From 49ee105c685cb84bc3057e8b7666fc0cc7090047 Mon Sep 17 00:00:00 2001 From: Paul Smith Date: Wed, 13 Apr 2005 03:16:33 +0000 Subject: Fix performance degradation introduced by the second expansion feature. I did this by adding intelligence into the algorithm such that the second expansion was only actually performed when the prerequisite list contained at least one "$", so we knew it is actually needed. Without this we were using up a LOT more memory, since every single target (even ones never used by make) had their file variables initialized. This also used a lot more CPU, since we needed to create and populate a new variable hash table for every target. There is one issue remaining with this feature: it leaks memory. In pattern_search() we now initialize the file variables for every pattern target, which allocates a hash table, etc. However, sometimes we recursively invoke pattern_search() (for intermediate files) with an automatic variable (alloca() I believe) as the file. When that function returns, obviously, the file variable hash memory is lost. --- implicit.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) (limited to 'implicit.c') diff --git a/implicit.c b/implicit.c index 338a29f..67f0559 100644 --- a/implicit.c +++ b/implicit.c @@ -509,19 +509,19 @@ pattern_search (struct file *file, int archive, break; /* No more words */ /* If the dependency name has %, substitute the stem. - Watch out, we are going to do something very smart - here. If we just replace % with the stem value, - later, when we do the second expansion, we will - re-expand this stem value once again. This is not - good especially if you have certain characters in - your setm (like $). + Watch out, we are going to do something tricky here. If + we just replace % with the stem value, later, when we do + the second expansion, we will re-expand this stem value + once again. This is not good especially if you have + certain characters in your setm (like $). - Instead, we will replace % with $* and allow the - second expansion to take care of it for us. This - way (since $* is a simple variable) there won't - be additional re-expansion of the stem.*/ + Instead, we will replace % with $* and allow the second + expansion to take care of it for us. This way (since $* + is a simple variable) there won't be additional + re-expansion of the stem. */ - for (p2 = p; p2 < p + len && *p2 != '%'; ++p2); + for (p2 = p; p2 < p + len && *p2 != '%'; ++p2) + ; if (p2 < p + len) { @@ -836,6 +836,7 @@ pattern_search (struct file *file, int archive, dep = (struct dep *) xmalloc (sizeof (struct dep)); dep->ignore_mtime = d->ignore_mtime; + dep->need_2nd_expansion = 0; s = d->name; /* Hijacking the name. */ d->name = 0; if (recursions == 0) @@ -908,6 +909,7 @@ pattern_search (struct file *file, int archive, struct dep *new = (struct dep *) xmalloc (sizeof (struct dep)); /* GKM FIMXE: handle '|' here too */ new->ignore_mtime = 0; + new->need_2nd_expansion = 0; new->name = p = (char *) xmalloc (rule->lens[i] + fullstemlen + 1); bcopy (rule->targets[i], p, rule->suffixes[i] - rule->targets[i] - 1); -- cgit v1.2.3