[driver] Explicitly specify `-fbuild-session-timestamp` in seconds.

Representation of the file's last modification time depends on the file
system and isn't guaranteed to be in seconds. Cast to seconds explicitly
and tighten the test case to check the magnitude of the calculated
value, so we can catch passing milliseconds or nanoseconds.

rdar://83915615

Differential Revision: https://reviews.llvm.org/D111205

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index b689301..8dabfff 100644 (file)
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -3573,11 +3573,11 @@ static void RenderModulesOptions(Compilation &C, const Driver &D,
     llvm::sys::fs::file_status Status;
     if (llvm::sys::fs::status(A->getValue(), Status))
       D.Diag(diag::err_drv_no_such_file) << A->getValue();
-    CmdArgs.push_back(
-        Args.MakeArgString("-fbuild-session-timestamp=" +
-                           Twine((uint64_t)Status.getLastModificationTime()
-                                     .time_since_epoch()
-                                     .count())));
+    CmdArgs.push_back(Args.MakeArgString(
+        "-fbuild-session-timestamp=" +
+        Twine((uint64_t)std::chrono::duration_cast<std::chrono::seconds>(
+                  Status.getLastModificationTime().time_since_epoch())
+                  .count())));
   }
 
   if (Args.getLastArg(options::OPT_fmodules_validate_once_per_build_session)) {

diff --git a/clang/test/Driver/modules.m b/clang/test/Driver/modules.m
index 73db4e7..6714092 100644 (file)
--- a/clang/test/Driver/modules.m
+++ b/clang/test/Driver/modules.m
@@ -11,7 +11,7 @@
 // RUN: %clang -fbuild-session-file=%t.build-session-file -### %s 2>&1 | FileCheck -check-prefix=TIMESTAMP_ONLY %s
 
 // RUN: %clang -fbuild-session-timestamp=1280703457 -### %s 2>&1 | FileCheck -check-prefix=TIMESTAMP_ONLY %s
-// TIMESTAMP_ONLY: -fbuild-session-timestamp=128
+// TIMESTAMP_ONLY: -fbuild-session-timestamp=128{{([[:digit:]]{7})[^[:digit:]]}}
 
 // RUN: %clang -fbuild-session-file=%t.build-session-file -fbuild-session-timestamp=123 -### %s 2>&1 | FileCheck -check-prefix=CONFLICT %s
 // CONFLICT: error: invalid argument '-fbuild-session-file={{.*}}.build-session-file' not allowed with '-fbuild-session-timestamp'
@@ -21,7 +21,7 @@
 // MODULES_VALIDATE_ONCE: -fmodules-validate-once-per-build-session
 
 // RUN: %clang -fbuild-session-file=%t.build-session-file -fmodules-validate-once-per-build-session -### %s 2>&1 | FileCheck -check-prefix=MODULES_VALIDATE_ONCE_FILE %s
-// MODULES_VALIDATE_ONCE_FILE: -fbuild-session-timestamp=128
+// MODULES_VALIDATE_ONCE_FILE: -fbuild-session-timestamp=128{{([[:digit:]]{7})[^[:digit:]]}}
 // MODULES_VALIDATE_ONCE_FILE: -fmodules-validate-once-per-build-session
 
 // RUN: %clang -fmodules-validate-once-per-build-session -### %s 2>&1 | FileCheck -check-prefix=MODULES_VALIDATE_ONCE_ERR %s