From 287e6e3b8151fac85b4beaeb64f729904551e897 Mon Sep 17 00:00:00 2001
From: vector-of-bool <vectorofbool@gmail.com>
Date: Tue, 5 Apr 2022 00:42:58 +0000
Subject: [PATCH 1/7] Add mlib to the source tree

---
 src/mlib/mlib.cmake | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 src/mlib/mlib.cmake

diff --git a/src/mlib/mlib.cmake b/src/mlib/mlib.cmake
new file mode 100644
index 000000000..5dfada555
--- /dev/null
+++ b/src/mlib/mlib.cmake
@@ -0,0 +1,31 @@
+set (MLIB_SRC_DIR "${CMAKE_CURRENT_LIST_DIR}")
+
+add_library (_mongo-mlib INTERFACE)
+get_filename_component (_inc_dir "${MLIB_SRC_DIR}" DIRECTORY)
+target_include_directories (_mongo-mlib INTERFACE "${_inc_dir}")
+target_compile_definitions (_mongo-mlib INTERFACE MLIB_USER)
+add_library (mongo::mlib ALIAS _mongo-mlib)
+
+set (_components error path str thread user-check)
+set (MLIB_SOURCES)
+foreach (comp IN LISTS _components)
+    set (test_file "${MLIB_SRC_DIR}/${comp}.test.c")
+    if (EXISTS "${test_file}")
+        add_executable (mlib.test.${comp} "${test_file}")
+        target_link_libraries (mlib.test.${comp} PRIVATE mongo::mlib)
+        add_test (mlib.test.${comp} mlib.test.${comp})
+        list (APPEND MLIB_SOURCE "${test_file}")
+    endif ()
+    list (APPEND MLIB_SOURCES "${MLIB_SRC_DIR}/${comp}.h")
+endforeach ()
+
+# This is only here to support export() of mongo::mlib-linked targets.
+# Nothing is actually installed
+install (TARGETS _mongo-mlib EXPORT _mongo-mlib)
+export (EXPORT _mongo-mlib)
+
+function (target_use_mlib)
+    foreach (t IN LISTS ARGV)
+        target_link_libraries("${t}" PRIVATE $<BUILD_INTERFACE:mongo::mlib>)
+    endforeach ()
+endfunction ()

From 751a56dea65c5a93170899362e440f4c7ca4ce5d Mon Sep 17 00:00:00 2001
From: vector-of-bool <vectorofbool@gmail.com>
Date: Thu, 7 Apr 2022 00:07:24 +0000
Subject: [PATCH 2/7] Tweak mlib usage in CMake

---
 src/mlib/mlib.cmake | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/mlib/mlib.cmake b/src/mlib/mlib.cmake
index 5dfada555..9be1d72ba 100644
--- a/src/mlib/mlib.cmake
+++ b/src/mlib/mlib.cmake
@@ -7,7 +7,6 @@ target_compile_definitions (_mongo-mlib INTERFACE MLIB_USER)
 add_library (mongo::mlib ALIAS _mongo-mlib)
 
 set (_components error path str thread user-check)
-set (MLIB_SOURCES)
 foreach (comp IN LISTS _components)
     set (test_file "${MLIB_SRC_DIR}/${comp}.test.c")
     if (EXISTS "${test_file}")
@@ -16,7 +15,6 @@ foreach (comp IN LISTS _components)
         add_test (mlib.test.${comp} mlib.test.${comp})
         list (APPEND MLIB_SOURCE "${test_file}")
     endif ()
-    list (APPEND MLIB_SOURCES "${MLIB_SRC_DIR}/${comp}.h")
 endforeach ()
 
 # This is only here to support export() of mongo::mlib-linked targets.
@@ -24,7 +22,7 @@ endforeach ()
 install (TARGETS _mongo-mlib EXPORT _mongo-mlib)
 export (EXPORT _mongo-mlib)
 
-function (target_use_mlib)
+function (targets_use_mlib)
     foreach (t IN LISTS ARGV)
         target_link_libraries("${t}" PRIVATE $<BUILD_INTERFACE:mongo::mlib>)
     endforeach ()

From bb3daca9edb6eb3b3999d8109486a45cf4c5a6a5 Mon Sep 17 00:00:00 2001
From: vector-of-bool <vectorofbool@gmail.com>
Date: Thu, 7 Apr 2022 15:44:58 -0600
Subject: [PATCH 3/7] Add an 'inline definition' function attribute macro

---
 src/mlib/error.h  |  2 +-
 src/mlib/macros.h | 44 ++++++++++++++++++++++
 src/mlib/path.h   | 35 ++++++++---------
 src/mlib/str.h    | 95 ++++++++++++++++++++++++-----------------------
 src/mlib/thread.h |  5 ++-
 5 files changed, 114 insertions(+), 67 deletions(-)
 create mode 100644 src/mlib/macros.h

diff --git a/src/mlib/error.h b/src/mlib/error.h
index 7dcb0bede..8fa18699d 100644
--- a/src/mlib/error.h
+++ b/src/mlib/error.h
@@ -19,7 +19,7 @@
  * @return mstr A new string containing the resulting error. Must be freed with
  * @ref mstr_free().
  */
-static inline mstr
+mlib_inline_def mstr
 merror_system_error_string (int errn)
 {
 #ifdef _WIN32
diff --git a/src/mlib/macros.h b/src/mlib/macros.h
new file mode 100644
index 000000000..48396eb04
--- /dev/null
+++ b/src/mlib/macros.h
@@ -0,0 +1,44 @@
+#ifndef MLIB_MACROS_H
+#define MLIB_MACROS_H
+
+#include "./user-check.h"
+
+/**
+ * @macro mlib_inline Expands to the compiler's "inline" keyword. On C99, just
+ * 'inline'. On older compilers pre-C99, an implementation-defined "inline"
+ */
+
+// clang-format off
+#if defined(__GNUC__) || defined(__clang__) || (defined(_MSC_VER) && _MSC_VER >= 1900)
+    #define mlib_inline inline
+#elif defined(_MSC_VER)
+    #define mlib_inline __inline
+#else
+    #define mlib_inline _Do_not_know_how_to_say_inline_on_this_compiler
+#endif
+
+/**
+ * @macro mlib_inline_def
+ * @brief Declare a function to be inline-defined, but with external linkage.
+ *
+ * This has the effect that there will be only one definiton if the final
+ * program, even if the function is defined in multiple translation units
+ * (e.g as the result of #inclusion). This mimicks the linkage behavior of
+ * C++ 'inline' keyword, which is not shared by C99's 'inline'.
+ */
+#ifdef __INTELLISENSE__
+    // Give a pretty definition for intellisense readers
+    #define mlib_inline_def inline
+#elif _WIN32
+    // On MSVC/Windows, inline functions are implicitly in COMDAT, even in C
+    #define mlib_inline_def extern mlib_inline
+#else
+    // On other platforms, declare the symbol "weak" to cause symbol merging,
+    // and "hidden" to disable the ability for the symbol to be overridden via
+    // interposition
+    #define mlib_inline_def extern __attribute__((weak, visibility("hidden")))
+#endif
+
+// clang-format on
+
+#endif // MLIB_MACROS_H
diff --git a/src/mlib/path.h b/src/mlib/path.h
index 2967f4613..628d1eca1 100644
--- a/src/mlib/path.h
+++ b/src/mlib/path.h
@@ -4,6 +4,7 @@
 #include "./user-check.h"
 
 #include "./str.h"
+#include "./macros.h"
 
 #include <inttypes.h>
 
@@ -34,7 +35,7 @@ typedef enum mpath_format {
  * @param c A path character
  * @param f The path format to use
  */
-static inline bool
+mlib_inline_def bool
 mpath_is_sep (char c, mpath_format f)
 {
    if (f == MPATH_WIN32) {
@@ -47,7 +48,7 @@ mpath_is_sep (char c, mpath_format f)
 /**
  * @brief Obtain the preferred path separator character for the given format
  */
-static inline char
+mlib_inline_def char
 mpath_preferred_sep (mpath_format f)
 {
    if (f == MPATH_WIN32) {
@@ -63,7 +64,7 @@ mpath_preferred_sep (mpath_format f)
  *
  * @return mstr A new string which must be freed with mstr_free()
  */
-static inline mstr
+mlib_inline_def mstr
 mpath_current_path ()
 {
 #if _WIN32
@@ -96,7 +97,7 @@ mpath_current_path ()
 /**
  * @brief Determine whether the given path string has a trailing path separator
  */
-static inline bool
+mlib_inline_def bool
 mpath_has_trailing_sep (mstr_view path, mpath_format f)
 {
    return path.len && mpath_is_sep (path.data[path.len - 1], f);
@@ -105,7 +106,7 @@ mpath_has_trailing_sep (mstr_view path, mpath_format f)
 /**
  * @brief Obtain the parent path of the given path.
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mpath_parent (mstr_view path, mpath_format f)
 {
    if (mpath_has_trailing_sep (path, f)) {
@@ -133,7 +134,7 @@ mpath_parent (mstr_view path, mpath_format f)
  * The returned path will include no directory separators. If the given path
  * ends with a directory separator, the single-dot '.' path is returned instead.
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mpath_filename (mstr_view path, mpath_format f)
 {
    if (!path.len) {
@@ -163,7 +164,7 @@ mpath_filename (mstr_view path, mpath_format f)
  * @param f The path format to use
  * @return mstr A new string resulting from the join
  */
-static inline mstr
+mlib_inline_def mstr
 mpath_join (mstr_view base, mstr_view suffix, mpath_format f)
 {
    if (!base.len) {
@@ -194,7 +195,7 @@ mpath_join (mstr_view base, mstr_view suffix, mpath_format f)
  * For the Windows format, this will return the drive letter, if present.
  * Otherwise, this will return an empty string.
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mpath_root_name (mstr_view path, mpath_format f)
 {
    if (f == MPATH_WIN32 && path.len > 1) {
@@ -212,7 +213,7 @@ mpath_root_name (mstr_view path, mpath_format f)
  *
  * @note This will not include the drive letter of a Win32 path.
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mpath_root_directory (mstr_view path, mpath_format f)
 {
    mstr_view rname = mpath_root_name (path, f);
@@ -229,7 +230,7 @@ mpath_root_directory (mstr_view path, mpath_format f)
  *
  * This will include both the root name and the root filepath, if present.
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mpath_root_path (mstr_view path, mpath_format f)
 {
    mstr_view rname = mpath_root_name (path, f);
@@ -243,7 +244,7 @@ mpath_root_path (mstr_view path, mpath_format f)
  *
  * @note A Win32 filepath without a drive letter is not absolute!
  */
-static inline bool
+mlib_inline_def bool
 mpath_is_absolute (mstr_view path, mpath_format f)
 {
    if (f == MPATH_WIN32) {
@@ -263,7 +264,7 @@ mpath_is_absolute (mstr_view path, mpath_format f)
  * If the path has a root path, returns the content of the path following that
  * root path, otherwise returns the same path itself.
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mpath_relative_path (mstr_view path, mpath_format f)
 {
    mstr_view root = mpath_root_path (path, f);
@@ -276,7 +277,7 @@ mpath_relative_path (mstr_view path, mpath_format f)
  *
  * @note The return value must be freed with mstr_free()
  */
-static inline mstr
+mlib_inline_def mstr
 mpath_to_format (mpath_format from, mstr_view path, mpath_format to)
 {
    mstr_mut ret = mstr_new (path.len);
@@ -296,7 +297,7 @@ mpath_to_format (mpath_format from, mstr_view path, mpath_format to)
 /**
  * @brief Determine whether the given path is relative (not absolute)
  */
-static inline bool
+mlib_inline_def bool
 mpath_is_relative (mstr_view path, mpath_format f)
 {
    return !mpath_is_absolute (path, f);
@@ -307,7 +308,7 @@ mpath_is_relative (mstr_view path, mpath_format f)
  *
  * @note The return value must be freed with mstr_free()
  */
-static inline mstr
+mlib_inline_def mstr
 mpath_absolute (mstr_view path, mpath_format f);
 
 /**
@@ -320,7 +321,7 @@ mpath_absolute (mstr_view path, mpath_format f);
  * @note If `base` is also a relative path, it will also be given to
  * mpath_absolute() to resolve it.
  */
-static inline mstr
+mlib_inline_def mstr
 mpath_absolute_from (mstr_view path, mstr_view base, mpath_format f)
 {
    mstr_view rname = mpath_root_name (path, f);
@@ -363,7 +364,7 @@ mpath_absolute_from (mstr_view path, mstr_view base, mpath_format f)
    }
 }
 
-static inline mstr
+mlib_inline_def mstr
 mpath_absolute (mstr_view path, mpath_format f)
 {
    if (mpath_is_absolute (path, f)) {
diff --git a/src/mlib/str.h b/src/mlib/str.h
index 33b4fb623..3898675f2 100644
--- a/src/mlib/str.h
+++ b/src/mlib/str.h
@@ -2,6 +2,7 @@
 #define MONGOCRYPT_STR_PRIVATE_H
 
 #include "./user-check.h"
+#include "./macros.h"
 
 #include <stdlib.h>
 #include <string.h>
@@ -141,7 +142,7 @@ typedef struct mstr_mut {
  * @note The @ref mstr_mut::mstr member MUST eventually be given to
  * @ref mstr_free().
  */
-static inline mstr_mut
+mlib_inline_def mstr_mut
 mstr_new (size_t len)
 {
 #ifndef __clang_analyzer__
@@ -160,7 +161,7 @@ mstr_new (size_t len)
  * @param len The length of the character array, in code units
  * @return mstr_view A non-owning string.
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mstrv_view_data (const char *s, size_t len)
 {
    return (mstr_view){.data = s, .len = len};
@@ -173,7 +174,7 @@ mstrv_view_data (const char *s, size_t len)
  * @param s A pointer to a null-terminated character array
  * @return mstr_view A view of the pointed-to string
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mstrv_view_cstr (const char *s)
 {
    return mstrv_view_data (s, strlen (s));
@@ -189,7 +190,7 @@ mstrv_view_cstr (const char *s)
  *
  * @note The resulting string will be null-terminated.
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_copy_data (const char *s, size_t len)
 {
    mstr_mut r = mstr_new (len);
@@ -203,7 +204,7 @@ mstr_copy_data (const char *s, size_t len)
  * @param s A pointer to a null-terminated character array
  * @return mstr A new string copied from the pointed-to string
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_copy_cstr (const char *s)
 {
    return mstr_copy_data (s, strlen (s));
@@ -215,7 +216,7 @@ mstr_copy_cstr (const char *s)
  * @param s A string view to copy from
  * @return mstr A new string copied from the given view
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_copy (mstr_view s)
 {
    return mstr_copy_data (s.data, s.len);
@@ -226,7 +227,7 @@ mstr_copy (mstr_view s)
  *
  * @param s The string to free
  */
-static inline void
+mlib_inline_def void
 mstr_free (mstr s)
 {
    free ((char *) s.data);
@@ -239,7 +240,7 @@ mstr_free (mstr s)
  * @param s The @ref mstr_mut to update
  * @param new_len The new length of the string
  */
-static inline void
+mlib_inline_def void
 mstrm_resize (mstr_mut *s, size_t new_len)
 {
    if (new_len <= s->len) {
@@ -283,7 +284,7 @@ mstrm_resize (mstr_mut *s, size_t new_len)
  * mstr_assign(&s, convert_to_uppercase(s.view));
  * ```
  */
-static inline void
+mlib_inline_def void
 mstr_assign (mstr *s, mstr from)
 {
    mstr_free (*s);
@@ -299,7 +300,7 @@ mstr_assign (mstr *s, mstr from)
  * @return int The zero-based index of the first instance of `needle` in
  * `given`, or -1 if no substring is found.
  */
-static inline int
+mlib_inline_def int
 mstr_find (mstr_view given, mstr_view needle)
 {
    const char *const scan_end = given.data + given.len;
@@ -335,7 +336,7 @@ mstr_find (mstr_view given, mstr_view needle)
  * @return int The zero-based index of the last instance of `needle` in
  * `given`, or -1 if no substring is found.
  */
-static inline int
+mlib_inline_def int
 mstr_rfind (mstr_view given, mstr_view needle)
 {
    if (needle.len > given.len) {
@@ -371,7 +372,7 @@ mstr_rfind (mstr_view given, mstr_view needle)
  * @param insert The string to insert at `at`.
  * @return mstr A new string that is the result of the splice
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_splice (mstr_view s, size_t at, size_t del_count, mstr_view insert)
 {
    assert (at <= s.len);
@@ -395,7 +396,7 @@ mstr_splice (mstr_view s, size_t at, size_t del_count, mstr_view insert)
 /**
  * @brief Append the given suffix to the given string
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_append (mstr_view s, mstr_view suffix)
 {
    return mstr_splice (s, s.len, 0, suffix);
@@ -404,7 +405,7 @@ mstr_append (mstr_view s, mstr_view suffix)
 /**
  * @brief Prepend the given prefix to the given string
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_prepend (mstr_view s, mstr_view prefix)
 {
    return mstr_splice (s, 0, 0, prefix);
@@ -418,7 +419,7 @@ mstr_prepend (mstr_view s, mstr_view prefix)
  * @param infix The string to insert into `s`
  * @return mstr A new string with `infix` inserted
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_insert (mstr_view s, size_t at, mstr_view infix)
 {
    return mstr_splice (s, at, 0, infix);
@@ -432,7 +433,7 @@ mstr_insert (mstr_view s, size_t at, mstr_view infix)
  * @param count The number of characters to remove
  * @return mstr A new string with the deletion result.
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_erase (mstr_view s, size_t at, size_t count)
 {
    return mstr_splice (s, at, count, mstrv_view_cstr (""));
@@ -441,7 +442,7 @@ mstr_erase (mstr_view s, size_t at, size_t count)
 /**
  * @brief Erase `len` characters from the beginning of the string
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_remove_prefix (mstr_view s, size_t len)
 {
    return mstr_erase (s, 0, len);
@@ -450,7 +451,7 @@ mstr_remove_prefix (mstr_view s, size_t len)
 /**
  * @brief Erase `len` characters from the end of the string
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_remove_suffix (mstr_view s, size_t len)
 {
    return mstr_erase (s, s.len - len, len);
@@ -465,7 +466,7 @@ mstr_remove_suffix (mstr_view s, size_t len)
  * remaining length.
  * @return mstr A new string that is a substring of `s`
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_substr (mstr_view s, size_t at, size_t len)
 {
    assert (at <= s.len);
@@ -487,7 +488,7 @@ mstr_substr (mstr_view s, size_t at, size_t len)
  * remaining length.
  * @return mstr_view A view of `s`.
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mstrv_subview (mstr_view s, size_t at, size_t len)
 {
    assert (at <= s.len);
@@ -502,7 +503,7 @@ mstrv_subview (mstr_view s, size_t at, size_t len)
  * @brief Obtain a view of another string by removing `len` characters from the
  * front
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mstrv_remove_prefix (mstr_view s, size_t len)
 {
    return mstrv_subview (s, len, s.len);
@@ -512,7 +513,7 @@ mstrv_remove_prefix (mstr_view s, size_t len)
  * @brief Obtain a view of another string by removing `len` characters from the
  * end.
  */
-static inline mstr_view
+mlib_inline_def mstr_view
 mstrv_remove_suffix (mstr_view s, size_t len)
 {
    return mstrv_subview (s, 0, s.len - len);
@@ -525,7 +526,7 @@ mstrv_remove_suffix (mstr_view s, size_t len)
  * @param new_len The new length of the string
  * @return mstr A new string copied from the beginning of `s`
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_trunc (mstr_view s, size_t new_len)
 {
    assert (new_len <= s.len);
@@ -543,7 +544,7 @@ mstr_trunc (mstr_view s, size_t new_len)
  *
  * @note If `find` is empty, returns a copy of `string`
  */
-static inline mstr
+mlib_inline_def mstr
 mstr_replace (const mstr_view string,
               const mstr_view find,
               const mstr_view subst)
@@ -578,7 +579,7 @@ mstr_replace (const mstr_view string,
 /**
  * @brief Determine whether two strings are equivalent.
  */
-static inline bool
+mlib_inline_def bool
 mstr_eq (mstr_view left, mstr_view right)
 {
    if (left.len != right.len) {
@@ -588,7 +589,7 @@ mstr_eq (mstr_view left, mstr_view right)
 }
 
 /// Determine whether the given character is an printable ASCII codepoint
-static inline bool
+mlib_inline_def bool
 mstr_is_printable (char c)
 {
    return (c >= ' ' && c <= '~');
@@ -596,7 +597,7 @@ mstr_is_printable (char c)
 
 /// Write the given string to `out`, rendering non-printable characters as hex
 /// escapes
-static inline void
+mlib_inline_def void
 _mstr_write_str_repr_ (FILE *out, mstr_view s)
 {
    for (char const *it = s.data; it != s.data + s.len; ++it) {
@@ -608,7 +609,7 @@ _mstr_write_str_repr_ (FILE *out, mstr_view s)
    }
 }
 
-static inline void
+mlib_inline_def void
 _mstr_assert_fail_ (mstr_view left,
                     const char *predicate,
                     mstr_view right,
@@ -623,7 +624,7 @@ _mstr_assert_fail_ (mstr_view left,
    abort ();
 }
 
-static inline void
+mlib_inline_def void
 _mstr_assert_ (mstr_view left,
                mstr_view right,
                bool (*pred) (mstr_view left, mstr_view right),
@@ -660,7 +661,7 @@ _mstr_assert_ (mstr_view left,
  * @return true If `given` contains at least one occurrence of `needle`
  * @return false Otherwise
  */
-static inline bool
+mlib_inline_def bool
 mstr_contains (mstr_view given, mstr_view needle)
 {
    return mstr_find (given, needle) >= 0;
@@ -669,7 +670,7 @@ mstr_contains (mstr_view given, mstr_view needle)
 /**
  * @brief Determine whether `given` starts with `prefix`
  */
-static inline bool
+mlib_inline_def bool
 mstr_starts_with (mstr_view given, mstr_view prefix)
 {
    given = mstrv_subview (given, 0, prefix.len);
@@ -679,7 +680,7 @@ mstr_starts_with (mstr_view given, mstr_view prefix)
 /**
  * @brief Determine whether `given` ends with `suffix`
  */
-static inline bool
+mlib_inline_def bool
 mstr_ends_with (mstr_view given, mstr_view suffix)
 {
    if (suffix.len > given.len) {
@@ -690,70 +691,70 @@ mstr_ends_with (mstr_view given, mstr_view suffix)
 }
 
 /// Compound in-place version of @ref mstr_splice
-static inline void
+mlib_inline_def void
 mstr_inplace_splice (mstr *s, size_t at, size_t del_count, mstr_view insert)
 {
    mstr_assign (s, mstr_splice (s->view, at, del_count, insert));
 }
 
 /// Compound in-place version of @ref mstr_append
-static inline void
+mlib_inline_def void
 mstr_inplace_append (mstr *s, mstr_view suffix)
 {
    mstr_assign (s, mstr_append (s->view, suffix));
 }
 
 /// Compound in-place version of @ref mstr_prepend
-static inline void
+mlib_inline_def void
 mstr_inplace_prepend (mstr *s, mstr_view prefix)
 {
    mstr_assign (s, mstr_prepend (s->view, prefix));
 }
 
 /// Compound in-place version of @ref mstr_insert
-static inline void
+mlib_inline_def void
 mstr_inplace_insert (mstr *s, size_t at, mstr_view infix)
 {
    mstr_assign (s, mstr_insert (s->view, at, infix));
 }
 
 /// Compound in-place version of @ref mstr_erase
-static inline void
+mlib_inline_def void
 mstr_inplace_erase (mstr *s, size_t at, size_t count)
 {
    mstr_assign (s, mstr_erase (s->view, at, count));
 }
 
 /// Compound in-place version of @ref mstr_remove_prefix
-static inline void
+mlib_inline_def void
 mstr_inplace_remove_prefix (mstr *s, size_t len)
 {
    mstr_assign (s, mstr_remove_prefix (s->view, len));
 }
 
 /// Compound in-place version of @ref mstr_remove_suffix
-static inline void
+mlib_inline_def void
 mstr_inplace_remove_suffix (mstr *s, size_t len)
 {
    mstr_assign (s, mstr_remove_suffix (s->view, len));
 }
 
 /// Compound in-place version of @ref mstr_substr
-static inline void
+mlib_inline_def void
 mstr_inplace_substr (mstr *s, size_t at, size_t count)
 {
    mstr_assign (s, mstr_substr (s->view, at, count));
 }
 
 /// Compound in-place version of @ref mstr_trunc
-static inline void
+mlib_inline_def void
 mstr_inplace_trunc (mstr *s, size_t new_len)
 {
    mstr_assign (s, mstr_trunc (s->view, new_len));
 }
 
 /// Compound in-place version of @ref mstr_replace
-static inline void
+mlib_inline_def void
 mstr_inplace_replace (mstr *s, mstr_view find, mstr_view subst)
 {
    mstr_assign (s, mstr_replace (s->view, find, subst));
@@ -777,7 +778,7 @@ typedef struct mstr_widen_result {
  *
  * @note The returned @ref mstr_widen_result::wstring must be given to free()
  */
-static inline mstr_widen_result
+mlib_inline_def mstr_widen_result
 mstr_win32_widen (mstr_view str)
 {
    int length = MultiByteToWideChar (
@@ -810,7 +811,7 @@ typedef struct mstr_narrow_result {
  * @note The returned @ref mstr_narrow_result::string must be freed with
  * mstr_free()
  */
-static inline mstr_narrow_result
+mlib_inline_def mstr_narrow_result
 mstr_win32_narrow (const wchar_t *wstring)
 {
    int length = WideCharToMultiByte (CP_UTF8,
@@ -855,7 +856,7 @@ struct _mstr_split_iter_ {
 };
 
 /// Hidden function to advance a string-split iterator
-static inline void
+mlib_inline_def void
 _mstr_split_iter_next_ (struct _mstr_split_iter_ *iter)
 {
    if (iter->once == 1) {
@@ -888,7 +889,7 @@ _mstr_split_iter_next_ (struct _mstr_split_iter_ *iter)
 }
 
 /// init a new split iterator
-static inline struct _mstr_split_iter_
+mlib_inline_def struct _mstr_split_iter_
 _mstr_split_iter_begin_ (mstr_view str, mstr_view split)
 {
    struct _mstr_split_iter_ iter = {.remaining = str, .splitter = split};
@@ -897,7 +898,7 @@ _mstr_split_iter_begin_ (mstr_view str, mstr_view split)
 }
 
 /// Check whether we are done iterating
-static inline bool
+mlib_inline_def bool
 _mstr_split_iter_done_ (struct _mstr_split_iter_ *iter)
 {
    return iter->state == 2;
diff --git a/src/mlib/thread.h b/src/mlib/thread.h
index d93fa3450..758b82f28 100644
--- a/src/mlib/thread.h
+++ b/src/mlib/thread.h
@@ -2,6 +2,7 @@
 #define MLIB_THREAD_H
 
 #include "./user-check.h"
+#include "./macros.h"
 
 #ifdef _WIN32
 #include "./windows-lean.h"
@@ -48,7 +49,7 @@ typedef void (*mlib_init_once_fn_t) (void);
 /**
  * An indirection layer for mlib_once on Windows platforms. Do not use directly.
  */
-static inline BOOL WINAPI
+mlib_inline_def BOOL WINAPI
 _mlib_win32_once_callthru (PINIT_ONCE once, PVOID param, PVOID *ctx)
 {
    (void) once;
@@ -73,7 +74,7 @@ _mlib_win32_once_callthru (PINIT_ONCE once, PVOID param, PVOID *ctx)
  * @param fn A callback to execute if the flag is not in the "finished" state
  * @return true on success, false otherwise
  */
-static inline bool
+mlib_inline_def bool
 mlib_call_once (mlib_once_flag *flag, mlib_init_once_fn_t fn)
 {
 #ifdef _WIN32

From 673bcdd7ab855a3270b68cf731930ce506842bf2 Mon Sep 17 00:00:00 2001
From: vector-of-bool <vectorofbool@gmail.com>
Date: Thu, 7 Apr 2022 01:34:17 +0000
Subject: [PATCH 4/7] Test case to check linker symbol merging

---
 src/mlib/linkcheck-1.test.c |  7 +++++++
 src/mlib/linkcheck-2.test.c |  7 +++++++
 src/mlib/linkcheck.test.c   | 15 +++++++++++++++
 src/mlib/macros.h           |  2 +-
 src/mlib/mlib.cmake         |  9 +++++++++
 5 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 src/mlib/linkcheck-1.test.c
 create mode 100644 src/mlib/linkcheck-2.test.c
 create mode 100644 src/mlib/linkcheck.test.c

diff --git a/src/mlib/linkcheck-1.test.c b/src/mlib/linkcheck-1.test.c
new file mode 100644
index 000000000..877065577
--- /dev/null
+++ b/src/mlib/linkcheck-1.test.c
@@ -0,0 +1,7 @@
+#include "./str.h"
+
+void *
+get_func_addr_1 ()
+{
+   return &mstr_new;
+}
\ No newline at end of file
diff --git a/src/mlib/linkcheck-2.test.c b/src/mlib/linkcheck-2.test.c
new file mode 100644
index 000000000..0816bd8eb
--- /dev/null
+++ b/src/mlib/linkcheck-2.test.c
@@ -0,0 +1,7 @@
+#include "./str.h"
+
+void *
+get_func_addr_2 ()
+{
+   return &mstr_new;
+}
diff --git a/src/mlib/linkcheck.test.c b/src/mlib/linkcheck.test.c
new file mode 100644
index 000000000..45ce716eb
--- /dev/null
+++ b/src/mlib/linkcheck.test.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+extern void *
+get_func_addr_1 ();
+extern void *
+get_func_addr_2 ();
+
+int
+main ()
+{
+   if (get_func_addr_1 () != get_func_addr_2 ()) {
+      fputs ("Multiply-defined symbols were not properly merged.", stderr);
+      return 1;
+   }
+}
diff --git a/src/mlib/macros.h b/src/mlib/macros.h
index 48396eb04..ddaefeb71 100644
--- a/src/mlib/macros.h
+++ b/src/mlib/macros.h
@@ -29,7 +29,7 @@
 #ifdef __INTELLISENSE__
     // Give a pretty definition for intellisense readers
     #define mlib_inline_def inline
-#elif _WIN32
+#elif defined(_WIN32)
     // On MSVC/Windows, inline functions are implicitly in COMDAT, even in C
     #define mlib_inline_def extern mlib_inline
 #else
diff --git a/src/mlib/mlib.cmake b/src/mlib/mlib.cmake
index 9be1d72ba..353281720 100644
--- a/src/mlib/mlib.cmake
+++ b/src/mlib/mlib.cmake
@@ -27,3 +27,12 @@ function (targets_use_mlib)
         target_link_libraries("${t}" PRIVATE $<BUILD_INTERFACE:mongo::mlib>)
     endforeach ()
 endfunction ()
+
+add_executable (mlib.test.comdat-link
+    "${MLIB_SRC_DIR}/linkcheck-1.test.c"
+    "${MLIB_SRC_DIR}/linkcheck-2.test.c"
+    "${MLIB_SRC_DIR}/linkcheck.test.c"
+    )
+
+add_test (mlib.test.comdat-link mlib.test.comdat-link)
+targets_use_mlib (mlib.test.comdat-link)

From bd82d4d42643dee6b05f90815c9608b6c83b8237 Mon Sep 17 00:00:00 2001
From: vector-of-bool <vectorofbool@gmail.com>
Date: Mon, 18 Apr 2022 22:23:11 +0000
Subject: [PATCH 5/7] MinGW lacks WC_ERR_INVALID_CHARS

---
 src/mlib/str.h | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/src/mlib/str.h b/src/mlib/str.h
index 3898675f2..26657743a 100644
--- a/src/mlib/str.h
+++ b/src/mlib/str.h
@@ -762,6 +762,7 @@ mstr_inplace_replace (mstr *s, mstr_view find, mstr_view subst)
 
 #ifdef _WIN32
 #include "./windows-lean.h"
+
 /**
  * @brief The result type of mstr_win32_widen
  */
@@ -814,8 +815,11 @@ typedef struct mstr_narrow_result {
 mlib_inline_def mstr_narrow_result
 mstr_win32_narrow (const wchar_t *wstring)
 {
+   // Some older versions of MinGW fail to include the WC_ERR_INVALID_CHARS
+   // flag, so we will specify it manually:
+   DWORD wcflags = 0x08; // WC_ERR_INVALID_CHARS
    int length = WideCharToMultiByte (CP_UTF8,
-                                     WC_ERR_INVALID_CHARS,
+                                     wcflags,
                                      wstring,
                                      -1 /* wstring is null-terminated */,
                                      NULL,
@@ -827,14 +831,8 @@ mstr_win32_narrow (const wchar_t *wstring)
                                   .error = GetLastError ()};
    }
    mstr_mut ret = mstr_new ((size_t) length);
-   int got_len = WideCharToMultiByte (CP_UTF8,
-                                      WC_ERR_INVALID_CHARS,
-                                      wstring,
-                                      -1,
-                                      ret.data,
-                                      (int) ret.len,
-                                      NULL,
-                                      NULL);
+   int got_len = WideCharToMultiByte (
+      CP_UTF8, wcflags, wstring, -1, ret.data, (int) ret.len, NULL, NULL);
    assert (length == got_len);
    return (mstr_narrow_result){.string = ret.mstr, .error = 0};
 }

From 54e62b216c935f619f7ae3c09b6568069e86847e Mon Sep 17 00:00:00 2001
From: vector-of-bool <vectorofbool@gmail.com>
Date: Mon, 18 Apr 2022 22:57:49 +0000
Subject: [PATCH 6/7] Include mlib.cmake to import the library

---
 CMakeLists.txt | 18 +-----------------
 1 file changed, 1 insertion(+), 17 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 61523edf5..efa6bf188 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -164,13 +164,7 @@ configure_file (
 
 # Define the mlib target, which is private and header-only. It is not exported
 # nor are its headers installed.
-add_library (_mongo-mlib INTERFACE)
-add_library (mongo::mlib ALIAS _mongo-mlib)
-set_property(
-   TARGET _mongo-mlib
-   APPEND PROPERTY INTERFACE_COMPILE_DEFINITIONS
-   MLIB_USER
-   )
+include (./src/mlib/mlib.cmake)
 
 # kms-message
 add_subdirectory (kms-message)
@@ -405,12 +399,6 @@ add_test (
    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
    )
 
-foreach (test IN ITEMS path str)
-   add_executable (mlib.${test}.test src/mlib/${test}.test.c)
-   add_test (mlib.${test} mlib.${test}.test)
-   target_link_libraries (mlib.${test}.test PRIVATE mongo::mlib)
-endforeach ()
-
 # Exclude example-state-machine since it requires native crypto.
 if (NOT MONGOCRYPT_CRYPTO STREQUAL none)
    # Define example-state-machine
@@ -453,10 +441,6 @@ install (
    INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
 )
 
-# This export set is not installed, and is only to allow export() of the mlib-using targets
-install (TARGETS _mongo-mlib EXPORT _exports_for_export)
-export (EXPORT _exports_for_export)
-
 install (
    FILES
       ${MONGOCRYPT_PUBLIC_HEADERS}

From 8bef7728e031aaea643b23f3f397fb7fba9248fa Mon Sep 17 00:00:00 2001
From: vector-of-bool <vectorofbool@gmail.com>
Date: Mon, 18 Apr 2022 18:10:14 -0600
Subject: [PATCH 7/7] Use WeakExternals on Windows

---
 src/mlib/macros.h | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/mlib/macros.h b/src/mlib/macros.h
index ddaefeb71..c6f3d1c65 100644
--- a/src/mlib/macros.h
+++ b/src/mlib/macros.h
@@ -30,8 +30,12 @@
     // Give a pretty definition for intellisense readers
     #define mlib_inline_def inline
 #elif defined(_WIN32)
-    // On MSVC/Windows, inline functions are implicitly in COMDAT, even in C
-    #define mlib_inline_def extern mlib_inline
+    #ifdef __GNUC__
+        #define mlib_inline_def extern __attribute__((weak, visibility("hidden")))
+    #else
+        // On MSVC/Windows, inline functions are implicitly in COMDAT, even in C
+        #define mlib_inline_def extern mlib_inline
+    #endif
 #else
     // On other platforms, declare the symbol "weak" to cause symbol merging,
     // and "hidden" to disable the ability for the symbol to be overridden via