Use soong_ui directly, instead of make

This will use ckati instead of make for dumping variables, for
consistent makefile parsing. It may also sandbox executions, etc.

Also skip the legacy make wrapper to build, and use soong_ui instead.
The command line arguments are equivalent, but -j is no longer
necessary, we'll default to a sane value.

Test: bit -b framework
Change-Id: Idc2c9d1abe84b6b783b8702925de5493d47a4509
diff --git a/tools/bit/command.cpp b/tools/bit/command.cpp
index 1ff7c22..f95ea11 100644
--- a/tools/bit/command.cpp
+++ b/tools/bit/command.cpp
@@ -189,7 +189,7 @@
 int
 exec_with_path_search(const char* prog, char const* const* argv, char const* const* envp)
 {
-    if (prog[0] == '/') {
+    if (strchr(prog, '/') != NULL) {
         return execve(prog, (char*const*)argv, (char*const*)envp);
     } else {
         char* pathEnv = strdup(getenv("PATH"));
diff --git a/tools/bit/main.cpp b/tools/bit/main.cpp
index ad23971..e81898f 100644
--- a/tools/bit/main.cpp
+++ b/tools/bit/main.cpp
@@ -588,12 +588,13 @@
     const string buildProduct = get_required_env("TARGET_PRODUCT", false);
     const string buildVariant = get_required_env("TARGET_BUILD_VARIANT", false);
     const string buildType = get_required_env("TARGET_BUILD_TYPE", false);
-    const string buildDevice = get_build_var(buildTop, "TARGET_DEVICE", false);
-    const string buildId = get_build_var(buildTop, "BUILD_ID", false);
-    const string buildOut = get_out_dir();
 
     chdir_or_exit(buildTop.c_str());
 
+    const string buildDevice = get_build_var("TARGET_DEVICE", false);
+    const string buildId = get_build_var("BUILD_ID", false);
+    const string buildOut = get_out_dir();
+
     // Get the modules for the targets
     map<string,Module> modules;
     read_modules(buildOut, buildDevice, &modules, false);
diff --git a/tools/bit/make.cpp b/tools/bit/make.cpp
index a800241..ef3ccc5 100644
--- a/tools/bit/make.cpp
+++ b/tools/bit/make.cpp
@@ -36,31 +36,16 @@
 
 map<string,string> g_buildVars;
 
-static unsigned int
-get_thread_count()
-{
-    unsigned int threads = std::thread::hardware_concurrency();
-    // Guess if the value cannot be computed
-    return threads == 0 ? 4 : static_cast<unsigned int>(threads * 1.3f);
-}
-
 string
-get_build_var(const string& buildTop, const string& name, bool quiet)
+get_build_var(const string& name, bool quiet)
 {
     int err;
 
     map<string,string>::iterator it = g_buildVars.find(name);
     if (it == g_buildVars.end()) {
-        Command cmd("make");
-        cmd.AddArg("--no-print-directory");
-        cmd.AddArg(string("-j") + std::to_string(get_thread_count()));
-        cmd.AddArg("-C");
-        cmd.AddArg(buildTop);
-        cmd.AddArg("-f");
-        cmd.AddArg("build/core/config.mk");
-        cmd.AddArg(string("dumpvar-") + name);
-        cmd.AddEnv("CALLED_FROM_SETUP", "true");
-        cmd.AddEnv("BUILD_SYSTEM", "build/core");
+        Command cmd("build/soong/soong_ui.bash");
+        cmd.AddArg("--dumpvar-mode");
+        cmd.AddArg(name);
 
         string output = trim(get_command_output(cmd, &err, quiet));
         if (err == 0) {
@@ -208,10 +193,8 @@
 int
 build_goals(const vector<string>& goals)
 {
-    Command cmd("make");
-    cmd.AddArg(string("-j") + std::to_string(get_thread_count()));
-    cmd.AddArg("-f");
-    cmd.AddArg("build/core/main.mk");
+    Command cmd("build/soong/soong_ui.bash");
+    cmd.AddArg("--make-mode");
     for (size_t i=0; i<goals.size(); i++) {
         cmd.AddArg(goals[i]);
     }
diff --git a/tools/bit/make.h b/tools/bit/make.h
index bb83c6e..1c9504d 100644
--- a/tools/bit/make.h
+++ b/tools/bit/make.h
@@ -31,7 +31,7 @@
     vector<string> installed;
 };
 
-string get_build_var(const string& buildTop, const string& name, bool quiet);
+string get_build_var(const string& name, bool quiet);
 
 /**
  * Poke around in the out directory and try to find a device name that matches