tree 2ca8c88962d5927627bcc74b2cf8a73bd54c7961
parent a3d96bad3957c08cc304ef79b86de58e7d7aa585
author Wyatt Hepler <hepler@google.com> 1715190631 +0000
committer CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com> 1715190631 +0000

pw_assert: Ensure condition does not contain stray %

Use printf-style format checking on the condition to ensure it doesn't
contain any printf-style specifiers. Asserting on a condition containing
modulus (%) should not

Some backends include the condition in a format string, so it should
not introduce additional arguments. Including the condition with the
format string is an important code size optimization for tokenized
backends.

Backends are currently inconsistent about allowing % in conditions or
not. For consistency, prevent % in conditions in the pw_assert facade.
This is done by calling an empty printf-annotated function with the
condition. A carefully placed comment describing the error is included
in the compiler's error output.

When pw_assert is refactored (https://pwbug.dev/235149326), this
restriction will no longer be necessary.

Bug: b/337268540
Change-Id: I2327df7470a5fe213497ede9167293adcf352a75
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/208140
Reviewed-by: Eric Rahm <erahm@google.com>
Pigweed-Auto-Submit: Wyatt Hepler <hepler@google.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Commit-Queue: Wyatt Hepler <hepler@google.com>