Run def-use analysis again after inlining (#3591)

* Run def-use analysis after inlining Signed-off-by: Mihai Budiu <mbudiu@vmware.com>
p4lang · Oct 24, 2022 · e60cb8a · e60cb8a
1 parent 6b86b5b
commit e60cb8a
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Showing 255 changed files with 276 additions and 1,297 deletions.
diff --git a/backends/p4tools/testgen/targets/bmv2/test/BMV2Xfail.cmake b/backends/p4tools/testgen/targets/bmv2/test/BMV2Xfail.cmake
@@ -46,7 +46,6 @@ p4tools_add_xfail_reason(
 p4tools_add_xfail_reason(
   "testgen-p4c-bmv2"
   "bad json"
-  invalid-hdr-warnings4.p4
   control-hs-index-test5.p4
 )
 

diff --git a/frontends/p4/frontend.cpp b/frontends/p4/frontend.cpp
@@ -243,6 +243,8 @@ const IR::P4Program *FrontEnd::run(const CompilerOptions &options, const IR::P4P
         new RemoveParserControlFlow(&refMap, &typeMap),  // more ifs may have been added to parsers
         new UniqueNames(&refMap),  // needed again after inlining
         new MoveDeclarations(),  // needed again after inlining
+        new SimplifyDefUse(&refMap, &typeMap),
+        new RemoveUnusedDeclarations(&refMap),
         new SimplifyControlFlow(&refMap, &typeMap),
         new HierarchicalNames(),
         new FrontEndLast(),

diff --git a/frontends/p4/simplifyDefUse.cpp b/frontends/p4/simplifyDefUse.cpp
@@ -478,7 +478,7 @@ class FindUninitialized : public Inspector {
                             const IR::ParameterList* parameters,
                             Definitions* defs) {
         LOG2("Checking output parameters of " << block <<
-             "; definitions are " << Log::endl << defs);
+             "; definitions are " << IndentCtl::endl << defs);
         for (auto p : parameters->parameters) {
             if (p->direction == IR::Direction::Out || p->direction == IR::Direction::InOut) {
                 auto storage = definitions->storageMap->getStorage(p);
@@ -1443,6 +1443,10 @@ class FindUninitialized : public Inspector {
         return false;
     }
 
+    void postorder(const IR::StructExpression* expression) override {
+        otherExpression(expression);
+    }
+
     void postorder(const IR::Operation_Unary* expression) override {
         otherExpression(expression);
     }
@@ -1490,7 +1494,7 @@ class RemoveUnused : public Transform {
                 return mcs;
             }
             // removing
-            LOG3("Removing statement " << getOriginal());
+            LOG3("Removing statement " << getOriginal() << IndentCtl::indent);
             return new IR::EmptyStatement(mcs->srcInfo);
         }
         return mcs;

diff --git a/testdata/p4_14_samples_outputs/action_inline1-frontend.p4 b/testdata/p4_14_samples_outputs/action_inline1-frontend.p4
@@ -32,7 +32,6 @@ control ingress(inout headers hdr, inout metadata meta, inout standard_metadata_
     @noWarn("unused") @name(".NoAction") action NoAction_1() {
     }
     @name(".setb1") action setb1(@name("val") bit<8> val, @name("port") bit<9> port) {
-        dest = hdr.data.b1;
         dest = val;
         hdr.data.b1 = dest;
         standard_metadata.egress_spec = port;

diff --git a/testdata/p4_14_samples_outputs/action_inline2-frontend.p4 b/testdata/p4_14_samples_outputs/action_inline2-frontend.p4
@@ -34,9 +34,6 @@ control ingress(inout headers hdr, inout metadata meta, inout standard_metadata_
     @noWarn("unused") @name(".NoAction") action NoAction_1() {
     }
     @name(".setb1") action setb1(@name("port") bit<9> port) {
-        dest = hdr.data.b1;
-        dest_3 = dest;
-        dest_4 = dest_3;
         dest_4 = hdr.data.b2;
         dest_3 = dest_4;
         dest = dest_3;

diff --git a/testdata/p4_16_samples_outputs/action-bind-frontend.p4 b/testdata/p4_16_samples_outputs/action-bind-frontend.p4
@@ -1,7 +1,6 @@
 control c(inout bit<32> x) {
     @name("c.b") bit<32> b_0;
     @name("c.a") action a(@name("d") bit<32> d) {
-        b_0 = x;
         b_0 = d;
         x = b_0;
     }

diff --git a/testdata/p4_16_samples_outputs/action_call_ubpf-frontend.p4 b/testdata/p4_16_samples_outputs/action_call_ubpf-frontend.p4
@@ -14,13 +14,10 @@ parser prs(packet_in p, out Headers_t headers, inout metadata meta, inout standa
 }
 
 control pipe(inout Headers_t headers, inout metadata meta, inout standard_metadata std_meta) {
-    @name("pipe.hasReturned") bool hasReturned;
     @name("pipe.RejectConditional") action RejectConditional(@name("condition") bit<1> condition) {
     }
     @name("pipe.act_return") action act_return() {
-        hasReturned = false;
         mark_to_pass();
-        hasReturned = true;
     }
     @name("pipe.act_exit") action act_exit() {
         mark_to_pass();

diff --git a/testdata/p4_16_samples_outputs/after-return-frontend.p4 b/testdata/p4_16_samples_outputs/after-return-frontend.p4
@@ -1,14 +1,7 @@
 control ctrl() {
     @name("ctrl.a") bit<32> a_0;
-    @name("ctrl.hasReturned") bool hasReturned;
     apply {
-        hasReturned = false;
         a_0 = 32w0;
-        if (a_0 == 32w0) {
-            hasReturned = true;
-        } else {
-            hasReturned = true;
-        }
     }
 }
 

diff --git a/testdata/p4_16_samples_outputs/control-as-param-frontend.p4 b/testdata/p4_16_samples_outputs/control-as-param-frontend.p4
@@ -3,7 +3,6 @@
 control E(out bit<1> b);
 control Ingress(out bit<1> b) {
     apply {
-        b = 1w1;
         b = 1w0;
     }
 }

diff --git a/testdata/p4_16_samples_outputs/control-as-param-midend.p4 b/testdata/p4_16_samples_outputs/control-as-param-midend.p4
@@ -2,18 +2,17 @@
 
 control E(out bit<1> b);
 control Ingress(out bit<1> b) {
-    @hidden action controlasparam7() {
-        b = 1w1;
+    @hidden action controlasparam13() {
         b = 1w0;
     }
-    @hidden table tbl_controlasparam7 {
+    @hidden table tbl_controlasparam13 {
         actions = {
-            controlasparam7();
+            controlasparam13();
         }
-        const default_action = controlasparam7();
+        const default_action = controlasparam13();
     }
     apply {
-        tbl_controlasparam7.apply();
+        tbl_controlasparam13.apply();
     }
 }
 

diff --git a/testdata/p4_16_samples_outputs/decl2-frontend.p4 b/testdata/p4_16_samples_outputs/decl2-frontend.p4
@@ -1,19 +1,7 @@
 control p() {
-    @name("p.z") bit<1> z_0;
-    @name("p.x_0") bit<1> x_0;
-    @name("p.x_1") bit<1> x_3;
-    @name("p.y_0") bit<1> y_0;
-    @name("p.x") bit<1> x_4;
-    @name("p.y") bit<1> y_2;
     @name("p.b") action b() {
-        x_4 = x_3;
-        x_0 = x_4;
-        z_0 = x_4 & x_0;
-        y_2 = z_0;
-        y_0 = y_2;
     }
     apply {
-        x_3 = 1w0;
         b();
     }
 }

diff --git a/testdata/p4_16_samples_outputs/def-use-frontend.p4 b/testdata/p4_16_samples_outputs/def-use-frontend.p4
@@ -21,7 +21,6 @@ control IngressI(inout H hdr, inout M meta, inout std_meta_t std_meta) {
 }
 
 control EgressI(inout H hdr, inout M meta, inout std_meta_t std_meta) {
-    @name("EgressI.hasReturned") bool hasReturned;
     @name("EgressI.a") action a() {
     }
     @name("EgressI.t") table t_0 {
@@ -31,10 +30,8 @@ control EgressI(inout H hdr, inout M meta, inout std_meta_t std_meta) {
         default_action = a();
     }
     apply {
-        hasReturned = false;
         switch (t_0.apply().action_run) {
             a: {
-                hasReturned = true;
             }
             default: {
             }

diff --git a/testdata/p4_16_samples_outputs/fabric_20190420/fabric.p4-stderr b/testdata/p4_16_samples_outputs/fabric_20190420/fabric.p4-stderr
@@ -0,0 +1,3 @@
+fabric.p4(84): [--Wwarn=invalid_header] warning: accessing a field of a potentially invalid header hdr.gtpu_ipv4
+        spgw_ingress.apply(hdr.gtpu_ipv4, hdr.gtpu_udp, hdr.gtpu,
+                           ^^^^^^^^^^^^^
diff --git a/testdata/p4_16_samples_outputs/function-frontend.p4 b/testdata/p4_16_samples_outputs/function-frontend.p4
@@ -14,7 +14,6 @@ control c(out bit<16> b) {
         if (hasReturned) {
             ;
         } else {
-            hasReturned = true;
             retval = right;
         }
         b = retval;

diff --git a/testdata/p4_16_samples_outputs/function.p4-stderr b/testdata/p4_16_samples_outputs/function.p4-stderr
@@ -0,0 +1,2 @@
+[--Wwarn=uninitialized_use] warning: retval may be uninitialized
+[--Wwarn=uninitialized_use] warning: retval may be uninitialized
diff --git a/testdata/p4_16_samples_outputs/gauntlet_action_return-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_action_return-bmv2-frontend.p4
@@ -35,11 +35,6 @@ control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
         } else {
             val_0 = 8w3;
         }
-        if (hasReturned) {
-            ;
-        } else {
-            hasReturned = true;
-        }
         h.h.a = val_0;
     }
     @name("ingress.simple_table") table simple_table_0 {

diff --git a/testdata/p4_16_samples_outputs/gauntlet_arithref_cast-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_arithref_cast-bmv2-frontend.p4
@@ -26,13 +26,10 @@ control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
     @name("ingress.tmp") bit<48> tmp;
     @name("ingress.tmp_0") bit<8> tmp_0;
     @name("ingress.tmp_1") bit<48> tmp_1;
-    @name("ingress.hasReturned") bool hasReturned;
     @name("ingress.retval") bit<8> retval;
     apply {
         if (h.eth_hdr.src_addr < 48w10) {
             tmp = h.eth_hdr.dst_addr;
-            hasReturned = false;
-            hasReturned = true;
             retval = 8w2;
             tmp_0 = retval;
             tmp_1 = tmp << tmp_0;

diff --git a/testdata/p4_16_samples_outputs/gauntlet_copy_out-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_copy_out-bmv2-frontend.p4
@@ -27,13 +27,11 @@ control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
     @name("ingress.inout_c") bit<8> inout_c_2;
     @name("ingress.do_thing") action do_thing() {
         inout_c_0 = c_0;
-        h.h.a = inout_c_0;
         c_0 = inout_c_0;
     }
     @name("ingress.do_thing") action do_thing_1() {
         inout_c_2 = c_0;
         h.h.a = inout_c_2;
-        c_0 = inout_c_2;
     }
     apply {
         c_0 = 8w12;

diff --git a/testdata/p4_16_samples_outputs/gauntlet_copy_out-bmv2-midend.p4 b/testdata/p4_16_samples_outputs/gauntlet_copy_out-bmv2-midend.p4
@@ -23,9 +23,9 @@ struct Meta {
 
 control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
     @name("ingress.do_thing") action do_thing() {
-        h.h.a = 8w12;
     }
     @name("ingress.do_thing") action do_thing_1() {
+        h.h.a = 8w12;
     }
     @hidden table tbl_do_thing {
         actions = {

diff --git a/testdata/p4_16_samples_outputs/gauntlet_exit_combination_18-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_exit_combination_18-bmv2-frontend.p4
@@ -28,7 +28,6 @@ control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
         dummy_0 = h.eth_hdr.src_addr;
         h.eth_hdr.src_addr = dummy_0;
         exit;
-        h.eth_hdr.src_addr = dummy_0;
     }
     apply {
         simple_action();

diff --git a/testdata/p4_16_samples_outputs/gauntlet_exit_combination_20-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_exit_combination_20-bmv2-frontend.p4
@@ -23,10 +23,7 @@ parser p(packet_in pkt, out Headers hdr, inout Meta m, inout standard_metadata_t
 }
 
 control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
-    @name("ingress.hasReturned") bool hasReturned;
     @name("ingress.simple_action") action simple_action() {
-        hasReturned = false;
-        hasReturned = true;
     }
     apply {
         simple_action();

diff --git a/testdata/p4_16_samples_outputs/gauntlet_exit_combination_3-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_exit_combination_3-bmv2-frontend.p4
@@ -29,18 +29,14 @@ control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
     @noWarn("unused") @name(".NoAction") action NoAction_1() {
     }
     @name("ingress.do_action") action do_action() {
-        val_0 = h.eth_hdr.src_addr;
         val_0 = 48w2;
         h.eth_hdr.src_addr = val_0;
         exit;
-        h.eth_hdr.src_addr = val_0;
     }
     @name("ingress.do_action") action do_action_1() {
-        val_2 = h.eth_hdr.dst_addr;
         val_2 = 48w2;
         h.eth_hdr.dst_addr = val_2;
         exit;
-        h.eth_hdr.dst_addr = val_2;
     }
     @name("ingress.simple_table") table simple_table_0 {
         key = {

diff --git a/testdata/p4_16_samples_outputs/gauntlet_exit_combination_8-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_exit_combination_8-bmv2-frontend.p4
@@ -23,10 +23,7 @@ parser p(packet_in pkt, out Headers hdr, inout Meta m, inout standard_metadata_t
 }
 
 control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
-    @name("ingress.hasReturned") bool hasReturned;
     apply {
-        hasReturned = false;
-        hasReturned = true;
     }
 }
 

diff --git a/testdata/p4_16_samples_outputs/gauntlet_function_if_hdr_return-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_function_if_hdr_return-bmv2-frontend.p4
@@ -23,11 +23,8 @@ parser p(packet_in pkt, out Headers hdr, inout Meta m, inout standard_metadata_t
 }
 
 control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
-    @name("ingress.hasReturned") bool hasReturned;
     @name("ingress.retval") ethernet_t retval;
     apply {
-        hasReturned = false;
-        hasReturned = true;
         retval.setValid();
         retval = (ethernet_t){dst_addr = 48w1,src_addr = 48w1,eth_type = 16w1};
         h.eth_hdr = retval;

diff --git a/testdata/p4_16_samples_outputs/gauntlet_function_return-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_function_return-bmv2-frontend.p4
@@ -16,15 +16,9 @@ struct Meta {
 control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
     @name("ingress.tmp") bit<8> tmp;
     @name("ingress.c") bit<32> c_0;
-    @name("ingress.d_0") bit<32> d;
-    @name("ingress.hasReturned") bool hasReturned;
     @name("ingress.retval") bit<8> retval;
     @name("ingress.action_thing") action action_thing() {
-        c_0 = sm.enq_timestamp;
-        hasReturned = false;
-        hasReturned = true;
         retval = 8w1;
-        c_0 = d;
         tmp = retval;
         c_0 = (bit<32>)tmp;
         sm.enq_timestamp = c_0;

diff --git a/testdata/p4_16_samples_outputs/gauntlet_function_return-bmv2.p4-stderr b/testdata/p4_16_samples_outputs/gauntlet_function_return-bmv2.p4-stderr
@@ -4,3 +4,4 @@ bit<8> do_thing(out bit<32> d) {
 gauntlet_function_return-bmv2.p4(15)
 bit<8> do_thing(out bit<32> d) {
        ^^^^^^^^
+[--Wwarn=uninitialized_use] warning: d_0 may be uninitialized
diff --git a/testdata/p4_16_samples_outputs/gauntlet_function_return_cast-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_function_return_cast-bmv2-frontend.p4
@@ -24,11 +24,8 @@ parser p(packet_in pkt, out Headers hdr, inout Meta m, inout standard_metadata_t
 
 control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
     @name("ingress.tmp") bit<8> tmp;
-    @name("ingress.hasReturned") bool hasReturned;
     @name("ingress.retval") bit<8> retval;
     apply {
-        hasReturned = false;
-        hasReturned = true;
         retval = 8w255;
         tmp = retval;
         h.eth_hdr.eth_type = (bit<16>)tmp;

diff --git a/testdata/p4_16_samples_outputs/gauntlet_hdr_function_cast-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_hdr_function_cast-bmv2-frontend.p4
@@ -28,7 +28,6 @@ control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
     @name("ingress.val_0") bit<16> val;
     @name("ingress.hasReturned") bool hasReturned;
     @name("ingress.retval") ethernet_t retval;
-    @name("ingress.hasReturned_0") bool hasReturned_0;
     @name("ingress.retval_0") ethernet_t retval_0;
     apply {
         val = h.eth_hdr1.eth_type;
@@ -45,14 +44,10 @@ control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
         if (hasReturned) {
             ;
         } else {
-            hasReturned = true;
             retval.setValid();
             retval = (ethernet_t){dst_addr = 48w3,src_addr = 48w3,eth_type = 16w3};
         }
-        h.eth_hdr1.eth_type = val;
         h.eth_hdr1 = retval;
-        hasReturned_0 = false;
-        hasReturned_0 = true;
         retval_0.setValid();
         retval_0 = (ethernet_t){dst_addr = 48w1,src_addr = 48w1,eth_type = 16w1};
         h.eth_hdr2 = retval_0;

diff --git a/testdata/p4_16_samples_outputs/gauntlet_hdr_function_cast-bmv2-midend.p4 b/testdata/p4_16_samples_outputs/gauntlet_hdr_function_cast-bmv2-midend.p4
@@ -46,7 +46,6 @@ control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
         hasReturned = false;
     }
     @hidden action gauntlet_hdr_function_castbmv2l26() {
-        hasReturned = true;
         retval.setValid();
         retval.dst_addr = 48w3;
         retval.src_addr = 48w3;

diff --git a/testdata/p4_16_samples_outputs/gauntlet_hdr_function_cast-bmv2.p4-stderr b/testdata/p4_16_samples_outputs/gauntlet_hdr_function_cast-bmv2.p4-stderr
@@ -0,0 +1,2 @@
+[--Wwarn=uninitialized_use] warning: retval may not be completely initialized
+[--Wwarn=uninitialized_use] warning: retval may not be completely initialized
diff --git a/testdata/p4_16_samples_outputs/gauntlet_hdr_in_value-bmv2-frontend.p4 b/testdata/p4_16_samples_outputs/gauntlet_hdr_in_value-bmv2-frontend.p4
@@ -23,11 +23,8 @@ parser p(packet_in pkt, out Headers hdr, inout Meta m, inout standard_metadata_t
 }
 
 control ingress(inout Headers h, inout Meta m, inout standard_metadata_t sm) {
-    @name("ingress.hasReturned") bool hasReturned;
     @name("ingress.retval") bit<16> retval;
     apply {
-        hasReturned = false;
-        hasReturned = true;
         retval = ((Headers){eth_hdr = (ethernet_t){dst_addr = 48w1,src_addr = 48w1,eth_type = 16w1}}).eth_hdr.eth_type + 16w1;
         h.eth_hdr.eth_type = retval;
     }

diff --git a/testdata/p4_16_samples_outputs/gauntlet_hdr_out_in_action-bmv2.p4-stderr b/testdata/p4_16_samples_outputs/gauntlet_hdr_out_in_action-bmv2.p4-stderr
@@ -1,3 +1,6 @@
 gauntlet_hdr_out_in_action-bmv2.p4(35): [--Wwarn=unused] warning: 'val' is unused
     action do_action(out ethernet_t val) {
                                     ^^^
+gauntlet_hdr_out_in_action-bmv2.p4(35): [--Wwarn=uninitialized_use] warning: val may not be completely initialized
+    action do_action(out ethernet_t val) {
+                                    ^^^