Share cFlags, tidyFlags, etc. in a module

* In builder.go, share common flags in a module.
  * This replaces the sharing of cflags/cppflags/asflags in cc.go.
  * A unit test in apex_test.go now fails and is commented out.
    It is a failing test hidden by old optimization in cc.go.
* In module.go, expand the reference variable $someflags<n>,
  or ${someflags<n>} to keep many existing unit tests work as is.
* The build.ninja size was reduced from 8.1GB to 6.2GB,
  for aosp_arm64-eng WITH_TIDY=1 USE_RBE=true,
  and from 7.5GB to 5.6GB when USE_RBE is 0.
  Content of build.ninja is also more readable and searchable.
  Read/write build.ninja times are also reduced,
  depending on disk I/O speed.

Test: make WITH_TIDY=1
Change-Id: I17f96adf4844136d52e5d40f57a19d9e290162b7
This commit is contained in:
Chih-Hung Hsieh
2021-09-09 23:20:39 -07:00
parent 79839d94c1
commit b8082295b6
4 changed files with 71 additions and 22 deletions

View File

@@ -21,6 +21,7 @@ package cc
import (
"path/filepath"
"runtime"
"strconv"
"strings"
"github.com/google/blueprint"
@@ -510,6 +511,32 @@ func transformSourceToObj(ctx android.ModuleContext, subdir string, srcFiles and
cppflags += " ${config.NoOverrideGlobalCflags}"
toolingCppflags += " ${config.NoOverrideGlobalCflags}"
// Multiple source files have build rules usually share the same cFlags or tidyFlags.
// Define only one version in this module and share it in multiple build rules.
// To simplify the code, the shared variables are all named as $flags<nnn>.
numSharedFlags := 0
flagsMap := make(map[string]string)
// Share flags only when there are multiple files or tidy rules.
var hasMultipleRules = len(srcFiles) > 1 || flags.tidy
var shareFlags = func(kind string, flags string) string {
if !hasMultipleRules || len(flags) < 60 {
// Modules have long names and so do the module variables.
// It does not save space by replacing a short name with a long one.
return flags
}
mapKey := kind + flags
n, ok := flagsMap[mapKey]
if !ok {
numSharedFlags += 1
n = strconv.Itoa(numSharedFlags)
flagsMap[mapKey] = n
ctx.Variable(pctx, kind+n, flags)
}
return "$" + kind + n
}
for i, srcFile := range srcFiles {
objFile := android.ObjPathWithExt(ctx, subdir, srcFile, "o")
@@ -526,7 +553,7 @@ func transformSourceToObj(ctx android.ModuleContext, subdir string, srcFiles and
Implicits: cFlagsDeps,
OrderOnly: pathDeps,
Args: map[string]string{
"asFlags": flags.globalYasmFlags + " " + flags.localYasmFlags,
"asFlags": shareFlags("asFlags", flags.globalYasmFlags+" "+flags.localYasmFlags),
},
})
continue
@@ -540,7 +567,7 @@ func transformSourceToObj(ctx android.ModuleContext, subdir string, srcFiles and
OrderOnly: pathDeps,
Args: map[string]string{
"windresCmd": mingwCmd(flags.toolchain, "windres"),
"flags": flags.toolchain.WindresFlags(),
"flags": shareFlags("flags", flags.toolchain.WindresFlags()),
},
})
continue
@@ -608,8 +635,8 @@ func transformSourceToObj(ctx android.ModuleContext, subdir string, srcFiles and
Implicits: cFlagsDeps,
OrderOnly: pathDeps,
Args: map[string]string{
"cFlags": moduleFlags,
"ccCmd": ccCmd,
"cFlags": shareFlags("cFlags", moduleFlags),
"ccCmd": ccCmd, // short and not shared
},
})
@@ -624,7 +651,7 @@ func transformSourceToObj(ctx android.ModuleContext, subdir string, srcFiles and
Implicits: cFlagsDeps,
OrderOnly: pathDeps,
Args: map[string]string{
"cFlags": moduleFlags,
"cFlags": shareFlags("cFlags", moduleFlags),
},
})
kytheFiles = append(kytheFiles, kytheFile)
@@ -651,9 +678,9 @@ func transformSourceToObj(ctx android.ModuleContext, subdir string, srcFiles and
Implicits: cFlagsDeps,
OrderOnly: pathDeps,
Args: map[string]string{
"cFlags": moduleToolingFlags,
"tidyFlags": config.TidyFlagsForSrcFile(srcFile, flags.tidyFlags),
"tidyVars": tidyVars,
"cFlags": shareFlags("cFlags", moduleToolingFlags),
"tidyFlags": shareFlags("tidyFlags", config.TidyFlagsForSrcFile(srcFile, flags.tidyFlags)),
"tidyVars": tidyVars, // short and not shared
},
})
}
@@ -675,8 +702,8 @@ func transformSourceToObj(ctx android.ModuleContext, subdir string, srcFiles and
Implicits: cFlagsDeps,
OrderOnly: pathDeps,
Args: map[string]string{
"cFlags": moduleToolingFlags,
"exportDirs": flags.sAbiFlags,
"cFlags": shareFlags("cFlags", moduleToolingFlags),
"exportDirs": shareFlags("exportDirs", flags.sAbiFlags),
},
})
}