logging: strip full paths from __FILE__ at compile-time

src/laminar.cpp

@@ -75,7 +75,7 @@ Laminar::Laminar(const char *home) :
     homePath(kj::Path::parse(&home[1])),
     fsHome(kj::newDiskFilesystem()->getRoot().openSubdir(homePath, kj::WriteMode::MODIFY))
 {
-    KJ_ASSERT(home[0] == '/');
+    LASSERT(home[0] == '/');
 
     archiveUrl = ARCHIVE_URL_DEFAULT;
     if(char* envArchive = getenv("LAMINAR_ARCHIVE_URL")) {

src/log.h

@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015 Oliver Giles
+/// Copyright 2015-2019 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -20,18 +20,51 @@
 #define LAMINAR_LOG_H_
 
 #include <kj/debug.h>
+#include <utility>
 
-// Simple override to prevent full paths to source files from
+// Prevent full file paths from appearing in log messages. With compiler
-// appearing in log messages. Assumes / is the path separator.
+// optimization, this compile-time method should completely prevent the
-// @see kj/debug.h
+// paths from being encoded into the binary at all. Assumes / is the
+// path separator.
+namespace _ {
+	constexpr const char* static_basename_impl(const char* b, const char* t) {
+		return *t == '\0' ? b : static_basename_impl(*t == '/' ? t+1 : b, t+1);
+	}
+	constexpr const char* static_basename(const char* p) {
+		return static_basename_impl(p, p); 
+	}
+	constexpr int static_strlen(const char* s) {
+		return *s == '\0' ? 0 : static_strlen(s + 1) + 1;
+	}
+	template<int N, int...I>
+	static constexpr decltype(auto) static_alloc_str_impl(const char* str, std::integer_sequence<int, I...>) { 
+		return (struct {char buf[N];}) {str[I]...};
+	}
+	template<int N>
+	static constexpr decltype(auto) static_alloc_str(const char* str) {
+		return static_alloc_str_impl<N>(str, std::make_integer_sequence<int, N>());
+	}
+}
+#define __FILE_BASE__ (_::static_alloc_str<_::static_strlen(_::static_basename(__FILE__))>(_::static_basename(__FILE__)).buf)
 
-#define _LBASENAME(path) strrchr(path, '/') ? strrchr(path, '/') + 1 : path
 
+// Provide alternative implementations to those from kj/debug.h which
+// use __FILE__ directly and thus cause the full path to be encoded in
+// the final binary
 #define LLOG(severity, ...) \
   if (!::kj::_::Debug::shouldLog(::kj::_::Debug::Severity::severity)) {} else \
-    ::kj::_::Debug::log(_LBASENAME(__FILE__), __LINE__, ::kj::_::Debug::Severity::severity, \
+    ::kj::_::Debug::log(__FILE_BASE__, __LINE__, \
-                        #__VA_ARGS__, __VA_ARGS__)
+      ::kj::_::Debug::Severity::severity, #__VA_ARGS__, __VA_ARGS__)
 
+#define LASSERT(cond, ...) \
+  if (KJ_LIKELY(cond)) {} else \
+    for (::kj::_::Debug::Fault f(__FILE_BASE__, __LINE__, \
+      ::kj::Exception::Type::FAILED, #cond, #__VA_ARGS__, ##__VA_ARGS__);; f.fatal())
+
+#define LSYSCALL(call, ...) \
+  if (auto _kjSyscallResult = ::kj::_::Debug::syscall([&](){return (call);}, false)) {} else \
+    for (::kj::_::Debug::Fault f(__FILE_BASE__, __LINE__, \
+      _kjSyscallResult.getErrorNumber(), #call, #__VA_ARGS__, ##__VA_ARGS__);; f.fatal())
 
 #endif // LAMINAR_LOG_H_
 

src/run.cpp

@@ -82,7 +82,7 @@ bool Run::configure(uint buildNum, std::shared_ptr<Node> nd, const kj::Directory
     kj::Path rd{"run",name,std::to_string(buildNum)};
     bool createWorkdir = true;
     KJ_IF_MAYBE(ls, fsHome.tryLstat(rd)) {
-        KJ_ASSERT(ls->type == kj::FsNode::Type::DIRECTORY);
+        LASSERT(ls->type == kj::FsNode::Type::DIRECTORY);
         LLOG(WARNING, "Working directory already exists, removing", rd.toString());
         if(fsHome.tryRemove(rd) == false) {
             LLOG(WARNING, "Failed to remove working directory");
@@ -194,7 +194,7 @@ bool Run::step() {
             PATH.append(p);
         }
 
-        KJ_SYSCALL(chdir((rootPath/currentScript.cwd).toString(true).cStr()));
+        LSYSCALL(chdir((rootPath/currentScript.cwd).toString(true).cStr()));
 
         // conf file env vars
         for(kj::Path& file : env) {

src/server.cpp

@@ -286,7 +286,7 @@ private:
         }, [](kj::Exception&& e){
             // server logs suggest early catching here avoids fatal exception later
             // TODO: reproduce in unit test
-            KJ_LOG(WARNING, e.getDescription());
+            LLOG(WARNING, e.getDescription());
             return kj::READY_NOW;
         });
     }