instead of deserializing the complete declaration context of the record.
Iterating over the fields of a record is very common (e.g to determine the layout), unfortunately we needlessly deserialize every declaration
that the declaration context of the record contains; this can be bad for large C++ classes that contain a lot of methods.
Fix this by allow deserialization of just the fields when we want to iterate over them.
Progress for rdar://7260160.
llvm-svn: 116507
following amusing sequence:
- AST writing schedules writing a type X* that it had never seen
before
- AST writing starts writing another declaration, ends up
deserializing X* from a prior AST file. Now we have two type IDs for
the same type!
- AST writer tries to write X*. It only has the lower-numbered ID
from the the prior AST file, so references to the higher-numbered ID
that was scheduled for writing go off into lalaland.
To fix this, keep the higher-numbered ID so we end up writing the type
twice. Since this issue occurs so rarely, and type records are
generally rather small, I deemed this better than the alternative: to
keep a separate mapping from the higher-numbered IDs to the
lower-numbered IDs, which we would end up having to check whenever we
want to deserialize any type.
Fixes <rdar://problem/8511624>, I think.
llvm-svn: 115647
identifier, we may have a Sema object but no translation unit scope
(because parsing is finished). In this case, we still need to update
the IdResolver, which might still be used when writing a PCH
containing another PCH (without chaining). This bug manifested as a
failure with precompiled preambles.
Also, add a little environment-variable-sensitive logging for
libclang.
llvm-svn: 114774
When including a PCH and later re-emitting to another PCH, the name lookup tables of DeclContexts
may be incomplete, since we now lazily deserialize the visible decls of a particular name.
Fix the issue by iterating over the un-deserialized visible decls and completing the lookup tables
of DeclContexts before writing them out.
llvm-svn: 111698
*Huge* improvement over the amount of deserializing that we do for C++ lookup.
e.g, if he have the Carbon header precompiled and include it on a file containing this:
int x;
these are the before/after stats:
BEFORE:
*** AST File Statistics:
578 stat cache hits
4 stat cache misses
548/30654 source location entries read (1.787695%)
15907/16501 types read (96.400223%)
53525/59955 declarations read (89.275291%)
33993/43525 identifiers read (78.099945%)
41516/51891 statements read (80.006165%)
77/5317 macros read (1.448185%)
0/6335 lexical declcontexts read (0.000000%)
1/5424 visible declcontexts read (0.018437%)
AFTER using the on-disk table:
*** AST File Statistics:
578 stat cache hits
4 stat cache misses
548/30654 source location entries read (1.787695%)
10/16501 types read (0.060602%)
9/59955 declarations read (0.015011%)
161/43525 identifiers read (0.369902%)
20/51891 statements read (0.038542%)
6/5317 macros read (0.112846%)
0/6335 lexical declcontexts read (0.000000%)
2/5424 visible declcontexts read (0.036873%)
There's only one issue affecting mostly the precompiled preambles which I will address soon.
llvm-svn: 111636