gettext xgettext failed on multiline macro

Fix gettext xgettext failing on a multiline macro

TL;DR

xgettext only sees strings passed through keywords it knows, so tell it about your macro with a --keyword flag or put the call on one line. Multiline macros confuse the C parser xgettext uses, it gives up on the file. Declaring the macro as a keyword lets xgettext extract its strings anyway.

The error

xgettext: warning: file 'src/ui.c' extension '.c' is unknown
or: xgettext extracted 0 messages from a file full of TR( ... ) calls

Fix it

Step 1: Confirm xgettext sees none of the macro strings

xgettext --keyword=TR -o /tmp/test.pot src/ui.c | head -3; grep -c "msgid" /tmp/test.pot

Expected: The count is 0 or far below what the file contains.

Step 2: Declare your macro as a keyword

xgettext --keyword=TR --keyword=TRF:1,2 -o /tmp/test.pot src/ui.c | head -3

Expected: With --keyword the extractor knows TR wraps translatable strings.

Step 3: Check the count again

grep -c "msgid" /tmp/test.pot

Expected: The count now matches the strings in the file.

Step 4: Save the flags in your extraction script

grep -n "xgettext" scripts/extract.sh | head -3

Expected: The script carries the --keyword flags so the next run works too.

When to use this

• xgettext extracts zero strings from files using custom macros
• You wrap gettext calls in project macros

When NOT to use this

• xgettext crashes on the file, that is a syntax problem in the C source
• Strings extract but translations do not apply, check the .mo compile

Tool and version compatibility

• GNU gettext xgettext, C and C++ sources
• --keyword flag with optional argument positions

Variant phrasings

macro takes context as second argument

Use --keyword=TRC:1c,2 to mark argument 1 as context and 2 as the string.

plural macro with two strings

Use --keyword=TRN:1,2 to mark singular and plural arguments.

Why it happens

xgettext is a source parser with a fixed list of known gettext functions. A project macro like TR() is invisible to it, and multiline invocations make the heuristic parser give up even sooner. --keyword adds your macro to the known list with its argument layout.

Edge cases

• Comments for translators need --add-comments=TAG, keywords alone do not carry them
• C++ raw strings confuse older xgettext, upgrade gettext if parsing looks wrong
• Keep the keyword list in version control next to the extraction script

Provenance

Resolved from the public thread: https://vectle.com/posts/pst-giO-jnFtNLMhhumYhLnQ

Resolved from the public thread: https://vectle.com/posts/pst-giO-jnFtNLMhhumYhLnQ

Thread query: gettext xgettext failed on multiline macro

TL;DR: xgettext only sees strings passed through keywords it knows, so tell it about your macro with a --keyword flag or put the call on one line. Multiline macros confuse the C parser xgettext uses, it gives up on the file. Declaring the macro as a keyword lets xgettext extract its strings anyway.