Building with meson on NixOS/nixpkgs

From 2d271aafd96a0ea21710a06ac5236e47217c36d1 Mon Sep 17 00:00:00 2001
From: Wolfgang Walther <walther@technowledgy.de>
Date: Sat, 2 Mar 2024 17:18:38 +0100
Subject: [PATCH v2 1/3] Fallback to uuid for ossp-uuid with meson

The upstream name for the ossp-uuid package / pkg-config file is "uuid". Many
distributions change this to be "ossp-uuid" to not conflict with e2fsprogs.

This lookup fails on distributions which don't change this name, for example
NixOS / nixpkgs. Both "ossp-uuid" and "uuid" are also checked in configure.ac.
---
 meson.build | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/meson.build b/meson.build
index c8fdfeb0ec3..942c79c8be3 100644
--- a/meson.build
+++ b/meson.build
@@ -1346,7 +1346,8 @@ if uuidopt != 'none'
     uuidfunc = 'uuid_to_string'
     uuidheader = 'uuid.h'
   elif uuidopt == 'ossp'
-    uuid = dependency('ossp-uuid', required: true)
+    # upstream is called "uuid", but many distros change this to "ossp-uuid"
+    uuid = dependency('ossp-uuid', 'uuid', required: true)
     uuidfunc = 'uuid_export'
     uuidheader = 'uuid.h'
   else
-- 
2.44.0

From f150a8dcb92b08eab40b5dfec130a18f297c709f Mon Sep 17 00:00:00 2001
From: Wolfgang Walther <walther@technowledgy.de>
Date: Sat, 2 Mar 2024 22:06:25 +0100
Subject: [PATCH v2 2/3] Fallback to clang in PATH with meson

Some distributions put clang into a different path than the llvm binary path.

For example, this is the case on NixOS / nixpkgs, which failed to find clang
with meson before this patch.
---
 meson.build | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/meson.build b/meson.build
index 942c79c8be3..f9e96b01cfa 100644
--- a/meson.build
+++ b/meson.build
@@ -759,7 +759,10 @@ if add_languages('cpp', required: llvmopt, native: false)
     llvm_binpath = llvm.get_variable(configtool: 'bindir')
 
     ccache = find_program('ccache', native: true, required: false)
-    clang = find_program(llvm_binpath / 'clang', required: true)
+
+    # Some distros put LLVM and clang in different paths, so fallback to
+    # find via PATH, too.
+    clang = find_program(llvm_binpath / 'clang', 'clang', required: true)
   endif
 elif llvmopt.auto()
   message('llvm requires a C++ compiler')
-- 
2.44.0

From fddee56b5e27a3b5e4c406e8caa2d230b49eb447 Mon Sep 17 00:00:00 2001
From: Wolfgang Walther <walther@technowledgy.de>
Date: Mon, 11 Mar 2024 19:54:41 +0100
Subject: [PATCH v2 3/3] Support absolute bindir/libdir in regression tests
 with meson

Passing an absolute bindir/libdir will install the binaries and libraries to
<build>/tmp_install/<bindir> and <build>/tmp_install/<libdir> respectively.

This is path is correctly passed to the regression test suite via configure/make,
but not via meson, yet. This is because the "/" operator in the following expression
throws away the whole left side when the right side is an absolute path:

  test_install_location / get_option('libdir')

This was already correctly handled for dir_prefix, which is likely absolute as well.
This patch handles both bindir and libdir in the same way - prefixing absolute paths
with the tmp_install path correctly.
---
 meson.build | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/meson.build b/meson.build
index f9e96b01cfa..144c443b5e4 100644
--- a/meson.build
+++ b/meson.build
@@ -3048,15 +3048,17 @@ test_install_destdir = meson.build_root() / 'tmp_install/'
 if build_system != 'windows'
   # On unixoid systems this is trivial, we just prepend the destdir
   assert(dir_prefix.startswith('/')) # enforced by meson
-  test_install_location = '@0@@1@'.format(test_install_destdir, dir_prefix)
+  temp_install_bindir = '@0@@1@'.format(test_install_destdir, dir_prefix / dir_bin)
+  temp_install_libdir = '@0@@1@'.format(test_install_destdir, dir_prefix / dir_lib)
 else
   # drives, drive-relative paths, etc make this complicated on windows, call
   # into a copy of meson's logic for it
   command = [
     python, '-c',
     'import sys; from pathlib import PurePath; d1=sys.argv[1]; d2=sys.argv[2]; print(str(PurePath(d1, *PurePath(d2).parts[1:])))',
-    test_install_destdir, dir_prefix]
-  test_install_location = run_command(command, check: true).stdout().strip()
+    test_install_destdir]
+  temp_install_bindir = run_command(command, dir_prefix / dir_bin, check: true).stdout().strip()
+  temp_install_libdir = run_command(command, dir_prefix / dir_lib, check: true).stdout().strip()
 endif
 
 meson_install_args = meson_args + ['install'] + {
@@ -3093,7 +3095,6 @@ testport = 40000
 
 test_env = environment()
 
-temp_install_bindir = test_install_location / get_option('bindir')
 test_initdb_template = meson.build_root() / 'tmp_install' / 'initdb-template'
 test_env.set('PG_REGRESS', pg_regress.full_path())
 test_env.set('REGRESS_SHLIB', regress_module.full_path())
@@ -3108,7 +3109,7 @@ test_env.set('PG_TEST_EXTRA', get_option('PG_TEST_EXTRA'))
 # that works (everything but windows, basically). On windows everything
 # library-like gets installed into bindir, solving that issue.
 if library_path_var != ''
-  test_env.prepend(library_path_var, test_install_location / get_option('libdir'))
+  test_env.prepend(library_path_var, temp_install_libdir)
 endif
 
 
-- 
2.44.0

From 1e7db8b57f69ed9866fdf874bbd0dcb33d25c045 Mon Sep 17 00:00:00 2001
From: Wolfgang Walther <walther@technowledgy.de>
Date: Sat, 2 Mar 2024 17:18:38 +0100
Subject: [PATCH v3 1/4] Fallback to uuid for ossp-uuid with meson

The upstream name for the ossp-uuid package / pkg-config file is "uuid". Many
distributions change this to be "ossp-uuid" to not conflict with e2fsprogs.

This lookup fails on distributions which don't change this name, for example
NixOS / nixpkgs. Both "ossp-uuid" and "uuid" are also checked in configure.ac.
---
 meson.build | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/meson.build b/meson.build
index 18b5be842e3..4be5f65e8b6 100644
--- a/meson.build
+++ b/meson.build
@@ -1346,7 +1346,8 @@ if uuidopt != 'none'
     uuidfunc = 'uuid_to_string'
     uuidheader = 'uuid.h'
   elif uuidopt == 'ossp'
-    uuid = dependency('ossp-uuid', required: true)
+    # upstream is called "uuid", but many distros change this to "ossp-uuid"
+    uuid = dependency('ossp-uuid', 'uuid', required: true)
     uuidfunc = 'uuid_export'
     uuidheader = 'uuid.h'
   else
-- 
2.44.0

From 28e8067b6b04ac601946fab4aa0849b3dfec5a7d Mon Sep 17 00:00:00 2001
From: Wolfgang Walther <walther@technowledgy.de>
Date: Sat, 2 Mar 2024 22:06:25 +0100
Subject: [PATCH v3 2/4] Fallback to clang in PATH with meson

Some distributions put clang into a different path than the llvm binary path.

For example, this is the case on NixOS / nixpkgs, which failed to find clang
with meson before this patch.
---
 meson.build | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/meson.build b/meson.build
index 4be5f65e8b6..4a6af978fd4 100644
--- a/meson.build
+++ b/meson.build
@@ -759,7 +759,10 @@ if add_languages('cpp', required: llvmopt, native: false)
     llvm_binpath = llvm.get_variable(configtool: 'bindir')
 
     ccache = find_program('ccache', native: true, required: false)
-    clang = find_program(llvm_binpath / 'clang', required: true)
+
+    # Some distros put LLVM and clang in different paths, so fallback to
+    # find via PATH, too.
+    clang = find_program(llvm_binpath / 'clang', 'clang', required: true)
   endif
 elif llvmopt.auto()
   message('llvm requires a C++ compiler')
-- 
2.44.0

From 01fda05ea14e8cf0d201b749c84b1f3cb532f353 Mon Sep 17 00:00:00 2001
From: Wolfgang Walther <walther@technowledgy.de>
Date: Mon, 11 Mar 2024 19:54:41 +0100
Subject: [PATCH v3 3/4] Support absolute bindir/libdir in regression tests
 with meson

Passing an absolute bindir/libdir will install the binaries and libraries to
<build>/tmp_install/<bindir> and <build>/tmp_install/<libdir> respectively.

This is path is correctly passed to the regression test suite via configure/make,
but not via meson, yet. This is because the "/" operator in the following expression
throws away the whole left side when the right side is an absolute path:

  test_install_location / get_option('libdir')

This was already correctly handled for dir_prefix, which is likely absolute as well.
This patch handles both bindir and libdir in the same way - prefixing absolute paths
with the tmp_install path correctly.
---
 meson.build | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/meson.build b/meson.build
index 4a6af978fd4..3e628659843 100644
--- a/meson.build
+++ b/meson.build
@@ -3048,15 +3048,17 @@ test_install_destdir = meson.build_root() / 'tmp_install/'
 if build_system != 'windows'
   # On unixoid systems this is trivial, we just prepend the destdir
   assert(dir_prefix.startswith('/')) # enforced by meson
-  test_install_location = '@0@@1@'.format(test_install_destdir, dir_prefix)
+  temp_install_bindir = '@0@@1@'.format(test_install_destdir, dir_prefix / dir_bin)
+  temp_install_libdir = '@0@@1@'.format(test_install_destdir, dir_prefix / dir_lib)
 else
   # drives, drive-relative paths, etc make this complicated on windows, call
   # into a copy of meson's logic for it
   command = [
     python, '-c',
     'import sys; from pathlib import PurePath; d1=sys.argv[1]; d2=sys.argv[2]; print(str(PurePath(d1, *PurePath(d2).parts[1:])))',
-    test_install_destdir, dir_prefix]
-  test_install_location = run_command(command, check: true).stdout().strip()
+    test_install_destdir]
+  temp_install_bindir = run_command(command, dir_prefix / dir_bin, check: true).stdout().strip()
+  temp_install_libdir = run_command(command, dir_prefix / dir_lib, check: true).stdout().strip()
 endif
 
 meson_install_args = meson_args + ['install'] + {
@@ -3093,7 +3095,6 @@ testport = 40000
 
 test_env = environment()
 
-temp_install_bindir = test_install_location / get_option('bindir')
 test_initdb_template = meson.build_root() / 'tmp_install' / 'initdb-template'
 test_env.set('PG_REGRESS', pg_regress.full_path())
 test_env.set('REGRESS_SHLIB', regress_module.full_path())
@@ -3108,7 +3109,7 @@ test_env.set('PG_TEST_EXTRA', get_option('PG_TEST_EXTRA'))
 # that works (everything but windows, basically). On windows everything
 # library-like gets installed into bindir, solving that issue.
 if library_path_var != ''
-  test_env.prepend(library_path_var, test_install_location / get_option('libdir'))
+  test_env.prepend(library_path_var, temp_install_libdir)
 endif
 
 
-- 
2.44.0

From f9dae8de174f27b44d6268a345d7cd03eb023561 Mon Sep 17 00:00:00 2001
From: Wolfgang Walther <walther@technowledgy.de>
Date: Fri, 29 Mar 2024 19:38:59 +0100
Subject: [PATCH v3 4/4] Support falling back to non-preferred readline
 implementation with meson

To build with -Dreadline=enabled one can use either readline or libedit. The
-Dlibedit_preferred flag is supposed to control the order of names to lookup.
This works fine when either both libraries are present or -Dreadline is set to
auto. However, explicitly enabling readline with only libedit present, but not
setting libedit_preferred, or alternatively enabling readline with only readline
present, but setting libedit_preferred, too, are both broken. This is because
cc.find_library will throw an error for a not found dependency as soon as the
first required dependency is checked, thus it's impossible to fallback to the
alternative.

Here we only check the second of the two dependencies for requiredness, thus
we only fail when none of the two can be found.
---
 meson.build | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/meson.build b/meson.build
index 3e628659843..3e899432485 100644
--- a/meson.build
+++ b/meson.build
@@ -1080,15 +1080,26 @@ endif
 
 if not get_option('readline').disabled()
   libedit_preferred = get_option('libedit_preferred')
-  # Set the order of readline dependencies
-  check_readline_deps = libedit_preferred ? \
-    ['libedit', 'readline'] : ['readline', 'libedit']
+  # Set the order of readline dependencies.
+  # cc.find_library breaks and throws on the first dependency which
+  # is marked as required=true and can't be found. Thus, we only mark
+  # the last dependency to look up as required, to not throw too early.
+  check_readline_deps = [
+    {
+      'name': libedit_preferred ? 'libedit' : 'readline',
+      'required': false
+    },
+    {
+      'name': libedit_preferred ? 'readline' : 'libedit',
+      'required': get_option('readline')
+    }
+  ]
 
   foreach readline_dep : check_readline_deps
-    readline = dependency(readline_dep, required: false)
+    readline = dependency(readline_dep['name'], required: false)
     if not readline.found()
-      readline = cc.find_library(readline_dep,
-        required: get_option('readline'),
+      readline = cc.find_library(readline_dep['name'],
+        required: readline_dep['required'],
         dirs: test_lib_d)
     endif
     if readline.found()
-- 
2.44.0

From 3dacd3b73c316bafd60c7aef9e6192591c6bf5f1 Mon Sep 17 00:00:00 2001
From: Tristan Partin <tristan@neon.tech>
Date: Fri, 9 Aug 2024 11:41:09 -0500
Subject: [PATCH v1] Use the found LLVM version when finding clang

find_program(version:) can be used to restrict the version of the
program to be found. In this case, we need a clang that is compatible
with LLVM.

Prior to 4d8de281b5834c8f5e0be6ae21e884e69dffd4ce, this worked as
intended, but since that change it was possible to pick an incompatible
clang and LLVM combination.

Reported-by: Andres Freund <andres@anarazel.de>
---
 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meson.build b/meson.build
index cc176f11b5d..73101e84036 100644
--- a/meson.build
+++ b/meson.build
@@ -802,7 +802,7 @@ if add_languages('cpp', required: llvmopt, native: false)
 
     # Some distros put LLVM and clang in different paths, so fallback to
     # find via PATH, too.
-    clang = find_program(llvm_binpath / 'clang', 'clang', required: true)
+    clang = find_program(llvm_binpath / 'clang', 'clang', version: llvm.version(), required: true)
   endif
 elif llvmopt.auto()
   message('llvm requires a C++ compiler')
-- 
Tristan Partin
Neon (https://neon.tech)