diff options
| author | Pedro F. Giffuni <pfg@FreeBSD.org> | 2016-12-02 16:28:18 +0000 |
|---|---|---|
| committer | Pedro F. Giffuni <pfg@FreeBSD.org> | 2016-12-02 16:28:18 +0000 |
| commit | b30bb755da3d57e5f41d6ab9338f2ce4b17640de (patch) | |
| tree | 3bf8ceb569878d23fef0046b50b0b1c60b2cfd26 /usr.bin/indent | |
| parent | 669f39b29c127c6a97e2341c4c7396bec34c604d (diff) | |
| download | src-b30bb755da3d57e5f41d6ab9338f2ce4b17640de.tar.gz src-b30bb755da3d57e5f41d6ab9338f2ce4b17640de.zip | |
indent(1): Optimize parser stack usage.
When special else-if processing is enabled (-ei), we can assume "else if"
and "if" to be equivalent for indentation purposes.
This reduction saves a lot of stack space in case of a long "if-else-if
... else-if" sequence; with this change,
Postgres/src/bin/psql/tab-complete.c as of 9.6beta3
requires minimum of the stack length to be 31 instead of 444.
Submitted by: Piotr Sephaniak
Notes
Notes:
svn path=/head/; revision=309415
Diffstat (limited to 'usr.bin/indent')
| -rw-r--r-- | usr.bin/indent/parse.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/usr.bin/indent/parse.c b/usr.bin/indent/parse.c index 52f21270096e..b2afe54413bd 100644 --- a/usr.bin/indent/parse.c +++ b/usr.bin/indent/parse.c @@ -94,7 +94,13 @@ parse(int tk) /* tk: the code for the construct scanned */ case ifstmt: /* scanned if (...) */ if (ps.p_stack[ps.tos] == elsehead && ps.else_if) /* "else if ..." */ - ps.i_l_follow = ps.il[ps.tos]; + /* + * Note that the stack pointer here is decremented, effectively + * reducing "else if" to "if". This saves a lot of stack space + * in case of a long "if-else-if ... else-if" sequence. + */ + ps.i_l_follow = ps.il[ps.tos--]; + /* the rest is the same as for dolit and forstmt */ case dolit: /* 'do' */ case forstmt: /* for (...) */ |