[llvm] 2e91a5f - [llvm-objdump] Add --build-id flag for debuginfod lookups without binary.

[Daniel Thornburgh via llvm-commits]

Author: Daniel Thornburgh
Date: 2022-10-04T13:44:25-07:00
New Revision: 2e91a5f546ad0d934e9619222983efe230b344b6

URL: https://github.com/llvm/llvm-project/commit/2e91a5f546ad0d934e9619222983efe230b344b6
DIFF: https://github.com/llvm/llvm-project/commit/2e91a5f546ad0d934e9619222983efe230b344b6.diff

LOG: [llvm-objdump] Add --build-id flag for debuginfod lookups without binary.

Adding a --build-id flag allows handling binaries that are referenced in
logs from remote systems, but that aren't necessarily present on the
local machine. These are fetched via debuginfod and handled as if they
were input filenames.

Reviewed By: jhenderson, MaskRay

Differential Revision: https://reviews.llvm.org/D133992

Added: 
    

Modified: 
    llvm/docs/CommandGuide/llvm-objdump.rst
    llvm/test/tools/llvm-objdump/debuginfod.test
    llvm/tools/llvm-objdump/ObjdumpOpts.td
    llvm/tools/llvm-objdump/llvm-objdump.cpp

Removed: 
    


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diff  --git a/llvm/docs/CommandGuide/llvm-objdump.rst b/llvm/docs/CommandGuide/llvm-objdump.rst
index 654a48fe7572..7879ac163b10 100644
--- a/llvm/docs/CommandGuide/llvm-objdump.rst
+++ b/llvm/docs/CommandGuide/llvm-objdump.rst
@@ -125,6 +125,11 @@ OPTIONS
   Specify the target architecture when disassembling. Use :option:`--version`
   for a list of available targets.
 
+.. option:: --build-id=<string>
+
+  Look up the object using the given build ID, specified as a hexadecimal
+  string. The found object is handled as if it were an input filename.
+
 .. option:: -C, --demangle
 
   Demangle symbol names in the output.

diff  --git a/llvm/test/tools/llvm-objdump/debuginfod.test b/llvm/test/tools/llvm-objdump/debuginfod.test
index c8f871dc8cf2..a2ef5a9d2c2d 100644
--- a/llvm/test/tools/llvm-objdump/debuginfod.test
+++ b/llvm/test/tools/llvm-objdump/debuginfod.test
@@ -61,6 +61,23 @@ RUN:   --debuginfod %t/stripped 2> %t.err | \
 RUN:   FileCheck %s --check-prefix=NOTFOUND
 RUN: count 0 < %t.err
 
+# Use debuginfod to look up build IDs.
+RUN: env DEBUGINFOD_CACHE_PATH=%t llvm-objdump -d --source \
+RUN:   --build-id 1512f769114c011387393822af15dd660c080295 | \
+RUN:   FileCheck %s --check-prefix=FOUND
+
+# Produce an error if malformed (not a hex string).
+RUN: not env DEBUGINFOD_CACHE_PATH=%t llvm-objdump -d --source --build-id foo \
+RUN:   2> %t.err
+RUN: FileCheck %s --check-prefix=MALFORMEDERROR --input-file %t.err
+MALFORMEDERROR: error: --build-id: expected a build ID, but got 'foo'
+
+# Produce an error if not found.
+RUN: not env DEBUGINFOD_CACHE_PATH=%t llvm-objdump -d --source --build-id abc \
+RUN:   2> %t.err
+RUN: FileCheck %s --check-prefix=NOTFOUNDERROR --input-file %t.err
+NOTFOUNDERROR: error: --build-id: could not find build ID 'abc'
+
 # Use debuginfod to recover symbols.
 RUN: llvm-strip --strip-sections %t/stripped
 RUN: env DEBUGINFOD_CACHE_PATH=%t llvm-objdump -d --debuginfod \

diff  --git a/llvm/tools/llvm-objdump/ObjdumpOpts.td b/llvm/tools/llvm-objdump/ObjdumpOpts.td
index 178267dc408c..01bad81f812e 100644
--- a/llvm/tools/llvm-objdump/ObjdumpOpts.td
+++ b/llvm/tools/llvm-objdump/ObjdumpOpts.td
@@ -38,6 +38,10 @@ def arch_name_EQ : Joined<["--"], "arch-name=">,
 def archive_headers : Flag<["--"], "archive-headers">,
   HelpText<"Display archive header information">;
 
+defm build_id :
+  Eq<"build-id", "Build ID to look up. Once found, added as an input file">,
+  MetaVarName<"<dir>">;
+
 def : Flag<["-"], "a">, Alias<archive_headers>,
   HelpText<"Alias for --archive-headers">;
 

diff  --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 689aa0ab7a82..f7d6666de379 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -2916,6 +2916,17 @@ static void parseIntArg(const llvm::opt::InputArgList &InputArgs, int ID,
   }
 }
 
+static object::BuildID parseBuildIDArg(const opt::Arg *A) {
+  StringRef V(A->getValue());
+  std::string Bytes;
+  if (!tryGetFromHex(V, Bytes))
+    reportCmdLineError(A->getSpelling() + ": expected a build ID, but got '" +
+                       V + "'");
+  ArrayRef<uint8_t> BuildID(reinterpret_cast<const uint8_t *>(Bytes.data()),
+                            Bytes.size());
+  return object::BuildID(BuildID.begin(), BuildID.end());
+}
+
 static void invalidArgValue(const opt::Arg *A) {
   reportCmdLineError("'" + StringRef(A->getValue()) +
                      "' is not a valid value for '" + A->getSpelling() + "'");
@@ -3084,6 +3095,17 @@ static void parseObjdumpOptions(const llvm::opt::InputArgList &InputArgs) {
     llvm::cl::ParseCommandLineOptions(2, Argv);
   }
 
+  // Look up any provided build IDs, then append them to the input filenames.
+  for (const opt::Arg *A : InputArgs.filtered(OBJDUMP_build_id)) {
+    object::BuildID BuildID = parseBuildIDArg(A);
+    Optional<std::string> Path = BIDFetcher->fetch(BuildID);
+    if (!Path) {
+      reportCmdLineError(A->getSpelling() + ": could not find build ID '" +
+                         A->getValue() + "'");
+    }
+    InputFilenames.push_back(std::move(*Path));
+  }
+
   // objdump defaults to a.out if no filenames specified.
   if (InputFilenames.empty())
     InputFilenames.push_back("a.out");
@@ -3153,8 +3175,9 @@ int main(int argc, char **argv) {
 
   // Initialize debuginfod.
   const bool ShouldUseDebuginfodByDefault =
-      HTTPClient::isAvailable() &&
-      !ExitOnErr(getDefaultDebuginfodUrls()).empty();
+      InputArgs.hasArg(OBJDUMP_build_id) ||
+      (HTTPClient::isAvailable() &&
+       !ExitOnErr(getDefaultDebuginfodUrls()).empty());
   std::vector<std::string> DebugFileDirectories =
       InputArgs.getAllArgValues(OBJDUMP_debug_file_directory);
   if (InputArgs.hasFlag(OBJDUMP_debuginfod, OBJDUMP_no_debuginfod,