[libxml2] Fix dependency resolution in configure.ac

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 88a8757bfe2734ab6928c783d5afec50c241f640
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Thu Sep 1 23:44:00 2022 +0200

    Fix dependency resolution in configure.ac
    
    This mainly fixes the case of disabling a single module, for example
    
        ./configure --without-xpath
    
    Before, there were still a few cases where a module wouldn't be disabled
    unless another module depending on it were disabled, too. Finding the
    correct options to really disable some modules could be extremely hard
    for casual users.
    
    Now every --without option should reliably disable dependent modules
    unless they were specifcally requested. In the latter case, a warning is
    printed consistently.
    
    Some missing dependencies were added and the logic was consolidated in a
    single code section.

 configure.ac | 302 +++++++++++++++++++++++++----------------------------------
 1 file changed, 125 insertions(+), 177 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index f2bbeddc..3e7879b5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -186,159 +186,143 @@ AC_ARG_WITH(coverage,
 dnl
 dnl hard dependencies on options
 dnl
-if test "$with_schemas" = "yes"
-then
-    with_pattern=yes
-    with_regexps=yes
-fi
-if test "$with_schematron" = "yes"
-then
-    with_pattern=yes
-    with_tree=yes
-    with_xpath=yes
-fi
-if test "$with_reader" = "yes"
-then
-    with_push=yes
-fi
-if test "$with_xptr_locs" = "yes"
-then
-    with_xptr=yes
-fi
-if test "$with_xptr" = "yes"
-then
-    with_xpath=yes
-fi
-dnl
-dnl option to build a minimal libxml2 library
-dnl
-if test "$with_minimum" = "yes"
-then
-    echo "Configuring for a minimal library"
-    if test "$with_c14n" = ""
-    then
-      with_c14n=no
-    fi
-    if test "$with_catalog" = ""
-    then
-      with_catalog=no
-    fi
-    echo So far so good!
-    if test "$with_debug" = ""
-    then
-      with_debug=no
-    fi
-    if test "$with_fexceptions" = ""
-    then
-      with_fexceptions=no
-    fi
-    if test "$with_history" = ""
-    then
-      with_history=no
-    fi
-    if test "$with_html" = ""
-    then
-      with_html=no
+if test "$with_c14n" = "yes"; then
+    if test "$with_output" = "no"; then
+        echo WARNING: --with-c14n overrides --without-output
     fi
-    if test "$with_http" = ""
-    then
-      with_http=no 
-    fi
-    if test "$with_iconv" = ""
-    then
-      with_iconv=no
+    with_output=yes
+    if test "$with_xpath" = "no"; then
+        echo WARNING: --with-c14n overrides --without-xpath
     fi
-    if test "$with_iso8859x" = ""
-    then
-      with_iso8859x=no
-    fi
-    if test "$with_mem_debug" = ""
-    then 
-      with_mem_debug=no
-    fi
-    if test "$with_output" = ""
-    then
-      with_output=no
-    fi
-    if test "$with_pattern" = ""
-    then
-      with_pattern=no
-    fi
-    if test "$with_push" = ""
-    then
-      with_push=no
+    with_xpath=yes
+fi
+if test "$with_schemas" = "yes"; then
+    if test "$with_pattern" = "no"; then
+        echo WARNING: --with-schemas overrides --without-pattern
     fi
-    if test "$with_python" = ""
-    then
-      with_python=no
+    with_pattern=yes
+    if test "$with_regexps" = "no"; then
+        echo WARNING: --with-schemas overrides --without-regexps
     fi
-    if test "$with_reader" = ""
-    then
-      with_reader=no
+    with_regexps=yes
+fi
+if test "$with_schematron" = "yes"; then
+    if test "$with_pattern" = "no"; then
+        echo WARNING: --with-schematron overrides --without-pattern
     fi
-    if test "$with_readline" = ""
-    then
-      with_readline=no
+    with_pattern=yes
+    if test "$with_tree" = "no"; then
+        echo WARNING: --with-schematron overrides --without-tree
     fi
-    if test "$with_regexps" = ""
-    then
-      with_regexps=no
+    with_tree=yes
+    if test "$with_xpath" = "no"; then
+        echo WARNING: --with-schematron overrides --without-xpath
     fi
-    if test "$with_run_debug" = ""
-    then
-      with_run_debug=no
+    with_xpath=yes
+fi
+if test "$with_reader" = "yes"; then
+    if test "$with_push" = "no"; then
+        echo WARNING: --with-reader overrides --without-push
     fi
-    if test "$with_sax1" = ""
-    then
-      with_sax1=no
+    with_push=yes
+    if test "$with_tree" = "no"; then
+        echo WARNING: --with-reader overrides --without-tree
     fi
-    if test "$with_schemas" = ""
-    then
-      with_schemas=no
+    with_tree=yes
+fi
+if test "$with_writer" = "yes"; then
+    if test "$with_output" = "no"; then
+        echo WARNING: --with-writer overrides --without-output
     fi
-    if test "$with_schematron" = ""
-    then
-      with_schematron=no
+    with_output=yes
+    if test "$with_push" = "no"; then
+        echo WARNING: --with-writer overrides --without-push
     fi
-    if test "$with_threads" = ""
-    then
-      with_threads=no
+    with_push=yes
+fi
+if test "$with_xinclude" = "yes"; then
+    if test "$with_xpath" = "no"; then
+        echo WARNING: --with-xinclude overrides --without-xpath
     fi
-    if test "$with_thread_alloc" = ""
-    then
-      with_thread_alloc=no
-   fi
-    if test "$with_tree" = ""
-    then
-      with_tree=no
+    with_xpath=yes
+fi
+if test "$with_xptr_locs" = "yes"; then
+    if test "$with_xptr" = "no"; then
+        echo WARNING: --with-xptr-locs overrides --without-xptr
     fi
-    if test "$with_valid" = ""
-    then
-      with_valid=no
+    with_xptr=yes
+fi
+if test "$with_xptr" = "yes"; then
+    if test "$with_xpath" = "no"; then
+        echo WARNING: --with-xptr overrides --without-xpath
     fi
-    if test "$with_writer" = ""
-    then
-      with_writer=no
+    with_xpath=yes
+fi
+
+if test "$with_minimum" = "yes"; then
+    dnl
+    dnl option to build a minimal libxml2 library
+    dnl
+    echo "Configuring for a minimal library"
+    test "$with_c14n" = "" && with_c14n=no
+    test "$with_catalog" = "" && with_catalog=no
+    test "$with_debug" = "" && with_debug=no
+    test "$with_fexceptions" = "" && with_fexceptions=no
+    test "$with_history" = "" && with_history=no
+    test "$with_html" = "" && with_html=no
+    test "$with_http" = "" && with_http=no
+    test "$with_iconv" = "" && with_iconv=no
+    test "$with_iso8859x" = "" && with_iso8859x=no
+    test "$with_mem_debug" = "" && with_mem_debug=no
+    test "$with_output" = "" && with_output=no
+    test "$with_pattern" = "" && with_pattern=no
+    test "$with_push" = "" && with_push=no
+    test "$with_python" = "" && with_python=no
+    test "$with_reader" = "" && with_reader=no
+    test "$with_readline" = "" && with_readline=no
+    test "$with_regexps" = "" && with_regexps=no
+    test "$with_run_debug" = "" && with_run_debug=no
+    test "$with_sax1" = "" && with_sax1=no
+    test "$with_schemas" = "" && with_schemas=no
+    test "$with_schematron" = "" && with_schematron=no
+    test "$with_threads" = "" && with_threads=no
+    test "$with_thread_alloc" = "" && with_thread_alloc=no
+    test "$with_tree" = "" && with_tree=no
+    test "$with_valid" = "" && with_valid=no
+    test "$with_writer" = "" && with_writer=no
+    test "$with_xinclude" = "" && with_xinclude=no
+    test "$with_xpath" = "" && with_xpath=no
+    test "$with_xptr" = "" && with_xptr=no
+    test "$with_zlib" = "" && with_zlib=no
+    test "$with_modules" = "" && with_modules=no
+else
+    dnl
+    dnl Disable dependent modules
+    dnl
+    if test "$with_output" = "no"; then
+        with_c14n=no
+        with_writer=no
     fi
-    if test "$with_xinclude" = ""
-    then
-      with_xinclude=no
+    if test "$with_pattern" = "no"; then
+        with_schemas=no
+        with_schematron=no
     fi
-    if test "$with_xpath" = ""
-    then
-      with_xpath=no
+    if test "$with_push" = "no"; then
+        with_reader=no
+        with_writer=no
     fi
-    if test "$with_xptr" = ""
-    then
-      with_xptr=no
+    if test "$with_regexps" = "no"; then
+        with_schemas=no
     fi
-    if test "$with_zlib" = ""
-    then
-      with_zlib=no
+    if test "$with_tree" = "no"; then
+        with_reader=no
+        with_schematron=no
     fi
-    if test "$with_modules" = ""
-    then
-      with_modules=no
+    if test "$with_xpath" = "no"; then
+        with_c14n=no
+        with_schematron=no
+        with_xinclude=no
+        with_xptr=no
     fi
 fi
 
@@ -985,10 +969,6 @@ if test "$with_reader" = "no" ; then
     WITH_READER=0
 else    
     WITH_READER=1
-    if test "$with_push" = "no" ; then
-        echo xmlReader requires Push interface - enabling it
-       with_push=yes
-    fi
 fi
 AC_SUBST(WITH_READER)
 AM_CONDITIONAL(WITH_READER_SOURCES, test "$WITH_READER" = "1")
@@ -998,14 +978,6 @@ if test "$with_writer" = "no" ; then
     WITH_WRITER=0
 else    
     WITH_WRITER=1
-    if test "$with_push" = "no" ; then
-        echo xmlWriter requires Push interface - enabling it
-       with_push=yes
-    fi
-    if test "$with_output" = "no" ; then
-        echo xmlWriter requires Output interface - enabling it
-       with_output=yes
-    fi
 fi
 AC_SUBST(WITH_WRITER)
 AM_CONDITIONAL(WITH_WRITER_SOURCES, test "$WITH_WRITER" = "1")
@@ -1069,29 +1041,22 @@ if test "$with_xptr" = "no" ; then
     WITH_XPTR_LOCS=0
 else    
     WITH_XPTR=1
-    if test "$with_xpath" = "no" ; then
-        echo XPointer requires XPath support - enabling it
-       with_xpath=yes
-    fi
-    if test "$with_xptr_locs" = "yes" ; then
-        WITH_XPTR_LOCS=1
-    else
-        WITH_XPTR_LOCS=0
-    fi
 fi
 AC_SUBST(WITH_XPTR)
-AC_SUBST(WITH_XPTR_LOCS)
 AM_CONDITIONAL(WITH_XPTR_SOURCES, test "$WITH_XPTR" = "1")
 
+if test "$with_xptr_locs" = "yes" ; then
+    WITH_XPTR_LOCS=1
+else
+    WITH_XPTR_LOCS=0
+fi
+AC_SUBST(WITH_XPTR_LOCS)
+
 if test "$with_c14n" = "no" ; then
     echo Disabling C14N support
     WITH_C14N=0
 else    
     WITH_C14N=1
-    if test "$with_xpath" = "no" ; then
-        echo C14N requires XPath support - enabling it
-       with_xpath=yes
-    fi
 fi
 AC_SUBST(WITH_C14N)
 AM_CONDITIONAL(WITH_C14N_SOURCES, test "$WITH_C14N" = "1")
@@ -1099,34 +1064,18 @@ AM_CONDITIONAL(WITH_C14N_SOURCES, test "$WITH_C14N" = "1")
 if test "$with_xinclude" = "no" ; then
     echo Disabling XInclude support
     WITH_XINCLUDE=0
-    with_xinclude="no"
 else    
     WITH_XINCLUDE=1
-    if test "$with_xpath" = "no" ; then
-        echo XInclude requires XPath support - enabling it
-       with_xpath=yes
-    fi
 fi
 AC_SUBST(WITH_XINCLUDE)
 AM_CONDITIONAL(WITH_XINCLUDE_SOURCES, test "$WITH_XINCLUDE" = "1")
 
-if test "$with_xptr" = "" && test "$with_xpath" = "no" ; then
-    with_xptr=no
-fi
-
-if test "$with_schematron" = "" && test "$with_xpath" = "no" ; then
-    with_schematron=no
-fi
-
 if test "$with_schematron" = "no" ; then
     echo "Disabling Schematron support"
     WITH_SCHEMATRON=0
 else 
     echo "Enabled Schematron support"
     WITH_SCHEMATRON=1
-    with_xpath=yes
-    with_pattern=yes
-    with_schematron=yes
 fi
 AC_SUBST(WITH_SCHEMATRON)
 AM_CONDITIONAL(WITH_SCHEMATRON_SOURCES, test "$WITH_SCHEMATRON" = "1")
@@ -1279,7 +1228,6 @@ if test "$with_schemas" = "no" ; then
 else    
     echo "Enabled Schemas/Relax-NG support"
     WITH_SCHEMAS=1
-    with_regexps=yes
 fi
 AC_SUBST(WITH_SCHEMAS)
 AM_CONDITIONAL(WITH_SCHEMAS_SOURCES, test "$WITH_SCHEMAS" = "1")