diff mbox series

[v3] README: start a section for documenting CFLAGS

Message ID 20200608223816.17039-1-william.c.roberts@intel.com (mailing list archive)
State Accepted
Headers show
Series [v3] README: start a section for documenting CFLAGS | expand

Commit Message

William Roberts June 8, 2020, 10:38 p.m. UTC 
From: William Roberts <william.c.roberts@intel.com>

Start a section in the README for documenting that custom CFLAGS yields
custom results and that your mileage may vary. The first CFLAG to
document that you likely want to include is -fno-semantic-interposition.

Signed-off-by: William Roberts <william.c.roberts@intel.com>
---
v3:
  - lowercased CUSTOM in the commit message.
  - Updated -fsemantic-interposition to -fno-semantic-interposition in
      the commit message and README file.
v2:
  - Fixed commit message spelling of yields.
  - Reduced usages of CFLAGS in documentation.
 README.md | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Stephen Smalley June 9, 2020, 11:57 a.m. UTC | #1 
On Mon, Jun 8, 2020 at 6:38 PM <bill.c.roberts@gmail.com> wrote:
>
> From: William Roberts <william.c.roberts@intel.com>
>
> Start a section in the README for documenting that custom CFLAGS yields
> custom results and that your mileage may vary. The first CFLAG to
> document that you likely want to include is -fno-semantic-interposition.
>
> Signed-off-by: William Roberts <william.c.roberts@intel.com>

Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
diff mbox series

Patch

diff --git a/README.md b/README.md
index 9d64f0b5cf90..4d33686da1f8 100644
--- a/README.md
+++ b/README.md
@@ -120,6 +120,17 @@  lacks library functions or other dependencies relied upon by your
 distribution.  If it breaks, you get to keep both pieces.
 
 
+## Setting CFLAGS
+
+Setting CFLAGS during the make process will cause the omission of many defaults. While the project strives
+to provide a reasonable set of default flags, custom CFLAGS could break the build, or have other undesired
+changes on the build output. Thus, be very careful when setting CFLAGS. CFLAGS that are encouraged to be
+set when overriding are:
+
+- -fno-semantic-interposition for gcc or compilers that do not do this. clang does this by default. clang-10 and up
+   will support passing this flag, but ignore it. Previous clang versions fail.
+
+
 macOS
 -----