CVS commit: pkgsrc/mk/compiler

["Greg Troxel" <gdt%netbsd.org@localhost>]

Module Name:    pkgsrc
Committed By:   gdt
Date:           Wed Jan  3 14:06:31 UTC 2024

Modified Files:
        pkgsrc/mk/compiler: gcc.mk

Log Message:
mk/compiler/gcc.mk: Expand comments about language versions/features

Explain more nuances of rounding up to NetBSD-release versions vs not.
Inspired by tech-pkg@ comments by nia@.

(This is a comment-only change.)


To generate a diff of this commit:
cvs rdiff -u -r1.270 -r1.271 pkgsrc/mk/compiler/gcc.mk

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: pkgsrc/mk/compiler/gcc.mk
diff -u pkgsrc/mk/compiler/gcc.mk:1.270 pkgsrc/mk/compiler/gcc.mk:1.271
--- pkgsrc/mk/compiler/gcc.mk:1.270     Wed Jan  3 08:11:51 2024
+++ pkgsrc/mk/compiler/gcc.mk   Wed Jan  3 14:06:30 2024
@@ -1,4 +1,4 @@
-# $NetBSD: gcc.mk,v 1.270 2024/01/03 08:11:51 mef Exp $
+# $NetBSD: gcc.mk,v 1.271 2024/01/03 14:06:30 gdt Exp $
 #
 # This is the compiler definition for the GNU Compiler Collection.
 #
@@ -156,14 +156,21 @@ GCC_REQD+=        2.8.0
 # Most of the time, GCC adds support for features of new C and C++
 # standards incrementally; we define USE_CXX_FEATURES=c++XX as
 # intending to require a compiler that fully supports the standard.
-# Whenever reasonable, we choose a gcc version shipped with a NetBSD
-# release, because those are known to work well, and because it is
-# simpler to limit selection to fewer versions.  Thus we tend to:
+# We tend towards a gcc version shipped with a NetBSD release, because
+# those are known to work well, and because it is simpler to limit
+# selection to fewer versions.  This tendency is much stronger for C++
+# versions, and less so for c11.
+#
+# Thus we tend to:
 #   - gcc 4.8, shipped with NetBSD 7 
 #   - gcc 5, shipped with NetBSD 8
 #   - gcc 7, shipped with NetBSD 9
 #   - gcc 10, shipped with NetBSD 10
 #
+# Other systems have different versions, and we note a few:
+#
+#  - gcc 8, shipped with Enterprise Linux 8
+#
 # Resources:
 # https://gcc.gnu.org/projects/cxx-status.html
 # https://gcc.gnu.org/wiki/C11Status
@@ -211,6 +218,7 @@ GCC_REQD+=  5
 GCC_REQD+=     3
 .endif
 
+# 4.9 supports c11; don't reject it by rounding up to 5
 .if !empty(USE_CC_FEATURES:Mc11)
 GCC_REQD+=     4.9
 .endif
@@ -222,10 +230,12 @@ GCC_REQD+=        4.9
 GCC_REQD+=     10.0
 .endif
 
+# Don't round to gcc 5.
 .if !empty(USE_CXX_FEATURES:Munique_ptr)
 GCC_REQD+=     4.9
 .endif
 
+# Don't round to gcc 5.
 .if !empty(USE_CXX_FEATURES:Mregex)
 GCC_REQD+=     4.9
 .endif
@@ -251,6 +261,7 @@ GCC_REQD+=  10
 GCC_REQD+=     10
 .endif
 
+# Don't round to gcc10.
 .if !empty(USE_CXX_FEATURES:Mcharconv)
 GCC_REQD+=     8
 .endif