compile_commands

src/SourceFile.cc

@@ -177,3 +177,14 @@ void SourceFile::compile(const std::string &outDir) const {
 	compileFlags_.clear();
 	hasCompileFlags_ = false;
 }
+
+std::vector<std::string> SourceFile::compileCommand(const std::string &outDir) const {
+	auto res = toolchain::getCompileCommand(compileFlags(), type_, dir_, name_, outDir);
+
+	// Nothing will need compile flags after this, so no reason to
+	// keep it around in memory
+	compileFlags_.clear();
+	hasCompileFlags_ = false;
+
+	return res;
+}

src/SourceFile.h

@@ -35,6 +35,7 @@ public:
 	std::vector<std::string> dependencies() const;
 	bool needsRecompile(const std::string &outDir) const;
 	void compile(const std::string &outDir) const;
+	std::vector<std::string> compileCommand(const std::string &outDir) const;
 
 private:
 	std::string dir_;

src/main.cc

@@ -159,6 +159,37 @@ static bool compileAndLink(
 	return false;
 }
 
+static void printCompileCommands(
+		const std::vector<SourceFile> &sources, const std::string &outDir,
+		std::ostream &os) {
+	std::string cwd = sys::cwd();
+
+	os << "[\n\t";
+
+	bool first = true;
+	for (auto &source: sources) {
+		std::string command;
+		for (auto arg: source.compileCommand(outDir)) {
+			command += arg + ' ';
+		}
+		command.pop_back();
+
+		if (!first) {
+			os << ", ";
+		}
+
+		os << "{\n"
+			<< "\t\t\"directory\":\"" << cwd << "\"\n"
+			<< "\t\t\"command\":\"" << command << "\"\n"
+			<< "\t\t\"file\":\"" << source.path() << "\"\n"
+			<< "\t}";
+
+		first = false;
+	}
+
+	os << "\n]\n";
+}
+
 static std::string findTargetName(
 		const BBParser::Variables &vars,
 		const std::vector<SourceFile> &sources) {
@@ -186,39 +217,40 @@ int main(int argc, char **argv) {
 	std::string target = "";
 
 	enum class Action {
-		BUILD, PRINT_STATE,
+		BUILD, PRINT_COMPILE_COMMANDS, PRINT_STATE,
 	};
 	Action action = Action::BUILD;
 
-	const char *shortopts = "hvo:j:C:t:p";
+	const char *shortopts = "hvo:j:C:cp";
 	const struct option opts[] = {
-		{ "help",        no_argument,       NULL, 'h' },
-		{ "verbose",     no_argument,       NULL, 'v' },
-		{ "output",      required_argument, NULL, 'o' },
-		{ "jobs",        required_argument, NULL, 'j' },
-		{ "directory",   required_argument, NULL, 'C' },
-		{ "target",      required_argument, NULL, 't' },
-		{ "print-state", no_argument,       NULL, 'p' },
+		{ "help",             no_argument,       NULL, 'h' },
+		{ "verbose",          no_argument,       NULL, 'v' },
+		{ "output",           required_argument, NULL, 'o' },
+		{ "jobs",             required_argument, NULL, 'j' },
+		{ "directory",        required_argument, NULL, 'C' },
+		{ "target",           required_argument, NULL, 't' },
+		{ "compile-commands", no_argument,       NULL, 'c' },
+		{ "print-state",      no_argument,       NULL, 'p' },
 		{},
 	};
 
 	const char usage[] =
 		"Usage: bbbuild [options...] [sources]\n"
 		"\n"
-		"  -h, --help             "
+		"  -h, --help              "
 			"Show this help text.\n"
-		"  -v, --verbose          "
-			"Show every command as it's executing."
-		"  -o, --output <dir>     "
+		"  -v, --verbose           "
+			"Show every command as it's executing.\n"
+		"  -o, --output <dir>      "
 			"Set output directory. Default: bbbuild\n"
-		"  -j, --jobs <count>     "
+		"  -j, --jobs <count>      "
 			"Set the number of jobs run simultaneously. "
 			"Default: the number of cores in the machine.\n"
-		"  -C, --directory <dir>  "
+		"  -C, --directory <dir>   "
 			"Change directory before doing anything else.\n"
-		"  -t, --target <name>    "
-			"Set the name of the executable.\n"
-		"  -p, --print-state      "
+		"  -c, --compile-commands  "
+			"Write compile commands to stdout.\n"
+		"  -p, --print-state       "
 			"Print the state instead of building.\n";
 
 	// Parse options from argv
@@ -255,6 +287,10 @@ int main(int argc, char **argv) {
 				workDir = optarg;
 				break;
 
+			case 'c':
+				action = Action::PRINT_COMPILE_COMMANDS;
+				break;
+
 			case 'p':
 				action = Action::PRINT_STATE;
 				break;
@@ -316,6 +352,10 @@ int main(int argc, char **argv) {
 		}
 		break;
 
+	case Action::PRINT_COMPILE_COMMANDS:
+		printCompileCommands(sources, outDir, std::cout);
+		break;
+
 	case Action::PRINT_STATE:
 		printState(sources);
 		break;

src/sys.cc

@@ -9,6 +9,7 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <stdexcept>
+#include <system_error>
 
 #include "logger.h"
 #include "globals.h"
@@ -44,14 +45,14 @@ bool fileExists(const std::string &path) {
 
 void mkdirp(const std::string &path) {
 	// TODO: Implement this in C++ instead
-	std::vector<const char *> argv;
+	std::vector<std::string> argv;
 	argv.push_back("mkdir");
 	argv.push_back("-p");
-	argv.push_back(path.c_str());
+	argv.push_back(path);
 	execute(argv, nullptr, global::verbose >= 2);
 }
 
-void execute(std::vector<const char *> &args, std::string *output, bool print) {
+void execute(const std::vector<std::string> &args, std::string *output, bool print) {
 	if (print) {
 		std::string str;
 		for (size_t i = 0; i < args.size(); ++i) {
@@ -72,7 +73,7 @@ void execute(std::vector<const char *> &args, std::string *output, bool print) {
 	argv.push_back(command.c_str());
 	argv.push_back("--");
 	for (size_t i = 1; i < args.size(); ++i) {
-		argv.push_back(args[i]);
+		argv.push_back(args[i].c_str());
 	}
 
 	argv.push_back(nullptr);
@@ -165,4 +166,22 @@ void chdir(const std::string &path) {
 	}
 }
 
+std::string cwd() {
+	std::vector<char> buf;
+	buf.reserve(128);
+	while (1) {
+		char *res = getcwd(buf.data(), buf.capacity());
+		if (res == NULL) {
+			if (errno == ERANGE) {
+				buf.reserve(buf.capacity() * 2);
+			} else {
+				throw std::system_error(EFAULT, std::generic_category());
+			}
+		} else {
+			std::string str(buf.data());
+			return str;
+		}
+	}
+}
+
 }

src/sys.h

@@ -14,8 +14,9 @@ struct FileInfo {
 FileInfo fileInfo(const std::string &path);
 bool fileExists(const std::string &path);
 void mkdirp(const std::string &path);
-void execute(std::vector<const char *> &args, std::string *output, bool print);
+void execute(const std::vector<std::string> &args, std::string *output, bool print);
 void readDir(const std::string &path, std::vector<std::string> &files);
 void chdir(const std::string &path);
+std::string cwd();
 
 }

src/toolchain.cc

@@ -129,11 +129,11 @@ std::string targetFilePath(
 }
 
 void getPkgConfigFlags(const std::vector<std::string> &pkgs, std::vector<std::string> &flags) {
-	std::vector<const char *> argv;
+	std::vector<std::string> argv;
 	argv.push_back(getPkgConfig());
 	argv.push_back("--cflags");
 	for (auto &pkg: pkgs) {
-		argv.push_back(pkg.c_str());
+		argv.push_back(pkg);
 	}
 
 	// Execute $(PKG_CONFIG) --cflags $(PKGS)
@@ -143,11 +143,11 @@ void getPkgConfigFlags(const std::vector<std::string> &pkgs, std::vector<std::st
 }
 
 void getPkgConfigLDLibs(const std::vector<std::string> &pkgs, std::vector<std::string> &flags) {
-	std::vector<const char *> argv;
+	std::vector<std::string> argv;
 	argv.push_back(getPkgConfig());
 	argv.push_back("--libs");
 	for (auto &pkg: pkgs) {
-		argv.push_back(pkg.c_str());
+		argv.push_back(pkg);
 	}
 
 	// Execute $(PKG_CONFIG) --libs $(PKGS)
@@ -164,19 +164,19 @@ void getDependencies(
 		std::vector<std::string> &deps) {
 	std::string sourcePath = srcDir + "/" + name;
 
-	std::vector<const char *> argv;
+	std::vector<std::string> argv;
 
 	// $(compiler)
 	argv.push_back(getCompilerFor(type));
 
 	// $(flags)
 	for (auto &flag: flags) {
-		argv.push_back(flag.c_str());
+		argv.push_back(flag);
 	}
 
 	// -MM $<
 	argv.push_back("-MM");
-	argv.push_back(sourcePath.c_str());
+	argv.push_back(sourcePath);
 
 	// Execute $(compiler) $(flags) -MM $<
 	std::string output;
@@ -188,20 +188,16 @@ void getDependencies(
 	}
 }
 
-void compile(
+std::vector<std::string> getCompileCommand(
 		const std::vector<std::string> &flags,
 		SourceFile::FileType type,
 		const std::string &srcDir,
 		const std::string &name,
 		const std::string &outDir) {
 	std::string sourcePath = srcDir + "/" + name;
-	std::string destDir = outDir + "/" + srcDir;
 	std::string objectPath = objectFilePath(srcDir, name, outDir);
 
-	// Ensure the output directory actually exists
-	sys::mkdirp(destDir);
-
-	std::vector<const char *> argv;
+	std::vector<std::string> argv;
 
 	// $(compiler)
 	argv.push_back(getCompilerFor(type));
@@ -213,11 +209,24 @@ void compile(
 
 	// -o $@ -c $<
 	argv.push_back("-o");
-	argv.push_back(objectPath.c_str());
+	argv.push_back(std::move(objectPath));
 	argv.push_back("-c");
-	argv.push_back(sourcePath.c_str());
+	argv.push_back(std::move(sourcePath));
+
+	return argv;
+}
+
+void compile(
+		const std::vector<std::string> &flags,
+		SourceFile::FileType type,
+		const std::string &srcDir,
+		const std::string &name,
+		const std::string &outDir) {
+	// Ensure the output directory actually exists
+	std::string destDir = outDir + "/" + srcDir;
+	sys::mkdirp(destDir);
 
-	// Execute $(compiler) $(flags) -o $@ -c $<
+	std::vector<std::string> argv = getCompileCommand(flags, type, srcDir, name, outDir);
 	sys::execute(argv, nullptr, global::verbose >= 1);
 }
 
@@ -234,28 +243,28 @@ void link(
 	// TODO: Use ar to create STATIC_LIBRARY,
 	// use GCC with -shared to make SHARED_LIBRARY
 
-	std::vector<const char *> argv;
+	std::vector<std::string> argv;
 
 	// $(compiler)
 	argv.push_back(getCompilerFor(type));
 
 	// $(ldflags)
 	for (auto &flag: ldFlags) {
-		argv.push_back(flag.c_str());
+		argv.push_back(flag);
 	}
 
 	// -o $@
 	argv.push_back("-o");
-	argv.push_back(outPath.c_str());
+	argv.push_back(outPath);
 
 	// $(objs)
 	for (auto &obj: objs) {
-		argv.push_back(obj.c_str());
+		argv.push_back(obj);
 	}
 
 	// $(ldlibs)
 	for (auto &flag: ldLibs) {
-		argv.push_back(flag.c_str());
+		argv.push_back(flag);
 	}
 
 	// Execute $(compiler) $(ldflags) -o $@ $(objs) $(ldlibs)

src/toolchain.h

@@ -32,6 +32,13 @@ void getDependencies(
 		const std::string &name,
 		std::vector<std::string> &deps);
 
+std::vector<std::string> getCompileCommand(
+		const std::vector<std::string> &flags,
+		SourceFile::FileType type,
+		const std::string &srcDir,
+		const std::string &name,
+		const std::string &outDir);
+
 void compile(
 		const std::vector<std::string> &flags,
 		SourceFile::FileType type,