Lines Matching refs:PTH

2 Pretokenized Headers (PTH)
5 This document first describes the low-level interface for using PTH and
14 options for generating and using PTH files.
16 To generate PTH files using ``clang -cc1``, use the option ``-emit-pth``:
22 This option is transparently used by ``clang`` when generating PTH
23 files. Similarly, PTH files can be used as prefix headers using the
30 Alternatively, Clang's PTH files can be used as a raw "token-cache" (or
32 This means that the contents of the PTH file are searched as substitutes
46 will be retrieved from ``test.h.pth``, as the PTH file is being used in
48 low-level interface used to both implement the high-level PTH interface
49 as well as to provide alternative means to use PTH-style caching.
51 PTH Design and Implementation
58 operators. Consequently, PTH serves to mainly directly speed up the
60 type-checking must be completely redone every time a PTH file is used.
72    PTH files work with any language that
76    pieces) does not require PTH to be modified.
79    Relatively speaking, PTH has a simple design and
81    machinery for PTH resides at the lower-levels of the Clang library
86 compared against) the PTH design in Clang yields several attractive
91    those of several other compilers), Clang's PTH files are architecture
92    independent, requiring only a single PTH file when building a
99    architecture-specific. Since a Clang PTH file essentially represents
100    a lexical cache of header files, a single PTH file can be safely used
102    compile times because only a single PTH file needs to be generated
106    Similar to GCC, Clang reads PTH files
108    memory maps PTH files as read-only, meaning that multiple invocations
110    memory-mapped PTH file. In comparison, GCC also memory maps its PCH
112    copy-on-write costs. The read-only nature of PTH can greatly reduce
117    PTH files can be generated in a small fraction
118    of the time needed to generate GCC's PCH files. Since PTH/PCH
123 Despite these strengths, PTH's simple design suffers some algorithmic
125 While PTH can greatly speed up the processing time of a header file, the
141 of the strengths of PTH such as reduced memory pressure (ideal for
144 Internal PTH Optimizations
147 While the main optimization employed by PTH is to reduce lexing time of
148 header files by caching pre-lexed tokens, PTH also employs several other
151 -  ``stat`` caching: PTH files cache information obtained via calls to
157 -  Fast skipping of ``#ifdef`` ... ``#endif`` chains: PTH files