Provide some default values for the ThinLTO Cache pruning

This control how the cache is pruned. The cache still has to
be explicitely enabled/disabled by providing a path.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268393 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm-c/lto.h b/include/llvm-c/lto.h
index 82f7fd74178326d5e3165f30dc113e4ee67a03c6..21a1ea4598c1a3e50de63d9890e61afc0e7d8575 100644 (file)
--- a/include/llvm-c/lto.h
+++ b/include/llvm-c/lto.h
@@ -659,6 +659,7 @@ extern lto_bool_t thinlto_codegen_set_pic_model(thinlto_code_gen_t cg,
 
 /**
  * Sets the path to a directory to use as a cache storage for incremental build.
+ * Setting this activates caching.
  *
  * \since LTO_API_VERSION=18
  */
@@ -667,7 +668,7 @@ extern void thinlto_codegen_set_cache_dir(thinlto_code_gen_t cg,
 
 /**
  * Sets the cache pruning interval (in seconds). A negative value disable the
- * pruning (default).
+ * pruning. An unspecified default value will be applied.
  *
  * \since LTO_API_VERSION=18
  */
@@ -678,7 +679,8 @@ extern void thinlto_codegen_set_cache_pruning_interval(thinlto_code_gen_t cg,
  * Sets the maximum cache size that can be persistent across build, in terms of
  * percentage of the available space on the the disk. Set to 100 to indicate
  * no limit, 50 to indicate that the cache size will not be left over half the
- * available space. A value over 100 will be reduced to 100.
+ * available space. A value over 100 will be reduced to 100. An unspecified 
+ * default value will be applied.
  *
  * The formula looks like:
  *  AvailableSpace = FreeSpace + ExistingCacheSize
@@ -690,7 +692,8 @@ extern void thinlto_codegen_set_final_cache_size_relative_to_available_space(
     thinlto_code_gen_t cg, unsigned percentage);
 
 /**
- * Sets the expiration (in seconds) for an entry in the cache.
+ * Sets the expiration (in seconds) for an entry in the cache. An unspecified
+ * default value will be applied.
  *
  * \since LTO_API_VERSION=18
  */

diff --git a/include/llvm/LTO/ThinLTOCodeGenerator.h b/include/llvm/LTO/ThinLTOCodeGenerator.h
index f215123752a8a4504f3534ede27bf13bbe922509..f2cc94dab460e63e5b51c3447410a18bc41cadeb 100644 (file)
--- a/include/llvm/LTO/ThinLTOCodeGenerator.h
+++ b/include/llvm/LTO/ThinLTOCodeGenerator.h
@@ -108,10 +108,10 @@ public:
    */
 
   struct CachingOptions {
-    std::string Path;
-    int PruningInterval = -1;               // seconds, -1 to disable pruning
-    unsigned int Expiration = 0;            // seconds.
-    unsigned MaxPercentageOfAvailableSpace = 0; // percentage.
+    std::string Path;                    // Path to the cache, empty to disable.
+    int PruningInterval = 1200;          // seconds, -1 to disable pruning.
+    unsigned int Expiration = 7 * 24 * 3600;     // seconds (1w default).
+    unsigned MaxPercentageOfAvailableSpace = 75; // percentage.
   };
 
   /// Provide a path to a directory where to store the cached files for