header.ninja

COMMONFLAGS = -stdlib=libc++ -pthread
DEBUGFLAGS = -ggdb3 -gsplit-dwarf
CXXFLAGS =  -fcolor-diagnostics -fPIC -Isrc -Ibuild/src -std=c++2a $COMMONFLAGS $DEBUGFLAGS
LIBS = -lc++fs -lc++experimental
LINKFLAGS = -fuse-ld=lld $COMMONFLAGS
#MODULE_CODEGEN = -Xclang -fmodules-debuginfo -Xclang -fmodules-codegen

MODULE_SCAN_SED_SCRIPT = -E -e '$
    s/^\s*(export\s+)?import\s+(<[^>]+>|"[^"]+")\s*;/#include \2\n/g ; $
    s/^\s*(export\s+)?import\s+([^;]+);/__MN_FAKE_IMPORT__ \2;/g $
    '
MODULE_SCAN_AWK_SCRIPT = $
    ' $
    match($$0, "^\\s*__MN_FAKE_IMPORT__\\s+([^;]*);", m) { print m[1] } $
    match($$0, "^\\s*((export)\\s+)?module\\s+([^;]*);", m) { mod = sprintf("module,%s,%s", m[2], m[3]) } END { if (mod) print(mod); }$
    '

rule SCAN
    command = $CXX $CXXFLAGS -w -E -x $KIND $in -o /dev/null -MD -MF $out.d -MT $out && $MAKE_NINJA --scan $out.d $in $out $PCMFLAGS_FILE
    description = SCAN $in
    deps = gcc
    depfile = $out.d
    restat = 1

rule HEADER_UNIT
    command = $CXX $CXXFLAGS @$PCMFLAGS_FILE $MODULE_CODEGEN -c -x c++-header -fmodule-name=$in --precompile $$(realpath $in) -o $out -MD -MF $out.d
    description = HEADER_UNIT $in
    deps = gcc
    depfile = $out.d
    restat = 1

rule HEADER_UNIT_CXX
    command = $CXX $DEBUGFLAGS -c $in -o $out
    description = HEADER_UNIT_CXX $out

rule MAYBE_MODULE_SCAN
    command = $
        echo '#line 1 "$in"' > $out.rewrite.cpp && $
        LC_ALL=C sed $MODULE_SCAN_SED_SCRIPT < $in >> $out.rewrite.cpp && $
        $CXX $CXXFLAGS -w -E -x $KIND -iquote $$(dirname $in) -Xclang -main-file-name -Xclang $in $out.rewrite.cpp -o $out.ii -MD -MF $out.d -MT $out && $
        LC_ALL=C gawk $MODULE_SCAN_AWK_SCRIPT < $out.ii > $out.ii.post && $
        $MAKE_NINJA --maybe-module-scan $out.d $out.ii.post $in $out $PCMFLAGS_FILE
    description = MAYBE_MODULE_SCAN $in
    deps = gcc
    depfile = $out.d
    restat = 1

rule CXXPRE
    command = $CXX $CXXFLAGS --precompile -x c++-module -c @$out.flags $in -MD -MF $out.d -MT $out && touch $out
    description = CXXPRE $in
    deps = gcc
    depfile = $out.d

# TODO split out cpp->o and pcm->o into separate rules and remove -Wno-unused-command-line-argument
rule CXX
    command = rm -f $out.d; $CXX $CXXFLAGS -Wno-unused-command-line-argument -c @$FLAGS_FILE -MD -MF $out.d -o $out && if [ ! -e $out.d ]; then echo '$out : ' > $out.d; fi
    description = CXX $in
    deps = gcc
    depfile = $out.d

rule LINKSCAN
    command = $MAKE_NINJA --link-scan $out $in
    description = LINKSCAN $out
    #deps = msvc
    #msvc_deps_prefix = opening:
    # restat = 1

rule BIN
    command = $CXX $LINKFLAGS -o $out -Wl,--start-group @$in.flags -Wl,--end-group $LIBS $EXTRALIBS
    description = BIN $out
    dyndep = $in
    
rule GENERATOR
    command = $MAKE_NINJA
    description = GENERATOR
    generator = 1
    restat = 1