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Makefile Functions & Text Processing/warning and error functions

Emit diagnostics or abort parsing.

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Section: Shell, call, eval, and generated rules

warning and error functions

makefile
makefile
$(warning building with DEBUG=$(DEBUG))
$(if $(DB_URL),,$(error DB_URL is required))
Explanation

Great for fail-fast validation of required inputs.

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Same sheet · prioritizing Shell, call, eval, and generated rules
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Capture shell command output at parse time.
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call macro with arguments
Invoke a user-defined macro like a function.
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value raw variable text
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file function
Write content to a file from make.
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Print information during parsing.
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