Automatically add name-anon-globals

If no-prepopulat-passes and ThinLTO buffers are used, automatically
add name-anon-globals, instead of forcing the user to specify it
explicitly.

Author: nikic

src/librustc_codegen_llvm/back/write.rs

@@ -346,8 +346,6 @@ pub(crate) unsafe fn optimize(
             }
 
             let mut extra_passes = Vec::new();
-            let mut have_name_anon_globals_pass = false;
-
             for pass_name in &config.passes {
                 if pass_name == "lint" {
                     // Linting should also be performed early, directly on the generated IR.
@@ -360,10 +358,6 @@ pub(crate) unsafe fn optimize(
                 } else {
                     diag_handler.warn(&format!("unknown pass `{}`, ignoring", pass_name));
                 }
-
-                if pass_name == "name-anon-globals" {
-                    have_name_anon_globals_pass = true;
-                }
             }
 
             add_sanitizer_passes(config, &mut extra_passes);
@@ -389,33 +383,17 @@ pub(crate) unsafe fn optimize(
                     llvm::LLVMPassManagerBuilderPopulateModulePassManager(b, mpm);
                 });
 
-                have_name_anon_globals_pass = have_name_anon_globals_pass || prepare_for_thin_lto;
                 if using_thin_buffers && !prepare_for_thin_lto {
                     llvm::LLVMRustAddPass(mpm, find_pass("name-anon-globals").unwrap());
-                    have_name_anon_globals_pass = true;
                 }
             } else {
                 // If we don't use the standard pipeline, directly populate the MPM
                 // with the extra passes.
                 for pass in extra_passes {
                     llvm::LLVMRustAddPass(mpm, pass);
                 }
-            }
-
-            if using_thin_buffers && !have_name_anon_globals_pass {
-                // As described above, this will probably cause an error in LLVM
-                if config.no_prepopulate_passes {
-                    diag_handler.err(
-                        "The current compilation is going to use thin LTO buffers \
-                                      without running LLVM's NameAnonGlobals pass. \
-                                      This will likely cause errors in LLVM. Consider adding \
-                                      -C passes=name-anon-globals to the compiler command line.",
-                    );
-                } else {
-                    bug!(
-                        "We are using thin LTO buffers without running the NameAnonGlobals pass. \
-                          This will likely cause errors in LLVM and should never happen."
-                    );
+                if using_thin_buffers {
+                    llvm::LLVMRustAddPass(mpm, find_pass("name-anon-globals").unwrap());
                 }
             }
         }

src/test/codegen/target-cpu-on-functions.rs

@@ -2,8 +2,7 @@
 // "target-cpu" attribute in LLVM.
 
 // no-prefer-dynamic
-// ignore-tidy-linelength
-// compile-flags: -C no-prepopulate-passes -C panic=abort -C linker-plugin-lto -Cpasses=name-anon-globals
+// compile-flags: -C no-prepopulate-passes -C panic=abort -C linker-plugin-lto
 
 #![crate_type = "staticlib"]
 

src/test/ui/feature-gates/feature-gate-unwind-attributes.rs

@@ -1,5 +1,5 @@
 // ignore-wasm32-bare compiled with panic=abort by default
-// compile-flags: -C no-prepopulate-passes -Cpasses=name-anon-globals
+// compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
 

src/test/ui/issues/issue-18804/main.rs

@@ -10,7 +10,7 @@
 // aux-build:lib.rs
 
 // rust-lang/rust#56772: nikic says we need this to be proper test.
-// compile-flags: -C no-prepopulate-passes -C passes=name-anon-globals
+// compile-flags: -C no-prepopulate-passes
 
 extern crate lib;
 

src/test/ui/issues/issue-38226.rs

@@ -6,7 +6,7 @@
 
 // Need -Cno-prepopulate-passes to really disable inlining, otherwise the faulty
 // code gets optimized out:
-// compile-flags: -Cno-prepopulate-passes -Cpasses=name-anon-globals
+// compile-flags: -Cno-prepopulate-passes
 
 extern crate issue_38226_aux;