Saint's Log

Building Firefox with Debug Symbols

Building firefox with debug symbols has been a rather tricky endeavor for me for quite some time. The documentation on how to do this seems to indicate that adding these lines to your mozconfig file should be sufficient:

export MOZ_DEBUG_SYMBOLS=1
ac_add_options --enable-debugger-info-modules=yes

should do the trick. However, I have (for months now) been running into this make error: no rule to make nspr4.pdb needed by export whenever I try to build with debug symbols. Bug 338224 has a pending patch for this issue. In the mean time, the following trick seems to solve the problem for me: force the -Zi compiler option into the compiler flags variable. For the nspr files, the PDB file will be generated as desired. For the other files, the -Zi option will be redundant but this fix gets you up and running ASAP. Here’s the associated patch file:

diff --git a/nsprpub/configure.in b/nsprpub/configure.in
--- a/nsprpub/configure.in
+++ b/nsprpub/configure.in
@@ -2827,18 +2827,18 @@ if test -n "$_SAVE_DEBUG_FLAGS"; then
 fi

 if test -n "$MOZ_OPTIMIZE"; then
     CFLAGS="$CFLAGS $_OPTIMIZE_FLAGS"
     CXXFLAGS="$CXXFLAGS $_OPTIMIZE_FLAGS"
 fi

 if test -n "$MOZ_DEBUG_SYMBOLS"; then
-    CFLAGS="$CFLAGS $_DEBUG_FLAGS"
-    CXXFLAGS="$CXXFLAGS $_DEBUG_FLAGS"
+    CFLAGS="$CFLAGS $_DEBUG_FLAGS -Zi"
+    CXXFLAGS="$CXXFLAGS $_DEBUG_FLAGS -Zi"
 fi

 if test -n "$MOZ_OPTIMIZE"; then
     OBJDIR_TAG=_OPT
 else
     OBJDIR_TAG=_DBG
 fi

Here is the mozconfig file I used with this patch:

. $topsrcdir/browser/config/mozconfig
mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/../obj
ac_add_options --disable-xpconnect-idispatch
ac_add_options --disable-activex
ac_add_options --disable-activex-scripting
ac_add_options --disable-accessibility
ac_add_options --enable-optimize=no
ac_add_options --enable-debug-symbols=yes