add build.warning policy

3 files changed, 36 insertions, 2 deletions

diff --git a/xmake/core/project/policy.lua b/xmake/core/project/policy.lua
index c169b921e..e6a20aef9 100644
--- a/xmake/core/project/policy.lua
+++ b/xmake/core/project/policy.lua
@@ -47,6 +47,8 @@ function policy.policies()
             ["build.merge_archive"]              = {description = "Enable merge archive intead of linking for all dependent targets.", default = false, type = "boolean"},
             -- C/C++ build cache
             ["build.ccache"]                     = {description = "Enable C/C++ build cache.", type = "boolean"},
+            -- Enable build warning output, it's disabled by default and we need `xmake -w/-vD` to look at it.
+            ["build.warning"]                    = {description = "Enable build warning output.", type = "boolean"},
             -- preprocessor configuration for ccache/distcc, we can disable linemarkers to speed up preprocess
             ["preprocessor.linemarkers"]         = {description = "Enable linemarkers for preprocessor.", default = true, type = "boolean"},
             -- preprocessor configuration for ccache/distcc, we can disable it to avoid cache object file with __DATE__, __TIME__
diff --git a/xmake/modules/core/tools/cl.lua b/xmake/modules/core/tools/cl.lua
index d736c0ad2..703250c8b 100644
--- a/xmake/modules/core/tools/cl.lua
+++ b/xmake/modules/core/tools/cl.lua
@@ -366,6 +366,22 @@ function _compargv_pch(self, pcheaderfile, pcoutputfile, flags)
     return self:program(), table.join("-c", "-Yc", pchflags, "-Fp" .. pcoutputfile, "-Fo" .. pcoutputfile .. ".obj", pcheaderfile)
 end
 
+-- has warnings output?
+function _has_warnings()
+    local warnings = _g.warnings
+    if warnings == nil then
+        warnings = option.get("diagnosis") or option.get("warning")
+        if warnings == nil and os.isfile(os.projectfile()) and project.policy("build.warning") ~= nil then
+            warnings = project.policy("build.warning")
+        end
+        if warnings == nil then
+            warnings = global.get("build_warning")
+        end
+        _g.warnings = warnings or false
+    end
+    return warnings
+end
+
 -- has /sourceDependencies xxx.json @see https://github.com/xmake-io/xmake/issues/868?
 function _has_source_dependencies(self)
     local has_source_dependencies = _g._HAS_SOURCE_DEPENDENCIES
@@ -616,7 +632,7 @@ function compile(self, sourcefile, objectfile, dependinfo, flags, opt)
             function (ok, outdata, errdata)
 
                 -- show warnings?
-                if ok and (option.get("diagnosis") or option.get("warning") or global.get("build_warning")) then
+                if ok and _has_warnings() then
                     local output = outdata or ""
                     if #output:trim() == 0 then
                         output = errdata or ""
diff --git a/xmake/modules/core/tools/gcc.lua b/xmake/modules/core/tools/gcc.lua
index cf8fad4db..93674a702 100644
--- a/xmake/modules/core/tools/gcc.lua
+++ b/xmake/modules/core/tools/gcc.lua
@@ -368,6 +368,22 @@ function link(self, objectfiles, targetkind, targetfile, flags)
     os.runv(program, argv, {envs = self:runenvs()})
 end
 
+-- has warnings output?
+function _has_warnings()
+    local warnings = _g.warnings
+    if warnings == nil then
+        warnings = option.get("diagnosis") or option.get("warning")
+        if warnings == nil and os.isfile(os.projectfile()) and project.policy("build.warning") ~= nil then
+            warnings = project.policy("build.warning")
+        end
+        if warnings == nil then
+            warnings = global.get("build_warning")
+        end
+        _g.warnings = warnings or false
+    end
+    return warnings
+end
+
 -- has color diagnostics?
 function _has_color_diagnostics(self)
     local colors_diagnostics = _g._HAS_COLOR_DIAGNOSTICS
@@ -657,7 +673,7 @@ function compile(self, sourcefile, objectfile, dependinfo, flags)
         {
             function (ok, outdata, errdata)
                 -- show warnings?
-                if ok and errdata and #errdata > 0 and (option.get("diagnosis") or option.get("warning") or global.get("build_warning")) then
+                if ok and errdata and #errdata > 0 and _has_warnings() then
                     local lines = errdata:split('\n', {plain = true})
                     if #lines > 0 then
                         if not option.get("diagnosis") then