Fix #2421 - Use compile_commands.json in build dirs to find roots

15 files changed, 78 insertions, 78 deletions

diff --git a/ale_linters/c/clangd.vim b/ale_linters/c/clangd.vim
index 918eadcc..79b600fa 100644
--- a/ale_linters/c/clangd.vim
+++ b/ale_linters/c/clangd.vim
@@ -4,12 +4,6 @@
 call ale#Set('c_clangd_executable', 'clangd')
 call ale#Set('c_clangd_options', '')
 
-function! ale_linters#c#clangd#GetProjectRoot(buffer) abort
-    let l:project_root = ale#path#FindNearestFile(a:buffer, 'compile_commands.json')
-
-    return !empty(l:project_root) ? fnamemodify(l:project_root, ':h') : ''
-endfunction
-
 function! ale_linters#c#clangd#GetCommand(buffer) abort
     return '%e' . ale#Pad(ale#Var(a:buffer, 'c_clangd_options'))
 endfunction
@@ -19,5 +13,5 @@ call ale#linter#Define('c', {
 \   'lsp': 'stdio',
 \   'executable': {b -> ale#Var(b, 'c_clangd_executable')},
 \   'command': function('ale_linters#c#clangd#GetCommand'),
-\   'project_root': function('ale_linters#c#clangd#GetProjectRoot'),
+\   'project_root': function('ale#c#FindProjectRoot'),
 \})
diff --git a/ale_linters/c/cquery.vim b/ale_linters/c/cquery.vim
index d2be9cd9..ff0f34af 100644
--- a/ale_linters/c/cquery.vim
+++ b/ale_linters/c/cquery.vim
@@ -5,13 +5,15 @@ call ale#Set('c_cquery_executable', 'cquery')
 call ale#Set('c_cquery_cache_directory', expand('~/.cache/cquery'))
 
 function! ale_linters#c#cquery#GetProjectRoot(buffer) abort
-    let l:project_root = ale#path#FindNearestFile(a:buffer, 'compile_commands.json')
+    " Try to find cquery configuration files first.
+    let l:config = ale#path#FindNearestFile(a:buffer, '.cquery')
 
-    if empty(l:project_root)
-        let l:project_root = ale#path#FindNearestFile(a:buffer, '.cquery')
+    if !empty(l:config)
+        return fnamemodify(l:config, ':h')
     endif
 
-    return !empty(l:project_root) ? fnamemodify(l:project_root, ':h') : ''
+    " Fall back on default project root detection.
+    return ale#c#FindProjectRoot(a:buffer)
 endfunction
 
 function! ale_linters#c#cquery#GetInitializationOptions(buffer) abort
diff --git a/ale_linters/cpp/clangcheck.vim b/ale_linters/cpp/clangcheck.vim
index b511a413..7d32a57c 100644
--- a/ale_linters/cpp/clangcheck.vim
+++ b/ale_linters/cpp/clangcheck.vim
@@ -12,7 +12,8 @@ function! ale_linters#cpp#clangcheck#GetCommand(buffer) abort
     let l:build_dir = ale#Var(a:buffer, 'c_build_dir')
 
     if empty(l:build_dir)
-        let l:build_dir = ale#path#Dirname(ale#c#FindCompileCommands(a:buffer))
+        let [l:root, l:json_file] = ale#c#FindCompileCommands(a:buffer)
+        let l:build_dir = ale#path#Dirname(l:json_file)
     endif
 
     " The extra arguments in the command are used to prevent .plist files from
diff --git a/ale_linters/cpp/clangd.vim b/ale_linters/cpp/clangd.vim
index 4a8ff4f6..fab605f4 100644
--- a/ale_linters/cpp/clangd.vim
+++ b/ale_linters/cpp/clangd.vim
@@ -4,12 +4,6 @@
 call ale#Set('cpp_clangd_executable', 'clangd')
 call ale#Set('cpp_clangd_options', '')
 
-function! ale_linters#cpp#clangd#GetProjectRoot(buffer) abort
-    let l:project_root = ale#path#FindNearestFile(a:buffer, 'compile_commands.json')
-
-    return !empty(l:project_root) ? fnamemodify(l:project_root, ':h') : ''
-endfunction
-
 function! ale_linters#cpp#clangd#GetCommand(buffer) abort
     return '%e' . ale#Pad(ale#Var(a:buffer, 'cpp_clangd_options'))
 endfunction
@@ -19,5 +13,5 @@ call ale#linter#Define('cpp', {
 \   'lsp': 'stdio',
 \   'executable': {b -> ale#Var(b, 'cpp_clangd_executable')},
 \   'command': function('ale_linters#cpp#clangd#GetCommand'),
-\   'project_root': function('ale_linters#cpp#clangd#GetProjectRoot'),
+\   'project_root': function('ale#c#FindProjectRoot'),
 \})
diff --git a/ale_linters/cpp/cquery.vim b/ale_linters/cpp/cquery.vim
index 0dd9f6ad..2971cdcb 100644
--- a/ale_linters/cpp/cquery.vim
+++ b/ale_linters/cpp/cquery.vim
@@ -5,13 +5,15 @@ call ale#Set('cpp_cquery_executable', 'cquery')
 call ale#Set('cpp_cquery_cache_directory', expand('~/.cache/cquery'))
 
 function! ale_linters#cpp#cquery#GetProjectRoot(buffer) abort
-    let l:project_root = ale#path#FindNearestFile(a:buffer, 'compile_commands.json')
+    " Try to find cquery configuration files first.
+    let l:config = ale#path#FindNearestFile(a:buffer, '.cquery')
 
-    if empty(l:project_root)
-        let l:project_root = ale#path#FindNearestFile(a:buffer, '.cquery')
+    if !empty(l:config)
+        return fnamemodify(l:config, ':h')
     endif
 
-    return !empty(l:project_root) ? fnamemodify(l:project_root, ':h') : ''
+    " Fall back on default project root detection.
+    return ale#c#FindProjectRoot(a:buffer)
 endfunction
 
 function! ale_linters#cpp#cquery#GetInitializationOptions(buffer) abort
diff --git a/ale_linters/objc/clangd.vim b/ale_linters/objc/clangd.vim
index ab52fec3..318d85b5 100644
--- a/ale_linters/objc/clangd.vim
+++ b/ale_linters/objc/clangd.vim
@@ -4,12 +4,6 @@
 call ale#Set('objc_clangd_executable', 'clangd')
 call ale#Set('objc_clangd_options', '')
 
-function! ale_linters#objc#clangd#GetProjectRoot(buffer) abort
-    let l:project_root = ale#path#FindNearestFile(a:buffer, 'compile_commands.json')
-
-    return !empty(l:project_root) ? fnamemodify(l:project_root, ':h') : ''
-endfunction
-
 function! ale_linters#objc#clangd#GetCommand(buffer) abort
     return '%e' . ale#Pad(ale#Var(a:buffer, 'objc_clangd_options'))
 endfunction
@@ -19,5 +13,5 @@ call ale#linter#Define('objc', {
 \   'lsp': 'stdio',
 \   'executable': {b -> ale#Var(b, 'objc_clangd_executable')},
 \   'command': function('ale_linters#objc#clangd#GetCommand'),
-\   'project_root': function('ale_linters#objc#clangd#GetProjectRoot'),
+\   'project_root': function('ale#c#FindProjectRoot'),
 \})
diff --git a/ale_linters/objcpp/clangd.vim b/ale_linters/objcpp/clangd.vim
index 3991d2ac..29455325 100644
--- a/ale_linters/objcpp/clangd.vim
+++ b/ale_linters/objcpp/clangd.vim
@@ -4,12 +4,6 @@
 call ale#Set('objcpp_clangd_executable', 'clangd')
 call ale#Set('objcpp_clangd_options', '')
 
-function! ale_linters#objcpp#clangd#GetProjectRoot(buffer) abort
-    let l:project_root = ale#path#FindNearestFile(a:buffer, 'compile_commands.json')
-
-    return !empty(l:project_root) ? fnamemodify(l:project_root, ':h') : ''
-endfunction
-
 function! ale_linters#objcpp#clangd#GetCommand(buffer) abort
     return '%e' . ale#Pad(ale#Var(a:buffer, 'objcpp_clangd_options'))
 endfunction
@@ -19,5 +13,5 @@ call ale#linter#Define('objcpp', {
 \   'lsp': 'stdio',
 \   'executable': {b -> ale#Var(b, 'objcpp_clangd_executable')},
 \   'command': function('ale_linters#objcpp#clangd#GetCommand'),
-\   'project_root': function('ale_linters#objcpp#clangd#GetProjectRoot'),
+\   'project_root': function('ale#c#FindProjectRoot'),
 \})
diff --git a/autoload/ale/c.vim b/autoload/ale/c.vim
index 42958d6e..2d2083da 100644
--- a/autoload/ale/c.vim
+++ b/autoload/ale/c.vim
@@ -23,27 +23,9 @@ function! ale#c#GetBuildDirectory(buffer) abort
         return l:build_dir
     endif
 
-    return ale#path#Dirname(ale#c#FindCompileCommands(a:buffer))
-endfunction
-
-
-function! ale#c#FindProjectRoot(buffer) abort
-    for l:project_filename in g:__ale_c_project_filenames
-        let l:full_path = ale#path#FindNearestFile(a:buffer, l:project_filename)
-
-        if !empty(l:full_path)
-            let l:path = fnamemodify(l:full_path, ':h')
-
-            " Correct .git path detection.
-            if fnamemodify(l:path, ':t') is# '.git'
-                let l:path = fnamemodify(l:path, ':h')
-            endif
+    let [l:root, l:json_file] = ale#c#FindCompileCommands(a:buffer)
 
-            return l:path
-        endif
-    endfor
-
-    return ''
+    return ale#path#Dirname(l:json_file)
 endfunction
 
 function! ale#c#AreSpecialCharsBalanced(option) abort
@@ -120,7 +102,7 @@ endfunction
 
 function! ale#c#ParseCFlagsFromMakeOutput(buffer, make_output) abort
     if !g:ale_c_parse_makefile
-        return ''
+        return v:null
     endif
 
     let l:buffer_filename = expand('#' . a:buffer . ':t')
@@ -140,14 +122,17 @@ function! ale#c#ParseCFlagsFromMakeOutput(buffer, make_output) abort
     return ale#c#ParseCFlags(l:makefile_dir, l:cflag_line)
 endfunction
 
-" Given a buffer number, find the build subdirectory with compile commands
-" The subdirectory is returned without the trailing /
+" Given a buffer number, find the project directory containing
+" compile_commands.json, and the path to the compile_commands.json file.
+"
+" If compile_commands.json cannot be found, two empty strings will be
+" returned.
 function! ale#c#FindCompileCommands(buffer) abort
     " Look above the current source file to find compile_commands.json
     let l:json_file = ale#path#FindNearestFile(a:buffer, 'compile_commands.json')
 
     if !empty(l:json_file)
-        return l:json_file
+        return [fnamemodify(l:json_file, ':h'), l:json_file]
     endif
 
     " Search in build directories if we can't find it in the project.
@@ -157,12 +142,42 @@ function! ale#c#FindCompileCommands(buffer) abort
             let l:json_file = l:c_build_dir . s:sep . 'compile_commands.json'
 
             if filereadable(l:json_file)
-                return l:json_file
+                return [l:path, l:json_file]
             endif
         endfor
     endfor
 
-    return ''
+    return ['', '']
+endfunction
+
+" Find the project root for C/C++ projects.
+"
+" The location of compile_commands.json will be used to find project roots.
+"
+" If compile_commands.json cannot be found, other common configuration files
+" will be used to detect the project root.
+function! ale#c#FindProjectRoot(buffer) abort
+    let [l:root, l:json_file] = ale#c#FindCompileCommands(a:buffer)
+
+    " Fall back on detecting the project root based on other filenames.
+    if empty(l:root)
+        for l:project_filename in g:__ale_c_project_filenames
+            let l:full_path = ale#path#FindNearestFile(a:buffer, l:project_filename)
+
+            if !empty(l:full_path)
+                let l:path = fnamemodify(l:full_path, ':h')
+
+                " Correct .git path detection.
+                if fnamemodify(l:path, ':t') is# '.git'
+                    let l:path = fnamemodify(l:path, ':h')
+                endif
+
+                return l:path
+            endif
+        endfor
+    endif
+
+    return l:root
 endfunction
 
 " Cache compile_commands.json data in a Dictionary, so we don't need to read
@@ -201,7 +216,7 @@ function! s:GetLookupFromCompileCommandsFile(compile_commands_file) abort
     let l:file_lookup = {}
     let l:dir_lookup = {}
 
-    for l:entry in l:raw_data
+    for l:entry in (type(l:raw_data) is v:t_list ? l:raw_data : [])
         let l:basename = tolower(fnamemodify(l:entry.file, ':t'))
         let l:file_lookup[l:basename] = get(l:file_lookup, l:basename, []) + [l:entry]
 
@@ -278,25 +293,25 @@ function! ale#c#FlagsFromCompileCommands(buffer, compile_commands_file) abort
 endfunction
 
 function! ale#c#GetCFlags(buffer, output) abort
-    let l:cflags = ' '
+    let l:cflags = v:null
 
     if ale#Var(a:buffer, 'c_parse_makefile') && !empty(a:output)
         let l:cflags = ale#c#ParseCFlagsFromMakeOutput(a:buffer, a:output)
     endif
 
     if ale#Var(a:buffer, 'c_parse_compile_commands')
-        let l:json_file = ale#c#FindCompileCommands(a:buffer)
+        let [l:root, l:json_file] = ale#c#FindCompileCommands(a:buffer)
 
         if !empty(l:json_file)
             let l:cflags = ale#c#FlagsFromCompileCommands(a:buffer, l:json_file)
         endif
     endif
 
-    if l:cflags is# ' '
+    if l:cflags is v:null
         let l:cflags = ale#c#IncludeOptions(ale#c#FindLocalHeaderPaths(a:buffer))
     endif
 
-    return l:cflags
+    return l:cflags isnot v:null ? l:cflags : ''
 endfunction
 
 function! ale#c#GetMakeCommand(buffer) abort
diff --git a/autoload/ale/handlers/ccls.vim b/autoload/ale/handlers/ccls.vim
index 29dd6aed..1e2aa318 100644
--- a/autoload/ale/handlers/ccls.vim
+++ b/autoload/ale/handlers/ccls.vim
@@ -3,15 +3,17 @@ scriptencoding utf-8
 " Description: Utilities for ccls
 
 function! ale#handlers#ccls#GetProjectRoot(buffer) abort
-    let l:project_root = ale#path#FindNearestFile(a:buffer, '.ccls-root')
+    " Try to find ccls configuration files first.
+    let l:config = ale#path#FindNearestFile(a:buffer, '.ccls-root')
 
-    if empty(l:project_root)
-        let l:project_root = ale#path#FindNearestFile(a:buffer, 'compile_commands.json')
+    if empty(l:config)
+        let l:config = ale#path#FindNearestFile(a:buffer, '.ccls')
     endif
 
-    if empty(l:project_root)
-        let l:project_root = ale#path#FindNearestFile(a:buffer, '.ccls')
+    if !empty(l:config)
+        return fnamemodify(l:config, ':h')
     endif
 
-    return !empty(l:project_root) ? fnamemodify(l:project_root, ':h') : ''
+    " Fall back on default project root detection.
+    return ale#c#FindProjectRoot(a:buffer)
 endfunction
diff --git a/test/command_callback/cquery_paths/with_compile_commands_json/compile_commands.json b/test/command_callback/cquery_paths/build/compile_commands.json
index e69de29b..e69de29b 100644
--- a/test/command_callback/cquery_paths/with_compile_commands_json/compile_commands.json
+++ b/test/command_callback/cquery_paths/build/compile_commands.json
diff --git a/test/command_callback/test_c_cquery_command_callbacks.vader b/test/command_callback/test_c_cquery_command_callbacks.vader
index 13b7a567..a2e03889 100644
--- a/test/command_callback/test_c_cquery_command_callbacks.vader
+++ b/test/command_callback/test_c_cquery_command_callbacks.vader
@@ -7,9 +7,9 @@ After:
 Execute(The project root should be detected correctly using compile_commands.json file):
   AssertLSPProject ''
 
-  call ale#test#SetFilename('cquery_paths/with_compile_commands_json/dummy.c')
+  call ale#test#SetFilename('cquery_paths/dummy.c')
 
-  AssertLSPProject ale#path#Simplify(g:dir . '/cquery_paths/with_compile_commands_json')
+  AssertLSPProject ale#path#Simplify(g:dir . '/cquery_paths')
 
 Execute(The project root should be detected correctly using .cquery file):
   AssertLSPProject ''
diff --git a/test/command_callback/test_c_import_paths.vader b/test/command_callback/test_c_import_paths.vader
index f941e0fa..6c616d89 100644
--- a/test/command_callback/test_c_import_paths.vader
+++ b/test/command_callback/test_c_import_paths.vader
@@ -2,6 +2,7 @@ Before:
   " Make sure the c.vim file is loaded first.
   call ale#c#FindProjectRoot(bufnr(''))
 
+  Save g:ale_c_parse_compile_commands
   Save g:ale_c_parse_makefile
   Save g:__ale_c_project_filenames
 
@@ -14,6 +15,7 @@ Before:
   \ 'v:val isnot# ''.git/HEAD'''
   \)
 
+  let g:ale_c_parse_compile_commands = 0
   let g:ale_c_parse_makefile = 0
 
 After:
diff --git a/test/command_callback/test_cpp_cquery_command_callbacks.vader b/test/command_callback/test_cpp_cquery_command_callbacks.vader
index 682c90d5..7eb2a284 100644
--- a/test/command_callback/test_cpp_cquery_command_callbacks.vader
+++ b/test/command_callback/test_cpp_cquery_command_callbacks.vader
@@ -10,9 +10,9 @@ After:
 Execute(The project root should be detected correctly using compile_commands.json file):
   AssertLSPProject ''
 
-  call ale#test#SetFilename('cquery_paths/with_compile_commands_json/dummy.cpp')
+  call ale#test#SetFilename('cquery_paths/dummy.cpp')
 
-  AssertLSPProject ale#path#Simplify(g:dir . '/cquery_paths/with_compile_commands_json')
+  AssertLSPProject ale#path#Simplify(g:dir . '/cquery_paths')
 
 Execute(The project root should be detected correctly using .cquery file):
   AssertLSPProject ''
diff --git a/test/test_c_projects/build/bad_folder_to_test_priority b/test/test_c_projects/build_compile_commands_project/build/bad_folder_to_test_priority
index e69de29b..e69de29b 100644
--- a/test/test_c_projects/build/bad_folder_to_test_priority
+++ b/test/test_c_projects/build_compile_commands_project/build/bad_folder_to_test_priority
diff --git a/test/test_c_projects/build/compile_commands.json b/test/test_c_projects/build_compile_commands_project/build/compile_commands.json
index e69de29b..e69de29b 100644
--- a/test/test_c_projects/build/compile_commands.json
+++ b/test/test_c_projects/build_compile_commands_project/build/compile_commands.json