diff options
Diffstat (limited to 'rules/hi-rule.mk')
| -rw-r--r-- | rules/hi-rule.mk | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/rules/hi-rule.mk b/rules/hi-rule.mk index a059ce1378..e478c17aea 100644 --- a/rules/hi-rule.mk +++ b/rules/hi-rule.mk @@ -32,11 +32,13 @@ # exit 1; \ # fi # -# This version adds a useful sanity check, and is a good solution on -# platforms other than Windows. But on Windows it is expensive, as -# spawning a shell takes a while (about 0.3s). We'd like to avoid the -# shell if necessary. This also hides the message "nothing to be done -# for 'all'", since make thinks it has actually done something. +# This version adds a useful sanity check, and is a good solution, +# except that it means spawning a shell. This can be expensive, +# especially on Windows where spawning a shell takes about 0.3s. +# We'd like to avoid the shell if necessary. This also hides the +# message "nothing to be done for 'all'", since make thinks it has +# actually done something. Therefore we only use this version +# if ExtraMakefileSanityChecks is enabled. # # %.hi : %.o # @@ -61,6 +63,13 @@ # the ';' at the end signifies an "empty command" (see the GNU make # documentation). An empty command is enough to get GNU make to think # it has updated %.hi, but without actually spawning a shell to do so. +# +# However, given that rule, make thinks that it can make .hi files +# for any object file, even if the object file was created from e.g. +# a C source file. We therefore also add a dependency on the .hs/.lhs +# source file, which means we finally end up with rules like: +# +# a/%.hi : a/%.o b/%.hs ; define hi-rule # $1 = source directory, $2 = object directory, $3 = way @@ -72,7 +81,7 @@ $(call hi-rule-helper,$2/%.$$($3_way_)hi-boot : $2/%.$$($3_way_)o-boot $1/%.lhs) endef -ifeq "$(TargetOS_CPP)" "mingw32" +ifeq "$(ExtraMakefileSanityChecks)" "NO" define hi-rule-helper # $1 = rule header $1 ; |