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NDK library: collect NDK headers for ABI monitoring

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Collect all NDK exported headers paths into a file that is used to
detect public types that should be ABI monitored.

Assume that we have the following code in exported header:

typedef struct Context Context;
typedef struct Output {
    ...
} Output;
void DoSomething(Context* ctx, Output* output);

If none of public headers exported to end-users contain definition of
"struct Context", then "struct Context" layout and members shouldn't be
monitored. However we use DWARF information from a real library, which
may have access to the definition of "string Context" from
implementation headers, and it will leak to ABI.

STG tool doesn't access source and header files, only DWARF information
from compiled library. And the DWARF contains file name where a type is
defined. So we need a rule to build a list of paths to public headers,
so STG can distinguish private types from public and do not monitor
private types that are not accessible to library users.

Bug: 156513478
Test: development/tools/ndk/update_ndk_abi.sh with enabled canDumpAbi
Change-Id: I9fa41e73450a41379638debb3dc56f421e0fb870
Signed-off-by: Aleksei Vetrov <vvvvvv@google.com>
This commit is contained in:
Aleksei Vetrov
2023-08-23 10:06:35 +00:00
parent 4d730a8f14
commit 262ed1a347
3 changed files with 80 additions and 19 deletions
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57
cc/ndk_sysroot.go
View File

@@ -54,6 +54,7 @@ package cc
import (
"android/soong/android"
"strings"
)
func init() {
@@ -96,15 +97,56 @@ func getNdkFullTimestampFile(ctx android.PathContext) android.WritablePath {
return android.PathForOutput(ctx, "ndk.timestamp")
}
// The list of all NDK headers as they are located in the repo.
// Used for ABI monitoring to track only structures defined in NDK headers.
func getNdkABIHeadersFile(ctx android.PathContext) android.WritablePath {
return android.PathForOutput(ctx, "ndk_abi_headers.txt")
}
func NdkSingleton() android.Singleton {
return &ndkSingleton{}
}
// Collect all NDK exported headers paths into a file that is used to
// detect public types that should be ABI monitored.
//
// Assume that we have the following code in exported header:
//
// typedef struct Context Context;
// typedef struct Output {
// ...
// } Output;
// void DoSomething(Context* ctx, Output* output);
//
// If none of public headers exported to end-users contain definition of
// "struct Context", then "struct Context" layout and members shouldn't be
// monitored. However we use DWARF information from a real library, which
// may have access to the definition of "string Context" from
// implementation headers, and it will leak to ABI.
//
// STG tool doesn't access source and header files, only DWARF information
// from compiled library. And the DWARF contains file name where a type is
// defined. So we need a rule to build a list of paths to public headers,
// so STG can distinguish private types from public and do not monitor
// private types that are not accessible to library users.
func writeNdkAbiSrcFilter(ctx android.BuilderContext,
headerSrcPaths android.Paths, outputFile android.WritablePath) {
var filterBuilder strings.Builder
filterBuilder.WriteString("[decl_file_allowlist]\n")
for _, headerSrcPath := range headerSrcPaths {
filterBuilder.WriteString(headerSrcPath.String())
filterBuilder.WriteString("\n")
}
android.WriteFileRule(ctx, outputFile, filterBuilder.String())
}
type ndkSingleton struct{}
func (n *ndkSingleton) GenerateBuildActions(ctx android.SingletonContext) {
var staticLibInstallPaths android.Paths
var headerPaths android.Paths
var headerSrcPaths android.Paths
var headerInstallPaths android.Paths
var installPaths android.Paths
var licensePaths android.Paths
ctx.VisitAllModules(func(module android.Module) {
@@ -113,19 +155,22 @@ func (n *ndkSingleton) GenerateBuildActions(ctx android.SingletonContext) {
}
if m, ok := module.(*headerModule); ok {
headerPaths = append(headerPaths, m.installPaths...)
headerSrcPaths = append(headerSrcPaths, m.srcPaths...)
headerInstallPaths = append(headerInstallPaths, m.installPaths...)
installPaths = append(installPaths, m.installPaths...)
licensePaths = append(licensePaths, m.licensePath)
}
if m, ok := module.(*versionedHeaderModule); ok {
headerPaths = append(headerPaths, m.installPaths...)
headerSrcPaths = append(headerSrcPaths, m.srcPaths...)
headerInstallPaths = append(headerInstallPaths, m.installPaths...)
installPaths = append(installPaths, m.installPaths...)
licensePaths = append(licensePaths, m.licensePath)
}
if m, ok := module.(*preprocessedHeadersModule); ok {
headerPaths = append(headerPaths, m.installPaths...)
headerSrcPaths = append(headerSrcPaths, m.srcPaths...)
headerInstallPaths = append(headerInstallPaths, m.installPaths...)
installPaths = append(installPaths, m.installPaths...)
licensePaths = append(licensePaths, m.licensePath)
}
@@ -175,9 +220,11 @@ func (n *ndkSingleton) GenerateBuildActions(ctx android.SingletonContext) {
ctx.Build(pctx, android.BuildParams{
Rule: android.Touch,
Output: getNdkHeadersTimestampFile(ctx),
Implicits: headerPaths,
Implicits: headerInstallPaths,
})
writeNdkAbiSrcFilter(ctx, headerSrcPaths, getNdkABIHeadersFile(ctx))
fullDepPaths := append(staticLibInstallPaths, getNdkBaseTimestampFile(ctx))
// There's a phony "ndk" rule defined in core/main.mk that depends on this.