[clang][pdb] Don't include -fmessage-length in PDB buildinfo

[thieta]

Summary

As discussed in https://reviews.llvm.org/D136474 -fmessage-length
creates problems with reproduciability in the PDB files.

This patch just drops that argument when writing the PDB file.

[thieta]

Ping

[hans]

lgtm with nits

clang/test/CodeGen/debug-info-codeview-buildinfo.c

47

could this be just
MESSAGELEN-NOT: -fmessage-length
?

llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp

911

nit: Period at the end (though I know we're not super consistent about this).

[thieta]

Updated from feedback

[thieta]

Thanks @hans

clang/test/CodeGen/debug-info-codeview-buildinfo.c

 // REQUIRES: x86-registered-target
 // RUN: %clang_cl --target=i686-windows-msvc /c /Z7 /Fo%t.obj -- %s
 // RUN: llvm-pdbutil dump --types %t.obj | FileCheck %s
 // RUN: %clang_cl -gcodeview-command-line --target=i686-windows-msvc /c /Z7 /Fo%t.obj -- %s
 // RUN: llvm-pdbutil dump --types %t.obj | FileCheck %s
 // RUN: %clang_cl --target=i686-windows-msvc /c /Z7 /Fo%t.obj -fdebug-compilation-dir=. -- %s
 // RUN: llvm-pdbutil dump --types %t.obj | FileCheck %s --check-prefix RELATIVE
 // RUN: %clang_cl -gno-codeview-command-line --target=i686-windows-msvc /c /Z7 /Fo%t.obj -- %s
 // RUN: llvm-pdbutil dump --types %t.obj | FileCheck %s --check-prefix DISABLE
 
+// -fmessage length shouldn't be included in the command line since it breaks reproducibility
+// RUN: %clang_cl -gcodeview-command-line --target=i686-windows-msvc -Xclang -fmessage-length=100 /c /Z7 /Fo%t.obj -- %s
+// RUN: llvm-pdbutil dump --types %t.obj | FileCheck %s --check-prefix MESSAGELEN
+
 int main(void) { return 42; }
 
 // CHECK:                       Types (.debug$T)
 // CHECK: ============================================================
 // CHECK: 0x[[PWD:.+]] | LF_STRING_ID [size = {{.+}}] ID: <no type>, String: [[PWDVAL:.+]]
 // CHECK: 0x[[FILEPATH:.+]] | LF_STRING_ID [size = {{.+}}] ID: <no type>, String: [[FILEPATHVAL:.+[\\/]debug-info-codeview-buildinfo.c]]
 // CHECK: 0x[[ZIPDB:.+]] | LF_STRING_ID [size = {{.+}}] ID: <no type>, String:
 // CHECK: 0x[[TOOL:.+]] | LF_STRING_ID [size = {{.+}}] ID: <no type>, String: [[TOOLVAL:.+[\\/]clang.*]]

 
 // DISABLE-NOT: cc1
 // DISABLE: 0x{{.+}} | LF_BUILDINFO [size = {{.+}}]
 // DISABLE-NEXT:          0x{{.+}}: `{{.*}}`
 // DISABLE-NEXT:          <no type>: ``
 // DISABLE-NEXT:          0x{{.+}}: `{{.*}}`
 // DISABLE-NEXT:          0x{{.+}}: ``
 // DISABLE-NEXT:          <no type>: ``
+
+// MESSAGELEN:                       Types (.debug$T)
+// MESSAGELEN: ============================================================
+// MESSAGELEN: 0x{{.+}} | LF_BUILDINFO [size = {{.+}}]
+// MESSAGELEN-NOT:          0x{{.+}}: `"{{.+}}-fmessage-length=

llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp

for (unsigned i = 0; i < Args.size(); i++) {
     if (Arg.empty())
       continue;
     if (Arg == "-main-file-name" || Arg == "-o") {
       i++; // Skip this argument and next one.
       continue;
     }
     if (Arg.startswith("-object-file-name") || Arg == MainFilename)
       continue;
+    // Skip fmessage-length for reproduciability
+    if (Arg.startswith("-fmessage-length"))
+      continue;
     if (PrintedOneArg)
       OS << " ";
     llvm::sys::printArg(OS, Arg, /*Quote=*/true);
     PrintedOneArg = true;
   }
   OS.flush();
   return FlatCmdLine;
 }