Version 1.20.10

Andreas Abel, 2025-09-14

• Drop support for GHC 7.
• Remove cabal flag old-locale.
• Compatibility with {-# LANGUAGE RecordDotSyntax #-} (Lennart Augustsson).
• Build tested with GHC 8.0 - 9.14 alpha1.

Version 1.20

• bugfixes for #if defined(FOO) && FOO(a,b)
• (1.20.1): fix version number
• (1.20.2): ensure all input/output is UTF8, regardless of locale
• (1.20.3): detect an absolute windows path with a drive letter in a #include
• (1.20.4): more windows path handling
• (1.20.5): revert change in 1.20.4
• (1.20.6): minor bugfix for crash in obscure corner case
• (1.20.7): bugfix for windows drive letter in #include
• (1.20.8): another bugfix for windows drive letter in #include

Version 1.19

• expose more of the cpphs API
• allow the static linking exception to the LGPL
• (1.19.1): don't warn about trailing comments in #ifdefs
• (1.19.2): fix build error
• (1.19.3): bugfix for hlint ticket #161 - interaction of --unlit/--linepragma

Version 1.18

• better lexing of Template Haskell single quotes (thanks to Stefan Wehr)
• (1.18.1): fix incomplete pattern match
• (1.18.2): bugfix for erroneous boolean intepretation of some macro expansions in #if clauses
• (1.18.3): further rewrites of the #if expression parser
• (1.18.4): fix the accidental flipping of comment-stripping behaviour with --cpp -traditional flags
• (1.18.5): fix a bug with windows filepath directory separators in a #include
• (1.18.6): bugfix to reject a macro usage with different arity than its definition
• (1.18.7): bugfix to accept a #include with absolute filepath
• (1.18.8): fix version number
• (1.18.9): accept #if defined foo as well as #if defined(foo)

Version 1.17

• recursively evaluate #if expressions after macro expansion (fix)
• (1.17.1): report the right version with cpphs --version

Version 1.16

• fix interaction of runCpphsReturningSymTab with --nomacro

Version 1.15

• Fix the interaction of --nomacro with --strip.
• Fix the error message received when # appears without a command.

Version 1.14

• New API to return symbol table after processing.

Version 1.13

• Accept -U cmdline option for compatibility with cpp.

Version 1.12

• Allow it to build with ghc-7.2.

Version 1.11

• API change: runCpphs, cppIfdef, and macroPass are now in the IO monad.

Version 1.10

• New command-line option: "--linepragma" It converts #line droppings into {-# LINE #-}.

Version 1.9

• Bugfix for #undef.

Version 1.8

• Bugfix for off-by-one error in line numbers with --include=file.

Version 1.7

• Bugfix in interaction of --unlit with \end{code}

Version 1.6

• New command-line option: "--include=filename".
• New command-line option: "--strip-eol" for comment-stripping.
• Line pragmas can have filenames containing spaces.

Version 1.5

• Parametrised macro-calls now permitted in #ifdef's.
• Recursive textual expansion now permitted in #ifdef's.
• Better options-handling when used as a library.
• Various small bugfixes

Version 1.4

• Added a "--pragma" option to retain #pragma in the output.
• Fixed a number of obscure corner cases involving the interaction of multiple features e.g. foo##LINE.
• Added the "--nowarn" option.

Version 1.3

• Added a "--cpp" option for drop-in compatibility with standard cpp. It causes cpphs to accept standard cpp flags and translate them to cpphs equivalents. Compatibility options include: -o, -ansi, -traditional, -stdc, -x, -include, -P, -C, -CC, -A. The file behaviour is different too - if two filenames are given on the commandline, then the second is treated as the output location.
• Fixed a corner-case bug in evaluating chained and overlapping #ifdefs.

Version 1.2

• Re-arranged the source files into hierarchical libraries.
• Exposed the library interface as an installable Cabal package, with Haddock documentation.
• Added the --unlit option, for removing literate-style comments.

Version 1.1

• Fix the .cabal way of building cpphs.
• Update the --version reported (forgotten in 1.0, which still reports 0.9)
• No longer throws an error when given an empty file as input.

Version 1.0

• Add a compatibility script cpphs.compat, allowing cpphs to act as a drop-in replacement for cpp, e.g. ghc -cpp -pgmP cpphs.compat
• Place quotes around replacements for special macros FILE, DATE, and TIME.
• If no files are specified, read from stdin.
• Ignore #! lines (e.g. in scripts)
• Parse -D commandline options once only, and consistently with cpp, i.e. -Dfoo means foo=1
• Fix compatibility with preprocessors like hsc2hs, which use non-cpp directives like #def. They are now passed through to the output with a warning to stderr.

Version 0.9

• Bugfix for ghc-6.4 -O: flush the output buffer.

Version 0.8

• Added the --text option, to signify the input should not be lexed as Haskell. This causes macros to be defined or expanded regardless of their location within comments, string delimiters, etc.
• Shuffle a few files around to make it easier to say 'hmake cpphs'. There is also now a runhugs script to invoke cpphs nicely.

Version 0.7

• Enable the FILE, LINE, DATE, and TIME specials, which can be useful for creating DIY error messages.

Version 0.6

• Recognise and ignore the #pragma cpp directive.
• Fix beginning-of-file bug, where in --noline mode, a # cpp directive at the top of the file appeared in the output.
• Fix chained parenthesised boolean exprs in #if, e.g. #if ( foo ) && ( bar )
• Fix precedence in chained unparenthesised boolean exprs in #if, e.g. #if foo && bar || baz && frob
• For better compatibility with cpp, and because otherwise there are certain constructs that cannot be expressed, we no longer permit whitespace in a #define between the symbolname and an opening parenthesis, e.g. #define f (f' id) Previously, this was interpreted as a parametrised macro, with arguments in the parens, and no expansion. Now, the space indicates that this is a textual replacement, and the parenthesised expression is in fact the replacement.

Version 0.5

• Added a --version flag to report the version number.
• Renamed --stringise to --hashes, and use it to turn on ## catenation as well.
• Bugfix for #if 1, previously taken as false.
• Bugfix for --nolines: it no longer adds extra spurious newlines.
• File inclusion now looks in the directory of the calling file.
• Failure to find an include file is now merely a warning to stderr rather than an error.
• Added a --layout flag. Previously, line continuations in a macro definition were always preserved in the output, permitting use of the Haskell layout rule even inside a macro. The default is now to remove line continuations for conformance with cpp, but the option of using --layout is still possible.

Version 0.4

• New flag -Ofile to redirect output
• Bugfix for precedence in #if !False && False
• Bugfix for whitespace between # and if
• Bugfix for #define F "blah"; #include F

Version 0.3

• Bugfix for recursive macro expansion.
• New flag --strip to remove C comments even outside cpp directives.
• New flag --stringise to recognise the # stringise operator in macros.

Version 0.2

• New flag --noline to eliminate #line directives from output.
• Add symbol-replacement and macro-expansion.
• New flag --nomacro to turn off symbol/macro-expansion.

2004-Apr-21

• Now accept multi-line # commands via the \ line continuation operator. The original file line numbering is preserved in the output by some tricky acrobatics.

Version 0.1

• Initial release.