmd_buf.size() > 100 * 1000) {
         fprintf(fp_, " rspfile = $out.rsp\n");
         fprintf(fp_, " rspfile_content = %s\n", cmd_buf.c_str());
         fprintf(fp_, " command = %s $out.rsp\n", shell_->c_str());
       } else {
         fprintf(fp_, " command = %s -c \"%s\"\n",
                 shell_->c_str(), EscapeShell(cmd_buf).c_str());
       }
     }

     EmitBuild(node, rule_name);
     if (use_local_pool)
       fprintf(fp_, " pool = local_pool\n");

     for (DepNode* d : node->deps) {
       EmitNode(d);
     }
     for (DepNode* d : node->order_onlys) {
       EmitNode(d);
     }
   }

   string EscapeBuildTarget(Symbol s) {
     if (s.str().find_first_of("$: ") == string::npos)
       return s.str();
     string r;
     for (char c : s.str()) {
       switch (c) {
         case '$':
         case ':':
         case ' ':
           r += '$';
           // fall through.
         default:
           r += c;
       }
     }
     return r;
   }

   string EscapeShell(string s) {
     if (s.find_first_of("$`!\\\"") == string::npos)
       return s;
     string r;
     bool lastDollar = false;
     for (char c : s) {
       switch (c) {
         case '$':
           if (lastDollar) {
             r += c;
             lastDollar = false;
           } else {
             r += '\\';
             r += c;
             lastDollar = true;
           }
           break;
         case '`':
         case '"':
         case '!':
         case '\\':
           r += '\\';
           // fall through.
         default:
           r += c;
           lastDollar = false;
       }
     }
     return r;
   }

   void EmitBuild(DepNode* node, const string& rule_name) {
     fprintf(fp_, "build %s: %s",
             EscapeBuildTarget(node->output).c_str(),
             rule_name.c_str());
     vector<Symbol> order_onlys;
     for (DepNode* d : node->deps) {
       fprintf(fp_, " %s", EscapeBuildTarget(d->output).c_str());
     }
     if (!node->order_onlys.empty()) {
       fprintf(fp_, " ||");
       for (DepNode* d : node->order_onlys) {
         fprintf(fp_, " %s", EscapeBuildTarget(d->output).c_str());
       }
     }
     fprintf(fp_, "\n");
   }

   void EmitRegenRules(const string& orig_args) {
     if (!g_gen_regen_rule)
       return;

     fprintf(fp_, "rule regen_ninja\n");
     fprintf(fp_, " command = %s\n", orig_args.c_str());
     fprintf(fp_, " generator = 1\n");
     fprintf(fp_, " description = Regenerate ninja files due to dependency\n");
     fprintf(fp_, "build %s: regen_ninja", GetNinjaFilename().c_str());
     unordered_set<string> makefiles;
     MakefileCacheManager::Get()->GetAllFilenames(&makefiles);
     for (const string& makefile : makefiles) {
       fprintf(fp_, " %.*s", SPF(makefile));
     }
     fprintf(fp_, " %s", kati_binary_.c_str());
     // TODO: Add dependencies to directories read by $(wildcard)
     // or $(shell find).
     if (!used_envs_.empty())
       fprintf(fp_, " %s", GetEnvlistFilename().c_str());
     fprintf(fp_, "\n\n");
   }

   string GetNinjaFilename() const {
     return StringPrintf("%s/build%s.ninja",
                         ninja_dir_.c_str(), ninja_suffix_.c_str());
   }

   string GetShellScriptFilename() const {
     return StringPrintf("%s/ninja%s.sh",
                         ninja_dir_.c_str(), ninja_suffix_.c_str());
   }

   string GetEnvlistFilename() const {
     return StringPrintf("%s/.kati_env%s",
                         ninja_dir_.c_str(), ninja_suffix_.c_str());
   }

   string GetLunchFilename() const {
     return StringPrintf("%s/.kati_lunch%s",
                         ninja_dir_.c_str(), ninja_suffix_.c_str());
   }

   void GenerateNinja(const vector<DepNode*>& nodes,
                      bool build_all_targets,
                      const string& orig_args) {
     fp_ = fopen(GetNinjaFilename().c_str(), "wb");
     if (fp_ == NULL)
       PERROR("fopen(build.ninja) failed");

     fprintf(fp_, "# Generated by kati %s\n", kGitVersion);
     fprintf(fp_, "\n");

     if (!used_envs_.empty()) {
       fprintf(fp_, "# Environment variables used:\n");
       for (const auto& p : used_envs_) {
         fprintf(fp_, "# %s=%s\n", p.first.c_str(), p.second.c_str());
       }
       fprintf(fp_, "\n");
     }

     if (g_goma_dir) {
       fprintf(fp_, "pool local_pool\n");
       fprintf(fp_, " depth = %d\n\n", g_num_jobs);
     }

     EmitRegenRules(orig_args);

     for (DepNode* node : nodes) {
       EmitNode(node);
     }

     if (!build_all_targets) {
       CHECK(!nodes.empty());
       fprintf(fp_, "\ndefault %s\n",
               EscapeBuildTarget(nodes.front()->output).c_str());
     }

     fprintf(fp_, "\n# shortcuts:\n");
     for (auto p : short_names_) {
       if (!p.second.empty() && !done_.count(p.first))
         fprintf(fp_, "build %s: phony %s\n", p.first.c_str(), p.second.c_str());
     }

     fclose(fp_);
   }

   void GenerateShell() {
     FILE* fp = fopen(GetShellScriptFilename().c_str(), "wb");
     if (fp == NULL)
       PERROR("fopen(ninja.sh) failed");

     fprintf(fp, "#!/bin/sh\n");
     fprintf(fp, "# Generated by kati %s\n", kGitVersion);
     fprintf(fp, "\n");
     if (ninja_dir_ == ".")
       fprintf(fp, "cd $(dirname \"$0\")\n");
     if (!ninja_suffix_.empty()) {
       fprintf(fp, "if [ -f %s ]; then\n export $(cat %s)\nfi\n",
               GetEnvlistFilename().c_str(), GetEnvlistFilename().c_str());
       fprintf(fp, "if [ -f %s ]; then\n export $(cat %s)\nfi\n",
               GetLunchFilename().c_str(), GetLunchFilename().c_str());
     }

     for (const auto& p : ev_->exports()) {
       if (p.second) {
         shared_ptr<string> val = ev_->EvalVar(p.first);
         fprintf(fp, "export '%s'='%s'\n", p.first.c_str(), val->c_str());
       } else {
         fprintf(fp, "unset '%s'\n", p.first.c_str());
       }
     }

     fprintf(fp, "exec ninja -f %s ", GetNinjaFilename().c_str());
     if (g_goma_dir) {
       fprintf(fp, "-j500 ");
     }
     fprintf(fp, "\"$@\"\n");

     if (chmod(GetShellScriptFilename().c_str(), 0755) != 0)
       PERROR("chmod ninja.sh failed");
   }

   void GenerateEnvlist() {
     if (used_envs_.empty())
       return;
     FILE* fp = fopen(GetEnvlistFilename().c_str(), "wb");
     for (const auto& p : used_envs_) {
       fprintf(fp, "%s=%s\n", p.first.c_str(), p.second.c_str());
     }
     fclose(fp);
   }

   CommandEvaluator ce_;
   Evaluator* ev_;
   FILE* fp_;
   unordered_set<Symbol> done_;
   int rule_id_;
   string gomacc_;
   string ninja_suffix_;
   string ninja_dir_;
   unordered_map<Symbol, Symbol> short_names_;
   shared_ptr<string> shell_;
   map<string, string> used_envs_;
   string kati_binary_;
 };

 void GenerateNinja(const char* ninja_suffix,
                    const char* ninja_dir,
                    const vector<DepNode*>& nodes,
                    Evaluator* ev,
                    bool build_all_targets,
                    const string& orig_args) {
   NinjaGenerator ng(ninja_suffix, ninja_dir, ev);
   ng.Generate(nodes, build_all_targets, orig_args);
 }
	// Copyright 2015 Google Inc. All rights reserved
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	// +build ignore

	#include "ninja.h"

	#include <stdio.h>
	#include <sys/stat.h>
	#include <unistd.h>

	#include <map>
	#include <memory>
	#include <string>
	#include <unordered_map>
	#include <unordered_set>

	#include "command.h"
	#include "dep.h"
	#include "eval.h"
	#include "file_cache.h"
	#include "fileutil.h"
	#include "flags.h"
	#include "log.h"
	#include "string_piece.h"
	#include "stringprintf.h"
	#include "strutil.h"
	#include "var.h"
	#include "version.h"

	static size_t FindCommandLineFlag(StringPiece cmd, StringPiece name) {
	const size_t found = cmd.find(name);
	if (found == string::npos \|\| found == 0)
	return string::npos;
	return found;
	}

	static StringPiece FindCommandLineFlagWithArg(StringPiece cmd,
	StringPiece name) {
	size_t index = FindCommandLineFlag(cmd, name);
	if (index == string::npos)
	return StringPiece();

	StringPiece val = TrimLeftSpace(cmd.substr(index + name.size()));
	index = val.find(name);
	while (index != string::npos) {
	val = TrimLeftSpace(val.substr(index + name.size()));
	index = val.find(name);
	}

	index = val.find_first_of(" \t");
	return val.substr(0, index);
	}

	static bool StripPrefix(StringPiece p, StringPiece* s) {
	if (!HasPrefix(*s, p))
	return false;
	*s = s->substr(p.size());
	return true;
	}

	size_t GetGomaccPosForAndroidCompileCommand(StringPiece cmdline) {
	size_t index = cmdline.find(' ');
	if (index == string::npos)
	return string::npos;
	StringPiece cmd = cmdline.substr(0, index);
	if (HasSuffix(cmd, "ccache")) {
	index++;
	size_t pos = GetGomaccPosForAndroidCompileCommand(cmdline.substr(index));
	return pos == string::npos ? string::npos : pos + index;
	}
	if (!StripPrefix("prebuilts/", &cmd))
	return string::npos;
	if (!StripPrefix("gcc/", &cmd) && !StripPrefix("clang/", &cmd))
	return string::npos;
	if (!HasSuffix(cmd, "gcc") && !HasSuffix(cmd, "g++") &&
	!HasSuffix(cmd, "clang") && !HasSuffix(cmd, "clang++")) {
	return string::npos;
	}

	StringPiece rest = cmdline.substr(index);
	return rest.find(" -c ") != string::npos ? 0 : string::npos;
	}

	static bool GetDepfileFromCommandImpl(StringPiece cmd, string* out) {
	if ((FindCommandLineFlag(cmd, " -MD") == string::npos &&
	FindCommandLineFlag(cmd, " -MMD") == string::npos) \|\|
	FindCommandLineFlag(cmd, " -c") == string::npos) {
	return false;
	}

	StringPiece mf = FindCommandLineFlagWithArg(cmd, " -MF");
	if (!mf.empty()) {
	mf.AppendToString(out);
	return true;
	}

	StringPiece o = FindCommandLineFlagWithArg(cmd, " -o");
	if (o.empty()) {
	ERROR("Cannot find the depfile in %s", cmd.as_string().c_str());
	return false;
	}

	StripExt(o).AppendToString(out);
	*out += ".d";
	return true;
	}

	bool GetDepfileFromCommand(string* cmd, string* out) {
	CHECK(!cmd->empty());
	if (!GetDepfileFromCommandImpl(*cmd, out))
	return false;

	// A hack for Android - llvm-rs-cc seems not to emit a dep file.
	if (cmd->find("bin/llvm-rs-cc ") != string::npos) {
	return false;
	}

	// TODO: A hack for Makefiles generated by automake.

	// A hack for Android to get .P files instead of .d.
	string p;
	StripExt(*out).AppendToString(&p);
	p += ".P";
	if (cmd->find(p) != string::npos) {
	const string rm_f = "; rm -f " + *out;
	const size_t found = cmd->find(rm_f);
	if (found == string::npos) {
	ERROR("Cannot find removal of .d file: %s", cmd->c_str());
	}
	cmd->erase(found, rm_f.size());
	return true;
	}

	// A hack for Android. For .s files, GCC does not use C
	// preprocessor, so it ignores -MF flag.
	string as = "/";
	StripExt(Basename(*out)).AppendToString(&as);
	as += ".s";
	if (cmd->find(as) != string::npos) {
	return false;
	}

	*cmd += "&& cp ";
	cmd += out;
	*cmd += ' ';
	cmd += out;
	*cmd += ".tmp ";
	*out += ".tmp";
	return true;
	}

	class NinjaGenerator {
	public:
	NinjaGenerator(const char* ninja_suffix, const char* ninja_dir, Evaluator* ev)
	: ce_(ev), ev_(ev), fp_(NULL), rule_id_(0) {
	ev_->set_avoid_io(true);
	shell_ = ev->EvalVar(kShellSym);
	if (g_goma_dir)
	gomacc_ = StringPrintf("%s/gomacc ", g_goma_dir);
	if (ninja_suffix) {
	ninja_suffix_ = ninja_suffix;
	}
	if (ninja_dir) {
	ninja_dir_ = ninja_dir;
	} else {
	ninja_dir_ = ".";
	}

	for (Symbol e : Vars::used_env_vars()) {
	shared_ptr<string> val = ev_->EvalVar(e);
	used_envs_.emplace(e.str(), *val);
	}

	if (g_gen_regen_rule)
	GetExecutablePath(&kati_binary_);
	}

	~NinjaGenerator() {
	ev_->set_avoid_io(false);
	}

	void Generate(const vector<DepNode*>& nodes,
	bool build_all_targets,
	const string& orig_args) {
	GenerateEnvlist();
	GenerateNinja(nodes, build_all_targets, orig_args);
	GenerateShell();
	}

	private:
	string GenRuleName() {
	return StringPrintf("rule%d", rule_id_++);
	}

	StringPiece TranslateCommand(const char* in, string* cmd_buf) {
	const size_t orig_size = cmd_buf->size();
	bool prev_backslash = false;
	// Set space as an initial value so the leading comment will be
	// stripped out.
	char prev_char = ' ';
	char quote = 0;
	for (; *in; in++) {
	switch (*in) {
	case '#':
	if (quote == 0 && isspace(prev_char)) {
	while (in[1] && *in != '\n')
	in++;
	} else {
	cmd_buf += in;
	}
	break;

	case '\'':
	case '"':
	case '`':
	if (quote) {
	if (quote == *in)
	quote = 0;
	} else if (!prev_backslash) {
	quote = *in;
	}
	cmd_buf += in;
	break;

	case '$':
	*cmd_buf += "$$";
	break;

	case '\n':
	if (prev_backslash) {
	cmd_buf->resize(cmd_buf->size()-1);
	} else {
	*cmd_buf += ' ';
	}
	break;

	case '\\':
	*cmd_buf += '\\';
	break;

	default:
	cmd_buf += in;
	}

	if (*in == '\\') {
	prev_backslash = !prev_backslash;
	} else {
	prev_backslash = false;
	}

	prev_char = *in;
	}

	while (true) {
	char c = (*cmd_buf)[cmd_buf->size()-1];
	if (!isspace(c) && c != ';')
	break;
	cmd_buf->resize(cmd_buf->size() - 1);
	}

	return StringPiece(cmd_buf->data() + orig_size,
	cmd_buf->size() - orig_size);
	}

	bool GetDescriptionFromCommand(StringPiece cmd, string *out) {
	if (!HasPrefix(cmd, "echo ")) {
	return false;
	}
	cmd = cmd.substr(5, cmd.size());

	bool prev_backslash = false;
	char quote = 0;
	string out_buf;

	// Strip outer quotes, and fail if it is not a single echo command
	for (StringPiece::iterator in = cmd.begin(); in != cmd.end(); in++) {
	if (prev_backslash) {
	prev_backslash = false;
	out_buf += *in;
	} else if (*in == '\\') {
	prev_backslash = true;
	out_buf += *in;
	} else if (quote) {
	if (*in == quote) {
	quote = 0;
	} else {
	out_buf += *in;
	}
	} else {
	switch (*in) {
	case '\'':
	case '"':
	case '`':
	quote = *in;
	break;

	case '<':
	case '>':
	case '&':
	case '\|':
	case ';':
	return false;

	default:
	out_buf += *in;
	}
	}
	}

	*out = out_buf;
	return true;
	}

	bool GenShellScript(const vector<Command*>& commands,
	string* cmd_buf,
	string* description) {
	bool got_descritpion = false;
	bool use_gomacc = false;
	bool should_ignore_error = false;
	for (const Command* c : commands) {
	if (!cmd_buf->empty()) {
	if (should_ignore_error) {
	*cmd_buf += " ; ";
	} else {
	*cmd_buf += " && ";
	}
	}
	should_ignore_error = c->ignore_error;

	const char* in = c->cmd->c_str();
	while (isspace(*in))
	in++;

	bool needs_subshell = commands.size() > 1;
	if (*in == '(') {
	needs_subshell = false;
	}

	if (needs_subshell)
	*cmd_buf += '(';

	size_t cmd_start = cmd_buf->size();
	StringPiece translated = TranslateCommand(in, cmd_buf);
	if (g_detect_android_echo && !got_descritpion && !c->echo &&
	GetDescriptionFromCommand(translated, description)) {
	got_descritpion = true;
	cmd_buf->resize(cmd_start);
	translated.clear();
	}
	if (translated.empty()) {
	*cmd_buf += "true";
	} else if (g_goma_dir) {
	size_t pos = GetGomaccPosForAndroidCompileCommand(translated);
	if (pos != string::npos) {
	cmd_buf->insert(cmd_start + pos, gomacc_);
	use_gomacc = true;
	}
	}

	if (c == commands.back() && c->ignore_error) {
	*cmd_buf += " ; true";
	}

	if (needs_subshell)
	*cmd_buf += ')';
	}
	return g_goma_dir && !use_gomacc;
	}

	void EmitDepfile(string* cmd_buf) {
	*cmd_buf += ' ';
	string depfile;
	bool result = GetDepfileFromCommand(cmd_buf, &depfile);
	cmd_buf->resize(cmd_buf->size()-1);
	if (!result)
	return;
	fprintf(fp_, " depfile = %s\n", depfile.c_str());
	fprintf(fp_, " deps = gcc\n");
	}

	void EmitNode(DepNode* node) {
	auto p = done_.insert(node->output);
	if (!p.second)
	return;

	// Removing this will fix auto_vars.mk, build_once.mk, and
	// command_vars.mk. However, this change will make
	// ninja_normalized_path2.mk fail and cause a lot of warnings for
	// Android build.
	if (node->cmds.empty() &&
	node->deps.empty() && node->order_onlys.empty() && !node->is_phony) {
	return;
	}

	StringPiece base = Basename(node->output.str());
	if (base != node->output.str()) {
	auto p = short_names_.emplace(Intern(base), node->output);
	if (!p.second) {
	// We generate shortcuts only for targets whose basename are unique.
	p.first->second = kEmptySym;
	}
	}

	vector<Command*> commands;
	ce_.Eval(node, &commands);

	string rule_name = "phony";
	bool use_local_pool = false;
	if (!commands.empty()) {
	rule_name = GenRuleName();
	fprintf(fp_, "rule %s\n", rule_name.c_str());

	string description = "build $out";
	string cmd_buf;
	use_local_pool \|= GenShellScript(commands, &cmd_buf, &description);
	fprintf(fp_, " description = %s\n", description.c_str());
	EmitDepfile(&cmd_buf);

	// It seems Linux is OK with ~130kB and Mac's limit is ~250kB.
	// TODO: Find this number automatically.
	if (cmd_buf.size() > 100 * 1000) {
	fprintf(fp_, " rspfile = $out.rsp\n");
	fprintf(fp_, " rspfile_content = %s\n", cmd_buf.c_str());
	fprintf(fp_, " command = %s $out.rsp\n", shell_->c_str());
	} else {
	fprintf(fp_, " command = %s -c \"%s\"\n",
	shell_->c_str(), EscapeShell(cmd_buf).c_str());
	}
	}

	EmitBuild(node, rule_name);
	if (use_local_pool)
	fprintf(fp_, " pool = local_pool\n");

	for (DepNode* d : node->deps) {
	EmitNode(d);
	}
	for (DepNode* d : node->order_onlys) {
	EmitNode(d);
	}
	}

	string EscapeBuildTarget(Symbol s) {
	if (s.str().find_first_of("$: ") == string::npos)
	return s.str();
	string r;
	for (char c : s.str()) {
	switch (c) {
	case '$':
	case ':':
	case ' ':
	r += '$';
	// fall through.
	default:
	r += c;
	}
	}
	return r;
	}

	string EscapeShell(string s) {
	if (s.find_first_of("$`!\\\"") == string::npos)
	return s;
	string r;
	bool lastDollar = false;
	for (char c : s) {
	switch (c) {
	case '$':
	if (lastDollar) {
	r += c;
	lastDollar = false;
	} else {
	r += '\\';
	r += c;
	lastDollar = true;
	}
	break;
	case '`':
	case '"':
	case '!':
	case '\\':
	r += '\\';
	// fall through.
	default:
	r += c;
	lastDollar = false;
	}
	}
	return r;
	}

	void EmitBuild(DepNode* node, const string& rule_name) {
	fprintf(fp_, "build %s: %s",
	EscapeBuildTarget(node->output).c_str(),
	rule_name.c_str());
	vector<Symbol> order_onlys;
	for (DepNode* d : node->deps) {
	fprintf(fp_, " %s", EscapeBuildTarget(d->output).c_str());
	}
	if (!node->order_onlys.empty()) {
	fprintf(fp_, " \|\|");
	for (DepNode* d : node->order_onlys) {
	fprintf(fp_, " %s", EscapeBuildTarget(d->output).c_str());
	}
	}
	fprintf(fp_, "\n");
	}

	void EmitRegenRules(const string& orig_args) {
	if (!g_gen_regen_rule)
	return;

	fprintf(fp_, "rule regen_ninja\n");
	fprintf(fp_, " command = %s\n", orig_args.c_str());
	fprintf(fp_, " generator = 1\n");
	fprintf(fp_, " description = Regenerate ninja files due to dependency\n");
	fprintf(fp_, "build %s: regen_ninja", GetNinjaFilename().c_str());
	unordered_set<string> makefiles;
	MakefileCacheManager::Get()->GetAllFilenames(&makefiles);
	for (const string& makefile : makefiles) {
	fprintf(fp_, " %.*s", SPF(makefile));
	}
	fprintf(fp_, " %s", kati_binary_.c_str());
	// TODO: Add dependencies to directories read by $(wildcard)
	// or $(shell find).
	if (!used_envs_.empty())
	fprintf(fp_, " %s", GetEnvlistFilename().c_str());
	fprintf(fp_, "\n\n");
	}

	string GetNinjaFilename() const {
	return StringPrintf("%s/build%s.ninja",
	ninja_dir_.c_str(), ninja_suffix_.c_str());
	}

	string GetShellScriptFilename() const {
	return StringPrintf("%s/ninja%s.sh",
	ninja_dir_.c_str(), ninja_suffix_.c_str());
	}

	string GetEnvlistFilename() const {
	return StringPrintf("%s/.kati_env%s",
	ninja_dir_.c_str(), ninja_suffix_.c_str());
	}

	string GetLunchFilename() const {
	return StringPrintf("%s/.kati_lunch%s",
	ninja_dir_.c_str(), ninja_suffix_.c_str());
	}

	void GenerateNinja(const vector<DepNode*>& nodes,
	bool build_all_targets,
	const string& orig_args) {
	fp_ = fopen(GetNinjaFilename().c_str(), "wb");
	if (fp_ == NULL)
	PERROR("fopen(build.ninja) failed");

	fprintf(fp_, "# Generated by kati %s\n", kGitVersion);
	fprintf(fp_, "\n");

	if (!used_envs_.empty()) {
	fprintf(fp_, "# Environment variables used:\n");
	for (const auto& p : used_envs_) {
	fprintf(fp_, "# %s=%s\n", p.first.c_str(), p.second.c_str());
	}
	fprintf(fp_, "\n");
	}

	if (g_goma_dir) {
	fprintf(fp_, "pool local_pool\n");
	fprintf(fp_, " depth = %d\n\n", g_num_jobs);
	}

	EmitRegenRules(orig_args);

	for (DepNode* node : nodes) {
	EmitNode(node);
	}

	if (!build_all_targets) {
	CHECK(!nodes.empty());
	fprintf(fp_, "\ndefault %s\n",
	EscapeBuildTarget(nodes.front()->output).c_str());
	}

	fprintf(fp_, "\n# shortcuts:\n");
	for (auto p : short_names_) {
	if (!p.second.empty() && !done_.count(p.first))
	fprintf(fp_, "build %s: phony %s\n", p.first.c_str(), p.second.c_str());
	}

	fclose(fp_);
	}

	void GenerateShell() {
	FILE* fp = fopen(GetShellScriptFilename().c_str(), "wb");
	if (fp == NULL)
	PERROR("fopen(ninja.sh) failed");

	fprintf(fp, "#!/bin/sh\n");
	fprintf(fp, "# Generated by kati %s\n", kGitVersion);
	fprintf(fp, "\n");
	if (ninja_dir_ == ".")
	fprintf(fp, "cd $(dirname \"$0\")\n");
	if (!ninja_suffix_.empty()) {
	fprintf(fp, "if [ -f %s ]; then\n export $(cat %s)\nfi\n",
	GetEnvlistFilename().c_str(), GetEnvlistFilename().c_str());
	fprintf(fp, "if [ -f %s ]; then\n export $(cat %s)\nfi\n",
	GetLunchFilename().c_str(), GetLunchFilename().c_str());
	}

	for (const auto& p : ev_->exports()) {
	if (p.second) {
	shared_ptr<string> val = ev_->EvalVar(p.first);
	fprintf(fp, "export '%s'='%s'\n", p.first.c_str(), val->c_str());
	} else {
	fprintf(fp, "unset '%s'\n", p.first.c_str());
	}
	}

	fprintf(fp, "exec ninja -f %s ", GetNinjaFilename().c_str());
	if (g_goma_dir) {
	fprintf(fp, "-j500 ");
	}
	fprintf(fp, "\"$@\"\n");

	if (chmod(GetShellScriptFilename().c_str(), 0755) != 0)
	PERROR("chmod ninja.sh failed");
	}

	void GenerateEnvlist() {
	if (used_envs_.empty())
	return;
	FILE* fp = fopen(GetEnvlistFilename().c_str(), "wb");
	for (const auto& p : used_envs_) {
	fprintf(fp, "%s=%s\n", p.first.c_str(), p.second.c_str());
	}
	fclose(fp);
	}

	CommandEvaluator ce_;
	Evaluator* ev_;
	FILE* fp_;
	unordered_set<Symbol> done_;
	int rule_id_;
	string gomacc_;
	string ninja_suffix_;
	string ninja_dir_;
	unordered_map<Symbol, Symbol> short_names_;
	shared_ptr<string> shell_;
	map<string, string> used_envs_;
	string kati_binary_;
	};

	void GenerateNinja(const char* ninja_suffix,
	const char* ninja_dir,
	const vector<DepNode*>& nodes,
	Evaluator* ev,
	bool build_all_targets,
	const string& orig_args) {
	NinjaGenerator ng(ninja_suffix, ninja_dir, ev);
	ng.Generate(nodes, build_all_targets, orig_args);
	}