please review fix for 7116322, enhance javac make rule with a little bit of instrumentation

[Kelly O'Hair]

Looks fine to me.

-kto

On Nov 28, 2011, at 8:00 PM, Stuart Marks wrote:

> 
> 
> On 11/28/11 7:00 PM, David Holmes wrote:
>> On 29/11/2011 10:42 AM, Stuart Marks wrote:
>>> Please review this change to add to the javac make rule some messages
>>> about the number of files being compiled, the current working directory,
>>> and a new message to demarcate the end of javac output.
>>> 
>>> This will help capture and analyze javac output, in particular, warning
>>> messages.
>>> diff -r 6fbd69f8e3ab make/common/Rules.gmk
>>> --- a/make/common/Rules.gmk Fri Nov 18 09:03:43 2011 +0000
>>> +++ b/make/common/Rules.gmk Mon Nov 28 16:34:34 2011 -0800
>>> @@ -236,9 +236,10 @@
>>> @if [ `$(CAT) $<.filtered | $(WC) -l` -ge 1 ] ; then \
>>> $(ECHO) "# Java sources to be compiled: (listed in file $<)"; \
>>> $(CAT) $<.filtered; \
>>> - $(ECHO) "# Running javac:"; \
>>> + $(ECHO) "# Running javac: `$(WC) -l < $<.filtered` files; in `pwd`"; \
>> 
>> Can we do this without running wc a second time?
>> 
>> Also shouldn't the current working directory be known from when the current
>> sub-dir is entered by make?
> 
> We can store the result of wc in a shell variable, but it has to be part of the same command as the if-statement that uses it, since successive lines of a make rule are executed by different shells. I've done this; see below.
> 
> The current directory can probably be deduced, but it's not as simple as tracking the current subdirectory. Often the current directory is arrived at after having left a subdirectory. For example, this rule is invoked after this fragment of enter/leave messages from make have occurred:
> 
> make[2]: Entering directory `/home/smarks/src/jdk8-jdk/make/java/java'
> make[3]: Entering directory `/home/smarks/src/jdk8-jdk/make/java/nio'
> make[3]: Leaving directory `/home/smarks/src/jdk8-jdk/make/java/nio'
> 
> The current directory is now ..../make/java/java which isn't from the most recent "Entering" message, nor is it the parent of the most recent "Leaving" message. In this case make/java/java/Makefile calls a recursive make in ../nio! So, a script would have to track all the enter/leave messages and keep a stack of directories entered and left in order to determine the current one. I could enhance the parsing scripts to do this, but it seems complex and error-prone.
> 
> If you're concerned about build performance, it *might* save a fork to replace a call to `pwd` with a make variable reference to $(CURDIR). The wc refactoring also saves a fork of the cat command. (Though I admit I don't know whether these actually speed things up or whether any change is measurable.)
> 
> Revised diff below. Note that I've indented the entire if-statement as well as its contents, which is why so many more lines are changed.
> 
> s'marks
> 
> 
> 
> diff -r 6fbd69f8e3ab make/common/Rules.gmk
> --- a/make/common/Rules.gmk     Fri Nov 18 09:03:43 2011 +0000
> +++ b/make/common/Rules.gmk     Mon Nov 28 19:40:34 2011 -0800
> @@ -233,13 +233,15 @@
>        @$(MKDIR) -p $(CLASSDESTDIR)
>        @$(RM) $<.filtered
>        @$(CAT) $< | $(NAWK) 'length>0' | $(SORT) -u > $<.filtered
> -       @if [ `$(CAT) $<.filtered | $(WC) -l` -ge 1 ] ; then \
> -         $(ECHO) "# Java sources to be compiled: (listed in file $<)"; \
> -         $(CAT) $<.filtered; \
> -         $(ECHO) "# Running javac:"; \
> -         $(ECHO) $(JAVAC_CMD) -sourcepath "$(SOURCEPATH)" -d $(CLASSDESTDIR) @$<.filtered; \
> -         $(JAVAC_CMD) -sourcepath "$(SOURCEPATH)" -d $(CLASSDESTDIR) @$<.filtered; \
> -       fi
> +       @numfiles=`$(WC) -l < $<.filtered` ; \
> +         if [ $$numfiles -ge 1 ] ; then \
> +           $(ECHO) "# Java sources to be compiled: (listed in file $<)"; \
> +           $(CAT) $<.filtered; \
> +           $(ECHO) "# Running javac: $$numfiles files; in $(CURDIR)"; \
> +           $(ECHO) $(JAVAC_CMD) -sourcepath "$(SOURCEPATH)" -d $(CLASSDESTDIR) @$<.filtered; \
> +           $(JAVAC_CMD) -sourcepath "$(SOURCEPATH)" -d $(CLASSDESTDIR) @$<.filtered; \
> +           $(ECHO) "# javac finished"; \
> +         fi
>        @$(java-vm-cleanup)
> 
> clobber clean::