[gcc(refs/users/marxin/heads/gcov-remove-io-buffering)] gcov: Use system IO buffering
Martin Liska
marxin@gcc.gnu.org
Tue Feb 16 09:13:49 GMT 2021
https://gcc.gnu.org/g:a38b2d2e44662a096a186b8d31a9a689190db8b5
commit a38b2d2e44662a096a186b8d31a9a689190db8b5
Author: marxin <mliska@suse.cz>
Date: Wed Nov 18 16:13:23 2020 +0100
gcov: Use system IO buffering
gcc/ChangeLog:
* gcov-io.c (gcov_write_block): Remove.
(gcov_write_words): Likewise.
(gcov_read_words): Re-implement using gcov_read_bytes.
(gcov_allocate): Remove.
(GCOV_BLOCK_SIZE): Likewise.
(struct gcov_var): Remove most of the fields.
(gcov_position): Implement with ftell.
(gcov_rewrite): Remove setting of start and offset fields.
(from_file): Re-format.
(gcov_open): Remove setbuf call. It should not be needed.
(gcov_close): Remove internal buffer handling.
(gcov_magic): Use __builtin_bswap32.
(gcov_write_counter): Use directly gcov_write_unsigned.
(gcov_write_string): Use direct fwrite and do not round
to 4 bytes.
(gcov_seek): Use directly fseek.
(gcov_write_tag): Use gcov_write_unsigned directly.
(gcov_write_length): Likewise.
(gcov_write_tag_length): Likewise.
(gcov_read_bytes): Use directly fread.
(gcov_read_unsigned): Use gcov_read_words.
(gcov_read_counter): Likewise.
(gcov_read_string): Use gcov_read_bytes.
* gcov-io.h (GCOV_WORD_SIZE): Adjust to reflect
that size is not in bytes, not words (4B).
(GCOV_TAG_FUNCTION_LENGTH): Likewise.
(GCOV_TAG_ARCS_LENGTH): Likewise.
(GCOV_TAG_ARCS_NUM): Likewise.
(GCOV_TAG_COUNTER_LENGTH): Likewise.
(GCOV_TAG_COUNTER_NUM): Likewise.
(GCOV_TAG_SUMMARY_LENGTH): Likewise.
libgcc/ChangeLog:
* libgcov-driver.c: Fix GNU coding style.
Diff:
---
gcc/gcov-io.c | 282 +++++++++++-------------------------------------
gcc/gcov-io.h | 17 +--
libgcc/libgcov-driver.c | 2 +-
3 files changed, 75 insertions(+), 226 deletions(-)
diff --git a/gcc/gcov-io.c b/gcc/gcov-io.c
index 80c9082a649..2347b8665fe 100644
--- a/gcc/gcov-io.c
+++ b/gcc/gcov-io.c
@@ -27,40 +27,14 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
/* Routines declared in gcov-io.h. This file should be #included by
another source file, after having #included gcov-io.h. */
-#if !IN_GCOV
-static void gcov_write_block (unsigned);
-static gcov_unsigned_t *gcov_write_words (unsigned);
-#endif
-static const gcov_unsigned_t *gcov_read_words (unsigned);
-#if !IN_LIBGCOV
-static void gcov_allocate (unsigned);
-#endif
-
-/* Optimum number of gcov_unsigned_t's read from or written to disk. */
-#define GCOV_BLOCK_SIZE (1 << 10)
+static gcov_unsigned_t *gcov_read_words (void *buffer, unsigned);
struct gcov_var
{
FILE *file;
- gcov_position_t start; /* Position of first byte of block */
- unsigned offset; /* Read/write position within the block. */
- unsigned length; /* Read limit in the block. */
- unsigned overread; /* Number of words overread. */
int error; /* < 0 overflow, > 0 disk error. */
- int mode; /* < 0 writing, > 0 reading */
+ int mode; /* < 0 writing, > 0 reading */
int endian; /* Swap endianness. */
-#if IN_LIBGCOV
- /* Holds one block plus 4 bytes, thus all coverage reads & writes
- fit within this buffer and we always can transfer GCOV_BLOCK_SIZE
- to and from the disk. libgcov never backtracks and only writes 4
- or 8 byte objects. */
- gcov_unsigned_t buffer[GCOV_BLOCK_SIZE + 1];
-#else
- /* Holds a variable length block, as the compiler can write
- strings and needs to backtrack. */
- size_t alloc;
- gcov_unsigned_t *buffer;
-#endif
} gcov_var;
/* Save the current position in the gcov file. */
@@ -71,8 +45,7 @@ static inline
gcov_position_t
gcov_position (void)
{
- gcov_nonruntime_assert (gcov_var.mode > 0);
- return gcov_var.start + gcov_var.offset;
+ return ftell (gcov_var.file);
}
/* Return nonzero if the error flag is set. */
@@ -92,20 +65,16 @@ GCOV_LINKAGE inline void
gcov_rewrite (void)
{
gcov_var.mode = -1;
- gcov_var.start = 0;
- gcov_var.offset = 0;
fseek (gcov_var.file, 0L, SEEK_SET);
}
#endif
-static inline gcov_unsigned_t from_file (gcov_unsigned_t value)
+static inline gcov_unsigned_t
+from_file (gcov_unsigned_t value)
{
#if !IN_LIBGCOV || defined (IN_GCOV_TOOL)
if (gcov_var.endian)
- {
- value = (value >> 16) | (value << 16);
- value = ((value & 0xff00ff) << 8) | ((value >> 8) & 0xff00ff);
- }
+ return __builtin_bswap32 (value);
#endif
return value;
}
@@ -140,9 +109,6 @@ gcov_open (const char *name, int mode)
#endif
gcov_nonruntime_assert (!gcov_var.file);
- gcov_var.start = 0;
- gcov_var.offset = gcov_var.length = 0;
- gcov_var.overread = -1u;
gcov_var.error = 0;
#if !IN_LIBGCOV || defined (IN_GCOV_TOOL)
gcov_var.endian = 0;
@@ -192,8 +158,6 @@ gcov_open (const char *name, int mode)
gcov_var.mode = mode ? mode : 1;
- setbuf (gcov_var.file, (char *)0);
-
return 1;
}
@@ -205,19 +169,9 @@ gcov_close (void)
{
if (gcov_var.file)
{
-#if !IN_GCOV
- if (gcov_var.offset && gcov_var.mode < 0)
- gcov_write_block (gcov_var.offset);
-#endif
fclose (gcov_var.file);
gcov_var.file = 0;
- gcov_var.length = 0;
}
-#if !IN_LIBGCOV
- free (gcov_var.buffer);
- gcov_var.alloc = 0;
- gcov_var.buffer = 0;
-#endif
gcov_var.mode = 0;
return gcov_var.error;
}
@@ -232,9 +186,8 @@ gcov_magic (gcov_unsigned_t magic, gcov_unsigned_t expected)
{
if (magic == expected)
return 1;
- magic = (magic >> 16) | (magic << 16);
- magic = ((magic & 0xff00ff) << 8) | ((magic >> 8) & 0xff00ff);
- if (magic == expected)
+
+ if (__builtin_bswap32 (magic) == expected)
{
gcov_var.endian = 1;
return -1;
@@ -243,71 +196,15 @@ gcov_magic (gcov_unsigned_t magic, gcov_unsigned_t expected)
}
#endif
-#if !IN_LIBGCOV
-static void
-gcov_allocate (unsigned length)
-{
- size_t new_size = gcov_var.alloc;
-
- if (!new_size)
- new_size = GCOV_BLOCK_SIZE;
- new_size += length;
- new_size *= 2;
-
- gcov_var.alloc = new_size;
- gcov_var.buffer = XRESIZEVAR (gcov_unsigned_t, gcov_var.buffer, new_size << 2);
-}
-#endif
-
#if !IN_GCOV
-/* Write out the current block, if needs be. */
-
-static void
-gcov_write_block (unsigned size)
-{
- if (fwrite (gcov_var.buffer, size << 2, 1, gcov_var.file) != 1)
- gcov_var.error = 1;
- gcov_var.start += size;
- gcov_var.offset -= size;
-}
-
-/* Allocate space to write BYTES bytes to the gcov file. Return a
- pointer to those bytes, or NULL on failure. */
-
-static gcov_unsigned_t *
-gcov_write_words (unsigned words)
-{
- gcov_unsigned_t *result;
-
- gcov_nonruntime_assert (gcov_var.mode < 0);
-#if IN_LIBGCOV
- if (gcov_var.offset >= GCOV_BLOCK_SIZE)
- {
- gcov_write_block (GCOV_BLOCK_SIZE);
- if (gcov_var.offset)
- {
- memcpy (gcov_var.buffer, gcov_var.buffer + GCOV_BLOCK_SIZE, 4);
- }
- }
-#else
- if (gcov_var.offset + words > gcov_var.alloc)
- gcov_allocate (gcov_var.offset + words);
-#endif
- result = &gcov_var.buffer[gcov_var.offset];
- gcov_var.offset += words;
-
- return result;
-}
-
-/* Write unsigned VALUE to coverage file. Sets error flag
- appropriately. */
+/* Write unsigned VALUE to coverage file. */
GCOV_LINKAGE void
gcov_write_unsigned (gcov_unsigned_t value)
{
- gcov_unsigned_t *buffer = gcov_write_words (1);
-
- buffer[0] = value;
+ gcov_unsigned_t r = fwrite (&value, sizeof (value), 1, gcov_var.file);
+ if (r != 1)
+ gcov_var.error = 1;
}
/* Write counter VALUE to coverage file. Sets error flag
@@ -317,13 +214,11 @@ gcov_write_unsigned (gcov_unsigned_t value)
GCOV_LINKAGE void
gcov_write_counter (gcov_type value)
{
- gcov_unsigned_t *buffer = gcov_write_words (2);
-
- buffer[0] = (gcov_unsigned_t) value;
+ gcov_write_unsigned ((gcov_unsigned_t) value);
if (sizeof (value) > sizeof (gcov_unsigned_t))
- buffer[1] = (gcov_unsigned_t) (value >> 32);
+ gcov_write_unsigned ((gcov_unsigned_t) (value >> 32));
else
- buffer[1] = 0;
+ gcov_write_unsigned (0);
}
#endif /* IN_LIBGCOV */
@@ -335,23 +230,16 @@ GCOV_LINKAGE void
gcov_write_string (const char *string)
{
unsigned length = 0;
- unsigned alloc = 0;
- gcov_unsigned_t *buffer;
if (string)
- {
- length = strlen (string);
- alloc = (length + 4) >> 2;
- }
-
- buffer = gcov_write_words (1 + alloc);
+ length = strlen (string) + 1;
- buffer[0] = alloc;
-
- if (alloc > 0)
+ gcov_write_unsigned (length);
+ if (length > 0)
{
- buffer[alloc] = 0; /* place nul terminators. */
- memcpy (&buffer[1], string, length);
+ gcov_unsigned_t r = fwrite (string, length, 1, gcov_var.file);
+ if (r != 1)
+ gcov_var.error = 1;
}
}
#endif
@@ -388,6 +276,14 @@ gcov_write_filename (const char *filename)
}
#endif
+/* Move to a given position in a gcov file. */
+
+GCOV_LINKAGE void
+gcov_seek (gcov_position_t base)
+{
+ fseek (gcov_var.file, base, SEEK_SET);
+}
+
#if !IN_LIBGCOV
/* Write a tag TAG and reserve space for the record length. Return a
value to be used for gcov_write_length. */
@@ -395,11 +291,9 @@ gcov_write_filename (const char *filename)
GCOV_LINKAGE gcov_position_t
gcov_write_tag (gcov_unsigned_t tag)
{
- gcov_position_t result = gcov_var.start + gcov_var.offset;
- gcov_unsigned_t *buffer = gcov_write_words (2);
-
- buffer[0] = tag;
- buffer[1] = 0;
+ gcov_position_t result = gcov_position ();
+ gcov_write_unsigned (tag);
+ gcov_write_unsigned (0);
return result;
}
@@ -412,19 +306,13 @@ gcov_write_tag (gcov_unsigned_t tag)
GCOV_LINKAGE void
gcov_write_length (gcov_position_t position)
{
- unsigned offset;
- gcov_unsigned_t length;
- gcov_unsigned_t *buffer;
-
+ gcov_position_t current_position = gcov_position ();
gcov_nonruntime_assert (gcov_var.mode < 0);
- gcov_nonruntime_assert (position + 2 <= gcov_var.start + gcov_var.offset);
- gcov_nonruntime_assert (position >= gcov_var.start);
- offset = position - gcov_var.start;
- length = gcov_var.offset - offset - 2;
- buffer = (gcov_unsigned_t *) &gcov_var.buffer[offset];
- buffer[1] = length;
- if (gcov_var.offset >= GCOV_BLOCK_SIZE)
- gcov_write_block (gcov_var.offset);
+ gcov_nonruntime_assert (current_position >= position + 2 * GCOV_WORD_SIZE);
+
+ gcov_seek (position + GCOV_WORD_SIZE);
+ gcov_write_unsigned (current_position - position - 2 * GCOV_WORD_SIZE);
+ gcov_seek (current_position);
}
#else /* IN_LIBGCOV */
@@ -434,10 +322,8 @@ gcov_write_length (gcov_position_t position)
GCOV_LINKAGE void
gcov_write_tag_length (gcov_unsigned_t tag, gcov_unsigned_t length)
{
- gcov_unsigned_t *buffer = gcov_write_words (2);
-
- buffer[0] = tag;
- buffer[1] = length;
+ gcov_write_unsigned (tag);
+ gcov_write_unsigned (length);
}
/* Write a summary structure to the gcov file. Return nonzero on
@@ -455,52 +341,28 @@ gcov_write_summary (gcov_unsigned_t tag, const struct gcov_summary *summary)
#endif /*!IN_GCOV */
-/* Return a pointer to read BYTES bytes from the gcov file. Returns
+/* Return a pointer to read COUNT bytes from the gcov file. Returns
NULL on failure (read past EOF). */
-static const gcov_unsigned_t *
-gcov_read_words (unsigned words)
+static void *
+gcov_read_bytes (void *buffer, unsigned count)
{
- const gcov_unsigned_t *result;
- unsigned excess = gcov_var.length - gcov_var.offset;
-
if (gcov_var.mode <= 0)
return NULL;
- if (excess < words)
- {
- gcov_var.start += gcov_var.offset;
- if (excess)
- {
-#if IN_LIBGCOV
- memcpy (gcov_var.buffer, gcov_var.buffer + gcov_var.offset, 4);
-#else
- memmove (gcov_var.buffer, gcov_var.buffer + gcov_var.offset,
- excess * 4);
-#endif
- }
- gcov_var.offset = 0;
- gcov_var.length = excess;
-#if IN_LIBGCOV
- excess = GCOV_BLOCK_SIZE;
-#else
- if (gcov_var.length + words > gcov_var.alloc)
- gcov_allocate (gcov_var.length + words);
- excess = gcov_var.alloc - gcov_var.length;
-#endif
- excess = fread (gcov_var.buffer + gcov_var.length,
- 1, excess << 2, gcov_var.file) >> 2;
- gcov_var.length += excess;
- if (gcov_var.length < words)
- {
- gcov_var.overread += words - gcov_var.length;
- gcov_var.length = 0;
- return 0;
- }
- }
- result = &gcov_var.buffer[gcov_var.offset];
- gcov_var.offset += words;
- return result;
+ unsigned read = fread (buffer, count, 1, gcov_var.file);
+ if (read != 1)
+ return NULL;
+
+ return buffer;
+}
+
+/* Read WORDS gcov_unsigned_t values from gcov file. */
+
+static gcov_unsigned_t *
+gcov_read_words (void *buffer, unsigned words)
+{
+ return (gcov_unsigned_t *)gcov_read_bytes (buffer, GCOV_WORD_SIZE * words);
}
/* Read unsigned value from a coverage file. Sets error flag on file
@@ -510,10 +372,12 @@ GCOV_LINKAGE gcov_unsigned_t
gcov_read_unsigned (void)
{
gcov_unsigned_t value;
- const gcov_unsigned_t *buffer = gcov_read_words (1);
+ gcov_unsigned_t allocated_buffer[1];
+ gcov_unsigned_t *buffer = gcov_read_words (&allocated_buffer, 1);
if (!buffer)
return 0;
+
value = from_file (buffer[0]);
return value;
}
@@ -525,7 +389,8 @@ GCOV_LINKAGE gcov_type
gcov_read_counter (void)
{
gcov_type value;
- const gcov_unsigned_t *buffer = gcov_read_words (2);
+ gcov_unsigned_t allocated_buffer[2];
+ gcov_unsigned_t *buffer = gcov_read_words (&allocated_buffer, 2);
if (!buffer)
return 0;
@@ -602,7 +467,8 @@ gcov_read_string (void)
if (!length)
return 0;
- return (const char *) gcov_read_words (length);
+ void *buffer = XNEWVEC (char *, length);
+ return (const char *) gcov_read_bytes (buffer, length);
}
#endif
@@ -624,27 +490,7 @@ gcov_sync (gcov_position_t base, gcov_unsigned_t length)
{
gcov_nonruntime_assert (gcov_var.mode > 0);
base += length;
- if (base - gcov_var.start <= gcov_var.length)
- gcov_var.offset = base - gcov_var.start;
- else
- {
- gcov_var.offset = gcov_var.length = 0;
- fseek (gcov_var.file, base << 2, SEEK_SET);
- gcov_var.start = ftell (gcov_var.file) >> 2;
- }
-}
-#endif
-
-#if IN_LIBGCOV
-/* Move to a given position in a gcov file. */
-
-GCOV_LINKAGE void
-gcov_seek (gcov_position_t base)
-{
- if (gcov_var.offset)
- gcov_write_block (gcov_var.offset);
- fseek (gcov_var.file, base << 2, SEEK_SET);
- gcov_var.start = ftell (gcov_var.file) >> 2;
+ fseek (gcov_var.file, base, SEEK_SET);
}
#endif
diff --git a/gcc/gcov-io.h b/gcc/gcov-io.h
index baed67609e2..017a4e21a11 100644
--- a/gcc/gcov-io.h
+++ b/gcc/gcov-io.h
@@ -241,22 +241,25 @@ typedef uint64_t gcov_type_unsigned;
/* The record tags. Values [1..3f] are for tags which may be in either
file. Values [41..9f] for those in the note file and [a1..ff] for
the data file. The tag value zero is used as an explicit end of
- file marker -- it is not required to be present. */
+ file marker -- it is not required to be present.
+ All length values are in bytes. */
+
+#define GCOV_WORD_SIZE 4
#define GCOV_TAG_FUNCTION ((gcov_unsigned_t)0x01000000)
-#define GCOV_TAG_FUNCTION_LENGTH (3)
+#define GCOV_TAG_FUNCTION_LENGTH (3 * GCOV_WORD_SIZE)
#define GCOV_TAG_BLOCKS ((gcov_unsigned_t)0x01410000)
#define GCOV_TAG_BLOCKS_LENGTH(NUM) (NUM)
#define GCOV_TAG_ARCS ((gcov_unsigned_t)0x01430000)
-#define GCOV_TAG_ARCS_LENGTH(NUM) (1 + (NUM) * 2)
-#define GCOV_TAG_ARCS_NUM(LENGTH) (((LENGTH) - 1) / 2)
+#define GCOV_TAG_ARCS_LENGTH(NUM) (1 + (NUM) * 2 * GCOV_WORD_SIZE)
+#define GCOV_TAG_ARCS_NUM(LENGTH) (((LENGTH / GCOV_WORD_SIZE) - 1) / 2)
#define GCOV_TAG_LINES ((gcov_unsigned_t)0x01450000)
#define GCOV_TAG_COUNTER_BASE ((gcov_unsigned_t)0x01a10000)
-#define GCOV_TAG_COUNTER_LENGTH(NUM) ((NUM) * 2)
-#define GCOV_TAG_COUNTER_NUM(LENGTH) ((LENGTH) / 2)
+#define GCOV_TAG_COUNTER_LENGTH(NUM) ((NUM) * 2 * GCOV_WORD_SIZE)
+#define GCOV_TAG_COUNTER_NUM(LENGTH) ((LENGTH / GCOV_WORD_SIZE) / 2)
#define GCOV_TAG_OBJECT_SUMMARY ((gcov_unsigned_t)0xa1000000)
#define GCOV_TAG_PROGRAM_SUMMARY ((gcov_unsigned_t)0xa3000000) /* Obsolete */
-#define GCOV_TAG_SUMMARY_LENGTH (2)
+#define GCOV_TAG_SUMMARY_LENGTH (2 * GCOV_WORD_SIZE)
#define GCOV_TAG_AFDO_FILE_NAMES ((gcov_unsigned_t)0xaa000000)
#define GCOV_TAG_AFDO_FUNCTION ((gcov_unsigned_t)0xac000000)
#define GCOV_TAG_AFDO_WORKING_SET ((gcov_unsigned_t)0xaf000000)
diff --git a/libgcc/libgcov-driver.c b/libgcc/libgcov-driver.c
index e474e032b54..f51dfd401ed 100644
--- a/libgcc/libgcov-driver.c
+++ b/libgcc/libgcov-driver.c
@@ -514,7 +514,7 @@ read_fatal:;
fn_buffer = free_fn_data (gi_ptr, fn_buffer, GCOV_COUNTERS);
if ((error = gcov_close ()))
- gcov_error (error < 0 ?
+ gcov_error (error < 0 ?
GCOV_PROF_PREFIX "Overflow writing\n" :
GCOV_PROF_PREFIX "Error writing\n",
gf->filename);
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