Move blob from compiler/ to util/

There's nothing whatsoever compiler-specific about it other than that's
currently where it's used.

Reviewed-by: Kristian H. Kristensen <[email protected]>
Reviewed-by: Lionel Landwerlin <[email protected]>

5 files changed, 1094 insertions, 0 deletions

diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources
index cf8c848ea6d..109de1ebf6e 100644
--- a/src/util/Makefile.sources
+++ b/src/util/Makefile.sources
@@ -5,6 +5,8 @@ MESA_UTIL_FILES := \
 	bitscan.c \
 	bitscan.h \
 	bitset.h \
+	blob.c \
+	blob.h \
 	build_id.c \
 	build_id.h \
 	crc32.c \
diff --git a/src/util/blob.c b/src/util/blob.c
new file mode 100644
index 00000000000..c89092e1cf3
--- /dev/null
+++ b/src/util/blob.c
@@ -0,0 +1,391 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <string.h>
+
+#include "main/macros.h"
+#include "blob.h"
+
+#ifdef HAVE_VALGRIND
+#include <valgrind.h>
+#include <memcheck.h>
+#define VG(x) x
+#else
+#define VG(x)
+#endif
+
+#define BLOB_INITIAL_SIZE 4096
+
+/* Ensure that \blob will be able to fit an additional object of size
+ * \additional.  The growing (if any) will occur by doubling the existing
+ * allocation.
+ */
+static bool
+grow_to_fit(struct blob *blob, size_t additional)
+{
+   size_t to_allocate;
+   uint8_t *new_data;
+
+   if (blob->out_of_memory)
+      return false;
+
+   if (blob->size + additional <= blob->allocated)
+      return true;
+
+   if (blob->fixed_allocation) {
+      blob->out_of_memory = true;
+      return false;
+   }
+
+   if (blob->allocated == 0)
+      to_allocate = BLOB_INITIAL_SIZE;
+   else
+      to_allocate = blob->allocated * 2;
+
+   to_allocate = MAX2(to_allocate, blob->allocated + additional);
+
+   new_data = realloc(blob->data, to_allocate);
+   if (new_data == NULL) {
+      blob->out_of_memory = true;
+      return false;
+   }
+
+   blob->data = new_data;
+   blob->allocated = to_allocate;
+
+   return true;
+}
+
+/* Align the blob->size so that reading or writing a value at (blob->data +
+ * blob->size) will result in an access aligned to a granularity of \alignment
+ * bytes.
+ *
+ * \return True unless allocation fails
+ */
+static bool
+align_blob(struct blob *blob, size_t alignment)
+{
+   const size_t new_size = ALIGN(blob->size, alignment);
+
+   if (blob->size < new_size) {
+      if (!grow_to_fit(blob, new_size - blob->size))
+         return false;
+
+      if (blob->data)
+         memset(blob->data + blob->size, 0, new_size - blob->size);
+      blob->size = new_size;
+   }
+
+   return true;
+}
+
+static void
+align_blob_reader(struct blob_reader *blob, size_t alignment)
+{
+   blob->current = blob->data + ALIGN(blob->current - blob->data, alignment);
+}
+
+void
+blob_init(struct blob *blob)
+{
+   blob->data = NULL;
+   blob->allocated = 0;
+   blob->size = 0;
+   blob->fixed_allocation = false;
+   blob->out_of_memory = false;
+}
+
+void
+blob_init_fixed(struct blob *blob, void *data, size_t size)
+{
+   blob->data = data;
+   blob->allocated = size;
+   blob->size = 0;
+   blob->fixed_allocation = true;
+   blob->out_of_memory = false;
+}
+
+bool
+blob_overwrite_bytes(struct blob *blob,
+                     size_t offset,
+                     const void *bytes,
+                     size_t to_write)
+{
+   /* Detect an attempt to overwrite data out of bounds. */
+   if (offset + to_write < offset || blob->size < offset + to_write)
+      return false;
+
+   VG(VALGRIND_CHECK_MEM_IS_DEFINED(bytes, to_write));
+
+   if (blob->data)
+      memcpy(blob->data + offset, bytes, to_write);
+
+   return true;
+}
+
+bool
+blob_write_bytes(struct blob *blob, const void *bytes, size_t to_write)
+{
+   if (! grow_to_fit(blob, to_write))
+       return false;
+
+   VG(VALGRIND_CHECK_MEM_IS_DEFINED(bytes, to_write));
+
+   if (blob->data)
+      memcpy(blob->data + blob->size, bytes, to_write);
+   blob->size += to_write;
+
+   return true;
+}
+
+intptr_t
+blob_reserve_bytes(struct blob *blob, size_t to_write)
+{
+   intptr_t ret;
+
+   if (! grow_to_fit (blob, to_write))
+      return -1;
+
+   ret = blob->size;
+   blob->size += to_write;
+
+   return ret;
+}
+
+intptr_t
+blob_reserve_uint32(struct blob *blob)
+{
+   align_blob(blob, sizeof(uint32_t));
+   return blob_reserve_bytes(blob, sizeof(uint32_t));
+}
+
+intptr_t
+blob_reserve_intptr(struct blob *blob)
+{
+   align_blob(blob, sizeof(intptr_t));
+   return blob_reserve_bytes(blob, sizeof(intptr_t));
+}
+
+bool
+blob_write_uint32(struct blob *blob, uint32_t value)
+{
+   align_blob(blob, sizeof(value));
+
+   return blob_write_bytes(blob, &value, sizeof(value));
+}
+
+#define ASSERT_ALIGNED(_offset, _align) \
+   assert(ALIGN((_offset), (_align)) == (_offset))
+
+bool
+blob_overwrite_uint32 (struct blob *blob,
+                       size_t offset,
+                       uint32_t value)
+{
+   ASSERT_ALIGNED(offset, sizeof(value));
+   return blob_overwrite_bytes(blob, offset, &value, sizeof(value));
+}
+
+bool
+blob_write_uint64(struct blob *blob, uint64_t value)
+{
+   align_blob(blob, sizeof(value));
+
+   return blob_write_bytes(blob, &value, sizeof(value));
+}
+
+bool
+blob_write_intptr(struct blob *blob, intptr_t value)
+{
+   align_blob(blob, sizeof(value));
+
+   return blob_write_bytes(blob, &value, sizeof(value));
+}
+
+bool
+blob_overwrite_intptr (struct blob *blob,
+                       size_t offset,
+                       intptr_t value)
+{
+   ASSERT_ALIGNED(offset, sizeof(value));
+   return blob_overwrite_bytes(blob, offset, &value, sizeof(value));
+}
+
+bool
+blob_write_string(struct blob *blob, const char *str)
+{
+   return blob_write_bytes(blob, str, strlen(str) + 1);
+}
+
+void
+blob_reader_init(struct blob_reader *blob, const void *data, size_t size)
+{
+   blob->data = data;
+   blob->end = blob->data + size;
+   blob->current = data;
+   blob->overrun = false;
+}
+
+/* Check that an object of size \size can be read from this blob.
+ *
+ * If not, set blob->overrun to indicate that we attempted to read too far.
+ */
+static bool
+ensure_can_read(struct blob_reader *blob, size_t size)
+{
+   if (blob->overrun)
+      return false;
+
+   if (blob->current <= blob->end && blob->end - blob->current >= size)
+      return true;
+
+   blob->overrun = true;
+
+   return false;
+}
+
+const void *
+blob_read_bytes(struct blob_reader *blob, size_t size)
+{
+   const void *ret;
+
+   if (! ensure_can_read (blob, size))
+      return NULL;
+
+   ret = blob->current;
+
+   blob->current += size;
+
+   return ret;
+}
+
+void
+blob_copy_bytes(struct blob_reader *blob, void *dest, size_t size)
+{
+   const void *bytes;
+
+   bytes = blob_read_bytes(blob, size);
+   if (bytes == NULL)
+      return;
+
+   memcpy(dest, bytes, size);
+}
+
+void
+blob_skip_bytes(struct blob_reader *blob, size_t size)
+{
+   if (ensure_can_read (blob, size))
+      blob->current += size;
+}
+
+/* These next three read functions have identical form. If we add any beyond
+ * these first three we should probably switch to generating these with a
+ * preprocessor macro.
+*/
+uint32_t
+blob_read_uint32(struct blob_reader *blob)
+{
+   uint32_t ret;
+   int size = sizeof(ret);
+
+   align_blob_reader(blob, size);
+
+   if (! ensure_can_read(blob, size))
+      return 0;
+
+   ret = *((uint32_t*) blob->current);
+
+   blob->current += size;
+
+   return ret;
+}
+
+uint64_t
+blob_read_uint64(struct blob_reader *blob)
+{
+   uint64_t ret;
+   int size = sizeof(ret);
+
+   align_blob_reader(blob, size);
+
+   if (! ensure_can_read(blob, size))
+      return 0;
+
+   ret = *((uint64_t*) blob->current);
+
+   blob->current += size;
+
+   return ret;
+}
+
+intptr_t
+blob_read_intptr(struct blob_reader *blob)
+{
+   intptr_t ret;
+   int size = sizeof(ret);
+
+   align_blob_reader(blob, size);
+
+   if (! ensure_can_read(blob, size))
+      return 0;
+
+   ret = *((intptr_t *) blob->current);
+
+   blob->current += size;
+
+   return ret;
+}
+
+char *
+blob_read_string(struct blob_reader *blob)
+{
+   int size;
+   char *ret;
+   uint8_t *nul;
+
+   /* If we're already at the end, then this is an overrun. */
+   if (blob->current >= blob->end) {
+      blob->overrun = true;
+      return NULL;
+   }
+
+   /* Similarly, if there is no zero byte in the data remaining in this blob,
+    * we also consider that an overrun.
+    */
+   nul = memchr(blob->current, 0, blob->end - blob->current);
+
+   if (nul == NULL) {
+      blob->overrun = true;
+      return NULL;
+   }
+
+   size = nul - blob->current + 1;
+
+   assert(ensure_can_read(blob, size));
+
+   ret = (char *) blob->current;
+
+   blob->current += size;
+
+   return ret;
+}
diff --git a/src/util/blob.h b/src/util/blob.h
new file mode 100644
index 00000000000..b56fa4b2fe0
--- /dev/null
+++ b/src/util/blob.h
@@ -0,0 +1,358 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef BLOB_H
+#define BLOB_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* The blob functions implement a simple, low-level API for serializing and
+ * deserializing.
+ *
+ * All objects written to a blob will be serialized directly, (without any
+ * additional meta-data to describe the data written). Therefore, it is the
+ * caller's responsibility to ensure that any data can be read later, (either
+ * by knowing exactly what data is expected, or by writing to the blob
+ * sufficient meta-data to describe what has been written).
+ *
+ * A blob is efficient in that it dynamically grows by doubling in size, so
+ * allocation costs are logarithmic.
+ */
+
+struct blob {
+   /* The data actually written to the blob. */
+   uint8_t *data;
+
+   /** Number of bytes that have been allocated for \c data. */
+   size_t allocated;
+
+   /** The number of bytes that have actual data written to them. */
+   size_t size;
+
+   /** True if \c data a fixed allocation that we cannot resize
+    *
+    * \see blob_init_fixed
+    */
+   bool fixed_allocation;
+
+   /**
+    * True if we've ever failed to realloc or if we go pas the end of a fixed
+    * allocation blob.
+    */
+   bool out_of_memory;
+};
+
+/* When done reading, the caller can ensure that everything was consumed by
+ * checking the following:
+ *
+ *   1. blob->current should be equal to blob->end, (if not, too little was
+ *      read).
+ *
+ *   2. blob->overrun should be false, (otherwise, too much was read).
+ */
+struct blob_reader {
+   const uint8_t *data;
+   const uint8_t *end;
+   const uint8_t *current;
+   bool overrun;
+};
+
+/**
+ * Init a new, empty blob.
+ */
+void
+blob_init(struct blob *blob);
+
+/**
+ * Init a new, fixed-size blob.
+ *
+ * A fixed-size blob has a fixed block of data that will not be freed on
+ * blob_finish and will never be grown.  If we hit the end, we simply start
+ * returning false from the write functions.
+ *
+ * If a fixed-size blob has a NULL data pointer then the data is written but
+ * it otherwise operates normally.  This can be used to determine the size
+ * that will be required to write a given data structure.
+ */
+void
+blob_init_fixed(struct blob *blob, void *data, size_t size);
+
+/**
+ * Finish a blob and free its memory.
+ *
+ * If \blob was initialized with blob_init_fixed, the data pointer is
+ * considered to be owned by the user and will not be freed.
+ */
+static inline void
+blob_finish(struct blob *blob)
+{
+   if (!blob->fixed_allocation)
+      free(blob->data);
+}
+
+/**
+ * Add some unstructured, fixed-size data to a blob.
+ *
+ * \return True unless allocation failed.
+ */
+bool
+blob_write_bytes(struct blob *blob, const void *bytes, size_t to_write);
+
+/**
+ * Reserve space in \blob for a number of bytes.
+ *
+ * Space will be allocated within the blob for these byes, but the bytes will
+ * be left uninitialized. The caller is expected to use \sa
+ * blob_overwrite_bytes to write to these bytes.
+ *
+ * \return An offset to space allocated within \blob to which \to_write bytes
+ * can be written, (or -1 in case of any allocation error).
+ */
+intptr_t
+blob_reserve_bytes(struct blob *blob, size_t to_write);
+
+/**
+ * Similar to \sa blob_reserve_bytes, but only reserves an uint32_t worth of
+ * space. Note that this must be used if later reading with \sa
+ * blob_read_uint32, since it aligns the offset correctly.
+ */
+intptr_t
+blob_reserve_uint32(struct blob *blob);
+
+/**
+ * Similar to \sa blob_reserve_bytes, but only reserves an intptr_t worth of
+ * space. Note that this must be used if later reading with \sa
+ * blob_read_intptr, since it aligns the offset correctly.
+ */
+intptr_t
+blob_reserve_intptr(struct blob *blob);
+
+/**
+ * Overwrite some data previously written to the blob.
+ *
+ * Writes data to an existing portion of the blob at an offset of \offset.
+ * This data range must have previously been written to the blob by one of the
+ * blob_write_* calls.
+ *
+ * For example usage, see blob_overwrite_uint32
+ *
+ * \return True unless the requested offset or offset+to_write lie outside
+ * the current blob's size.
+ */
+bool
+blob_overwrite_bytes(struct blob *blob,
+                     size_t offset,
+                     const void *bytes,
+                     size_t to_write);
+
+/**
+ * Add a uint32_t to a blob.
+ *
+ * \note This function will only write to a uint32_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be added to the
+ * blob if this write follows some unaligned write (such as
+ * blob_write_string).
+ *
+ * \return True unless allocation failed.
+ */
+bool
+blob_write_uint32(struct blob *blob, uint32_t value);
+
+/**
+ * Overwrite a uint32_t previously written to the blob.
+ *
+ * Writes a uint32_t value to an existing portion of the blob at an offset of
+ * \offset.  This data range must have previously been written to the blob by
+ * one of the blob_write_* calls.
+ *
+ *
+ * The expected usage is something like the following pattern:
+ *
+ *	size_t offset;
+ *
+ *	offset = blob_reserve_uint32(blob);
+ *	... various blob write calls, writing N items ...
+ *	blob_overwrite_uint32 (blob, offset, N);
+ *
+ * \return True unless the requested position or position+to_write lie outside
+ * the current blob's size.
+ */
+bool
+blob_overwrite_uint32(struct blob *blob,
+                      size_t offset,
+                      uint32_t value);
+
+/**
+ * Add a uint64_t to a blob.
+ *
+ * \note This function will only write to a uint64_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be added to the
+ * blob if this write follows some unaligned write (such as
+ * blob_write_string).
+ *
+ * \return True unless allocation failed.
+ */
+bool
+blob_write_uint64(struct blob *blob, uint64_t value);
+
+/**
+ * Add an intptr_t to a blob.
+ *
+ * \note This function will only write to an intptr_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be added to the
+ * blob if this write follows some unaligned write (such as
+ * blob_write_string).
+ *
+ * \return True unless allocation failed.
+ */
+bool
+blob_write_intptr(struct blob *blob, intptr_t value);
+
+/**
+ * Overwrite an intptr_t previously written to the blob.
+ *
+ * Writes a intptr_t value to an existing portion of the blob at an offset of
+ * \offset.  This data range must have previously been written to the blob by
+ * one of the blob_write_* calls.
+ *
+ * For example usage, see blob_overwrite_uint32
+ *
+ * \return True unless the requested position or position+to_write lie outside
+ * the current blob's size.
+ */
+bool
+blob_overwrite_intptr(struct blob *blob,
+                      size_t offset,
+                      intptr_t value);
+
+/**
+ * Add a NULL-terminated string to a blob, (including the NULL terminator).
+ *
+ * \return True unless allocation failed.
+ */
+bool
+blob_write_string(struct blob *blob, const char *str);
+
+/**
+ * Start reading a blob, (initializing the contents of \blob for reading).
+ *
+ * After this call, the caller can use the various blob_read_* functions to
+ * read elements from the data array.
+ *
+ * For all of the blob_read_* functions, if there is insufficient data
+ * remaining, the functions will do nothing, (perhaps returning default values
+ * such as 0). The caller can detect this by noting that the blob_reader's
+ * current value is unchanged before and after the call.
+ */
+void
+blob_reader_init(struct blob_reader *blob, const void *data, size_t size);
+
+/**
+ * Read some unstructured, fixed-size data from the current location, (and
+ * update the current location to just past this data).
+ *
+ * \note The memory returned belongs to the data underlying the blob reader. The
+ * caller must copy the data in order to use it after the lifetime of the data
+ * underlying the blob reader.
+ *
+ * \return The bytes read (see note above about memory lifetime).
+ */
+const void *
+blob_read_bytes(struct blob_reader *blob, size_t size);
+
+/**
+ * Read some unstructured, fixed-size data from the current location, copying
+ * it to \dest (and update the current location to just past this data)
+ */
+void
+blob_copy_bytes(struct blob_reader *blob, void *dest, size_t size);
+
+/**
+ * Skip \size bytes within the blob.
+ */
+void
+blob_skip_bytes(struct blob_reader *blob, size_t size);
+
+/**
+ * Read a uint32_t from the current location, (and update the current location
+ * to just past this uint32_t).
+ *
+ * \note This function will only read from a uint32_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be skipped.
+ *
+ * \return The uint32_t read
+ */
+uint32_t
+blob_read_uint32(struct blob_reader *blob);
+
+/**
+ * Read a uint64_t from the current location, (and update the current location
+ * to just past this uint64_t).
+ *
+ * \note This function will only read from a uint64_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be skipped.
+ *
+ * \return The uint64_t read
+ */
+uint64_t
+blob_read_uint64(struct blob_reader *blob);
+
+/**
+ * Read an intptr_t value from the current location, (and update the
+ * current location to just past this intptr_t).
+ *
+ * \note This function will only read from an intptr_t-aligned offset from the
+ * beginning of the blob's data, so some padding bytes may be skipped.
+ *
+ * \return The intptr_t read
+ */
+intptr_t
+blob_read_intptr(struct blob_reader *blob);
+
+/**
+ * Read a NULL-terminated string from the current location, (and update the
+ * current location to just past this string).
+ *
+ * \note The memory returned belongs to the data underlying the blob reader. The
+ * caller must copy the string in order to use the string after the lifetime
+ * of the data underlying the blob reader.
+ *
+ * \return The string read (see note above about memory lifetime). However, if
+ * there is no NULL byte remaining within the blob, this function returns
+ * NULL.
+ */
+char *
+blob_read_string(struct blob_reader *blob);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLOB_H */
diff --git a/src/util/blob_test.c b/src/util/blob_test.c
new file mode 100644
index 00000000000..21b8b1efdc1
--- /dev/null
+++ b/src/util/blob_test.c
@@ -0,0 +1,328 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+/* A collection of unit tests for blob.c */
+
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#ifdef _MSC_VER
+#include <BaseTsd.h>
+typedef SSIZE_T ssize_t;
+#endif
+
+#include "util/ralloc.h"
+#include "blob.h"
+
+#define bytes_test_str     "bytes_test"
+#define reserve_test_str   "reserve_test"
+
+/* This placeholder must be the same length as the next overwrite_test_str */
+#define placeholder_str    "XXXXXXXXXXXXXX"
+#define overwrite_test_str "overwrite_test"
+#define uint32_test        0x12345678
+#define uint32_placeholder 0xDEADBEEF
+#define uint32_overwrite   0xA1B2C3D4
+#define uint64_test        0x1234567890ABCDEF
+#define string_test_str    "string_test"
+
+bool error = false;
+
+static void
+expect_equal(uint64_t expected, uint64_t actual, const char *test)
+{
+   if (actual != expected) {
+      fprintf(stderr,
+              "Error: Test '%s' failed: "
+              "Expected=%" PRIu64 ", "
+              "Actual=%" PRIu64 "\n",
+               test, expected, actual);
+      error = true;
+   }
+}
+
+static void
+expect_unequal(uint64_t expected, uint64_t actual, const char *test)
+{
+   if (actual == expected) {
+      fprintf(stderr,
+              "Error: Test '%s' failed: Result=%" PRIu64 ", "
+              "but expected something different.\n",
+               test, actual);
+      error = true;
+   }
+}
+
+static void
+expect_equal_str(const char *expected, const char *actual, const char *test)
+{
+   if (strcmp(expected, actual)) {
+      fprintf (stderr, "Error: Test '%s' failed:\n\t"
+               "Expected=\"%s\", Actual=\"%s\"\n",
+               test, expected, actual);
+      error = true;
+   }
+}
+
+static void
+expect_equal_bytes(uint8_t *expected, const uint8_t *actual,
+                   size_t num_bytes, const char *test)
+{
+   size_t i;
+
+   if (memcmp(expected, actual, num_bytes)) {
+      fprintf (stderr, "Error: Test '%s' failed:\n\t", test);
+
+      fprintf (stderr, "Expected=[");
+      for (i = 0; i < num_bytes; i++) {
+         if (i != 0)
+            fprintf(stderr, ", ");
+         fprintf(stderr, "0x%02x", expected[i]);
+      }
+      fprintf (stderr, "]");
+
+      fprintf (stderr, "Actual=[");
+      for (i = 0; i < num_bytes; i++) {
+         if (i != 0)
+            fprintf(stderr, ", ");
+         fprintf(stderr, "0x%02x", actual[i]);
+      }
+      fprintf (stderr, "]\n");
+
+      error = true;
+   }
+}
+
+/* Test at least one call of each blob_write_foo and blob_read_foo function,
+ * verifying that we read out everything we wrote, that every bytes is
+ * consumed, and that the overrun bit is not set.
+ */
+static void
+test_write_and_read_functions (void)
+{
+   struct blob blob;
+   struct blob_reader reader;
+   ssize_t reserved;
+   size_t str_offset, uint_offset;
+   uint8_t reserve_buf[sizeof(reserve_test_str)];
+
+   blob_init(&blob);
+
+   /*** Test blob by writing one of every possible kind of value. */
+
+   blob_write_bytes(&blob, bytes_test_str, sizeof(bytes_test_str));
+
+   reserved = blob_reserve_bytes(&blob, sizeof(reserve_test_str));
+   blob_overwrite_bytes(&blob, reserved, reserve_test_str, sizeof(reserve_test_str));
+
+   /* Write a placeholder, (to be replaced later via overwrite_bytes) */
+   str_offset = blob.size;
+   blob_write_bytes(&blob, placeholder_str, sizeof(placeholder_str));
+
+   blob_write_uint32(&blob, uint32_test);
+
+   /* Write a placeholder, (to be replaced later via overwrite_uint32) */
+   uint_offset = blob.size;
+   blob_write_uint32(&blob, uint32_placeholder);
+
+   blob_write_uint64(&blob, uint64_test);
+
+   blob_write_intptr(&blob, (intptr_t) &blob);
+
+   blob_write_string(&blob, string_test_str);
+
+   /* Finally, overwrite our placeholders. */
+   blob_overwrite_bytes(&blob, str_offset, overwrite_test_str,
+                        sizeof(overwrite_test_str));
+   blob_overwrite_uint32(&blob, uint_offset, uint32_overwrite);
+
+   /*** Now read each value and verify. */
+   blob_reader_init(&reader, blob.data, blob.size);
+
+   expect_equal_str(bytes_test_str,
+                    blob_read_bytes(&reader, sizeof(bytes_test_str)),
+                    "blob_write/read_bytes");
+
+   blob_copy_bytes(&reader, reserve_buf, sizeof(reserve_buf));
+   expect_equal_str(reserve_test_str, (char *) reserve_buf,
+                    "blob_reserve_bytes/blob_copy_bytes");
+
+   expect_equal_str(overwrite_test_str,
+                    blob_read_bytes(&reader, sizeof(overwrite_test_str)),
+                    "blob_overwrite_bytes");
+
+   expect_equal(uint32_test, blob_read_uint32(&reader),
+                "blob_write/read_uint32");
+   expect_equal(uint32_overwrite, blob_read_uint32(&reader),
+                "blob_overwrite_uint32");
+   expect_equal(uint64_test, blob_read_uint64(&reader),
+                "blob_write/read_uint64");
+   expect_equal((intptr_t) &blob, blob_read_intptr(&reader),
+                "blob_write/read_intptr");
+   expect_equal_str(string_test_str, blob_read_string(&reader),
+                    "blob_write/read_string");
+
+   expect_equal(reader.end - reader.data, reader.current - reader.data,
+                "read_consumes_all_bytes");
+   expect_equal(false, reader.overrun, "read_does_not_overrun");
+
+   blob_finish(&blob);
+}
+
+/* Test that data values are written and read with proper alignment. */
+static void
+test_alignment(void)
+{
+   struct blob blob;
+   struct blob_reader reader;
+   uint8_t bytes[] = "ABCDEFGHIJKLMNOP";
+   size_t delta, last, num_bytes;
+
+   blob_init(&blob);
+
+   /* First, write an intptr value to the blob and capture that size. This is
+    * the expected offset between any pair of intptr values (if written with
+    * alignment).
+    */
+   blob_write_intptr(&blob, (intptr_t) &blob);
+
+   delta = blob.size;
+   last = blob.size;
+
+   /* Then loop doing the following:
+    *
+    *   1. Write an unaligned number of bytes
+    *   2. Verify that write results in an unaligned size
+    *   3. Write an intptr_t value
+    *   2. Verify that that write results in an aligned size
+    */
+   for (num_bytes = 1; num_bytes < sizeof(intptr_t); num_bytes++) {
+      blob_write_bytes(&blob, bytes, num_bytes);
+
+      expect_unequal(delta, blob.size - last, "unaligned write of bytes");
+
+      blob_write_intptr(&blob, (intptr_t) &blob);
+
+      expect_equal(2 * delta, blob.size - last, "aligned write of intptr");
+
+      last = blob.size;
+   }
+
+   /* Finally, test that reading also does proper alignment. Since we know
+    * that values were written with all the right alignment, all we have to do
+    * here is verify that correct values are read.
+    */
+   blob_reader_init(&reader, blob.data, blob.size);
+
+   expect_equal((intptr_t) &blob, blob_read_intptr(&reader),
+                "read of initial, aligned intptr_t");
+
+   for (num_bytes = 1; num_bytes < sizeof(intptr_t); num_bytes++) {
+      expect_equal_bytes(bytes, blob_read_bytes(&reader, num_bytes),
+                         num_bytes, "unaligned read of bytes");
+      expect_equal((intptr_t) &blob, blob_read_intptr(&reader),
+                   "aligned read of intptr_t");
+   }
+
+   blob_finish(&blob);
+}
+
+/* Test that we detect overrun. */
+static void
+test_overrun(void)
+{
+   struct blob blob;
+   struct blob_reader reader;
+   uint32_t value = 0xdeadbeef;
+
+   blob_init(&blob);
+
+   blob_write_uint32(&blob, value);
+
+   blob_reader_init(&reader, blob.data, blob.size);
+
+   expect_equal(value, blob_read_uint32(&reader), "read before overrun");
+   expect_equal(false, reader.overrun, "overrun flag not set");
+   expect_equal(0, blob_read_uint32(&reader), "read at overrun");
+   expect_equal(true, reader.overrun, "overrun flag set");
+
+   blob_finish(&blob);
+}
+
+/* Test that we can read and write some large objects, (exercising the code in
+ * the blob_write functions to realloc blob->data.
+ */
+static void
+test_big_objects(void)
+{
+   void *ctx = ralloc_context(NULL);
+   struct blob blob;
+   struct blob_reader reader;
+   int size = 1000;
+   int count = 1000;
+   size_t i;
+   char *buf;
+
+   blob_init(&blob);
+
+   /* Initialize our buffer. */
+   buf = ralloc_size(ctx, size);
+   for (i = 0; i < size; i++) {
+      buf[i] = i % 256;
+   }
+
+   /* Write it many times. */
+   for (i = 0; i < count; i++) {
+      blob_write_bytes(&blob, buf, size);
+   }
+
+   blob_reader_init(&reader, blob.data, blob.size);
+
+   /* Read and verify it many times. */
+   for (i = 0; i < count; i++) {
+      expect_equal_bytes((uint8_t *) buf, blob_read_bytes(&reader, size), size,
+                         "read of large objects");
+   }
+
+   expect_equal(reader.end - reader.data, reader.current - reader.data,
+                "number of bytes read reading large objects");
+
+   expect_equal(false, reader.overrun,
+                "overrun flag not set reading large objects");
+
+   blob_finish(&blob);
+   ralloc_free(ctx);
+}
+
+int
+main (void)
+{
+   test_write_and_read_functions ();
+   test_alignment ();
+   test_overrun ();
+   test_big_objects ();
+
+   return error ? 1 : 0;
+}
diff --git a/src/util/meson.build b/src/util/meson.build
index c981a146de1..60989c924ea 100644
--- a/src/util/meson.build
+++ b/src/util/meson.build
@@ -29,6 +29,8 @@ files_mesa_util = files(
   'bitscan.c',
   'bitscan.h',
   'bitset.h',
+  'blob.c',
+  'blob.h',
   'build_id.c',
   'build_id.h',
   'crc32.c',
@@ -144,6 +146,7 @@ deps_for_libmesa_util = [
   dep_thread,
   dep_atomic,
   dep_m,
+  dep_valgrind,
 ]
 
 if with_platform_android
@@ -203,6 +206,18 @@ if with_tests
   )
 
   test(
+    'blob',
+    executable(
+      'blob_test',
+      files('blob_test.c'),
+      include_directories : inc_common,
+      dependencies : idep_mesautil,
+      c_args : [c_msvc_compat_args],
+    ),
+    suite : ['util'],
+  )
+
+  test(
     'roundeven',
     executable(
       'roundeven_test',