Don't rebuild dependency files unnecessarily when doing "make 1" etc
[ghc.git] / rules / build-dependencies.mk
1 # -----------------------------------------------------------------------------
2 #
3 # (c) 2009 The University of Glasgow
4 #
5 # This file is part of the GHC build system.
6 #
7 # To understand how the build system works and how to modify it, see
8 # http://hackage.haskell.org/trac/ghc/wiki/Building/Architecture
9 # http://hackage.haskell.org/trac/ghc/wiki/Building/Modifying
10 #
11 # -----------------------------------------------------------------------------
12
13 define build-dependencies
14 # $1 = dir
15 # $2 = distdir
16 # $3 = GHC stage to use (0 == bootstrapping compiler)
17
18 $1_$2_depfile_haskell = $$($1_$2_depfile_base).haskell
19 $1_$2_depfile_c_asm = $$($1_$2_depfile_base).c_asm
20
21 $1_$2_C_FILES_DEPS = $$(filter-out $$($1_$2_C_FILES_NODEPS),$$($1_$2_C_FILES))
22
23 $1_$2_MKDEPENDHS_FLAGS = -dep-makefile $$($1_$2_depfile_haskell).tmp $$(foreach way,$$(filter-out v,$$($1_$2_WAYS)),-dep-suffix $$(way))
24 ifneq "$3" "0"
25 $1_$2_MKDEPENDHS_FLAGS += -include-pkg-deps
26 endif
27
28 ifneq "$$($1_$2_NO_BUILD_DEPS)" "YES"
29
30 $$($1_$2_depfile_haskell) : $$($1_$2_HS_SRCS) $$($1_$2_HS_BOOT_SRCS) $$($1_$2_HC_MK_DEPEND_DEP) | $$$$(dir $$$$@)/.
31 "$$(RM)" $$(RM_OPTS) $$@.tmp
32 touch $$@.tmp
33 ifneq "$$($1_$2_HS_SRCS)" ""
34 "$$($1_$2_HC_MK_DEPEND)" -M $$($1_$2_MKDEPENDHS_FLAGS) \
35 $$(filter-out -split-objs, $$($1_$2_v_ALL_HC_OPTS)) \
36 $$($1_$2_HS_SRCS)
37 endif
38 echo "$1_$2_depfile_haskell_EXISTS = YES" >> $$@.tmp
39 ifneq "$$($1_$2_SLASH_MODS)" ""
40 for dir in $$(sort $$(foreach mod,$$($1_$2_SLASH_MODS),$1/$2/build/$$(dir $$(mod)))); do \
41 if test ! -d $$$$dir; then mkdir -p $$$$dir; fi \
42 done
43 endif
44 mv $$@.tmp $$@
45
46 $$($1_$2_depfile_c_asm) : $$($1_$2_C_FILES_DEPS) $$($1_$2_S_FILES) | $$$$(dir $$$$@)/.
47 "$$(RM)" $$(RM_OPTS) $$@.tmp
48 touch $$@.tmp
49 ifneq "$$(strip $$($1_$2_C_FILES_DEPS)$$($1_$2_S_FILES))" ""
50 # We ought to actually do this for each way in $$($1_$2_WAYS), but then
51 # it takes a long time to make the C deps for the RTS (30 seconds rather
52 # than 3), so instead we just pass the list of ways in and let addCFileDeps
53 # copy the deps for each way on the assumption that they are the same
54 $$(foreach f,$$($1_$2_C_FILES_DEPS) $$($1_$2_S_FILES), \
55 $$(call addCFileDeps,$1,$2,$$($1_$2_depfile_c_asm),$$f,$$($1_$2_WAYS)))
56 "$$(RM)" $$(RM_OPTS) $$@.bit
57 endif
58 echo "$1_$2_depfile_c_asm_EXISTS = YES" >> $$@.tmp
59 mv $$@.tmp $$@
60
61 endif # $1_$2_NO_BUILD_DEPS
62
63 # Note sed magic above: mkdependC can't do -odir stuff, so we have to
64 # munge the dependencies it generates to refer to the correct targets.
65
66 # Seems as good a place as any to attach the unlit dependency
67 $$($1_$2_depfile_haskell) : $$(UNLIT)
68
69 ifneq "$$(NO_INCLUDE_DEPS)" "YES"
70 # This next test stops us rebuilding all the dep files when doing e.g.
71 # "make 1" in compiler or ghc. If stage is blank (just building normally.
72 # so we want all deps), or if $3 is stage-1 (when building stage n, we
73 # use stage n-1, so we want any dependencies used by the stage n-1
74 # compiler), then we want to include the dependencies.
75 ifneq "$$(or $$(if $$(stage),,YES),$$(findstring $3,$$(word $$(stage),0 1 2 3)))" ""
76 ifneq "$$(strip $$($1_$2_HS_SRCS) $$($1_$2_HS_BOOT_SRCS))" ""
77 include $$($1_$2_depfile_haskell)
78 endif
79 include $$($1_$2_depfile_c_asm)
80 else
81 ifeq "$$(DEBUG)" "YES"
82 $$(warning not building dependencies in $1)
83 endif
84 endif
85 endif
86
87 endef
88
89 # This comment is outside the "define addCFileDeps" as that definition
90 # is a list of command lines, and if it is inside it then we pass this
91 # comment to the shell every time we call the definition.
92 # $1 = dir
93 # $2 = distdir
94 # $3 = depfile
95 # $4 = file
96 # $5 = ways
97 #
98 # The formatting of this definition (e.g. the blank line above) is
99 # important, in order to get make to generate the right makefile code.
100 #
101 # "1s|\.o|\.$($w_osuf)|"
102 # We will have dependencies for .o files, so we need to fix them up
103 # for the right object suffix for the way we're doing
104 # "1s|^|$(dir $4)|"
105 # We always get deps for just foo.o when the file we're making is
106 # a/b/c/foo.o, so we need to prepend the directory of the source file
107 # "1s|$1/|$1/$2/build/|"
108 # Well, almost. We actually need to insert e.g. "dist/build" in the
109 # middle of that directory
110 # "1s|$2/build/$2/build|$2/build|g"
111 # But some source files, e.g. sm/Evac_thr.c, are also inside the
112 # "dist/build" directory, so now we've just made
113 # "dist/build/dist/build", so we need to remove the duplication
114 # again
115 # "s|$(TOP)/||g$(CASE_INSENSITIVE_SED)"
116 # Finally, when making deps for packages like ghc stage2, we have
117 # some include paths for packages registered in the in-tree package
118 # database. These include paths are full (i.e. not relative) paths,
119 # which means that the "cpp -MM" output uses full paths in some cases.
120 # This causes 2 problems:
121 # * they don't match up with the rules to rebuild the files, where
122 # appropriate.
123 # * on Windows, make interprets the colon in c:/foo/bar.h as make
124 # syntax.
125 # So we sed off $(TOP). Unfortunately, on Windows, the case for the
126 # drive letter is sometimes different in what $(TOP) starts with, and
127 # what the path in the package database starts with. We therefore
128 # need to do the substitution case-insensitively on Windows. But
129 # the s///i modifier isn't portable, so we set CASE_INSENSITIVE_SED
130 # to "i" on Windows and "" on any other platform.
131 define addCFileDeps
132
133 $(CPP) $($1_$2_MKDEPENDC_OPTS) $($1_$2_v_ALL_CC_OPTS) $($(basename $4)_CC_OPTS) -MM $4 -MF $3.bit
134 $(foreach w,$5,sed -e "1s|\.o|\.$($w_osuf)|" -e "1s|^|$(dir $4)|" -e "1s|$1/|$1/$2/build/|" -e "1s|$2/build/$2/build|$2/build|g" -e "s|$(TOP)/||g$(CASE_INSENSITIVE_SED)" $3.bit >> $3.tmp &&) true
135 endef
136
137 ifeq "$(Windows)" "YES"
138 CASE_INSENSITIVE_SED = i
139 else
140 CASE_INSENSITIVE_SED =
141 endif
142