Re: [ccache] [PATCH] Support for Clang precompiled headers

2012-07-13 Thread Lubos Lunak
On Thursday 12 of July 2012, Joel Rosdahl wrote:
 On 6 July 2012 19:09, Lubos Lunak l.lu...@suse.cz wrote:
  the attached patches modify ccache to also support Clang PCH in addition
  to GCC PCH.

 Thanks!

 Regarding 0002-hash-clang-s-.pch-file-explicitly.patch: Why is the third
 assignment of pch_file done outside the if (stat(pchpath, st) == 0)
 block? This means that pch_file and included_pch_file can be set even when
 there is no .pch file, so remember_include_file will fail to stat the file
 and then turn off the direct mode. The test suite also fails after the
 patch, but passes if the pch_file assignment is moved into the block.

 Right. I guess that was an oversight when I moved the Multiple precompiled 
headers used error to one place. Fixed version attached.

 The patches look good otherwise.

  PS: Since I've noticed in the archives the recent mail about issues with
  ccache and warnings about unused arguments: The proper way to use ccache
  with Clang is to set CCACHE_CPP2, which not only avoids these warnings,
  but in general Clang works suboptimally if passed preprocessed output
  (warning/error messages quoting sources are affected, some warnings are
  not supressed in headers).

 Do you have any idea about the performance impact of using CCACHE_CPP2 for
 clang?

 Debug build of LibreOffice, warm disk caches, empty ccache, make -j4 in 
xmloff module:

CCACHE_CPP2=1:

494.64user 34.99system 2:15.60elapsed 390%CPU (0avgtext+0avgdata 
1309824maxresident)k
0inputs+3752560outputs (507major+13592550minor)pagefaults 0swaps

not set:

457.17user 28.94system 2:06.15elapsed 385%CPU (0avgtext+0avgdata 
1309312maxresident)k
0inputs+3758600outputs (444major+12098612minor)pagefaults 0swaps

 So in this case CCACHE_CPP2 adds about 8% overhead. It might make a 
difference for somebody, but I myself would prefer to get better error 
messages from Clang (and I actually use ccache only for a buildbot, so I 
don't find this worth the effort).

 If somebody would feel like playing with this, note that Clang 3.2 will 
have -E -Wp,-rewrite-includes, which only processes #include directives and 
nothing more (I wrote the feature to solve a similar problem when using Clang 
with Icecream for distributed builds, and I assume this is the only thing 
ccache in fact wants from -E too). So using this in ccache for Clang should 
presumably reduce this overhead.

-- 
 Lubos Lunak
 l.lu...@suse.cz
From d897f0388b35ca0b8e333e7e8edbd57a0c4ba3e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lubo=C5=A1=20Lu=C5=88=C3=A1k?= l.lu...@suse.cz
Date: Fri, 6 Jul 2012 18:45:05 +0200
Subject: [PATCH 2/2] hash clang's .pch file explicitly

It does not appear anywhere in the preprocessed output, so
process_preprocessed_file() would miss it.
---
 ccache.c |   31 +++
 1 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/ccache.c b/ccache.c
index 12b62a4..926d6b2 100644
--- a/ccache.c
+++ b/ccache.c
@@ -171,6 +171,11 @@ static bool profile_generate = false;
  */
 static bool using_precompiled_header = false;
 
+/*
+ * The .gch/.pch file used for compilation.
+ */
+static char *included_pch_file = NULL;
+
 /* How long (in microseconds) to wait before breaking a stale lock. */
 unsigned lock_staleness_limit = 200;
 
@@ -532,6 +537,16 @@ process_preprocessed_file(struct mdfour *hash, const char *path)
 
 	hash_buffer(hash, p, (end - p));
 	free(data);
+
+	/* Explicitly check the .gch/.pch file, Clang does not include any mention of it
+	   in the preprocessed output. */
+	if (included_pch_file) {
+		char *path = x_strdup(included_pch_file);
+		path = make_relative_path(path);
+		hash_string(hash, path);
+		remember_include_file(path, strlen(included_pch_file), hash);
+	}
+
 	return true;
 }
 
@@ -1680,6 +1695,7 @@ cc_process_args(struct args *orig_args, struct args **preprocessor_args,
 		 */
 		if (compopt_takes_path(argv[i])) {
 			char *relpath;
+			char *pch_file = NULL;
 			if (i == argc-1) {
 cc_log(Missing argument to %s, argv[i]);
 stats_update(STATS_ARGS);
@@ -1696,23 +1712,37 @@ cc_process_args(struct args *orig_args, struct args **preprocessor_args,
 if (stat(argv[i+1], st) == 0) {
 	cc_log(Detected use of precompiled header: %s, argv[i+1]);
 	found_pch = true;
+	pch_file = x_strdup(argv[i+1]);
 }
 			} else {
 char* gchpath = format(%s.gch, argv[i+1]);
 if (stat(gchpath, st) == 0) {
 	cc_log(Detected use of precompiled header: %s, gchpath);
 	found_pch = true;
+	pch_file = x_strdup(gchpath);
 } else {
 	char* pchpath = format(%s.pch, argv[i+1]);
 	if (stat(pchpath, st) == 0) {
 		cc_log(Detected use of precompiled header: %s, pchpath);
 		found_pch = true;
+		pch_file = x_strdup(pchpath);
 	}
 	free(pchpath);
 }
 free(gchpath);
 			}
 
+			if (pch_file) {
+if (included_pch_file) {
+	cc_log(Multiple precompiled headers used: %s and %s\n,
+	included_pch_file, pch_file);
+	

Re: [ccache] [PATCH] Support for Clang precompiled headers

2012-07-13 Thread Lubos Lunak
On Friday 13 of July 2012, Lubos Lunak wrote:
  If somebody would feel like playing with this, note that Clang 3.2 will
 have -E -Wp,-rewrite-includes,

 Make that -E -frewrite-includes, looks like upstream has changed that.

 which only processes #include directives and 
 nothing more (I wrote the feature to solve a similar problem when using
 Clang with Icecream for distributed builds, and I assume this is the only
 thing ccache in fact wants from -E too). So using this in ccache for Clang
 should presumably reduce this overhead.

-- 
 Lubos Lunak
 l.lu...@suse.cz
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Re: [ccache] [PATCH] Support for Clang precompiled headers

2012-07-13 Thread Joel Rosdahl
On 13 July 2012 11:48, Lubos Lunak l.lu...@suse.cz wrote:
 Right. I guess that was an oversight when I moved the Multiple precompiled
 headers used error to one place. Fixed version attached.

Thanks, applied.

-- Joel
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Re: [ccache] [PATCH] Support for Clang precompiled headers

2012-07-12 Thread Joel Rosdahl
On 6 July 2012 19:09, Lubos Lunak l.lu...@suse.cz wrote:
 the attached patches modify ccache to also support Clang PCH in addition to
 GCC PCH.

Thanks!

Regarding 0002-hash-clang-s-.pch-file-explicitly.patch: Why is the third
assignment of pch_file done outside the if (stat(pchpath, st) == 0) block?
This means that pch_file and included_pch_file can be set even when there is no
.pch file, so remember_include_file will fail to stat the file and then turn
off the direct mode. The test suite also fails after the patch, but passes if
the pch_file assignment is moved into the block.

The patches look good otherwise.

 PS: Since I've noticed in the archives the recent mail about issues with
 ccache and warnings about unused arguments: The proper way to use ccache with
 Clang is to set CCACHE_CPP2, which not only avoids these warnings, but in
 general Clang works suboptimally if passed preprocessed output (warning/error
 messages quoting sources are affected, some warnings are not supressed in
 headers).

Do you have any idea about the performance impact of using CCACHE_CPP2 for
clang?

-- Joel
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[ccache] [PATCH] Support for Clang precompiled headers

2012-07-06 Thread Lubos Lunak

 Hello,

 the attached patches modify ccache to also support Clang PCH in addition to 
GCC PCH.

 The changes are:

- Clang uses .pch as the extension, not .gch
- the .pch file can be directly passed using -include-pch, instead of 
using -include and trying to find the .pch file
- the use of a .pch is not reflected in the resulting .ii , so it needs to be 
explicitly added to the hash for checking if used files have changed
- I also believe that path_len passed to remember_include_file() is incorrect, 
as make_relative_path() may change the string

PS: Since I've noticed in the archives the recent mail about issues with 
ccache and warnings about unused arguments: The proper way to use ccache with 
Clang is to set CCACHE_CPP2, which not only avoids these warnings, but in 
general Clang works suboptimally if passed preprocessed output (warning/error 
messages quoting sources are affected, some warnings are not supressed in 
headers).

-- 
 Lubos Lunak
 l.lu...@suse.cz
From 768ffacb434d116759fc73cf0d2723aba6b5af4c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lubo=C5=A1=20Lu=C5=88=C3=A1k?= l.lu...@suse.cz
Date: Fri, 6 Jul 2012 18:09:36 +0200
Subject: [PATCH 1/3] support for precompiled headers with clang

Support the clang-specific -include-pch option, which references
the PCH file itself, and support the .pch extension when using
the gcc -include way.
---
 MANUAL.txt |2 ++
 ccache.c   |   29 +
 compopt.c  |1 +
 3 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/MANUAL.txt b/MANUAL.txt
index 4be33ae..478d36b 100644
--- a/MANUAL.txt
+++ b/MANUAL.txt
@@ -629,6 +629,8 @@ things to make it work properly:
 --
 ** use the *-include* compiler option to include the precompiled header
(i.e., don't use *#include* in the source code to include the header); or
+** (Clang compiler) use the *-include-pch* compiler option to include
+   the PCH file generated from the precompiled header; or
 ** add the *-fpch-preprocess* compiler option when compiling.
 
 If you don't do this, either the non-precompiled version of the header file
diff --git a/ccache.c b/ccache.c
index 8b50c36..12b62a4 100644
--- a/ccache.c
+++ b/ccache.c
@@ -167,7 +167,7 @@ static bool profile_use = false;
 static bool profile_generate = false;
 
 /*
- * Whether we are using a precompiled header (either via -include or #include).
+ * Whether we are using a precompiled header (either via -include, #include or clang's -include-pch).
  */
 static bool using_precompiled_header = false;
 
@@ -1355,7 +1355,7 @@ find_compiler(char** argv)
 bool
 is_precompiled_header(const char *path)
 {
-	return str_eq(get_extension(path), .gch);
+	return str_eq(get_extension(path), .gch) || str_eq(get_extension(path), .pch);
 }
 
 /*
@@ -1680,7 +1680,6 @@ cc_process_args(struct args *orig_args, struct args **preprocessor_args,
 		 */
 		if (compopt_takes_path(argv[i])) {
 			char *relpath;
-			char *pchpath;
 			if (i == argc-1) {
 cc_log(Missing argument to %s, argv[i]);
 stats_update(STATS_ARGS);
@@ -1693,13 +1692,27 @@ cc_process_args(struct args *orig_args, struct args **preprocessor_args,
 			args_add(stripped_args, relpath);
 
 			/* Try to be smart about detecting precompiled headers */
-			pchpath = format(%s.gch, argv[i+1]);
-			if (stat(pchpath, st) == 0) {
-cc_log(Detected use of precompiled header: %s, pchpath);
-found_pch = true;
+			if (str_eq(argv[i], -include-pch)) {
+if (stat(argv[i+1], st) == 0) {
+	cc_log(Detected use of precompiled header: %s, argv[i+1]);
+	found_pch = true;
+}
+			} else {
+char* gchpath = format(%s.gch, argv[i+1]);
+if (stat(gchpath, st) == 0) {
+	cc_log(Detected use of precompiled header: %s, gchpath);
+	found_pch = true;
+} else {
+	char* pchpath = format(%s.pch, argv[i+1]);
+	if (stat(pchpath, st) == 0) {
+		cc_log(Detected use of precompiled header: %s, pchpath);
+		found_pch = true;
+	}
+	free(pchpath);
+}
+free(gchpath);
 			}
 
-			free(pchpath);
 			free(relpath);
 			i++;
 			continue;
diff --git a/compopt.c b/compopt.c
index 77b57f5..908302e 100644
--- a/compopt.c
+++ b/compopt.c
@@ -61,6 +61,7 @@ static const struct compopt compopts[] = {
 	{-imacros,AFFECTS_CPP | TAKES_ARG | TAKES_PATH},
 	{-imultilib,  AFFECTS_CPP | TAKES_ARG | TAKES_PATH},
 	{-include,AFFECTS_CPP | TAKES_ARG | TAKES_PATH},
+	{-include-pch,AFFECTS_CPP | TAKES_ARG | TAKES_PATH},
 	{-install_name,   TAKES_ARG}, /* Darwin linker option */
 	{-iprefix,AFFECTS_CPP | TAKES_ARG | TAKES_PATH},
 	{-iquote, AFFECTS_CPP | TAKES_ARG | TAKES_PATH},
-- 
1.7.7

From bbfc0ed55a6f730023d068773fc9fece16b94c74 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lubo=C5=A1=20Lu=C5=88=C3=A1k?= l.lu...@suse.cz
Date: Fri, 6 Jul 2012 18:46:25 +0200
Subject: [PATCH 3/3] do not pass incorrect length to remember_include_file()

---
 ccache.c |7 ---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git