add better support for IWYU and fix things

Remove the "make iwyu" build target. Move the functionality into the
recently introduced lint.fish script. Fix a lot, but not all, of the
include-what-you-use errors. Specifically, it fixes all of the IWYU errors
on my OS X server but only removes some of them on my Ubuntu 14.04 server.

Fixes #2957

3 files changed, 157 insertions, 9 deletions

diff --git a/build_tools/iwyu.linux.imp b/build_tools/iwyu.linux.imp
new file mode 100644
index 00000000..6fc614ae
--- /dev/null
+++ b/build_tools/iwyu.linux.imp
@@ -0,0 +1,17 @@
+# Map file for the include-what-you-use tool on Linux.
+[
+    { include: ["<bits/fcntl-linux.h>", "private", "<fcntl.h>", "public"] },
+    { include: ["<bits/mman-linux.h>", "private", "<sys/mman.h>", "public"] },
+    { include: ["<bits/socket-linux.h>", "private", "<sys/socket.h>", "public"] },
+    { include: ["<bits/socket_type.h>", "private", "<sys/socket.h>", "public"] },
+    { include: ["<bits/local_lim.h>", "private", "<limits.h>", "public"] },
+    { include: ["<tr1/memory>", "public", "<memory>", "public"] },
+    { include: ["<features.h>", "public", "<stdio.h>", "public"] },
+    { include: ["<features.h>", "public", "<stddef.h>", "public"] },
+    { include: ["<features.h>", "public", "<unistd.h>", "public"] },
+
+    { symbol: ["size_t", "private", "<unistd.h>", "public"] },
+    { symbol: ["size_t", "private", "<stddef.h>", "public"] },
+    { symbol: ["size_t", "private", "<stdlib.h>", "public"] },
+    { symbol: ["uint64_t", "private", "<sys/types.h>", "public"] },
+]
diff --git a/build_tools/iwyu.osx.imp b/build_tools/iwyu.osx.imp
new file mode 100644
index 00000000..cad467cd
--- /dev/null
+++ b/build_tools/iwyu.osx.imp
@@ -0,0 +1,97 @@
+# Map file for the include-what-you-use tool on OS X. For some reason
+# the version installed by HomeBrew doesn't have useful mappings for the
+# system provided private headers.
+[
+    { include: ["<sys/_pthread/_pthread_once_t.h>", "private", "<pthread.h>", "public"] },
+    { include: ["<sys/_pthread/_pthread_mutex_t.h>", "private", "<pthread.h>", "public"] },
+    { include: ["<sys/_pthread/_pthread_rwlock_t.h>", "private", "<pthread.h>", "public"] },
+    { include: ["<sys/_pthread/_pthread_mutexattr_t.h>", "private", "<pthread.h>", "public"] },
+    { include: ["<sys/_pthread/_pthread_cond_t.h>", "private", "<pthread.h>", "public"] },
+    { include: ["<sys/_pthread/_pthread_t.h>", "private", "<pthread.h>", "public"] },
+    { include: ["<sys/_pthread/_pthread_key_t.h>", "private", "<pthread.h>", "public"] },
+    { include: ["<sys/_types/_posix_vdisable.h>", "private", "<pthread.h>", "public"] },
+    { include: ["<sys/_types/_time_t.h>", "private", "<time.h>", "public"] },
+    { include: ["<sys/_types/_suseconds_t.h>", "private", "<time.h>", "public"] },
+    { include: ["<sys/_types/_suseconds_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/errno.h>", "private", "<errno.h>", "public"] },
+    { include: ["<sys/unistd.h>", "private", "<unistd.h>", "public"] },
+    { include: ["<_wctype.h>", "private", "<wctype.h>", "public"] },
+    { include: ["<sys/fcntl.h>", "private", "<fcntl.h>", "public"] },
+    { include: ["<sys/_types/_seek_set.h>", "private", "<fcntl.h>", "public"] },
+    { include: ["<sys/_types/_mbstate_t.h>", "private", "<wchar.h>", "public"] },
+    { include: ["<iosfwd>", "private", "<string>", "public"] },
+    { include: ["<sys/_types/_s_ifmt.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_size_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_size_t.h>", "private", "<stdlib.h>", "public"] },
+    { include: ["<sys/_types/_mode_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_pid_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_fd_def.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_fd_isset.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_fd_set.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_fd_zero.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_timeval.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_uid_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<_types/_intmax_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<_types/_uintmax_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<_types/_uint8_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_int32_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<_types/_uint64_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_uintptr_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_dev_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_ino_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_va_list.h>", "private", "<stdio.h>", "public"] },
+    { include: ["<__functional_base>", "private", "<memory>", "public"] },
+    { include: ["<__functional_base>", "private", "<vector>", "public"] },
+    { include: ["<__functional_base>", "private", "<string>", "public"] },
+    { include: ["<__tree>", "private", "<map>", "public"] },
+    { include: ["<__tree>", "private", "<set>", "public"] },
+    { include: ["<_types/_uint32_t.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_va_list.h>", "private", "<sys/types.h>", "public"] },
+    { include: ["<sys/_types/_sigset_t.h>", "private", "<signal.h>", "public"] },
+    { include: ["<sys/signal.h>", "private", "<signal.h>", "public"] },
+    { include: ["<strings.h>", "private", "<string.h>", "public"] },
+    { include: ["<sys/termios.h>", "private", "<termios.h>", "public"] },
+    { include: ["<sys/ttycom.h>", "private", "<termios.h>", "public"] },
+    { include: ["<sys/syslimits.h>", "private", "<limits.h>", "public"] },
+    { include: ["<i386/limits.h>", "private", "<limits.h>", "public"] },
+    { include: ["<sys/_types/_wint_t.h>", "private", "<stddef.h>", "public"] },
+    { include: ["<sys/_select.h>", "private", "<select.h>", "public"] },
+    { include: ["<sys/cdefs.h>", "private", "<unistd.h>", "public"] },
+    { include: ["<istream>", "private", "<iostream>", "public"] },
+    { include: ["<sys/_endian.h>", "private", "<netinet/in.h>", "public"] },
+    { include: ["<sys/_types/_timespec.h>", "private", "<time.h>", "public"] },
+    { include: ["<sys/spawn.h>", "private", "<spawn.h>", "public"] },
+    { include: ["<sys/dirent.h>", "private", "<dirent.h>", "public"] },
+#   { include: ["<>", "private", "<>", "public"] },
+
+    { symbol: ["NULL", "private", "<stddef.h>", "public"] },
+    { symbol: ["NULL", "private", "<stdlib.h>", "public"] },
+    { symbol: ["NULL", "private", "<stdio.h>", "public"] },
+    { symbol: ["NULL", "private", "<unistd.h>", "public"] },
+    { symbol: ["off_t", "private", "<unistd.h>", "public"] },
+    { symbol: ["size_t", "private", "<unistd.h>", "public"] },
+    { symbol: ["size_t", "private", "<stddef.h>", "public"] },
+    { symbol: ["size_t", "private", "<stdlib.h>", "public"] },
+    { symbol: ["off_t", "private", "<sys/types.h>", "public"] },
+    { symbol: ["size_t", "private", "<sys/types.h>", "public"] },
+    { symbol: ["ssize_t", "private", "<sys/types.h>", "public"] },
+    { symbol: ["intptr_t", "private", "<unistd.h>", "public"] },
+    { symbol: ["ssize_t", "private", "<unistd.h>", "public"] },
+    { symbol: ["gid_t", "private", "<unistd.h>", "public"] },
+    { symbol: ["uid_t", "private", "<unistd.h>", "public"] },
+    { symbol: ["pid_t", "private", "<unistd.h>", "public"] },
+    { symbol: ["pid_t", "private", "<sys/types.h>", "public"] },
+    { symbol: ["uid_t", "private", "<sys/types.h>", "public"] },
+    { symbol: ["gid_t", "private", "<sys/types.h>", "public"] },
+    { symbol: ["uint32_t", "private", "<sys/types.h>", "public"] },
+    { symbol: ["uint32_t", "private", "<stdint.h>", "public"] },
+    { symbol: ["intptr_t", "private", "<stdint.h>", "public"] },
+    { symbol: ["size_t", "private", "<stdint.h>", "public"] },
+    { symbol: ["tparm", "private", "<ncurses.h>", "public"] },
+    { symbol: ["ERR", "private", "<ncurses.h>", "public"] },
+    { symbol: ["select", "private", "<sys/select.h>", "public"] },
+    { symbol: ["_LIBCPP_VERSION", "private", "<stddef.h>", "public"] },
+    { symbol: ["_LIBCPP_VERSION", "private", "<unistd.h>", "public"] },
+    { symbol: ["MB_CUR_MAX", "private", "<xlocale.h>", "public"] },
+    { symbol: ["MB_CUR_MAX", "private", "<stdlib.h>", "public"] },
+]
diff --git a/build_tools/lint.fish b/build_tools/lint.fish
index 287269da..5ac05d7d 100755
--- a/build_tools/lint.fish
+++ b/build_tools/lint.fish
@@ -7,6 +7,8 @@ set cppchecks warning,performance,portability,information,missingInclude
 set cppcheck_args
 set c_files
 set all no
+set kernel_name (uname -s)
+set machine_type (uname -m)
 
 set -gx CXX $argv[1]
 set -e argv[1]
@@ -17,15 +19,27 @@ if test "$argv[1]" = "--all"
     set -e argv[1]
 end
 
+if test $kernel_name = Linux
+    # This is an awful hack. However, the include-what-you-use program spews lots of errors like
+    #   /usr/include/unistd.h:226:10: fatal error: 'stddef.h' file not found
+    # if we don't explicitly tell it where to find the system headers on Linux. See
+    # http://stackoverflow.com/questions/19642590/libtooling-cant-find-stddef-h-nor-other-headers/
+    set -l sys_includes (eval $CXX -v -c src/builtin.cpp 2>&1 | \
+        sed -n -e '/^#include <...> search/,/^End of search list/s/^ *//p')[2..-2]
+    set -x CPLUS_INCLUDE_PATH (string join ':' $sys_includes)
+end
+
 # We only want -D and -I options to be passed thru to cppcheck.
 for arg in $argv
     if string match -q -- '-D*' $arg
         set cppcheck_args $cppcheck_args $arg
     else if string match -q -- '-I*' $arg
         set cppcheck_args $cppcheck_args $arg
+    else if string match -q -- '-iquote*' $arg
+        set cppcheck_args $cppcheck_args $arg
     end
 end
-if test (uname -m) = "x86_64"
+if test "$machine_type" = "x86_64"
     set cppcheck_args -D__x86_64__ -D__LP64__ $cppcheck_args
 end
 
@@ -37,7 +51,7 @@ else
     set files (git status --porcelain --short --untracked-files=all | sed -e 's/^ *[^ ]* *//')
     if not set -q files[1]
         # No pending changes so lint the files in the most recent commit.
-        set files (git show --word-diff=porcelain --name-only --pretty=oneline head)[2..-1]
+        set files (git show --word-diff=porcelain --name-only --pretty=oneline)[2..-1]
     end
 
     # Extract just the C/C++ files.
@@ -46,6 +60,26 @@ end
 
 # We now have a list of files to check so run the linters.
 if set -q c_files[1]
+    if type -q iwyu
+        # The stderr to stdout redirection is because cppcheck, incorrectly IMHO, writes its
+        # diagnostic messages to stderr. Anyone running this who wants to capture its output will
+        # expect those messages to be written to stdout.
+        for c_file in $c_files
+            echo
+            echo ========================================
+            echo Running IWYU on $c_file
+            echo ========================================
+            switch $kernel_name
+                case Darwin
+                    include-what-you-use -Xiwyu --no_default_mappings -Xiwyu --mapping_file=build_tools/iwyu.osx.imp $cppcheck_args $c_file 2>&1
+                case Linux
+                    include-what-you-use -Xiwyu --mapping_file=build_tools/iwyu.linux.imp $cppcheck_args $c_file 2>&1
+                case '*' # hope for the best
+                    include-what-you-use $cppcheck_args $c_file 2>&1
+            end
+        end
+    end
+
     if type -q cppcheck
         echo
         echo ========================================
@@ -54,7 +88,7 @@ if set -q c_files[1]
         # The stderr to stdout redirection is because cppcheck, incorrectly IMHO, writes its
         # diagnostic messages to stderr. Anyone running this who wants to capture its output will
         # expect those messages to be written to stdout.
-        cppcheck -q --verbose --std=posix --std=c11 --language=c++ --template "[{file}:{line}]: {severity} ({id}): {message}" --suppress=missingIncludeSystem --inline-suppr --enable=$cppchecks $cppcheck_args $c_files 2>& 1
+        cppcheck -q --verbose --std=posix --std=c11 --language=c++ --template "[{file}:{line}]: {severity} ({id}): {message}" --suppress=missingIncludeSystem --inline-suppr --enable=$cppchecks $cppcheck_args $c_files 2>&1
     end
 
     if type -q oclint
@@ -65,25 +99,25 @@ if set -q c_files[1]
         # The stderr to stdout redirection is because oclint, incorrectly writes its final summary
         # counts of the errors detected to stderr. Anyone running this who wants to capture its
         # output will expect those messages to be written to stdout.
-        if test (uname -s) = "Darwin"
+        if test "$kernel_name" = "Darwin"
             if not test -f compile_commands.json
-                xcodebuild > xcodebuild.log
-                oclint-xcodebuild xcodebuild.log > /dev/null
+                xcodebuild >xcodebuild.log
+                oclint-xcodebuild xcodebuild.log >/dev/null
             end
             if test $all = yes
-                oclint-json-compilation-database -e '/pcre2-10.21/' -- -enable-global-analysis 2>& 1
+                oclint-json-compilation-database -e '/pcre2-10.21/' -- -enable-global-analysis 2>&1
             else
                 set i_files
                 for f in $c_files
                     set i_files $i_files -i $f
                 end
                 echo oclint-json-compilation-database -e '/pcre2-10.21/' $i_files
-                oclint-json-compilation-database -e '/pcre2-10.21/' $i_files 2>& 1
+                oclint-json-compilation-database -e '/pcre2-10.21/' $i_files 2>&1
             end
         else
             # Presumably we're on Linux or other platform not requiring special
             # handling for oclint to work.
-            oclint $c_files -- $argv 2>& 1
+            oclint $c_files -- $argv 2>&1
         end
     end
 else