To reduce maintenance effort, delete the `noerror-` variants of the compiler flags files (#1033)

* Avoid maintenance headaches: delete the `noerror-` variants of the
compiler flags files, since they essentially duplicate the `error-`
files modulo the replacement of `-Werror=` with `-W` and any changes in
comments.  (I verified the duplication with a script.)

For autoconf, reinstate the use of the `demote_errors` shell function to
derive the `noerror-` content from the `error-` content.  `demote_errors`
replaces `-Werror=` with `-W` when `WARNINGS_AS_ERRORS` is `no`.

Slightly reorder `configure.ac` so that the setting of
`WARNINGS_AS_ERRORS` takes effect before the `error-` files are sourced.

* Take a stab at updating the CMake files to match the changes I made to
the autoconf files to remove `noerror-` files.  I'm not much of a CMake
user so these changes are quite rough.

Looks like the duplication can be reduced with the introduction of a new
macro.

* Delete `noerror-` files from the MANIFEST.

* Reduce duplication in the CMake files: perform the
HDF5_ENABLE_WARNINGS_AS_ERRORS test once in the ADD_H5_FLAGS macro.

* Add a release note.

5 files changed, 0 insertions, 172 deletions

diff --git a/config/gnu-warnings/cxx-noerror-5 b/config/gnu-warnings/cxx-noerror-5
deleted file mode 100644
index 7bce3e8..0000000
--- a/config/gnu-warnings/cxx-noerror-5
+++ /dev/null
@@ -1,11 +0,0 @@
-#
-# In GCC 4.4.7, the compiler gripes about shadowed global
-# declarations when a local variable uses the name of a
-# function that's in a system header file.  For some reason,
-# later versions of GCC (e.g., 5.2.0) don't complain about
-# the shadowed globals.  Maybe later versions are less fussy?
-# Anyway, the shadowing seems to be harmless, and GCC 4.4.7
-# is not a supported compiler, so let us promote shadowed globals
-# warnings to errors only for GCC 5 and later.
-#
--Wshadow
diff --git a/config/gnu-warnings/cxx-noerror-general b/config/gnu-warnings/cxx-noerror-general
deleted file mode 100644
index 8cc1d94..0000000
--- a/config/gnu-warnings/cxx-noerror-general
+++ /dev/null
@@ -1,32 +0,0 @@
-#
-# HDF5 code should not trigger the following warnings under any
-# circumstances, so ask the compiler to treat them as errors:
-#
-# NOTE: c++/test files are not compatible with these warnings as errors
-#     c++/test/tcompound.cpp
-#       -Werror=cast-align
--Wcast-align
-# NOTE: c++/src files are not compatible with these warnings as errors
-#     c++/src/H5Object.cpp
-#       -Werror=missing-declarations
--Wmissing-declarations
--Wpacked
--Wredundant-decls
--Wswitch
-# NOTE: c++/test files are not compatible with these warnings as errors
-#     c++/test/tattr.cpp
-#       -Werror=unused-but-set-variable
--Wunused-but-set-variable
--Wunused-function
--Wunused-variable
-# NOTE: c++/src files are not compatible with these warnings as errors
-#     c++/src/H5Object.cpp,c++/src/H5StrType.cpp,c++/src/H5PredType.cpp
-#       -Werror=unused-parameter
--Wunused-parameter
-#
-# Other files not compatible
-# NOTE: c++/test files are not compatible with these warnings as errors
-#     c++/test/titerate.cpp,c++/test/tarray.cpp
-#       -Werror=missing-declarations
-#     c++/test/titerate.cpp,c++/test/tarray.cpp,c++/test/tlinks.cpp,c++/test/ttypes.cpp,c++/test/dsets.cpp
-#       -Werror=unused-parameter
diff --git a/config/gnu-warnings/noerror-5 b/config/gnu-warnings/noerror-5
deleted file mode 100644
index a7d40dd..0000000
--- a/config/gnu-warnings/noerror-5
+++ /dev/null
@@ -1,12 +0,0 @@
--Wincompatible-pointer-types
-#
-# In GCC 4.4.7, the compiler gripes about shadowed global
-# declarations when a local variable uses the name of a
-# function that's in a system header file.  For some reason,
-# later versions of GCC (e.g., 5.2.0) don't complain about
-# the shadowed globals.  Maybe later versions are less fussy?
-# Anyway, the shadowing seems to be harmless, and GCC 4.4.7
-# is not a supported compiler, so let us promote shadowed globals
-# warnings to errors only for GCC 5 and later.
-#
--Wshadow
diff --git a/config/gnu-warnings/noerror-8 b/config/gnu-warnings/noerror-8
deleted file mode 100644
index 2f54a4d..0000000
--- a/config/gnu-warnings/noerror-8
+++ /dev/null
@@ -1,25 +0,0 @@
-# NOTE: src/ files are not compatible with these warnings as errors
-#     src/H5Dchunk.c
-#       -Werror=cast-function-type
--Wcast-function-type
-#
-# For GCC 8, promote maybe-initialized warnings to an error.  GCC 8
-# reports 0 maybe-uninitialized warnings where earlier versions
-# make many false reports.  GCC 8 seems to analyze calls to static
-# in order to detect initializations that occur there.  It's possible
-# that GCC 8 only performs that analysis at -O3, though.
-#
-#
-# NOTE: File Driver files are not compatible with these warnings as errors
-#     H5FDlog.c,
-#       -Werror=maybe-uninitialized
--Wmaybe-uninitialized
-# NOTE: src/ files are not compatible with these warnings as errors
-#     src/H5Shyper.c,src/H5SL.c,src/H5Shyper.c
-#       -Werror=maybe-uninitialized
-# NOTE: Test files are not compatible with these warnings as errors
-#     test/cache_common.c,
-#       -Werror=maybe-uninitialized
-# NOTE: hl/src/ files are not compatible with these warnings as errors
-#     hl/src/H5DS.c,
-#       -Werror=maybe-uninitialized
diff --git a/config/gnu-warnings/noerror-general b/config/gnu-warnings/noerror-general
deleted file mode 100644
index f49d89a..0000000
--- a/config/gnu-warnings/noerror-general
+++ /dev/null
@@ -1,92 +0,0 @@
-#
-# These warnings will be treated as errors, using the error-general file,
-# when HDF5_ENABLE_WARNINGS_AS_ERRORS is set to true for CMake or
-# the --enable-warnings-as-errors option is specified for configure.
-#   Otherwise this file will be used to treat them as warnings.
-#
--Wbad-function-cast
--Wimplicit-function-declaration
--Wmissing-declarations
--Wmissing-prototypes
--Wnested-externs
--Wold-style-definition
--Wpacked
--Wpointer-sign
--Wpointer-to-int-cast
--Wredundant-decls
--Wstrict-prototypes
--Wswitch
-#
-#-Werror=discarded-qualifiers
-#
-#
-# NOTE: File Driver files are not compatible with these warnings as errors
-#     H5FDdirect.c,H5FDmpio.c,H5FDros3.c,
-#       -Werror=unused-function
-#
--Wunused-function
-#
-#     H5FDdrvr_module.h
-#       -Werror=unused-variable
-#
--Wunused-variable
-#
-#     H5VLpassthru.c
-#       -Werror=unused-parameter
-#
--Wunused-parameter
-#
-#
-#
-# NOTE: Tools files are not compatible with these warnings as errors
-#     lib/h5tools.c
-#       -Werror=cast-align
-#
--Wcast-align
-#
-#     lib/h5diff_array.c
-#       -Werror=unused-but-set-variable
-#
--Wunused-but-set-variable
-#
-#     lib/h5tools_utils.c
-#       -Werror=unused-parameter
-#
-#
-# NOTE: JNI files are not compatible with these warnings as errors
-#     jni/h5pDCPLImp.c,jni/nativeData.c,jni/h5util.c,jni/h5rImp.c
-#     jni/h5sImp.c,jni/h5tImp.c
-#       -Werror=cast-align
-#     jni/h5util.c
-#       -Werror=format(-overflow)
-#
--Wformat
-#
-#
-#Examples and tests do not use the same set of extensive warning flags as libraries
-# Here is a list of tests and examples that have issues with the stricter warnings as error
-#
-# NOTE: Test files are not compatible with these warnings as errors
-#     thread_id.c,
-#       -Werror=unused-function
-#     dsets.c
-#       -Werror=unused-parameter
-#     external.c,perform/sio_engine.c
-#       -Werror=format(-truncation)
-#
-#
-# NOTE: Examples files are not compatible with these warnings as errors
-#     h5_vds-eiger.c,h5_vds-exclim.c,h5_vds.c,h5_vds-exc.c,h5_vds-percival-unlim-maxmin.c
-#     h5_vds-percival.c,h5_read.c,h5_rdwt.c,h5_mount.c,h5_extend.c,h5_extend_write.c
-#     h5_write.c,h5_vds-simpleIO.c,h5_ref2reg_deprec.c,h5_crtgrp.c,h5_select.c
-#     h5_vds-percival-unlim.c,h5_crtatt.c,h5_group.c,h5_attribute.c,h5_crtdat.c
-#     h5_reference_deprec.c
-#     h5_rdwt.c,h5_crtgrp.c,h5_crtatt.c,h5_crtdat.c
-#       -Werror=strict-prototypes
-#     h5_rdwt.c,h5_crtgrp.c,h5_crtatt.c,h5_crtdat.c
-#       -Werror=old-style-definition
-#     h5_vds-exclim.c,h5_vds.c,h5_vds-exc.c,
-#       -Werror=unused-variable
-#     h5_elink_unix2win.c,h5_extlink.c,h5_attribute.c
-#       -Werror=unused-parameter
-