build/bazel_cc_fix/main.go - monogon - Gitiles

 // Copyright 2020 The Monogon Project Authors.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
 // 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.

 // bazel_cc_fix rewrites include directives in C and C++ code. It rewrites all
 // includes in the target workspace to be workspace-relative and additionally
 // supports rewriting includes via a prototxt-based spec file to for example
 // fix up includes for external libraries.
 // The rewritten code can then be used in Bazel intra- and inter-workspace
 // without dealing with any copts or include- related attributes.
 // To know where an include would resolve to it expects a compilation database
 // (see https://clang.llvm.org/docs/JSONCompilationDatabase.html) as an input.
 // It looks at all files in that database and their transitive dependencies and
 // rewrites all of them according to the include paths specified in the
 // compilation command from the database.
 // The compilation database itself is either generated by the original build
 // system or by using intercept-build, which intercepts calls to the compiler
 // and records them into a compilation database.
 package main

 import (
 	"encoding/json"
 	"flag"
 	"fmt"
 	"log"
 	"os"
 	"path/filepath"
 	"regexp"
 	"strings"

 	"github.com/mattn/go-shellwords"
 	"google.golang.org/protobuf/encoding/prototext"

 	"source.monogon.dev/build/bazel_cc_fix/ccfixspec"
 )

 // compilationDBEntry is a single entry from the compilation database which
 // represents a single compiler invocation on a C/C++ source file. It contains
 // the compiler working directory, arguments and input file path.
 type compilationDBEntry struct {
 	Directory string   `json:"directory"`
 	Command   string   `json:"command"`
 	Arguments []string `json:"arguments"`
 	File      string   `json:"file"`
 	Output    string   `json:"output"`
 }

 // compilationDB is a collection of compilationDBEntries usually stored in a
 // big JSON-serialized document.
 // https://clang.llvm.org/docs/JSONCompilationDatabase.html
 type compilationDB []compilationDBEntry

 // rewrites represents a list of include rewrites with the key being the
 // original include statement (like "#include <xyz.h>", with whitespace trimmed
 // on both sides) and the value being another
 type rewrites map[string]string

 // replacer returns a strings.Replacer which efficiently performs all
 // replacements in a single pass
 func (r rewrites) replacer() *strings.Replacer {
 	var replacerArgs []string
 	for from, to := range r {
 		replacerArgs = append(replacerArgs, from, to)
 	}
 	return strings.NewReplacer(replacerArgs...)
 }

 // addWorkspace adds a rewrite from a given directive to a workspace-relative path.
 func (r rewrites) addWorkspace(oldDirective, workspaceRelativePath string) {
 	normalizedDirective := strings.TrimSpace(oldDirective)
 	replacementDirective := fmt.Sprintf("#include \"%s\"", workspaceRelativePath)
 	oldRewrite, ok := r[normalizedDirective]
 	if !ok {
 		r[normalizedDirective] = replacementDirective
 	} else if oldRewrite != replacementDirective {
 		log.Printf("WARNING: inconsistent rewrite detected: %s => %s | %s", normalizedDirective, oldRewrite, replacementDirective)
 	}
 }

 // Type rewriteMetadata is a map of a file path to rewrite metadata for that file
 type rewriteMetadata map[string]rewriteMetadataFile

 type rewriteMetadataFile struct {
 	rewrites rewrites
 	source   string
 }

 var (
 	compilationDBPath = flag.String("compilation_db", "", "Path the the compilation_database.json file for the project")
 	workspacePath     = flag.String("workspace", "", "Path to the workspace root")
 	specPath          = flag.String("spec", "", "Path to the spec (ccfixspec.CCFixSpec)")
 )

 var (
 	reGlobalInclude = regexp.MustCompile("^-I(.*)")
 	reSystemInclude = regexp.MustCompile("^-isystem(.*)")
 	reQuoteInclude  = regexp.MustCompile("^-iquote(.*)")
 )

 var (
 	reIncludeDirective = regexp.MustCompile(`(?m:^\s*#\s*include\s*([<"])(.*)([>"]))`)
 )

 // applyReplaceDirectives applies all directives of the given replaceType in
 // directives to originalPath and returns the resulting string. If
 // returnUnmodified is unset, it returns an empty string when no replacements
 // were performed, otherwise it returns the unmodified originalPath.
 // The first rewrite wins, it does not do any recursive processing.
 func applyReplaceDirectives(directives []*ccfixspec.Replace, replaceType ccfixspec.Replace_Type, originalPath string, returnUnmodified bool) string {
 	for _, d := range directives {
 		if d.Type != replaceType {
 			continue
 		}
 		if d.From == originalPath {
 			return d.To
 		} else if strings.HasSuffix(d.From, "/") && strings.HasPrefix(originalPath, d.From) {
 			return d.To + strings.TrimPrefix(originalPath, d.From)
 		}
 	}
 	if returnUnmodified {
 		return originalPath
 	}
 	return ""
 }

 // findFileInWorkspace takes a path from a C include directive and uses the
 // given search path to find its absolute path. If that absolute path is
 // outside the workspace, it returns an empty string, otherwise it returns the
 // path of the file relative to the workspace. It pretends that all files in
 // isGeneratedFile exist on the filesystem.
 func findFileInWorkspace(searchPath []string, inclFile string, isGeneratedFile map[string]bool) string {
 	var inclPath string
 	for _, path := range searchPath {
 		inclPathTry := filepath.Join(path, inclFile)
 		if isGeneratedFile[inclPathTry] {
 			inclPath = inclPathTry
 			break
 		}
 		if _, err := os.Stat(inclPathTry); err == nil {
 			inclPath = inclPathTry
 			break
 		}
 	}
 	if inclPath == "" {
 		// We haven't found the included file. This can happen for system
 		// includes (<stdio.h>) or includes from other operating systems.
 		return ""
 	}

 	// Ignore all include directives that don't resolve into our workspace
 	// after processing
 	if !filepath.HasPrefix(inclPath, *workspacePath) {
 		return ""
 	}

 	workspaceRelativeFilePath, err := filepath.Rel(*workspacePath, inclPath)
 	if err != nil {
 		panic(err)
 	}
 	return workspaceRelativeFilePath
 }

 // fixIncludesAndGetRefs opens a file, looks at all its includes, records
 // rewriting data into rewriteMetadata and returns all files included by the
 // file for further analysis.
 func (m rewriteMetadata) fixIncludesAndGetRefs(filePath string, quoteIncludes, systemIncludes []string, spec *ccfixspec.CCFixSpec, isGeneratedFile map[string]bool) []string {
 	meta, ok := m[filePath]
 	if !ok {
 		cSourceRaw, err := os.ReadFile(filePath)
 		if err != nil {
 			log.Printf("failed to open source file: %v", err)
 			return nil
 		}
 		cSource := string(cSourceRaw)
 		m[filePath] = rewriteMetadataFile{
 			rewrites: make(rewrites),
 			source:   cSource,
 		}
 		meta = m[filePath]
 	}
 	var includeFiles []string
 	// Find all include directives
 	out := reIncludeDirective.FindAllStringSubmatch(meta.source, -1)
 	for _, incl := range out {
 		inclDirective := incl[0]
 		inclType := incl[1]
 		inclFile := incl[2]
 		var workspaceRelativeFilePath string
 		var searchPath []string
 		if inclType == "\"" {
 			searchPath = quoteIncludes
 		} else if inclType == "<" {
 			searchPath = systemIncludes
 			workspaceRelativeFilePath = applyReplaceDirectives(spec.Replace, ccfixspec.Replace_SYSTEM, inclFile, false)
 		}
 		if workspaceRelativeFilePath == "" {
 			workspaceRelativeFilePath = findFileInWorkspace(searchPath, inclFile, isGeneratedFile)
 		}
 		workspaceRelativeFilePath = applyReplaceDirectives(spec.Replace, ccfixspec.Replace_WORKSPACE, workspaceRelativeFilePath, true)

 		// Mark generated files as generated
 		foundGenerated := isGeneratedFile[filepath.Join(*workspacePath, workspaceRelativeFilePath)]

 		if !foundGenerated {
 			includeFiles = append(includeFiles, filepath.Join(*workspacePath, workspaceRelativeFilePath))
 		}

 		// Pretend that a generated file exists at the given path when
 		// stripping the BuildDir prefix. This is generally true for all
 		// out-of-tree build systems and saves the user from needing to
 		// manually specify lots of GeneratedFiles.
 		if spec.BuildDir != "" && filepath.HasPrefix(workspaceRelativeFilePath, spec.BuildDir+"/") {
 			workspaceRelativeFilePath = filepath.Clean(strings.TrimPrefix(workspaceRelativeFilePath, spec.BuildDir+"/"))
 			foundGenerated = true
 		}

 		// Shorten include paths when both files are in the same directory
 		// except when a generated file is involved as these end up in
 		// physically different locations and need to be referenced using a
 		// full workspace- relative path
 		if !foundGenerated && filepath.Dir(filePath) == filepath.Dir(filepath.Join(*workspacePath, workspaceRelativeFilePath)) {
 			workspaceRelativeFilePath = filepath.Base(workspaceRelativeFilePath)
 		}
 		// Don't perform rewrites when both include directives are semantically
 		// equivalent
 		if workspaceRelativeFilePath == inclFile && inclType == "\"" {
 			continue
 		}
 		meta.rewrites.addWorkspace(inclDirective, workspaceRelativeFilePath)
 	}
 	return includeFiles
 }

 // getIncludeDirs takes a compilation database entry and returns the search
 // paths for both system and quote includes
 func getIncludeDirs(entry compilationDBEntry) (quoteIncludes []string, systemIncludes []string, err error) {
 	// Normalize arguments
 	if len(entry.Arguments) == 0 {
 		commandArgs, err := shellwords.Parse(entry.Command)
 		if err != nil {
 			return []string{}, []string{}, fmt.Errorf("failed to parse command: %w", err)
 		}
 		entry.Arguments = commandArgs
 	}

 	// Parse out and generate include search paths
 	var preSystemIncludes []string
 	var systemIncludesRaw []string
 	var quoteIncludesRaw []string
 	filePath := entry.File
 	if !filepath.IsAbs(entry.File) {
 		filePath = filepath.Join(entry.Directory, entry.File)
 	}
 	quoteIncludesRaw = append(quoteIncludesRaw, filepath.Dir(filePath))
 	for i, arg := range entry.Arguments {
 		includeMatch := reGlobalInclude.FindStringSubmatch(arg)
 		if len(includeMatch) > 0 {
 			if len(includeMatch[1]) == 0 {
 				preSystemIncludes = append(preSystemIncludes, entry.Arguments[i+1])
 			} else {
 				preSystemIncludes = append(preSystemIncludes, includeMatch[1])
 			}
 		}
 		includeMatch = reSystemInclude.FindStringSubmatch(arg)
 		if len(includeMatch) > 0 {
 			if len(includeMatch[1]) == 0 {
 				systemIncludesRaw = append(systemIncludesRaw, entry.Arguments[i+1])
 			} else {
 				systemIncludesRaw = append(systemIncludesRaw, includeMatch[1])
 			}
 		}
 		includeMatch = reQuoteInclude.FindStringSubmatch(arg)
 		if len(includeMatch) > 0 {
 			if len(includeMatch[1]) == 0 {
 				quoteIncludesRaw = append(quoteIncludesRaw, entry.Arguments[i+1])
 			} else {
 				quoteIncludesRaw = append(quoteIncludesRaw, includeMatch[1])
 			}
 		}
 	}
 	systemIncludesRaw = append(preSystemIncludes, systemIncludesRaw...)
 	quoteIncludesRaw = append(quoteIncludesRaw, systemIncludesRaw...)

 	// Deduplicate and keep the first one
 	systemIncludeSeen := make(map[string]bool)
 	quoteIncludeSeen := make(map[string]bool)
 	for _, systemInclude := range systemIncludesRaw {
 		if !filepath.IsAbs(systemInclude) {
 			systemInclude = filepath.Join(entry.Directory, systemInclude)
 		}
 		if !systemIncludeSeen[systemInclude] {
 			systemIncludeSeen[systemInclude] = true
 			systemIncludes = append(systemIncludes, systemInclude)
 		}
 	}
 	for _, quoteInclude := range quoteIncludesRaw {
 		if !filepath.IsAbs(quoteInclude) {
 			quoteInclude = filepath.Join(entry.Directory, quoteInclude)
 		}
 		if !quoteIncludeSeen[quoteInclude] {
 			quoteIncludeSeen[quoteInclude] = true
 			quoteIncludes = append(quoteIncludes, quoteInclude)
 		}
 	}
 	return
 }

 func main() {
 	flag.Parse()
 	compilationDBFile, err := os.Open(*compilationDBPath)
 	if err != nil {
 		log.Fatalf("failed to open compilation db: %v", err)
 	}
 	var compilationDB compilationDB
 	if err := json.NewDecoder(compilationDBFile).Decode(&compilationDB); err != nil {
 		log.Fatalf("failed to read compilation db: %v", err)
 	}
 	specRaw, err := os.ReadFile(*specPath)
 	var spec ccfixspec.CCFixSpec
 	if err := prototext.Unmarshal(specRaw, &spec); err != nil {
 		log.Fatalf("failed to load spec: %v", err)
 	}

 	isGeneratedFile := make(map[string]bool)
 	for _, entry := range spec.GeneratedFile {
 		isGeneratedFile[filepath.Join(*workspacePath, entry.Path)] = true
 	}

 	rewriteMetadata := make(rewriteMetadata)

 	// Iterate over all source files in the compilation database and analyze
 	// them one-by-one
 	for _, entry := range compilationDB {
 		quoteIncludes, systemIncludes, err := getIncludeDirs(entry)
 		if err != nil {
 			log.Println(err)
 			continue
 		}
 		filePath := entry.File
 		if !filepath.IsAbs(entry.File) {
 			filePath = filepath.Join(entry.Directory, entry.File)
 		}
 		includedFiles := rewriteMetadata.fixIncludesAndGetRefs(filePath, quoteIncludes, systemIncludes, &spec, isGeneratedFile)

 		// seen stores the path of already-visited files, similar to #pragma once
 		seen := make(map[string]bool)
 		// rec recursively resolves includes and records rewrites
 		var rec func([]string)
 		rec = func(files []string) {
 			for _, f := range files {
 				if seen[f] {
 					continue
 				}
 				seen[f] = true
 				icf2 := rewriteMetadata.fixIncludesAndGetRefs(f, quoteIncludes, systemIncludes, &spec, isGeneratedFile)
 				rec(icf2)
 			}
 		}
 		rec(includedFiles)
 	}

 	// Perform all recorded rewrites on the actual files
 	for file, rew := range rewriteMetadata {
 		outFile, err := os.Create(file)
 		if err != nil {
 			log.Fatalf("failed to open file for writing output: %v", err)
 		}
 		defer outFile.Close()
 		if _, err := rew.rewrites.replacer().WriteString(outFile, rew.source); err != nil {
 			log.Fatalf("failed to write file %v: %v", file, err)
 		}
 	}
 }
	// Copyright 2020 The Monogon Project Authors.
	//
	// SPDX-License-Identifier: Apache-2.0
	//
	// 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.

	// bazel_cc_fix rewrites include directives in C and C++ code. It rewrites all
	// includes in the target workspace to be workspace-relative and additionally
	// supports rewriting includes via a prototxt-based spec file to for example
	// fix up includes for external libraries.
	// The rewritten code can then be used in Bazel intra- and inter-workspace
	// without dealing with any copts or include- related attributes.
	// To know where an include would resolve to it expects a compilation database
	// (see https://clang.llvm.org/docs/JSONCompilationDatabase.html) as an input.
	// It looks at all files in that database and their transitive dependencies and
	// rewrites all of them according to the include paths specified in the
	// compilation command from the database.
	// The compilation database itself is either generated by the original build
	// system or by using intercept-build, which intercepts calls to the compiler
	// and records them into a compilation database.
	package main

	import (
	"encoding/json"
	"flag"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"regexp"
	"strings"

	"github.com/mattn/go-shellwords"
	"google.golang.org/protobuf/encoding/prototext"

	"source.monogon.dev/build/bazel_cc_fix/ccfixspec"
	)

	// compilationDBEntry is a single entry from the compilation database which
	// represents a single compiler invocation on a C/C++ source file. It contains
	// the compiler working directory, arguments and input file path.
	type compilationDBEntry struct {
	Directory string `json:"directory"`
	Command string `json:"command"`
	Arguments []string `json:"arguments"`
	File string `json:"file"`
	Output string `json:"output"`
	}

	// compilationDB is a collection of compilationDBEntries usually stored in a
	// big JSON-serialized document.
	// https://clang.llvm.org/docs/JSONCompilationDatabase.html
	type compilationDB []compilationDBEntry

	// rewrites represents a list of include rewrites with the key being the
	// original include statement (like "#include <xyz.h>", with whitespace trimmed
	// on both sides) and the value being another
	type rewrites map[string]string

	// replacer returns a strings.Replacer which efficiently performs all
	// replacements in a single pass
	func (r rewrites) replacer() *strings.Replacer {
	var replacerArgs []string
	for from, to := range r {
	replacerArgs = append(replacerArgs, from, to)
	}
	return strings.NewReplacer(replacerArgs...)
	}

	// addWorkspace adds a rewrite from a given directive to a workspace-relative path.
	func (r rewrites) addWorkspace(oldDirective, workspaceRelativePath string) {
	normalizedDirective := strings.TrimSpace(oldDirective)
	replacementDirective := fmt.Sprintf("#include \"%s\"", workspaceRelativePath)
	oldRewrite, ok := r[normalizedDirective]
	if !ok {
	r[normalizedDirective] = replacementDirective
	} else if oldRewrite != replacementDirective {
	log.Printf("WARNING: inconsistent rewrite detected: %s => %s \| %s", normalizedDirective, oldRewrite, replacementDirective)
	}
	}

	// Type rewriteMetadata is a map of a file path to rewrite metadata for that file
	type rewriteMetadata map[string]rewriteMetadataFile

	type rewriteMetadataFile struct {
	rewrites rewrites
	source string
	}

	var (
	compilationDBPath = flag.String("compilation_db", "", "Path the the compilation_database.json file for the project")
	workspacePath = flag.String("workspace", "", "Path to the workspace root")
	specPath = flag.String("spec", "", "Path to the spec (ccfixspec.CCFixSpec)")
	)

	var (
	reGlobalInclude = regexp.MustCompile("^-I(.*)")
	reSystemInclude = regexp.MustCompile("^-isystem(.*)")
	reQuoteInclude = regexp.MustCompile("^-iquote(.*)")
	)

	var (
	reIncludeDirective = regexp.MustCompile(`(?m:^\s#\sinclude\s([<"])(.)([>"]))`)
	)

	// applyReplaceDirectives applies all directives of the given replaceType in
	// directives to originalPath and returns the resulting string. If
	// returnUnmodified is unset, it returns an empty string when no replacements
	// were performed, otherwise it returns the unmodified originalPath.
	// The first rewrite wins, it does not do any recursive processing.
	func applyReplaceDirectives(directives []*ccfixspec.Replace, replaceType ccfixspec.Replace_Type, originalPath string, returnUnmodified bool) string {
	for _, d := range directives {
	if d.Type != replaceType {
	continue
	}
	if d.From == originalPath {
	return d.To
	} else if strings.HasSuffix(d.From, "/") && strings.HasPrefix(originalPath, d.From) {
	return d.To + strings.TrimPrefix(originalPath, d.From)
	}
	}
	if returnUnmodified {
	return originalPath
	}
	return ""
	}

	// findFileInWorkspace takes a path from a C include directive and uses the
	// given search path to find its absolute path. If that absolute path is
	// outside the workspace, it returns an empty string, otherwise it returns the
	// path of the file relative to the workspace. It pretends that all files in
	// isGeneratedFile exist on the filesystem.
	func findFileInWorkspace(searchPath []string, inclFile string, isGeneratedFile map[string]bool) string {
	var inclPath string
	for _, path := range searchPath {
	inclPathTry := filepath.Join(path, inclFile)
	if isGeneratedFile[inclPathTry] {
	inclPath = inclPathTry
	break
	}
	if _, err := os.Stat(inclPathTry); err == nil {
	inclPath = inclPathTry
	break
	}
	}
	if inclPath == "" {
	// We haven't found the included file. This can happen for system
	// includes (<stdio.h>) or includes from other operating systems.
	return ""
	}

	// Ignore all include directives that don't resolve into our workspace
	// after processing
	if !filepath.HasPrefix(inclPath, *workspacePath) {
	return ""
	}

	workspaceRelativeFilePath, err := filepath.Rel(*workspacePath, inclPath)
	if err != nil {
	panic(err)
	}
	return workspaceRelativeFilePath
	}

	// fixIncludesAndGetRefs opens a file, looks at all its includes, records
	// rewriting data into rewriteMetadata and returns all files included by the
	// file for further analysis.
	func (m rewriteMetadata) fixIncludesAndGetRefs(filePath string, quoteIncludes, systemIncludes []string, spec *ccfixspec.CCFixSpec, isGeneratedFile map[string]bool) []string {
	meta, ok := m[filePath]
	if !ok {
	cSourceRaw, err := os.ReadFile(filePath)
	if err != nil {
	log.Printf("failed to open source file: %v", err)
	return nil
	}
	cSource := string(cSourceRaw)
	m[filePath] = rewriteMetadataFile{
	rewrites: make(rewrites),
	source: cSource,
	}
	meta = m[filePath]
	}
	var includeFiles []string
	// Find all include directives
	out := reIncludeDirective.FindAllStringSubmatch(meta.source, -1)
	for _, incl := range out {
	inclDirective := incl[0]
	inclType := incl[1]
	inclFile := incl[2]
	var workspaceRelativeFilePath string
	var searchPath []string
	if inclType == "\"" {
	searchPath = quoteIncludes
	} else if inclType == "<" {
	searchPath = systemIncludes
	workspaceRelativeFilePath = applyReplaceDirectives(spec.Replace, ccfixspec.Replace_SYSTEM, inclFile, false)
	}
	if workspaceRelativeFilePath == "" {
	workspaceRelativeFilePath = findFileInWorkspace(searchPath, inclFile, isGeneratedFile)
	}
	workspaceRelativeFilePath = applyReplaceDirectives(spec.Replace, ccfixspec.Replace_WORKSPACE, workspaceRelativeFilePath, true)

	// Mark generated files as generated
	foundGenerated := isGeneratedFile[filepath.Join(*workspacePath, workspaceRelativeFilePath)]

	if !foundGenerated {
	includeFiles = append(includeFiles, filepath.Join(*workspacePath, workspaceRelativeFilePath))
	}

	// Pretend that a generated file exists at the given path when
	// stripping the BuildDir prefix. This is generally true for all
	// out-of-tree build systems and saves the user from needing to
	// manually specify lots of GeneratedFiles.
	if spec.BuildDir != "" && filepath.HasPrefix(workspaceRelativeFilePath, spec.BuildDir+"/") {
	workspaceRelativeFilePath = filepath.Clean(strings.TrimPrefix(workspaceRelativeFilePath, spec.BuildDir+"/"))
	foundGenerated = true
	}

	// Shorten include paths when both files are in the same directory
	// except when a generated file is involved as these end up in
	// physically different locations and need to be referenced using a
	// full workspace- relative path
	if !foundGenerated && filepath.Dir(filePath) == filepath.Dir(filepath.Join(*workspacePath, workspaceRelativeFilePath)) {
	workspaceRelativeFilePath = filepath.Base(workspaceRelativeFilePath)
	}
	// Don't perform rewrites when both include directives are semantically
	// equivalent
	if workspaceRelativeFilePath == inclFile && inclType == "\"" {
	continue
	}
	meta.rewrites.addWorkspace(inclDirective, workspaceRelativeFilePath)
	}
	return includeFiles
	}

	// getIncludeDirs takes a compilation database entry and returns the search
	// paths for both system and quote includes
	func getIncludeDirs(entry compilationDBEntry) (quoteIncludes []string, systemIncludes []string, err error) {
	// Normalize arguments
	if len(entry.Arguments) == 0 {
	commandArgs, err := shellwords.Parse(entry.Command)
	if err != nil {
	return []string{}, []string{}, fmt.Errorf("failed to parse command: %w", err)
	}
	entry.Arguments = commandArgs
	}

	// Parse out and generate include search paths
	var preSystemIncludes []string
	var systemIncludesRaw []string
	var quoteIncludesRaw []string
	filePath := entry.File
	if !filepath.IsAbs(entry.File) {
	filePath = filepath.Join(entry.Directory, entry.File)
	}
	quoteIncludesRaw = append(quoteIncludesRaw, filepath.Dir(filePath))
	for i, arg := range entry.Arguments {
	includeMatch := reGlobalInclude.FindStringSubmatch(arg)
	if len(includeMatch) > 0 {
	if len(includeMatch[1]) == 0 {
	preSystemIncludes = append(preSystemIncludes, entry.Arguments[i+1])
	} else {
	preSystemIncludes = append(preSystemIncludes, includeMatch[1])
	}
	}
	includeMatch = reSystemInclude.FindStringSubmatch(arg)
	if len(includeMatch) > 0 {
	if len(includeMatch[1]) == 0 {
	systemIncludesRaw = append(systemIncludesRaw, entry.Arguments[i+1])
	} else {
	systemIncludesRaw = append(systemIncludesRaw, includeMatch[1])
	}
	}
	includeMatch = reQuoteInclude.FindStringSubmatch(arg)
	if len(includeMatch) > 0 {
	if len(includeMatch[1]) == 0 {
	quoteIncludesRaw = append(quoteIncludesRaw, entry.Arguments[i+1])
	} else {
	quoteIncludesRaw = append(quoteIncludesRaw, includeMatch[1])
	}
	}
	}
	systemIncludesRaw = append(preSystemIncludes, systemIncludesRaw...)
	quoteIncludesRaw = append(quoteIncludesRaw, systemIncludesRaw...)

	// Deduplicate and keep the first one
	systemIncludeSeen := make(map[string]bool)
	quoteIncludeSeen := make(map[string]bool)
	for _, systemInclude := range systemIncludesRaw {
	if !filepath.IsAbs(systemInclude) {
	systemInclude = filepath.Join(entry.Directory, systemInclude)
	}
	if !systemIncludeSeen[systemInclude] {
	systemIncludeSeen[systemInclude] = true
	systemIncludes = append(systemIncludes, systemInclude)
	}
	}
	for _, quoteInclude := range quoteIncludesRaw {
	if !filepath.IsAbs(quoteInclude) {
	quoteInclude = filepath.Join(entry.Directory, quoteInclude)
	}
	if !quoteIncludeSeen[quoteInclude] {
	quoteIncludeSeen[quoteInclude] = true
	quoteIncludes = append(quoteIncludes, quoteInclude)
	}
	}
	return
	}

	func main() {
	flag.Parse()
	compilationDBFile, err := os.Open(*compilationDBPath)
	if err != nil {
	log.Fatalf("failed to open compilation db: %v", err)
	}
	var compilationDB compilationDB
	if err := json.NewDecoder(compilationDBFile).Decode(&compilationDB); err != nil {
	log.Fatalf("failed to read compilation db: %v", err)
	}
	specRaw, err := os.ReadFile(*specPath)
	var spec ccfixspec.CCFixSpec
	if err := prototext.Unmarshal(specRaw, &spec); err != nil {
	log.Fatalf("failed to load spec: %v", err)
	}

	isGeneratedFile := make(map[string]bool)
	for _, entry := range spec.GeneratedFile {
	isGeneratedFile[filepath.Join(*workspacePath, entry.Path)] = true
	}

	rewriteMetadata := make(rewriteMetadata)

	// Iterate over all source files in the compilation database and analyze
	// them one-by-one
	for _, entry := range compilationDB {
	quoteIncludes, systemIncludes, err := getIncludeDirs(entry)
	if err != nil {
	log.Println(err)
	continue
	}
	filePath := entry.File
	if !filepath.IsAbs(entry.File) {
	filePath = filepath.Join(entry.Directory, entry.File)
	}
	includedFiles := rewriteMetadata.fixIncludesAndGetRefs(filePath, quoteIncludes, systemIncludes, &spec, isGeneratedFile)

	// seen stores the path of already-visited files, similar to #pragma once
	seen := make(map[string]bool)
	// rec recursively resolves includes and records rewrites
	var rec func([]string)
	rec = func(files []string) {
	for _, f := range files {
	if seen[f] {
	continue
	}
	seen[f] = true
	icf2 := rewriteMetadata.fixIncludesAndGetRefs(f, quoteIncludes, systemIncludes, &spec, isGeneratedFile)
	rec(icf2)
	}
	}
	rec(includedFiles)
	}

	// Perform all recorded rewrites on the actual files
	for file, rew := range rewriteMetadata {
	outFile, err := os.Create(file)
	if err != nil {
	log.Fatalf("failed to open file for writing output: %v", err)
	}
	defer outFile.Close()
	if _, err := rew.rewrites.replacer().WriteString(outFile, rew.source); err != nil {
	log.Fatalf("failed to write file %v: %v", file, err)
	}
	}
	}