From ca2921b11ce6024a570ff080d3d15c669f4becc1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Filip=20Str=C3=B6mb=C3=A4ck?= <fstromback@gmail.com>
Date: Mon, 11 Jan 2016 11:14:49 +0100
Subject: [PATCH] Added checks for precompiled header usage.

---
 .gitignore       |  2 ++
 src/cmdline.cpp  |  1 +
 src/compile.cpp  | 12 +++++++++++-
 src/includes.cpp | 47 ++++++++++++++++++++++++++++++++++++++++-------
 src/includes.h   |  7 +++++--
 todo.org         |  1 -
 6 files changed, 59 insertions(+), 11 deletions(-)

diff --git a/.gitignore b/.gitignore
index bd253b2..51db656 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,5 @@ mymake
 
 *.exe
 *.lib
+*.pch
+*.gch
diff --git a/src/cmdline.cpp b/src/cmdline.cpp
index d469d46..c3b4e0c 100644
--- a/src/cmdline.cpp
+++ b/src/cmdline.cpp
@@ -178,6 +178,7 @@ bool CmdLine::parseOption(char opt) {
 		break;
 	case 'a':
 		state = sArguments;
+		execute = tYes;
 		break;
 	case 'e':
 		execute = (state == sNegate) ? tNo : tYes;
diff --git a/src/compile.cpp b/src/compile.cpp
index 17aa6e6..883c1f2 100644
--- a/src/compile.cpp
+++ b/src/compile.cpp
@@ -45,7 +45,8 @@ namespace compile {
 		String outputName = config.getStr("output");
 
 		// Compile pre-compiled header first.
-		addFile(q, config.getStr("pch"), true);
+		String pchStr = config.getStr("pch");
+		addFile(q, pchStr, true);
 
 		// Add initial files.
 		addFiles(q, config.getArray("input"));
@@ -73,6 +74,15 @@ namespace compile {
 
 			// Add all other files we need.
 			IncludeInfo info = includes.info(now);
+
+			// Check so that any pch file is included first.
+			if (!pchStr.empty() && pchStr != info.firstInclude) {
+				PLN("ERROR: Precompiled header " << pchStr << " must be included first in each implementation file.");
+				PLN("This is not the case for " << now.makeRelative(wd) << ".");
+				PLN("You need to use '#include \"" << pchStr << "\"' (exactly like that), and use 'include=./'.");
+				return false;
+			}
+
 			for (set<Path>::const_iterator i = info.includes.begin(); i != info.includes.end(); ++i) {
 				DEBUG(now << " depends on " << *i, VERBOSE);
 				addFile(q, *i);
diff --git a/src/includes.cpp b/src/includes.cpp
index 6c53e35..41f1797 100644
--- a/src/includes.cpp
+++ b/src/includes.cpp
@@ -14,6 +14,8 @@ Timestamp IncludeInfo::lastModified() const {
 
 ostream &operator <<(ostream &to, const IncludeInfo &i) {
 	to << i.file << ": ";
+	if (!i.firstInclude.empty())
+		to << "(first: " << i.firstInclude << ") ";
 	join(to, i.includes);
 	return to;
 }
@@ -47,8 +49,7 @@ IncludeInfo Includes::info(const Path &file) {
 	}
 
 	// We need to update the cache...
-	IncludeInfo r(file);
-	r.includes = recursiveIncludesIn(file);
+	IncludeInfo r = recursiveIncludesIn(file);
 
 	cache[file] = Info(r, Timestamp());
 
@@ -69,17 +70,23 @@ Path Includes::resolveInclude(const Path &fromFile, const String &src) const {
 	throw IncludeError("The include " + src + " in file " + toS(fromFile) + " was not found!");
 }
 
-set<Path> Includes::recursiveIncludesIn(const Path &file) {
-	set<Path> result;
+IncludeInfo Includes::recursiveIncludesIn(const Path &file) {
+	bool first = true;
+	IncludeInfo result(file);
 
 	PathQueue to;
 	to.push(file);
 
 	while (to.any()) {
 		Path now = to.pop();
-		result << now;
+		result.includes << now;
 
-		includesIn(now, to);
+		if (first) {
+			includesIn(now, to, &result.firstInclude);
+			first = false;
+		} else {
+			includesIn(now, to, null);
+		}
 	}
 
 	return result;
@@ -108,18 +115,38 @@ static bool isInclude(const String &line, String &out) {
 	return true;
 }
 
-void Includes::includesIn(const Path &file, PathQueue &to) {
+static bool isBlank(const String &line) {
+	for (nat i = 0; i < line.size(); i++) {
+		switch (line[i]) {
+		case ' ':
+		case '\t':
+		case '\r':
+			break;
+		default:
+			return false;
+		}
+	}
+	return true;
+}
+
+void Includes::includesIn(const Path &file, PathQueue &to, String *firstInclude) {
 	ifstream in(toS(file).c_str());
+	bool first = true;
 
 	String include;
 	String line;
 	while (getline(in, line)) {
 		if (isInclude(line, include)) {
 			try {
+				if (first && firstInclude)
+					*firstInclude = include;
 				to << resolveInclude(file, include);
 			} catch (const IncludeError &e) {
 				WARNING(e.what());
 			}
+			first = false;
+		} else if (!isBlank(line)) {
+			first = false;
 		}
 	}
 }
@@ -163,6 +190,11 @@ void Includes::load(const Path &from) {
 
 			cache[path] = Info(path, time);
 			current = &cache[path];
+		} else if (type == '>') {
+			if (!current)
+				return;
+
+			getline(src, current->info.firstInclude);
 		} else if (type == '-') {
 			if (!current)
 				return;
@@ -185,6 +217,7 @@ void Includes::save(const Path &to) const {
 		const Info &info = i->second;
 
 		dest << "+" << info.lastModified.time << ' ' << info.info.file << endl;
+		dest << ">" << info.info.firstInclude << endl;
 
 		for (set<Path>::const_iterator i = info.info.includes.begin(); i != info.info.includes.end(); ++i) {
 			dest << "-" << *i << endl;
diff --git a/src/includes.h b/src/includes.h
index dd5f09b..8f6e98f 100644
--- a/src/includes.h
+++ b/src/includes.h
@@ -27,6 +27,9 @@ class IncludeInfo {
 	// The file itself.
 	Path file;
 
+	// The first included file (if any).
+	String firstInclude;
+
 	// All files included from this file.
 	set<Path> includes;
 
@@ -83,9 +86,9 @@ class Includes {
 	InfoMap cache;
 
 	// Find includes in file, and all files included from there.
-	set<Path> recursiveIncludesIn(const Path &file);
+	IncludeInfo recursiveIncludesIn(const Path &file);
 
 	// Find includes in file.
-	void includesIn(const Path &file, PathQueue &to);
+	void includesIn(const Path &file, PathQueue &to, String *firstInclude);
 
 };
diff --git a/todo.org b/todo.org
index d222620..579c256 100644
--- a/todo.org
+++ b/todo.org
@@ -2,7 +2,6 @@
   
   Move constants used with Config into string constants somewhere.
 
-  We should check so that precompiled headers are always included first in every .cpp-file.