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| author | Harald van Dijk <harald@gigawatt.nl> | 2019-11-22 00:27:39 +0100 |
|---|---|---|
| committer | Joseph Myers <jsm28@gcc.gnu.org> | 2019-11-21 23:27:39 +0000 |
| commit | ee573dca11f327566829d93d8130f745b03f16a4 (patch) | |
| tree | 48213f8620c1c860c87e27aa3bda69ab2e1a42a3 | |
| parent | 6c80b1b56dec2691436f3e2676e3d1b105b01b89 (diff) | |
| download | gcc-ee573dca11f327566829d93d8130f745b03f16a4.zip gcc-ee573dca11f327566829d93d8130f745b03f16a4.tar.gz gcc-ee573dca11f327566829d93d8130f745b03f16a4.tar.bz2 | |
doc: Remove claim about ISO C
The patch to make -fcommon the default introduces a bogus claim into
the GCC documentation.
-fcommon was claimed to be incompatible with ISO C for preventing
duplicate definitions from being diagnosed. It does, but as that
elicits undefined behaviour (the requirement that there shall be no
more than one external definition is not a constraint), ISO C does not
require any diagnostic for it. In the absence of any other rule this
would violate, both -fcommon and -fno-common are fully compatible with
all versions of ISO C.
2019-11-21 Harald van Dijk <harald@gigawatt.nl>
* doc/invoke.texi (-fcommon): Remove claim about ISO C.
From-SVN: r278604
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/doc/invoke.texi | 6 |
2 files changed, 7 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2ccdedb..8389a86 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2019-11-21 Harald van Dijk <harald@gigawatt.nl> + + * doc/invoke.texi (-fcommon): Remove claim about ISO C. + 2019-11-21 Joseph Myers <joseph@codesourcery.com> * gimplify.c (expand_FALLTHROUGH_r, expand_FALLTHROUGH): Use diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index c162b0d..34549e0 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -14141,9 +14141,9 @@ than one compilation unit. The @option{-fcommon} places uninitialized global variables in a common block. This allows the linker to resolve all tentative definitions of the same variable in different compilation units to the same object, or to a non-tentative -definition. This behavior does not conform to ISO C, is inconsistent with C++, -and on many targets implies a speed and code size penalty on global variable -references. It is mainly useful to enable legacy code to link without errors. +definition. This behavior is inconsistent with C++, and on many targets implies +a speed and code size penalty on global variable references. It is mainly +useful to enable legacy code to link without errors. @item -fno-ident @opindex fno-ident |