This patch adds the -fminimize-whitespace with the following effects:
* If combined with -E, remove as much non-line-breaking whitespace as
possible.
* If combined with -E -P, removes as much whitespace as possible,
including line-breaks.
The motivation is to reduce the amount of insignificant changes in the
preprocessed output with source files where only whitespace has been
changed (add/remove comments, clang-format, etc.) which is in particular
useful with ccache.
A patch for ccache for using this flag has been proposed to ccache as well:
https://github.com/ccache/ccache/pull/815, which will use
-fnormalize-whitespace when clang-13 has been detected, and additionally
uses -P in "unify_mode". ccache already had a unify_mode in an older
version which was removed because of problems that using the
preprocessor itself does not have (such that the custom tokenizer did
not recognize C++11 raw strings).
This patch slightly reorganizes which part is responsible for adding
newlines that are required for semantics. It is now either
startNewLineIfNeeded() or MoveToLine() but never both; this avoids the
ShouldUpdateCurrentLine workaround and avoids redundant lines being
inserted in some cases. It also fixes a mandatory newline not inserted
after a _Pragma("...") that is expanded into a #pragma.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D104601
The whitespace should come from the argument name in the macro
expansion, rather than from the token passed to the macro (same as it
does when not pasting).
Added a new test case for the change in behavior to stringize_space.c.
FileCheck'ized macro_paste_commaext.c, tweaked the test case, and
added a comment; no behavioral change to this test.
Differential Revision: https://reviews.llvm.org/D30427
llvm-svn: 302195
first token of the expansion, don't forget to copy the "is at the start of a
line" token (which is always false, as newlines cannot appear within a macro
body); otherwise, stringizing the result can insert spurious whitespace.
llvm-svn: 257863
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
Michael Kruse