From 68f693b7cf44012d3099983b41eee6da55f5452f Mon Sep 17 00:00:00 2001
From: Nazir Bilal Yavuz <byavuz81@gmail.com>
Date: Wed, 12 Mar 2025 10:44:46 +0300
Subject: [PATCH v9 6/6] meson: Add LLVM bitcode emission for backend sources

Since generated backend sources may have their own compilation flags and
must also be included in the postgres.index.bc, the way to make it work
with current code was to create a new variable, called
`bc_generated_backend_sources`, which is a list of dictionaries, each
one having an optional 'additional_flags' and a `srclist` pointing to
the list of custom_target generated sources.

An example of a possible structure of bitcode_modules which is processed
by the main meson llvm bitcode emission file
src/backend/jit/llvm/bitcode/meson.build:
```
bitcode_modules = [
  {
    'name': 'postgres',
    'target': postgres_lib,
    'src_file': backend_sources,
    'gen_srcfiles': [
      {
        'additional_flags': [
          '-I/path/postgresl/src/backend/parser',
          '-I/path/postgresl/build/src/backend/parser',
        ],
        'srcfiles': [
                <custom_target for scan.c>,
                <custom_target for gram.c>
        ]
      }
    ]
  }
]
```

Author: Diego Fronza <diego.fronza@percona.com>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/206b001d-1884-4081-bd02-bed5c92f02ba%40eisentraut.org
---
 src/backend/bootstrap/meson.build   | 2 ++
 src/backend/meson.build             | 2 ++
 src/backend/parser/meson.build      | 8 ++++++++
 src/backend/replication/meson.build | 4 ++++
 src/backend/utils/fmgr/meson.build  | 1 +
 5 files changed, 17 insertions(+)

diff --git a/src/backend/bootstrap/meson.build b/src/backend/bootstrap/meson.build
index 2f9115fc97c..f49e27f3889 100644
--- a/src/backend/bootstrap/meson.build
+++ b/src/backend/bootstrap/meson.build
@@ -13,6 +13,7 @@ bootscanner = custom_target('bootscanner',
 )
 generated_sources += bootscanner
 boot_parser_sources += bootscanner
+bc_generated_backend_sources += {'srcfiles': [bootscanner]}
 
 bootparse = custom_target('bootparse',
   input: 'bootparse.y',
@@ -20,6 +21,7 @@ bootparse = custom_target('bootparse',
 )
 generated_sources += bootparse.to_list()
 boot_parser_sources += bootparse
+bc_generated_backend_sources += {'srcfiles': [bootparse[0]]}
 
 boot_parser = static_library('boot_parser',
   boot_parser_sources,
diff --git a/src/backend/meson.build b/src/backend/meson.build
index e41e278dbc0..109741a9dca 100644
--- a/src/backend/meson.build
+++ b/src/backend/meson.build
@@ -5,6 +5,7 @@ backend_sources = []
 backend_link_with = [pgport_srv, common_srv]
 
 generated_backend_sources = []
+bc_generated_backend_sources = []
 post_export_backend_sources = []
 
 subdir('access')
@@ -144,6 +145,7 @@ bitcode_modules += {
   'name': 'postgres',
   'target': postgres_lib,
   'srcfiles': backend_sources,
+  'gen_sources': bc_generated_backend_sources,
 }
 
 pg_mod_c_args = cflags_mod
diff --git a/src/backend/parser/meson.build b/src/backend/parser/meson.build
index 924ee87a453..177b57496c0 100644
--- a/src/backend/parser/meson.build
+++ b/src/backend/parser/meson.build
@@ -42,6 +42,14 @@ backend_parser = custom_target('gram',
 generated_sources += backend_parser.to_list()
 parser_sources += backend_parser
 
+bc_generated_backend_sources += {
+  'additional_flags': [
+    '-I@0@'.format(meson.current_build_dir()),
+    '-I@0@'.format(meson.current_source_dir()),
+  ],
+  'srcfiles': [backend_scanner, backend_parser[0]],
+}
+
 parser = static_library('parser',
   parser_sources,
   dependencies: [backend_code],
diff --git a/src/backend/replication/meson.build b/src/backend/replication/meson.build
index ce9be4117ad..a4789f1f86f 100644
--- a/src/backend/replication/meson.build
+++ b/src/backend/replication/meson.build
@@ -19,6 +19,7 @@ repl_scanner = custom_target('repl_scanner',
 )
 generated_sources += repl_scanner
 repl_parser_sources += repl_scanner
+bc_generated_backend_sources += {'srcfiles': [repl_scanner]}
 
 repl_gram = custom_target('repl_gram',
   input: 'repl_gram.y',
@@ -26,6 +27,7 @@ repl_gram = custom_target('repl_gram',
 )
 generated_sources += repl_gram.to_list()
 repl_parser_sources += repl_gram
+bc_generated_backend_sources += {'srcfiles': [repl_gram[0]]}
 
 syncrep_scanner = custom_target('syncrep_scanner',
   input: 'syncrep_scanner.l',
@@ -34,6 +36,7 @@ syncrep_scanner = custom_target('syncrep_scanner',
 )
 generated_sources += syncrep_scanner
 repl_parser_sources += syncrep_scanner
+bc_generated_backend_sources += {'srcfiles': [syncrep_scanner]}
 
 syncrep_gram = custom_target('syncrep_gram',
   input: 'syncrep_gram.y',
@@ -41,6 +44,7 @@ syncrep_gram = custom_target('syncrep_gram',
 )
 generated_sources += syncrep_gram.to_list()
 repl_parser_sources += syncrep_gram
+bc_generated_backend_sources += {'srcfiles': [syncrep_gram[0]]}
 
 repl_parser = static_library('repl_parser',
   repl_parser_sources,
diff --git a/src/backend/utils/fmgr/meson.build b/src/backend/utils/fmgr/meson.build
index 3a90deba979..71dad370d1d 100644
--- a/src/backend/utils/fmgr/meson.build
+++ b/src/backend/utils/fmgr/meson.build
@@ -8,3 +8,4 @@ backend_sources += files(
 
 # fmgrtab.c
 generated_backend_sources += fmgrtab_target[2]
+bc_generated_backend_sources += {'srcfiles': [fmgrtab_target[2]]}
-- 
2.47.3