There were some frustrating problems with the implementation of
-Wwrite-strings. First and foremost, once the positive form of the flag
was passed, it could never be disabled by passing -Wno-write-strings.
Also, the diagnostic engine couldn't in turn use -Wwrite-strings to
control diagnostics (as GCC does) because it was essentially hijacked to
drive the language semantics.
Fix this by giving CC1 a clean '-fconst-strings' flag to enable
const-qualified strings in C and ObjC compilations. Corresponding
'-fno-const-strings' is also added. Then the driver is taught to
introduce '-fconst-strings' in the CC1 command when '-Wwrite-strings'
dominates.
This entire flag is basically GCC-bug-compatibility driven, so we also
match GCC's bug where '-w' doesn't actually disable -Wwrite-strings. I'm
open to changing this though as it seems insane.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@130051 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index cef9496..442488b 100644
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -257,8 +257,6 @@
HelpText<"Use colors in diagnostics">;
def Wno_rewrite_macros : Flag<"-Wno-rewrite-macros">,
HelpText<"Silence ObjC rewriting warnings">;
-def Wwrite_strings : Flag<"-Wwrite-strings">,
- HelpText<"Remove const qualifier from string literals">;
def verify : Flag<"-verify">,
HelpText<"Verify emitted diagnostics and warnings">;
@@ -526,6 +524,10 @@
HelpText<"Process trigraph sequences">;
def fwritable_strings : Flag<"-fwritable-strings">,
HelpText<"Store string literals as writable data">;
+def fconst_strings : Flag<"-fconst-strings">,
+ HelpText<"Use a const qualified type for string literals in C and ObjC">;
+def fno_const_strings : Flag<"-fno-const-strings">,
+ HelpText<"Don't use a const qualified type for string literals in C and ObjC">;
def fno_bitfield_type_align : Flag<"-fno-bitfield-type-align">,
HelpText<"Ignore bit-field types when aligning structures">;
def traditional_cpp : Flag<"-traditional-cpp">,