[PATCH] libnotmuch: build symbols list without relying on gcc -aux-info.

[PATCH] libnotmuch: build symbols list without relying on gcc -aux-info.

[david]

From: David Bremner <bremner@debian.org>

Carl reports "gcc -aux-info notmuch.aux lib/notmuch.h" does not
generate notmuch.aux for him with Debian gcc 4.6.0-8. A small
modification of the original sed regular expression allows us to work
directly from lib/notmuch.h, rather than preprocessing with gcc.

As with most such simple regex based "parsing", this is quite
sensitive to the input format, and needs that each symbol to be
exported from libnotmuch should

- start with "notmuch_"
- be the first non-whitespace token on the line
- be followed by an open parenthesis.
---
 lib/Makefile.local |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/lib/Makefile.local b/lib/Makefile.local
index a33ba34..0459fd0 100644
--- a/lib/Makefile.local
+++ b/lib/Makefile.local
@@ -76,9 +76,8 @@ $(dir)/$(LIBNAME): $(libnotmuch_modules) notmuch.sym
 	$(call quiet,CXX $(CXXFLAGS)) $(libnotmuch_modules) $(FINAL_LIBNOTMUCH_LDFLAGS) $(LIBRARY_LINK_FLAG) -o $@
 
 notmuch.sym: lib/notmuch.h
-	gcc -aux-info notmuch.aux $<
 	printf "{\nglobal:\n" > notmuch.sym
-	sed  -n 's/.*\(notmuch_[a-z_]*\) (.*/\t\1;/p' notmuch.aux >> notmuch.sym
+	sed  -n 's/^\s*\(notmuch_[a-z_]*\)\s*(.*/\t\1;/p' $< >> notmuch.sym
 	printf "local: *;\n};\n" >> notmuch.sym
 
 $(dir)/$(SONAME): $(dir)/$(LIBNAME)
@@ -103,4 +102,4 @@ install-$(dir): $(dir)/$(LIBNAME)
 	$(LIBRARY_INSTALL_POST_COMMAND)
 
 SRCS  := $(SRCS) $(libnotmuch_c_srcs) $(libnotmuch_cxx_srcs)
-CLEAN := $(CLEAN) $(libnotmuch_modules) $(dir)/$(SONAME) $(dir)/$(LINKER_NAME) $(dir)$(LIBNAME) libnotmuch.a notmuch.aux notmuch.sym
+CLEAN := $(CLEAN) $(libnotmuch_modules) $(dir)/$(SONAME) $(dir)/$(LINKER_NAME) $(dir)$(LIBNAME) libnotmuch.a notmuch.sym
-- 
1.7.5.4

[PATCH] libnotmuch: build symbols list without relying on gcc -aux-info.

[david]

From: David Bremner <bremner@debian.org>

Carl reports "gcc -aux-info notmuch.aux lib/notmuch.h" does not
generate notmuch.aux for him with Debian gcc 4.6.0-8.

Based on a suggestion by Austin Clements, this version uses objdump to
get the symbols from the object files.

Any symbol that

    - is in some object file in $(libnotmuch_modules), and
    - starts with notmuch_

will be exported.
---

 Here is another way of doing this, probably better unless you are
 very attached to the idea of declaring the API in the header file.
 

 lib/Makefile.local |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/lib/Makefile.local b/lib/Makefile.local
index a33ba34..38913c6 100644
--- a/lib/Makefile.local
+++ b/lib/Makefile.local
@@ -75,10 +75,9 @@ $(dir)/$(LIBNAME): $(libnotmuch_modules) notmuch.sym
 	echo $(libnotmuch_modules)
 	$(call quiet,CXX $(CXXFLAGS)) $(libnotmuch_modules) $(FINAL_LIBNOTMUCH_LDFLAGS) $(LIBRARY_LINK_FLAG) -o $@
 
-notmuch.sym: lib/notmuch.h
-	gcc -aux-info notmuch.aux $<
+notmuch.sym: $(libnotmuch_modules)
 	printf "{\nglobal:\n" > notmuch.sym
-	sed  -n 's/.*\(notmuch_[a-z_]*\) (.*/\t\1;/p' notmuch.aux >> notmuch.sym
+	objdump -t $(libnotmuch_modules)| awk '$$4 == ".text" && $$6 ~ "^notmuch" {print "\t"$$6";"}' >>notmuch.sym
 	printf "local: *;\n};\n" >> notmuch.sym
 
 $(dir)/$(SONAME): $(dir)/$(LIBNAME)
@@ -103,4 +102,4 @@ install-$(dir): $(dir)/$(LIBNAME)
 	$(LIBRARY_INSTALL_POST_COMMAND)
 
 SRCS  := $(SRCS) $(libnotmuch_c_srcs) $(libnotmuch_cxx_srcs)
-CLEAN := $(CLEAN) $(libnotmuch_modules) $(dir)/$(SONAME) $(dir)/$(LINKER_NAME) $(dir)$(LIBNAME) libnotmuch.a notmuch.aux notmuch.sym
+CLEAN := $(CLEAN) $(libnotmuch_modules) $(dir)/$(SONAME) $(dir)/$(LINKER_NAME) $(dir)$(LIBNAME) libnotmuch.a notmuch.sym
-- 
1.7.5.4

Re: [PATCH] libnotmuch: build symbols list without relying on gcc -aux-info.

[Carl Worth]

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On Sun, 26 Jun 2011 23:42:25 -0300, david@tethera.net wrote:
>  Here is another way of doing this, probably better unless you are
>  very attached to the idea of declaring the API in the header file.

Thanks for both of these, David. I've gone ahead and pushed the first,
(generating the symbol list with sed and notmuch.h).

I assume by "better" you mean that this one is less fragile to issues
like the precise formatting of our notmuch.h header file.

Meanwhile, though, our API *is* declared in the header file, (that's
what the header file exists for), so I do prefer to base our symbol list
on it.

In fact, the ideal would probably be to take the objdump method and use
it in the test suite to verify that its output matches the contents of
notmuch.sym generated from the header file.

-Carl

-- 
carl.d.worth@intel.com

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Re: [PATCH] libnotmuch: build symbols list without relying on gcc -aux-info.

[David Bremner]

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On Tue, 28 Jun 2011 12:04:39 -0700, Carl Worth <cworth@cworth.org> wrote:

> I assume by "better" you mean that this one is less fragile to issues
> like the precise formatting of our notmuch.h header file.

Yes, that's what I meant.

> Meanwhile, though, our API *is* declared in the header file, (that's
> what the header file exists for), so I do prefer to base our symbol list
> on it.

Sure, that makes sense to me.  I cherry-picked the sed patch to the
release branch.

> In fact, the ideal would probably be to take the objdump method and use
> it in the test suite to verify that its output matches the contents of
> notmuch.sym generated from the header file.

The second patch being turned into a test sounds like a great idea. I
can do that.

d



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New test for exported symbols

[David Bremner]

As long promised, here is a test to compare the list of symbols
retrieved with objdump to those from notmuch.sym

I didn't verify whether this runs properly during out of tree builds.

[PATCH 1/2] test/symbol-hiding: add some whitespace between tests

[David Bremner]

This is in preparation for adding a third test to this file
---
 test/symbol-hiding |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/test/symbol-hiding b/test/symbol-hiding
index f67b653..6d4e4ff 100755
--- a/test/symbol-hiding
+++ b/test/symbol-hiding
@@ -19,7 +19,9 @@ output="A Xapian exception occurred opening database: Couldn't stat 'fakedb/.not
 caught No chert database found at path \`./nonexistant'"
 
 mkdir -p fakedb/.notmuch
+
 test_expect_success 'running test' run_test
+
 test_begin_subtest 'checking output'
 test_expect_equal "$result" "$output" 
 test_done
-- 
1.7.5.4

[PATCH 2/2] test/symbol-hiding: compare exported symbols with existing one

[David Bremner]

We assume that any symbol starting with notmuch_ in lib/*.o should be
exported, and that only those symbols should be exported.
---
 test/symbol-hiding |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/test/symbol-hiding b/test/symbol-hiding
index 6d4e4ff..68f0d1b 100755
--- a/test/symbol-hiding
+++ b/test/symbol-hiding
@@ -24,4 +24,10 @@ test_expect_success 'running test' run_test
 
 test_begin_subtest 'checking output'
 test_expect_equal "$result" "$output" 
+
+test_begin_subtest 'comparing existing to exported symbols'
+objdump -t $TEST_DIRECTORY/../lib/*.o | awk '$4 == ".text" && $6 ~ "^notmuch" {print $6}' | sort | uniq > ACTUAL
+sed -n 's/[[:blank:]]*\(notmuch_[^;]*\);/\1/p' $TEST_DIRECTORY/../notmuch.sym | sort | uniq > EXPORTED
+test_expect_equal_file EXPORTED ACTUAL
+
 test_done
-- 
1.7.5.4

Re: New test for exported symbols

[David Bremner]

On Mon, 28 Nov 2011 22:51:14 -0800, David Bremner <bremner@debian.org> wrote:
> As long promised, here is a test to compare the list of symbols
> retrieved with objdump to those from notmuch.sym
> 
> I didn't verify whether this runs properly during out of tree builds.

aidecoe did verify this for me on Gentoo, so I pushed these