diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs
index 380dfd387235d..82c3c2006eb14 100644
--- a/compiler/rustc_codegen_llvm/src/back/write.rs
+++ b/compiler/rustc_codegen_llvm/src/back/write.rs
@@ -161,6 +161,7 @@ pub fn target_machine_factory(
     let ffunction_sections =
         sess.opts.debugging_opts.function_sections.unwrap_or(sess.target.function_sections);
     let fdata_sections = ffunction_sections;
+    let funique_section_names = !sess.opts.debugging_opts.no_unique_section_names;
 
     let code_model = to_llvm_code_model(sess.code_model());
 
@@ -205,6 +206,7 @@ pub fn target_machine_factory(
                 use_softfp,
                 ffunction_sections,
                 fdata_sections,
+                funique_section_names,
                 trap_unreachable,
                 singlethread,
                 asm_comments,
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 45fb638e3b49f..d57573558da55 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -2187,6 +2187,7 @@ extern "C" {
         UseSoftFP: bool,
         FunctionSections: bool,
         DataSections: bool,
+        UniqueSectionNames: bool,
         TrapUnreachable: bool,
         Singlethread: bool,
         AsmComments: bool,
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index dab4d485e2d0b..2d3cb52f5fd47 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -744,6 +744,7 @@ fn test_debugging_options_tracking_hash() {
     tracked!(new_llvm_pass_manager, Some(true));
     tracked!(no_generate_arange_section, true);
     tracked!(no_link, true);
+    tracked!(no_unique_section_names, true);
     tracked!(no_profiler_runtime, true);
     tracked!(osx_rpath_install_name, true);
     tracked!(panic_abort_tests, true);
diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index d6dc54c8d0ad6..32b866e81b131 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -462,6 +462,7 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     LLVMRustCodeGenOptLevel RustOptLevel, bool UseSoftFloat,
     bool FunctionSections,
     bool DataSections,
+    bool UniqueSectionNames,
     bool TrapUnreachable,
     bool Singlethread,
     bool AsmComments,
@@ -491,6 +492,7 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
   }
   Options.DataSections = DataSections;
   Options.FunctionSections = FunctionSections;
+  Options.UniqueSectionNames = UniqueSectionNames;
   Options.MCOptions.AsmVerbose = AsmComments;
   Options.MCOptions.PreserveAsmComments = AsmComments;
   Options.MCOptions.ABIName = ABIStr;
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 782055b9a77da..3ff91c0553afe 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -1214,6 +1214,8 @@ options! {
         "compile without linking"),
     no_parallel_llvm: bool = (false, parse_no_flag, [UNTRACKED],
         "run LLVM in non-parallel mode (while keeping codegen-units and ThinLTO)"),
+    no_unique_section_names: bool = (false, parse_bool, [TRACKED],
+        "do not use unique names for text and data sections when -Z function-sections is used"),
     no_profiler_runtime: bool = (false, parse_no_flag, [TRACKED],
         "prevent automatic injection of the profiler_builtins crate"),
     normalize_docs: bool = (false, parse_bool, [TRACKED],
diff --git a/src/doc/unstable-book/src/compiler-flags/no-unique-section-names.md b/src/doc/unstable-book/src/compiler-flags/no-unique-section-names.md
new file mode 100644
index 0000000000000..5c1c7cda7013e
--- /dev/null
+++ b/src/doc/unstable-book/src/compiler-flags/no-unique-section-names.md
@@ -0,0 +1,9 @@
+# `no-unique-section-names`
+
+------------------------
+
+This flag currently applies only to ELF-based targets using the LLVM codegen backend. It prevents the generation of unique ELF section names for each separate code and data item when `-Z function-sections` is also in use, which is the default for most targets. This option can reduce the size of object files, and depending on the linker, the final ELF binary as well.
+
+For example, a function `func` will by default generate a code section called `.text.func`. Normally this is fine because the linker will merge all those `.text.*` sections into a single one in the binary. However, starting with [LLVM 12](https://github.com/llvm/llvm-project/commit/ee5d1a04), the backend will also generate unique section names for exception handling, so you would see a section name of `.gcc_except_table.func` in the object file and potentially in the final ELF binary, which could add significant bloat to programs that contain many functions.
+
+This flag instructs LLVM to use the same `.text` and `.gcc_except_table` section name for each function, and it is analogous to Clang's `-fno-unique-section-names` option.