backends/ebpf: Fix #4098 by renaming conflicting write_partial macro.

p4lang · Sep 11, 2023 · 32630ac · 32630ac
1 parent 555029d
commit 32630ac
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Showing 5 changed files with 24 additions and 23 deletions.
diff --git a/backends/ebpf/ebpfControl.cpp b/backends/ebpf/ebpfControl.cpp
@@ -191,7 +191,7 @@ void ControlBodyTranslator::compileEmitField(const IR::Expression *expr, cstring
             builder->appendFormat("write_byte(%s, BYTES(%s) + %d, (%s) << %d)",
                                   program->packetStartVar.c_str(), program->offsetVar.c_str(), i,
                                   program->byteVar.c_str(), 8 - bitsToWrite);
-        else
+        else  // FIXME change to use write_partial_ex
             builder->appendFormat("write_partial(%s + BYTES(%s) + %d, %d, (%s) << %d)",
                                   program->packetStartVar.c_str(), program->offsetVar.c_str(), i,
                                   alignment, program->byteVar.c_str(), 8 - bitsToWrite);

diff --git a/backends/ebpf/ebpfDeparser.cpp b/backends/ebpf/ebpfDeparser.cpp
@@ -247,7 +247,7 @@ void DeparserHdrEmitTranslator::emitField(CodeBuilder *builder, cstring field,
                                   program->byteVar.c_str());
         } else {  // write partial
             shift = (8 - alignment - bitsToWrite);
-            builder->appendFormat("write_partial(%s + BYTES(%s) + %d, %d, %d, (%s >> %d))",
+            builder->appendFormat("write_partial_ex(%s + BYTES(%s) + %d, %d, %d, (%s >> %d))",
                                   program->packetStartVar.c_str(), program->offsetVar.c_str(),
                                   i,  // do not reverse byte order
                                   bitsToWrite, shift, program->byteVar.c_str(),
@@ -266,7 +266,7 @@ void DeparserHdrEmitTranslator::emitField(CodeBuilder *builder, cstring field,
                                       i,  // do not reverse byte order
                                       program->byteVar.c_str(), 8 - alignment % 8);
             } else {
-                builder->appendFormat("write_partial(%s + BYTES(%s) + %d + 1, %d, %d, (%s))",
+                builder->appendFormat("write_partial_ex(%s + BYTES(%s) + %d + 1, %d, %d, (%s))",
                                       program->packetStartVar.c_str(), program->offsetVar.c_str(),
                                       i,  // do not reverse byte order
                                       bitsToWrite, 8 + alignment - bitsToWrite,

diff --git a/backends/ebpf/ebpfProgram.cpp b/backends/ebpf/ebpfProgram.cpp
@@ -180,16 +180,7 @@ class ErrorCodesVisitor : public Inspector {
 };
 }  // namespace
 
-void EBPFProgram::emitPreamble(CodeBuilder *builder) {
-    builder->emitIndent();
-    builder->appendFormat("enum %s ", errorEnum.c_str());
-    builder->blockStart();
-
-    ErrorCodesVisitor visitor(builder);
-    program->apply(visitor);
-
-    builder->blockEnd(false);
-    builder->endOfStatement(true);
+void EBPFProgram::emitCommonPreamble(CodeBuilder *builder) {
     builder->newline();
     builder->appendLine("#define EBPF_MASK(t, w) ((((t)(1)) << (w)) - (t)1)");
     builder->appendLine("#define BYTES(w) ((w) / 8)");
@@ -198,10 +189,28 @@ void EBPFProgram::emitPreamble(CodeBuilder *builder) {
         "{ u8 mask = EBPF_MASK(u8, s); "
         "*((u8*)a) = ((*((u8*)a)) & ~mask) | (((v) >> (8 - (s))) & mask); "
         "} while (0)");
+    builder->appendLine(
+        "#define write_partial_ex(a, w, s, v) do { *((u8*)a) = ((*((u8*)a)) "
+        "& ~(EBPF_MASK(u8, w) << s)) | (v << s) ; } while (0)");
     builder->appendLine(
         "#define write_byte(base, offset, v) do { "
         "*(u8*)((base) + (offset)) = (v); "
         "} while (0)");
+}
+
+void EBPFProgram::emitPreamble(CodeBuilder *builder) {
+    builder->emitIndent();
+    builder->appendFormat("enum %s ", errorEnum.c_str());
+    builder->blockStart();
+
+    ErrorCodesVisitor visitor(builder);
+    program->apply(visitor);
+
+    builder->blockEnd(false);
+    builder->endOfStatement(true);
+
+    emitCommonPreamble(builder);
+
     builder->newline();
     builder->appendLine("void* memcpy(void* dest, const void* src, size_t num);");
     builder->newline();

diff --git a/backends/ebpf/ebpfProgram.h b/backends/ebpf/ebpfProgram.h
@@ -90,6 +90,7 @@ class EBPFProgram : public EBPFObject {
     virtual void emitPipeline(CodeBuilder *builder);
 
  public:
+    virtual void emitCommonPreamble(CodeBuilder *builder);
     virtual void emitGeneratedComment(CodeBuilder *builder);
     virtual void emitH(CodeBuilder *builder, cstring headerFile);  // emits C headers
     virtual void emitC(CodeBuilder *builder, cstring headerFile);  // emits C program

diff --git a/backends/ebpf/psa/ebpfPsaGen.cpp b/backends/ebpf/psa/ebpfPsaGen.cpp
@@ -87,16 +87,7 @@ void PSAEbpfGenerator::emitPreamble(CodeBuilder *builder) const {
 }
 
 void PSAEbpfGenerator::emitCommonPreamble(CodeBuilder *builder) const {
-    builder->newline();
-    builder->appendLine("#define EBPF_MASK(t, w) ((((t)(1)) << (w)) - (t)1)");
-    builder->appendLine("#define BYTES(w) ((w) / 8)");
-    builder->appendLine(
-        "#define write_partial(a, w, s, v) do { *((u8*)a) = ((*((u8*)a)) "
-        "& ~(EBPF_MASK(u8, w) << s)) | (v << s) ; } while (0)");
-    builder->appendLine(
-        "#define write_byte(base, offset, v) do { "
-        "*(u8*)((base) + (offset)) = (v); "
-        "} while (0)");
+    ingress->emitCommonPreamble(builder);  // from ebpfProgram
     builder->target->emitPreamble(builder);
 }