GN standalone: extra_{target,host}_cflags + fstack-protector-strong
- Switch to -fstack-protector-strong. CrOS prefers that and there
doesn't seem to be a good reason for not applying it globally to
our standalone builds.
- Introduce a new set extra_{target,host}_{c,cxx,ld}flags. This is
to allow the embedder overriding flags only for one toolchain.
For context see https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2251681
- Allow the embedder to disable the stacktrace reporting on
debug builds, as that require a further dependency on
libbacktrace.
Bug: 147789115
Change-Id: I1c1f9c8853bac9e97702c060db51fefdb9ed963ediff --git a/docs/contributing/build-instructions.md b/docs/contributing/build-instructions.md
index 2bc82ae..109cff3 100644
--- a/docs/contributing/build-instructions.md
+++ b/docs/contributing/build-instructions.md
@@ -165,5 +165,15 @@
`is_ubsan = true`:
Enables [Undefined Behavior Sanitizer](https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html)
+`extra_{cflags,cxxflags, ldflags} = "-fXXX"`:
+This is the moral equivalent of the common Makefile practice:
+`CFLAGS=...` `CXXFLAGS=...` `LDFLAGS=...`.
+If you want to propagate these env variables into GN, set:
+`extra_cxxflags=\"$CXXFLAGS\"`.
+See the [build_fuzzers](/infra/oss-fuzz/build_fuzzers) script for an example.
+Note that these flags will be appended both to target and host toolchains.
+If you want to append flags only to one toolchain use, respectively,
+`extra_target_{cflags,cxxflags,ldflags}` and
+`extra_host_{cflags,cxxflags,ldflags}`.
[gn-quickstart]: https://gn.googlesource.com/gn/+/master/docs/quick_start.md
diff --git a/gn/perfetto.gni b/gn/perfetto.gni
index 42aa474..dd79c2a 100644
--- a/gn/perfetto.gni
+++ b/gn/perfetto.gni
@@ -203,6 +203,12 @@
# none ("off"). We disable it by default for embedders to avoid spamming their
# console.
perfetto_force_dlog = perfetto_force_dlog_default
+
+ # Installs a signal handler for the most common crash signals which unwinds
+ # the stack and prints the stack trace on stderr. Requires a dependency on
+ # libbacktrace when enabled.
+ enable_perfetto_stderr_crash_dump =
+ is_debug && perfetto_build_standalone && !is_wasm
}
declare_args() {
diff --git a/gn/standalone/BUILD.gn b/gn/standalone/BUILD.gn
index f11bb5f..40127a6 100644
--- a/gn/standalone/BUILD.gn
+++ b/gn/standalone/BUILD.gn
@@ -93,7 +93,7 @@
cflags += [
"-fstrict-aliasing",
- "-fstack-protector",
+ "-fstack-protector-strong",
"-fPIC",
"-g",
"-Wformat",
diff --git a/gn/standalone/BUILDCONFIG.gn b/gn/standalone/BUILDCONFIG.gn
index e6117a4..aa0c2bc 100644
--- a/gn/standalone/BUILDCONFIG.gn
+++ b/gn/standalone/BUILDCONFIG.gn
@@ -18,9 +18,8 @@
is_system_compiler = false
is_lto = false
- extra_cflags = ""
- extra_cxxflags = ""
- extra_ldflags = ""
+ # This is defined here because it's needed below for determining the value of
+ # |is_cross_compiling|.
target_triplet = ""
}
diff --git a/gn/standalone/toolchain/BUILD.gn b/gn/standalone/toolchain/BUILD.gn
index 8c3c36d..9f9bd61 100644
--- a/gn/standalone/toolchain/BUILD.gn
+++ b/gn/standalone/toolchain/BUILD.gn
@@ -26,6 +26,21 @@
declare_args() {
cc_wrapper = ""
+
+ # These apply to both target and host toolchains.
+ extra_cflags = ""
+ extra_cxxflags = ""
+ extra_ldflags = ""
+
+ # These apply only to the target toolchain.
+ extra_target_cflags = ""
+ extra_target_cxxflags = ""
+ extra_target_ldflags = ""
+
+ # These apply only to the host toolchain.
+ extra_host_cflags = ""
+ extra_host_cxxflags = ""
+ extra_host_ldflags = ""
}
# First of all determine the host toolchain. The user can override this by:
@@ -153,6 +168,9 @@
lib_switch = "-l"
lib_dir_switch = "-L"
ld_arg = ""
+ external_cflags = ""
+ external_cxxflags = ""
+ external_ldflags = ""
if (defined(invoker.linker) && invoker.linker != "") {
_invoker_linker = invoker.linker
ld_arg = "-fuse-ld=$_invoker_linker"
@@ -167,10 +185,19 @@
_invoker_gcc_toolchain = invoker.gcc_toolchain
ld_arg = "$ld_arg --gcc-toolchain=$_invoker_gcc_toolchain"
}
+ if (defined(invoker.external_cflags)) {
+ external_cflags = invoker.external_cflags
+ }
+ if (defined(invoker.external_cxxflags)) {
+ external_cxxflags = invoker.external_cxxflags
+ }
+ if (defined(invoker.external_ldflags)) {
+ external_ldflags = invoker.external_ldflags
+ }
tool("cc") {
depfile = "{{output}}.d"
- command = "$cc_wrapper $cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_c}} ${extra_cflags} -c {{source}} -o {{output}}"
+ command = "$cc_wrapper $cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_c}} ${external_cflags} -c {{source}} -o {{output}}"
depsformat = "gcc"
outputs =
[ "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o" ]
@@ -179,7 +206,7 @@
tool("cxx") {
depfile = "{{output}}.d"
- command = "$cc_wrapper $cxx -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}} ${extra_cflags} ${extra_cxxflags} -c {{source}} -o {{output}}"
+ command = "$cc_wrapper $cxx -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}} ${external_cflags} ${external_cxxflags} -c {{source}} -o {{output}}"
depsformat = "gcc"
outputs =
[ "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o" ]
@@ -219,7 +246,7 @@
rpath = "-Wl,-install_name,@rpath/$soname"
}
- command = "$cc_wrapper $cxx $ld_arg -shared {{ldflags}} ${extra_ldflags} {{inputs}} {{solibs}} {{libs}} $rpath -o {{output}}"
+ command = "$cc_wrapper $cxx $ld_arg -shared {{ldflags}} ${external_ldflags} {{inputs}} {{solibs}} {{libs}} $rpath -o {{output}}"
outputs = [ "{{root_out_dir}}/$soname" ]
output_prefix = "lib"
default_output_extension = ".so"
@@ -227,7 +254,7 @@
}
tool("link") {
- command = "$cc_wrapper $cxx $ld_arg {{ldflags}} ${extra_ldflags} {{inputs}} {{solibs}} {{libs}} -o {{output}}"
+ command = "$cc_wrapper $cxx $ld_arg {{ldflags}} ${external_ldflags} {{inputs}} {{solibs}} {{libs}} -o {{output}}"
outputs =
[ "{{root_out_dir}}/{{target_output_name}}{{output_extension}}" ]
description = "link {{output}}"
@@ -259,6 +286,21 @@
linker = target_linker
sysroot = target_sysroot
gcc_toolchain = target_gcc_toolchain
+ external_cflags = string_join(" ",
+ [
+ extra_cflags,
+ extra_target_cflags,
+ ])
+ external_cxxflags = string_join(" ",
+ [
+ extra_cxxflags,
+ extra_target_cxxflags,
+ ])
+ external_ldflags = string_join(" ",
+ [
+ extra_ldflags,
+ extra_target_ldflags,
+ ])
}
gcc_like_toolchain("gcc_like_host") {
@@ -270,6 +312,21 @@
linker = linker
sysroot = sysroot
gcc_toolchain = gcc_toolchain
+ external_cflags = string_join(" ",
+ [
+ extra_cflags,
+ extra_host_cflags,
+ ])
+ external_cxxflags = string_join(" ",
+ [
+ extra_cxxflags,
+ extra_host_cxxflags,
+ ])
+ external_ldflags = string_join(" ",
+ [
+ extra_ldflags,
+ extra_host_ldflags,
+ ])
}
gcc_like_toolchain("wasm") {
diff --git a/src/base/BUILD.gn b/src/base/BUILD.gn
index 083faf3..055d70d 100644
--- a/src/base/BUILD.gn
+++ b/src/base/BUILD.gn
@@ -17,8 +17,6 @@
import("../../gn/test.gni")
import("../../gn/wasm.gni")
-enable_stack_trace = is_debug && perfetto_build_standalone && !is_wasm
-
source_set("base") {
deps = [ "../../gn:default_deps" ]
public_deps = [
@@ -53,12 +51,12 @@
]
}
- if (enable_stack_trace) {
+ if (enable_perfetto_stderr_crash_dump) {
deps += [ ":debug_crash_stack_trace" ]
}
}
-if (enable_stack_trace) {
+if (enable_perfetto_stderr_crash_dump) {
source_set("debug_crash_stack_trace") {
sources = [ "debug_crash_stack_trace.cc" ]
deps = [
