This commit adds an optimization to clang-scan-deps and clang's preprocessor that skips excluded preprocessor
blocks by bumping the lexer pointer, and not lexing the tokens until reaching appropriate #else/#endif directive.
The skip positions and lexer offsets are computed when the file is minimized, directly from the minimized tokens.
On an 18-core iMacPro with macOS Catalina Beta I got 10-15% speed-up from this optimization when running clang-scan-deps on
the compilation database for a recent LLVM and Clang (3511 files).
Differential Revision: https://reviews.llvm.org/D67127
llvm-svn: 371656
We should re-emit `#pragma once` to ensure the preprocessor will
still honor it when running on minimized sources.
Differential Revision: https://reviews.llvm.org/D64945
llvm-svn: 366509
single quotes are not digit separators after a valid character literal prefix
The single quote character can act as a c++ digit separator.
However, the minimizer shouldn't treat it as such when it's actually following
a valid character literal prefix, like L, U, u, or u8.
Differential Revision: https://reviews.llvm.org/D64525
llvm-svn: 365700
r362459 introduced DependencyDirectivesSourceMinimizerTest.cpp, which
hits an MSVC bug:
developercommunity.visualstudio.com/content/problem/67300/stringifying-raw-string-literal.html
This only happens when the parameter to a macro is stringified in the
macro. This patch removes the string from the assert so that the
warning no longer happens.
llvm-svn: 363074
that might affect the dependency list for a compilation
This commit introduces a dependency directives source minimizer to clang
that minimizes header and source files to the minimum necessary preprocessor
directives for evaluating includes. It reduces the source down to #define, #include,
The source minimizer works by lexing the input with a custom fast lexer that recognizes
the preprocessor directives it cares about, and emitting those directives in the minimized source.
It ignores source code, comments, and normalizes whitespace. It gives up and fails if seems
any directives that it doesn't recognize as valid (e.g. #define 0).
In addition to the source minimizer this patch adds a
-print-dependency-directives-minimized-source CC1 option that allows you to invoke the minimizer
from clang directly.
Differential Revision: https://reviews.llvm.org/D55463
llvm-svn: 362459